Double-Gate Operation of Metal Nanodot-Array-Based Single-Electron Device

Multidot single-electron devices (SEDs) can realize new types of computing technologies, such as reconfigurable and reservoir computing. The self-assembled metal nanodot-array film attached with multiple gates is a candidate for use in such SEDs to achieve high functionality. However, the single-electron properties of such a film have not yet been investigated in use with optimally controlled multiple gates because of structural complexity having many nanodots. In this study, Fe nanodot-array-based double-gate SEDs were fabricated and their single-electron properties modulated by the top- and bottom-gate voltages (VT and VB, respectively) were investigated. As reported in our previous study, the drain current (ID) exhibited clear oscillations against VB (i.e., Coulomb blockade oscillation) in a part of the devices, originating from a single dot among several dots. The phase of the Coulomb blockade oscillation systematically shifted with VT, indicating that the charge state of the single dot was clearly controlled by both the gate voltages despite the multidot structure and the metal multidot SED has potential for logic-gate operation. The top and bottom gates affected the electronic state of the dot unevenly owing to the geometrical effect caused by the dot shape and size of the surrounding dots.

PENENTUAN POLA OPERASI PINTU PELIMPAH DALAM RANGKA PENGENDALIAN BANJIR BENDUNGAN DELINGAN, JAWA TENGAH

A spillway is one of many important components of a dam, which is operated to prevent the dam from overtopping. Spillway with gate structures requires to have a good operation pattern by considering a minimum critical height and outflow discharge to prevent any flooding events in the downstream part of the spillway channel. The case study in this research is the Delingan Dam which has two ogee spillways, four main sluice gates and four additional sluice gates. Located in Karanganyar District, West Java, Delingan Dam is considered as a vast infrastructure which is potentially threatening if the spillway’s operation is not optimal. This study aims to analyze the spillway gate operations’ pattern of Delingan Dam in order to control the flooding event. The methodology used in this study is flood routing by utilizing several scenarios in order to obtain the optimal simulation results. Five scenarios that were simulated on the designated flood discharge have various combinations on the number of gates and their opening, as well as the time in which the operation started. The results show that the operation only using ogee spillway still meets the criteria for minimum critical height and maximum allowable discharge for return period of 25, 50, and 100 year.As the discharge with 1000 year return period, half of PMF, and PMF,the recommended operation is, foremost, to occupy the main gate in which results in the peak outflow discharge of 23.65 m3/s, 62.4 m3/s, and 140.9 m3/s, with the minimum critical height of 1.45 m, 1.41 m, and 1.35 m, respectively. However, this operation is not adequate for the half of PMF, and the PMF discharge, since the capacity in the spillway channel is estimated about 24.7 m3/s.Keywords: spillway, flood control, spillway gate operation, the delingan dam

Thermodynamics of Organic Electrochemical Transistors

Bioelectronics which bridge the gap between conventional electronics and biological systems are actively researched due to their fascinating perspectives in healthcare and other fields. A key element of future bioelectronics is the organic electrochemical transistor (OECT) that, by employing a mixed ion-electron conducting materials, can perform switching tasks in electrolytic environments and serve as sensoric or actoric element. OECTs differ substantially from their inorganic field-effect counterparts, mainly due to their electrochemical, rather than electrostatic, gate operation principle. However, the working mechanism of OECTs is modeled as the one of the field-effect transistor: this approach not only fails to give quantitative agreement with experimental observation but also ignores the material properties of the channel and the chemical dynamics that stem for the operation of the device. Here, we present a new comprehensive unified model that can explain the behavior of OECTs across a broad range of materials, designs, and operation regimes. We treat the polymeric channel as a thermodynamic binary system and show that the entropy of mixing is the major driving force behind the operation of the OECT. We are able to quantify the entropic and enthalpic interactions between charged species for a variety of materials and solvents and harness this knowledge to provide guidelines for material modeling and insights for device fine-tuning for targeted applications. Finally, our thermodynamic model provides a description of the intrinsic origin of the ubiquitous hysteretic behavior of OECTs.

Application of Stage-Fall-Discharge Rating Curves to a Reservoir Based on Acoustic Doppler Velocity Meter Measurement Data

The applicability of the stage-fall-discharge (SFD) method in combination with acoustic Doppler velocity meter (ADVM) data, upstream of a hydraulic structure, specifically, the Sejong-weir located in the Geum River, Korea, was examined. We developed three rating curves: a conventional simple rating curve with the data measured using an acoustic Doppler current profiler (ADCP) and floating objects, an SFD rating curve with the data measured using the ADCP and floating objects, and an SFD rating curve with the data measured using an ADVM. Because of the gate operation effect, every rating curve involved many uncertainties under 1000 m3/s (3.13 m2/s, specific discharge). In terms of the hydrograph reconstruction, compared with the conventional simple rating curve, the SFD developed using ADVM data exhibited a higher agreement with the measured data in terms of the pattern. Furthermore, the measured discharge over 1000 m3/s primarily ranged between 97.5% and 2.5% in the graph comparing the ratio of the median and observed discharge. Based on this experiment, it is confirmed that the SFD rating curve with data to represent the backwater effect, such as ADVM data, can reduce the uncertainties induced by the typical rating curve

All-optical simultaneous XOR-AND operation using 1-D periodic nonlinear material

In this paper, an all-optical XOR-AND gate operation has been proposed using one-dimensional periodic nonlinear material model. This structure consists of alternating layers of different nonlinear materials. In this design, we can obtain XOR and AND logical operation simultaneously at the reflected and transmitted port of the periodic structure. Numerical simulation has also been done using the finite-difference-time-domain (FDTD) method. The response time of this switching operation is picoseconds (ps) range order. We find low insertion loss (−3.01 dB), high contrast ratio (14.13 dB) and high extension ratio (10.93 dB) of this device. This design will be useful in future all-optical computing.

Phase analysis on the error scaling of entangled qubits in a 53-qubit system

We have studied carefully the behaviors of entangled qubits on the IBM Rochester with various connectivities and under a “noisy” environment. A phase trajectory analysis based on our measurements of the GHZ-like states is performed. Our results point to an important fact that entangled qubits are “protected” against environmental noise by a scaling property that impacts only the weighting of their amplitudes. The reproducibility of most measurements has been confirmed within a reasonably short gate operation time. But there still are a few combinations of qubits that show significant entanglement evolution in the form of transitions between quantum states. The phase trajectory of an entangled evolution, and the impact of the sudden death of GHZ-like states and the revival of newly excited states are analyzed in details. All observed trajectories of entangled qubits arise under the influences of the newly excited states in a “noisy” intermediate-scale quantum (NISQ) computer.