Mirror instability driven by pickup ions in the outer heliosheath

Mapping Intimacies ◽

10.5194/egusphere-egu2020-2107 ◽

2020 ◽

Author(s):

Amenehsadat Mousavianzehaie ◽

Kaijun Liu ◽

Kyungguk Min

Keyword(s):

Velocity Distribution ◽

Linear Instability ◽

Stability Study ◽

Global Modeling ◽

Pickup Ions ◽

Mirror Mode ◽

Linear Instability Analysis ◽

The Stability ◽

Hybrid Simulations

Kinetic linear instability analysis and hybrid simulations are carried out to examine the role of mirror instability in scattering the pickup ions in the outer heliosheath. The dynamics of these pickup ions is essential to the understanding of the energetic neutral atom (ENA) ribbon observed by the Interstellar Boundary EXplorer (IBEX). While most previous studies have focused on the ion cyclotron instability driven by the pickup ions, recent work based on a simple ring velocity distribution of the pickup ions suggested that the mirror mode can also be unstable and contribute to the scattering of the pickup ions. The present study performs linear analysis as well as hybrid simulations for a more realistic, multi-component pickup ion velocity distribution given by the global modeling of neutral atoms in the heliosphere. The linear theory results indicate unstable mirror modes with considerable growth rates. The corresponding hybrid simulations further confirm that the mirror modes can grow and aid the pitch-angle broadening of the pickup ions. So the role of mirror mode should not be ignored in the stability study of the outer heliosheath pickup ions.

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Simulink implementation of a new optoelectronic integrated circuit: Stability analysis and infinite-scroll attractor

10.21203/rs.3.rs-401092/v1 ◽

2021 ◽

Author(s):

Eba David Essebe ◽

A. D. Mengue ◽

B. Z. Essimbi

Keyword(s):

Stability Analysis ◽

Integrated Circuit ◽

Gain Coefficient ◽

Stability Control ◽

Stability Study ◽

Optoelectronic System ◽

Tunneling Diode ◽

Fractal Attractor ◽

The Stability

Abstract In this paper a 6-D optoelectronic system consists of a resonant tunneling diode (RTD) driven by an optical injected semiconductor laser (LD) is reported. A stability analysis of the hybrid system is analytically and numerically performed and paramount role of the effective gain coefficient (EGC) is stuck out in the framework of new stability control. As a result, this parameter allows improving the accuracy of the stability study by circumscribing locked and unlocked regions. Besides, a narrow area of stability is pointed up within the sea of unstable points from which a complex fractal attractor so-called infinite-scroll attractor is highligted. Thereby, Simulink shows generation effectiveness of infinite-scroll attractor erratically interpersed by laminar phases. Also dynamics of Lyapunov exponents has confirmed that it refers to a strange fractal attractor. Moreover chaos control is structurally carried out by direct current (DC) polarisation.

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Development of Phosphorylated Glucomannan-Coated Chitosan Nanoparticles as Nanocarriers for Protein Delivery

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2006.435 ◽

2006 ◽

Vol 6 (9) ◽

pp. 2887-2895 ◽

Cited By ~ 40

Author(s):

M. Cuña ◽

M. Alonso-Sande ◽

C. Remuñán-López ◽

J. P. Pivel ◽

J. L. Alonso-Lebrero ◽

...

Keyword(s):

Protein Delivery ◽

Sodium Phosphate ◽

Chitosan Nanoparticles ◽

Stability Study ◽

Ionic Gelation ◽

Positive Role ◽

Cryoprotective Agents ◽

Freeze Dried ◽

The Stability

The aim of the present work was to develop a new nanoparticle carrier, adapted for the oral administration of proteins and their delivery to the immune system. Chitosan and phosphorylated glucomannan were chosen as major constituents of the nanoparticles. Chitosan nanoparticles were formed by ionic gelation and then coated with glucomannan. Two different protocols were adopted for the formation of the glucomannan coating: protocol I, in which chitosan nanoparticles were isolated before their coating; protocol II, in which chitosan nanoparticles were not isolated, but coated with glucomannan in the presence of free chitosan. The results showed that, under the selected formulation conditions, the sizes of the nanoparticles ranged between 170 and 300 nm and their zeta potential values were inverted from positive to negative by the glucomannan coating. The nanoparticles prepared by the two protocols could be freeze-dried, in the presence or absence of cryoprotective agents, preserving their original characteristics. The results of the stability study evidenced the positive role of the glucomannan coating in preventing the aggregation of the nanoparticles in buffered media. Finally, the association of the inmunomodulatory protein complex P1 to the chitosan-glucomannan nanoparticles was investigated. The results showed that the association was not dependent on the chitosan: sodium tripoliphosphate ratio, but it was significantly affected by the presence of sodium phosphate in the protein structure.

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A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽

10.32964/tj8.1.20 ◽

2009 ◽

Vol 8 (1) ◽

pp. 20-26 ◽

Cited By ~ 1

Author(s):

PEEYUSH TRIPATHI ◽

MARGARET JOYCE ◽

PAUL D. FLEMING ◽

MASAHIRO SUGIHARA

Keyword(s):

Boundary Layer ◽

Experimental Design ◽

High Speed ◽

Statistical Study ◽

Process Variables ◽

High Speeds ◽

The Stability ◽

Air Removal ◽

Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

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Divergence entropy to characterize the stability in selected enzymes – The role of disulfide bonds in respect to the structure of hydrophobic core

10.3390/ecea-2-b009 ◽

2015 ◽

Author(s):

Irena Roterman ◽

Mateusz Banach ◽

Leszek Konieczny ◽

Barbara Kalinowska

Keyword(s):

Disulfide Bonds ◽

Hydrophobic Core ◽

The Stability

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The Role of Hydrophobicity in the Stability and pH-Switchability of (RXDX)4 and Coumarin-RXDX Conjugate β-Sheets

10.26434/chemrxiv.11493060 ◽

2020 ◽

Author(s):

Ryan Weber ◽

Martin McCullagh

Keyword(s):

Biological Imaging ◽

Ph Sensing ◽

Hydrophobic Residue ◽

Ideal Candidate ◽

Self Assembling ◽

Sensing Applications ◽

Β Sheets ◽

The Stability ◽

Dynamics Simulations

pH-switchable, self-assembling materials are of interest in biological imaging and sensing applications. Here we propose that combining the pH-switchability of RXDX (X=Ala, Val, Leu, Ile, Phe) peptides and the optical properties of coumarin creates an ideal candidate for these materials. This suggestion is tested with a thorough set of all-atom molecular dynamics simulations. We first investigate the dependence of pH-switchabiliy on the identity of the hydrophobic residue, X, in the bare (RXDX)4 systems. Increasing the hydrophobicity stabilizes the fiber which, in turn, reduces the pH-switchabilty of the system. This behavior is found to be somewhat transferable to systems in which a single hydrophobic residue is replaced with a coumarin containing amino acid. In this case, conjugates with X=Ala are found to be unstable and both pHs while conjugates with X=Val, Leu, Ile and Phe are found to form stable β-sheets at least at neutral pH. The (RFDF)4-coumarin conjugate is found to have the largest relative entropy value of 0.884 +/- 0.001 between neutral and acidic coumarin ordering distributions. Thus, we posit that coumarin-(RFDF)4 containing peptide sequences are ideal candidates for pH-sensing bioelectronic materials.

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Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

10.26434/chemrxiv.11742687 ◽

2020 ◽

Author(s):

Shubham Deolka ◽

Orestes Rivada Wheelaghan ◽

Sandra Aristizábal ◽

Robert Fayzullin ◽

Shrinwantu Pal ◽

...

Keyword(s):

Alkyl Group ◽

Bond Activation ◽

Bond Cleavage ◽

Terminal Alkyne ◽

Alkyl Aryl ◽

Metal Metal ◽

The Stability ◽

Selective Formation ◽

Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

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LANDSLIDE RISK MANAGEMENT IN THE COASTAL ZONE OF THE KUIBYSHEV RESERVOIR DUE THE DESIGN OF HIGH-SPEED LINE "MOSCOW-KAZAN"

Proceedings of International Conference "Managinag risks to coastal regions and communities in a changinag world" (EMECS'11 - SeaCoasts XXVI) ◽

10.31519/conferencearticle_5b1b9403c99983.72529271 ◽

2017 ◽

Author(s):

Nikolai Petrov ◽

Inna Nikonorova ◽

Vladimir Mashin ◽

...

Keyword(s):

High Speed ◽

Computational Models ◽

Stable State ◽

Landslide Risk ◽

Kuibyshev Reservoir ◽

Stepped Surface ◽

The Stability ◽

Landslide Slope ◽

The Village

High-speed railway "Moscow-Kazan" by the draft crosses the Volga (Kuibyshev reservoir) in Chuvashia region 500 m below the village of New Kushnikovo. The crossing plot is a right-bank landslide slope with a stepped surface. Its height is 80 m; the slope steepness -15-16o. The authors should assess the risk of landslides and recommend anti-landslide measures to ensure the safety of the future bridge. For this landslide factors have been analyzed, slope stability assessment has been performed and recommendations have been suggested. The role of the following factors have been analyzed: 1) hydrologic - erosion and abrasion reservoir and runoff role; 2) lithologyc (the presence of Urzhum and Northern Dvina horizons of plastically deformable rocks, displacement areas); 3) hydrogeological (the role of perched, ground and interstratal water); 4) geomorphological (presence of the elemental composition of sliding systems and their structure in the relief); 5) exogeodynamic (cycles and stages of landslide systems development, mechanisms and relationship between landslide tiers of different generations and blocks contained in tiers). As a result 6-7 computational models at each of the three engineering-geological sections were made. The stability was evaluated by the method “of the leaning slope”. It is proved that the slope is in a very stable state and requires the following measures: 1) unloading (truncation) of active heads blocks of landslide tiers) and the edge of the plateau, 2) regulation of the surface and groundwater flow, 3) concrete dam, if necessary.

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Short-Term Ultramicronized Palmitoylethanolamide Therapy in Patients with Myasthenia Gravis: a Pilot Study to Possible Future Implications of Treatment

CNS & Neurological Disorders - Drug Targets ◽

10.2174/1871527318666190131121827 ◽

2019 ◽

Vol 18 (3) ◽

pp. 232-238 ◽

Cited By ~ 5

Author(s):

Emanuela Onesti ◽

Vittorio Frasca ◽

Marco Ceccanti ◽

Giorgio Tartaglia ◽

Maria Cristina Gori ◽

...

Keyword(s):

Pilot Study ◽

Myasthenia Gravis ◽

Repetitive Nerve Stimulation ◽

Beneficial Effects ◽

Antibody Titers ◽

The Stability ◽

Ultramicronized Palmitoylethanolamide ◽

Open Pilot

Background: The cannabinoid system may be involved in the humoral mechanisms at the neuromuscular junction. Ultramicronized-palmitoylethanolamide (μm-PEA) has recently been shown to reduce the desensitization of Acetylcholine (ACh)-evoked currents in denervated patients modifying the stability of ACh receptor (AChR) function. Objective: To analyze the possible beneficial effects of μm-PEA in patients with myasthenia gravis (MG) on muscular fatigue and neurophysiological changes. Method: The duration of this open pilot study, which included an intra-individual control, was three weeks. Each patient was assigned to a 1-week treatment period with μm-PEA 600 mg twice a day. A neurophysiological examination based on repetitive nerve stimulation (RNS) of the masseteric and the axillary nerves was performed, and the quantitative MG (QMG) score was calculated in 22 MG patients every week in a three-week follow-up period. AChR antibody titer was investigated to analyze a possible immunomodulatory effect of PEA in MG patients. Results: PEA had a significant effect on the QMG score (p=0.03418) and on RNS of the masseteric nerve (p=0.01763), thus indicating that PEA reduces the level of disability and decremental muscle response. Antibody titers did not change significantly after treatment. Conclusion: According to our observations, μm-PEA as an add-on therapy could improve muscular response to fatigue in MG. The possible modulation of AChR currents as a means of eliciting a direct effect from PEA on the conformation of ACh receptors should be investigated. The co-role of cytokines also warrants an analysis. Given the rapidity and reversibility of the response, we suppose that PEA acts directly on AChR, though further studies are needed to confirm this hypothesis.

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On the Structure of Lead(II) Complexes in Aqueous Solutions. I. Trinuclear Clusters

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19950527 ◽

1995 ◽

Vol 60 (4) ◽

pp. 527-536 ◽

Cited By ~ 10

Author(s):

Martin Breza ◽

Alena Manová

Keyword(s):

Quantum Chemistry ◽

Aqueous Solutions ◽

Electronic Structures ◽

Mndo Method ◽

Model Systems ◽

Trinuclear Clusters ◽

The Stability ◽

Semiempirical Mndo

Using semiempirical MNDO method of quantum chemistry the optimal geometries and corresponding electronic structures of [Pb3(OH)n]6-n model systems as well as of their hydrated [Pb3(OH)n(H2O)8-n]6-n analogues (n = 4, 5) are investigated. The most stable trinuclear lead(II) complexes present in aqueous solutions correspond to cyclo-(μ3-OH)(μ2-OH)3Pb32+, Pb(μ-OH)2Pb(μ-OH)2Pb2+, cyclo-(μ3-OH)2(μ2-OH)3Pb3+, Pb(OH)(μ-OH)2Pb(μ-OH)Pb(OH)+ and Pb(OH)(μ-OH)2Pb(μ-OH)2Pb+ systems. The key role of OH bridges (by vanishing direct Pb-Pb bonds) on the stability of individual isomers is discussed.

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