24 research outputs found
Diffusion-Controlled Faradaic Charge Storage in High-Performance Solid Electrolyte-Gated Zinc Oxide Thin-Film Transistors
An electrochemical device capable of manifesting reversible charge storage at the interface of an active layer offers formidable advantages, such as low switching energy and long retention time, in realizing synaptic behavior for ultralow power neuromorphic systems. Contrary to a supercapacitor-based field-effect device that is prone to low memory retention due to fast discharge, a solid electrolyte-gated ZnO thin-film device exhibiting a battery-controlled charge storage mechanism via mobile charges at its interface with tantalum oxide is demonstrated. Analysis via cyclic voltammetry and chronoamperometry uniquely distinguishes the battery behavior of these devices, with an electromotive force generated due to polarization of charges strongly dependent on the scan rate of the applied voltage. The Faradaic-type diffusion-controlled charge storage mechanism exhibited by these devices is capable of delivering robust enhancement in the channel conductance and leads to a superior ON-OFF ratio of 108-109. The nonvolatile behavior of the interface charge storage and slow diffusion of ions is utilized in efficiently emulating spike timing-dependent plasticity (STDP) at similar time scales of biological synapses and unveils the possibility of STDP behavior using multiple in-plane gates that alleviate additional requirement of waveform-shaping circuits
Nanoionics-Based Three-Terminal Synaptic Device Using Zinc Oxide
Artificial synaptic thin film transistors (TFTs) capable of simultaneously manifesting signal transmission and self-learning are demonstrated using transparent zinc oxide (ZnO) in combination with high Îș tantalum oxide as gate insulator. The devices exhibit pronounced memory retention with a memory window in excess of 4 V realized using an operating voltage less than 6 V. Gate polarity induced motion of oxygen vacancies in the gate insulator is proposed to play a vital role in emulating synaptic behavior, directly measured as the transmission of a signal between the source and drain (S/D) terminals, but with the added benefit of independent control of synaptic weight. Unlike in two terminal memristor/resistive switching devices, multistate memory levels are demonstrated using the gate terminal without hampering the signal transmission across the S/D electrodes. Synaptic functions in the devices can be emulated using a low programming voltage of 200 mV, an order of magnitude smaller than in conventional resistive random access memory and other field effect transistor based synaptic technologies. Robust synaptic properties demonstrated using fully transparent, ecofriendly inorganic materials chosen here show greater promise in realizing scalable synaptic devices compared to organic synaptic and other liquid electrolyte gated device technologies. Most importantly, the strong coupling between the in-plane gate and semiconductor channel through ionic charge in the gate insulator shown by these devices, can lead to an artificial neural network with multiple presynaptic terminals for complex synaptic learning processes. This provides opportunities to alleviate the extreme requirements of component and interconnect density in realizing brainlike systems
A generalized semi-Pareto minification process
Minification processes, Pareto and semi-Pareto distribution, Uniformly mixing sequences, Geometric extremes, Consistent estimators,
Hypolipidemic effect of <i>Coriandrum sativum </i>L. in<b> </b>triton-induced hyperlipidemic rats
909-912In the biphasic model of triton-induced hyperlipidemia,
C. sativum at a dose of 1g/kg body weight reduced cholesterol and triglycerides
levels in both synthesis and excretory phases in rats, and the results were comparable
with that of Liponil, a commercially available herbal hypolipidemic drug. The results
suggest that coriander decreases the uptake and enhances
the breakdown of lipids. From the study it
can be assumed that coriander has the potential to be popularized as a household
herbal remedy with preventive and curative effect against hyperlipidemia
On generalized semi-Pareto and semi-Burr distributions and random coefficient minification processes
Burr distribution, Burr processes, Characterizations, Pareto distribution, Semi-Pareto distribution, Semi-Pareto processes,
Cation controlled wetting properties of vermiculite membranes and its promise for fouling resistant oilâwater separation
The surface free energy is one of the most fundamental properties of solids,
hence, manipulating the surface energy and thereby the wetting properties of
solids, has tremendous potential for various physical, chemical, biological as
well as industrial processes. Typically, this is achieved by either chemical
modification or by controlling the hierarchical structures of surfaces. Here we
report a phenomenon whereby the wetting properties of vermiculite laminates are
controlled by the hydrated cations on the surface and in the interlamellar
space. We find that by exploiting this mechanism, vermiculite laminates can be
tuned from superhydrophillic to hydrophobic simply by exchanging the cations;
hydrophilicity decreases with increasing cation hydration free energy, except
for lithium. Lithium, which has a higher hydration free energy than potassium,
is found to provide a superhydrophilic surface due to its anomalous hydrated
structure at the vermiculite surface. Building on these findings, we
demonstrate the potential application of superhydrophilic lithium exchanged
vermiculite as a thin coating layer on microfiltration membranes to resist
fouling, and thus, we address a major challenge for oil-water separation
technology