Enhanced magnetic response of fluids using self-assembled petal-like iron oxide particles

Using self-assembled iron oxide (SAIO) particles with petal-like morphology, aqueous fluids containing magnetic particles were prepared and the effect of hierarchical particle surface on the viscoelasticity under magnetic was investigated. The fluids consisting of self-assembled iron oxide particles exhibit highly tunable viscoelasticity which is controlled by applying external magnetic field. A difference between SAIO particles and spherical particles is explained by the fact that surface features of the self-assembled particles increased the network strength between particles in the fluids. © 2010 American Institute of Physics

Human genetics and genomics a decade after the release of the draft sequence of the human genome

10.1186/1479-7364-5-6-577Human Genomics56577-62

Sorption-desorption kinetics for powdered and non-powered coal

Diffusion through macro- and meso-pores with the subsequent filling of open micropores is a relatively fast process and the manometric measurements with fifteen minute pressure stabilization steps provide a good estimate of excess (ad)sorption. This can be followed by a much slower processes of the penetrant diffusion into the macromolecular network, accompanied by its structural relaxation, with or without free volume changes. The “free volume” effect is a change of the sample’s excluded volume because of the penetrant molecules mixing within the formerly excluded volume of the network or because of contraction (either reversible or semi-permanent) due to external pressure. If the resulting swelling of the sample leads to the mixture’s volume equal to the sum of the initial volumes of the components, there is no apparent change to the void volume and no pressure relaxation is observed (b). On the other hand, if the external forces (either macroscopic pressure or microscopic molecular interaction forces) change the excluded volume of the network (its density), without exchange of the sorbent molecules between the sample and the free fluid phase, such change causes a corresponding change in the void volume, which constitutes a pure free volume effect (c). In this case, no post-decompression exodus of the sorbent out of the sample is observed. As a special case, we consider an incorporation of the penetrant molecules into the network without any change in the volume of the mixture (d), though mathematically this can be written as a superposition of the previous two case

Some Physical and Chemical Characteristics of Peanut Pods and Kernels in an Irrigation Study

Agronomy (Field Crops

The Amplitude of Non-Equilibrium Quantum Interference in Metallic Mesoscopic Systems

We study the influence of a DC bias voltage V on quantum interference corrections to the measured differential conductance in metallic mesoscopic wires and rings. The amplitude of both universal conductance fluctuations (UCF) and Aharonov-Bohm effect (ABE) is enhanced several times for voltages larger than the Thouless energy. The enhancement persists even in the presence of inelastic electron-electron scattering up to V ~ 1 mV. For larger voltages electron-phonon collisions lead to the amplitude decaying as a power law for the UCF and exponentially for the ABE. We obtain good agreement of the experimental data with a model which takes into account the decrease of the electron phase-coherence length due to electron-electron and electron-phonon scattering.Comment: New title, refined analysis. 7 pages, 3 figures, to be published in Europhysics Letter

Design and Characterization of a Non-Linear Variable Inerter in Vehicle Suspension System

Inerter is a two-terminal component in suspension system such that the force at the two terminals is directly proportional to the relative acceleration of these two points. Studies have shown that the inerter can provide satisfactory vibration isolation for a number of suspension applications, including train suspension, building suspension and vehicle suspension. In the context of vehicle suspension, the existing passive inerter has been shown to provide benefits to vehicle dynamics performance measures, such as ride comfort and road holding ability. However, a basic passive inerter has fixed characteristic, and hence its potential is limited. This study overcome this limitation by incorporating variable inertia in inerter flywheel, however its non-linear characteristic needs to be determined. The method of achieving variable inertia in inerter flywheel is through introduction of movable masses or sliders attached with springs into inerter flywheel. The change of moment of inertia is caused by position change of sliders due to centrifugal force when the flywheel is rotating. Results showed that the proposed variable inerter exhibits a non-linear force-acceleration relationship with respect to its operating rotational speed. A vehicle suspension system equipped with a variable inerter is also able to further reduce vertical vehicle body acceleration and vehicle’s dynamic tire load when compared with vehicle suspension system without inerter and equipped with a passive inerter, which indirectly relates to a better vehicle ride and handling performance improvements. Hence, it can be proved that the proposed variable inerter is better than a passive inerter and is able to provide better ride comfort and road holding ability to a vehicle

Design and Characterization of a Non-Linear Variable Inerter in Vehicle Suspension System

Inerter is a two-terminal component in suspension system such that the force at the two terminals is directly proportional to the relative acceleration of these two points. Studies have shown that the inerter can provide satisfactory vibration isolation for a number of suspension applications, including train suspension, building suspension and vehicle suspension. In the context of vehicle suspension, the existing passive inerter has been shown to provide benefits to vehicle dynamics performance measures, such as ride comfort and road holding ability. However, a basic passive inerter has fixed characteristic, and hence its potential is limited. This study overcome this limitation by incorporating variable inertia in inerter flywheel, however its non-linear characteristic needs to be determined. The method of achieving variable inertia in inerter flywheel is through introduction of movable masses or sliders attached with springs into inerter flywheel. The change of moment of inertia is caused by position change of sliders due to centrifugal force when the flywheel is rotating. Results showed that the proposed variable inerter exhibits a non-linear force-acceleration relationship with respect to its operating rotational speed. A vehicle suspension system equipped with a variable inerter is also able to further reduce vertical vehicle body acceleration and vehicle’s dynamic tire load when compared with vehicle suspension system without inerter and equipped with a passive inerter, which indirectly relates to a better vehicle ride and handling performance improvements. Hence, it can be proved that the proposed variable inerter is better than a passive inerter and is able to provide better ride comfort and road holding ability to a vehicle

Triboelectrostatic Separation of Mineral Matter from Slovakian Coals

V èlánku sú diskutované niektoré technické aspekty triboelektrostatickej separácie a výs-ledky aplikácie tohto postupu pri úprave troch typov uhlia, konkrétne energetického uhlia z Cíg¾a, Handlovej a Novák. Bolo zistené, e úèinnos separácie ve¾mi úzko závisí na druhu separovan uhlia. Prvé výsledky preukázali súvislos medzi úèinnosou separácie obsahom popola v uhlí

Alternative Splicing of P/Q-Type Ca2+ Channels Shapes Presynaptic Plasticity

Alternative splicing of pre-mRNAs is prominent in the mammalian brain, where it is thought to expand proteome diversity. For example, alternative splicing of voltage-gated Ca2+ channel (VGCC) α1 subunits can generate thousands of isoforms with differential properties and expression patterns. However, the impact of this molecular diversity on brain function, particularly on synaptic transmission, which crucially depends on VGCCs, is unclear. Here, we investigate how two major splice isoforms of P/Q-type VGCCs (Cav2.1[EFa/b]) regulate presynaptic plasticity in hippocampal neurons. We find that the efficacy of P/Q-type VGCC isoforms in supporting synaptic transmission is markedly different, with Cav2.1[EFa] promoting synaptic depression and Cav2.1[EFb] synaptic facilitation. Following a reduction in network activity, hippocampal neurons upregulate selectively Cav2.1[EFa], the isoform exhibiting the higher synaptic efficacy, thus effectively supporting presynaptic homeostatic plasticity. Therefore, the balance between VGCC splice variants at the synapse is a key factor in controlling neurotransmitter release and presynaptic plasticity