Dual-channel Configuration Research Articles

Unified multifunctional-reconfigurable architecture for device-circuit co-design

In this article, we propose a novel unified device-circuit co-design for functional scalability and diversifiability within the same footprint. The proposed design comprises two L-shaped NMOS monolithically integrated with two L-shaped PMOS utilizing common silicon reservoir with charge-plasma (CP) induced source and drain regions. The CP regions are induced by choosing appropriate work functions for the metal electrodes using calibrated TCAD simulations. Through source-drain interchangeability among individual transistors and appropriate signal bias, we have demonstrated the possible reconfigurations of the proposed single architecture to perform various device and/or circuit level operations concurrently/separately. For device level analyses, we realized concurrent NMOS and PMOS in single-channel and/or dual-channel configurations. Further, for circuit level analyses, we realized a CMOS inverter in addition to an NMOS and a PMOS, all three operating independently. Next, we demonstrated two independent inverters with possible realization of a buffer. Lastly, we present NAND and NOR Gates, each in two possible configurations, obtained through the proposed single-device architecture.

Efficient Strategic Pricing in a Dual-Channel Stackelberg Supply Chain: Incorporating Remanufacturing and Sales Commissions across Multiple Periods

The rise of e-commerce has significantly impacted consumer shopping habits, resulting in profit loss for traditional supply chains. In response to intense competition, numerous companies have transitioned their business models to embrace dual-channel configurations, seeking to captivate customers and increase their market share. Nonetheless, research on decentralized dual-channel supply chain configurations is scarce and predominantly concentrates on single-period pricing. This paper addresses this gap by employing Stackelberg’s game theory to investigate the multi-periodic pricing and remanufacturing decisions within a decentralized dual-channel supply chain with reverse logistics, specialized in the manufacturing and sales of pharmaceutical products. Moreover, this work considers that the online channel pays a sales commission to the pharmacy in return for the provided after-sales services, aiming to incorporate the aspect of sharing revenues. A mathematical formulation is proposed in a multi-periodic environment allowing us to simultaneously maximize the total profits of the manufacturer, the pharmacy and the online channel, by optimizing the pricing and remanufacturing strategies. Numerical analyses examine the customer purchasing preference’s effect on the demand and pricing decisions of each channel, the impact of the collection cost on the optimal remanufacturing strategy, and assess the break-even point of the total profits generated in both channels according to the sales commission. This study’s novelty lies in employing Stackelberg’s game theory to develop a mathematical formulation for the multi-periodic pricing and remanufacturing problem within a decentralized dual-channel supply chain, incorporating a sales commission between both distributors.

Nanoscale-doped dual-channel for improved performance and reliability of Hf: IGTO / a-IGTO thin film transistor

Amorphous oxide semiconductors are widely used in the backplane thin film transistors (TFTs) of displays and are extensively researched as materials for next-generation memory devices. However, they face reliability degradation due to stress factors such as thermal, bias, and light exposure. To mitigate these issues, extensive research is focused on improvements, including doping, enhancing crystallinity, and applying pre-and post-treatments. This study investigates the significantly improved reliability and electrical properties of amorphous indium gallium tin oxide (a-IGTO) TFTs by adopting a dual-channel configuration through simultaneous co-sputtering of HfO2 and IGTO targets. The device fabrication involved co-sputtering HfO2 and IGTO at the gate oxide interface, followed by depositing an IGTO-only layer, rather than doping the entire channel material. The effect of varying Hf concentration was evaluated by applying different HfO2 sputtering powers. Optimal hafnium doping reduced the threshold voltage of the a-IGTO TFT from −0.85V to 0.15V compared to the pristine a-IGTO TFT, while enhancing the field-effect mobility (μFE). Furthermore, the Hf-doped device exhibited improved stability, with a reduced threshold voltage shift (ΔVth) under positive (+15 V) and negative(-15 V) bias stress at 3000s, decreasing from 11.5 V to 4.8 V, and 4.7 V–1.1 V, respectively. This study proposes a novel device fabrication method to enhance the reliability of amorphous oxide semiconductor, addressing their inherent stress-related issues.

Design and experiment study of a novel dual-channel independent-coil magnetorheological grease damper

In order to address the issue of reduced damping force dynamic range in magnetorheological (MR) damper caused by the high zero-field viscosity of MR grease, known for its sedimentation stability, this paper introduces a novel dual-channel independent-coil MR damper (DCICMRD). Firstly, the dual-channel configuration and the magnetic circuit structure of independent coils were meticulously designed, and a genetic algorithm was employed to conduct multi-objective optimization of the structural parameters for DCICMRD. The optimization results indicate that all performance metrics of the damper post-optimization exhibit improvements exceeding 15%. Then, the theocratical model of the damping force for DCICMRD under three operational modes are established, and the output damping force of various input currents for different operating mode is obtained. Finally, the DCICMRD was manufactured and subjected to dynamic performance testing. The results revealed that the damping force dynamic range in Mode III, i.e. dual-channel structure, can achieve approximately 15 times, whereas Mode I, i.e. traditional single-channel structure, only attains approximately 9 times. The aforementioned research holds significant implications for expanding the further engineering applications of MR dampers.

Hydrothermal analysis of archimedean spiral single and dual channel heat sink for CPU cooling

Engineering modeling and simulation represent a predominantly design tool in the modern manufacturing industry in which the actual system is reproduced using a mathematical and scientific model. This requires CPUs with higher computational capacities. However, increas-ing the computational capacities of CPU and GPU imposes challenges in the cooling process due to space limitations. CPU liquid cooling system has attracted more interest as an efficient heat dissipation tool. This work presents computational modeling of the conjugate heat and flow for the CPU liquid heat sink cooling. An Archimedean spiral channel is grooved into the cold plate of the heat sink. Single and dual channel passes are used in this work. The out-er diameter of the cold plate is 105 mm and the channel depth is 5 mm for both single and dual-channel configurations. The conjugate heat sink model was constructed to have four different domains: CPU (alumina), glue layer (ethoxy), cold plate (copper), and liquid cool-ant (water). To incorporate the effect of turbulence, the flow rate varied to cover a range of Reynolds number from 3000 up to 15000 at a constant inlet temperature of 25 °C. The used turbulence model was the Shear Stress Transport (k-ω) to better capture the viscous, high-fre-quency flow fluctuation in the near-wall region. The bottom surface of the CPU is subjected to 450 W of heat energy. The results showed that the channel configuration and Reynolds number have a decisive impact on controlling the CPU temperature. The CPU temperature decrease as Reynolds number increases, however, the pressure drop increases at an exponen-tial rate. These findings are supported by Darcy–Weisbach equation for internal flow in which the pressure drop depends on the square of the average fluid velocity and it was noticed that the pressure drop in the dual channel was three times higher than that in the single channel. The hydrothermal performance of the Archimedean spiral channel rapidly decreased with Reynolds number and the single-channel had a slightly better performance compared with the dual-channel.

Multipair Förster Resonance Energy Transfer via Spectrally Resolved Single-Molecule Detection.

Förster resonance energy transfer (FRET) is a powerful tool for studying molecular interactions. Its use for studying interactions involving more than two molecules, however, has been limited by spectral crosstalk among the fluorophores. Here, we report multispectral FRET (msFRET) for imaging multiple pairs of interactions in parallel by spectrally resolving single fluorescent molecules. By using a dual (positional and spectral) channel and wide-field imaging configuration, fluorophores with emission maxima as close as 6-10 nm could be reliably distinguished. We demonstrate msFRET by continuously monitoring the hybridization dynamics among 2 × 2 pairs of DNA oligos in parallel using Cy3 and Cy3.5 as donors and Cy5 and Cy5.5 as acceptors. Aside from studying molecular interactions, msFRET may also find applications in probing fluorophore photophysics during FRET and in multiplexed superresolution imaging.

Benzoindole-based bifunctional ratiometric turn-on sensor with an ICT effect for trapping of H+ and Al3+ in dual-channel cell imaging and samples.

Abnormal changes in H+ and Al3+ concentrations in living cells can alter neurological diseases. A small-molecule sensor combined with a fluorescence imaging technique holds great promise for monitoring changes in proton and metal-ion concentration. In this work, a bifunctional ratiometric naked-eye fluorescence sensor (BIBC) was developed for turn-on detection of H+ and Al3+ in H2O/EtOH (v/v=1:1) mixtures. BIBC exhibits a pKa value of 4.58 within a linear pH variation from 4.1 to 4.7 (R2=0.9939). Moreover, the fluorescence intensity ratio (I566 nm/I524 nm) shows a good linear relationship (R2=0.9965) within an Al3+ concentration range of 7.0-10.0μM. The detection limit (DL) for the sensor was calculated to be 1.58μM. The practical application of BIBC for Al3+ detection in real samples was further discussed, and satisfactory results were obtained. Furthermore, the sensor was applied to real-time visualization of changes in H+ and Al3+ concentration in living cells, with great photostability and low cytotoxicity observed. Fluorescence images of H+ and Al3+ were collected by using a fluorescence microscope in a dual-channel configuration, wherein they were labeled green and yellow, respectively.

Dual-mode and two-signal-wavelength femtosecond optical parametric oscillator based on LiB3O5.

We demonstrate a tunable femtosecond dual-beam-mode (cylindrical vector beam [CVB] and Gaussian beam [GB]), dual-signal-wavelength optical parametric oscillator based on a temperature-tuned lithium triborate crystal, synchronously pumped by a frequency-doubled mode-locked Yb-doped fiber laser. When fixing the CVB wavelength at 780 nm, the central wavelength of the GB signal could be continuously tuned from 664 to 722 nm. The maximum total signal output power is 515 mW at a 4 W pump with dual-wavelength operation (664 and 780 nm). All the measured signal pulse durations are around 150 fs. Moreover, sum-frequency-generation with Gaussian mode tuning from 548 to 588 nm is obtained, with the maximum power of 52 mW at 548 nm. Thanks to the dual-channel configuration, the wavelengths of a CVB and GB can be tuned independently. Such a flexible and versatile configuration makes it a practical tool for many applications such as high-resolution microscopy and high-capacity optical communication.

A novel blade tip clearance measurement method based on event capture technique

Blade tip clearance (BTC) measurement is an essential technology in turbomachinery health monitoring so as to enhance efficiency and reliability as well as to ensure timely maintenance. The existing BTC measurement methods, which based on continuous sampling technique, depend highly on the devices sampling frequency, data transmission speed, storage memory, and computation capability, can hardly achieve online real-time measurement and long-term continuous monitoring. BTC distribution of a turbomachinery possesses discreteness, symmetry, monotonicity and quasi-periodicity, based on these characteristics, this paper proposes a novel BTC measurement method based on event capture technique. The method sorts the sensors signal into distinct events according to pre-set trigger thresholds, describes the relationship between the event kinds and the BTC distribution via mathematical equations, and solves the BTC values accordingly. The measurement error, measuring sensitivity, measurable range, and solving stability of the proposed method are demonstrated. A test to validate the proposed method for BTC measurement in the inlet section of a turboengine is performed, and the results show that, the event capture technique is capable of achieving fast and accurate BTC measurement. The proposed methods own a measurement error within 0.02 mm (for dual-channel configuration) and 0.01 mm (for multi-channel configuration) comparing with the continuous sampling technique. Meanwhile their hardware resource requirement are reduced to 0.02% (for dual-channel configuration) and 0.1% (for multi-channel configuration) comparing with the continuous sampling technique. For processing these performances, the proposed method can be applied for online real-time BTC measurement and long-term continuous BTC monitoring.

Performance evaluation of mass transport enhancement in novel dual-channel design of micro-reactors

Various design configurations of semi-T-shaped dual-channel micro-reactors were numerically examined for their laminar mass transport performance in heterogeneous catalytic combustion of methane and air. One single-channel and five dual-channel configurations (i.e., parallel, divergent, convergent, zig-zag, and curved configurations) were investigated with a two-dimensional computational fluid dynamics model. These innovative design configuration were compared in terms of CH4 utilization, pressure drop, CO/CO2 ratio, catalyst utilization, and a performance index at various Reynolds numbers. Dual-channel micro-reactors were found to enhance mass transport due to the well mixed flow and the increased reaction contact area. By suitably modifying the dual-channel layout angle and shape, recirculation zones can be formed within the reactor which increase CH4 utilization. However, the improved conversion rate is achieved at the cost of high pressure drop. The parallel dual-channel design provides the highest conversion per unit pressure drop over the range of the Reynolds numbers studied. For Reynolds numbers of 20 and 40, compared to the single-channel micro-reactor, divergent, convergent and curved channel designs yield higher conversion per unit pumping power. However, further increase of Reynolds number (i.e., 60, 80, and 100) deteriorates their performance due to the significantly increased pressure drop and shorter residence time.

300 GHz quadrature phase shift keying and QAM16 56 Gbps wireless data links using silicon photonics photodiodes

In this Letter, the authors report the achievement of terahertz transmissions using advanced quadrature amplitude modulation (QAM)16 signals using 300 GHz silicon photonics devices, developed in industrial foundry process PIC25G. Up to 56 Gbps is obtained using QAM16 single channel modulation and up to 50 Gbps in a dual-channel configuration.

On the interplay between plasma discharge instability and formation of free-standing graphene nanosheets in a dual-channel microwave plasma torch at atmospheric pressure

The influence of the interplay between central (QC) and secondary (QS) channel gas flow, as well as delivered microwave power (PMW), during graphene nanosheet synthesis in a dual-channel electrode configuration of a microwave plasma torch at atmospheric pressure by ethanol decomposition was investigated. In the dual-channel configuration, plasma discharge can be sustained, even at high flow rates of ethanol, due to the separation of argon working and carrier gas. The plasma discharge instability was mainly influenced by an increase in the central channel flow, and a minor influence of secondary channel flow was also observed. With respect to the dependence on experimental conditions, the synthesized nanopowder consisted of amorphous carbon and nanocrystalline diamond nanoparticles, defective carbon nanosheets or few-layer graphene nanosheets. The synthesized nanosheets are rectangular in shape with a lateral size of several hundreds of nanometres and a few graphene layers thick, as shown by electron microscopy. Raman and x-ray photoelectron spectroscopy analysis of the synthesized nanosheets showed a good degree of graphitization, low oxygen content and increasing quality of graphene nanosheets with increasing microwave power. The number of defects in the synthesized nanosheets could be decreased by elongation of the graphene nanosheet assembly zone. An increase in the C2/C emission line intensity ratio correlated with a decrease in the number of defects in the graphene nanosheet structure. The achieved conversion yield of ethanol into graphene nanosheets was 8.3%, without negatively affecting the nanosheet quality.

Improved experimental and diagnostic techniques for dynamic tensile stress–strain measurement with a Kolsky tension bar

Kolsky tension bar experiments were improved for dynamic tensile stress–strain measurements with higher fidelity and minimal uncertainties. The difficulties associated with specimen gripping, relatively short gage section, and geometric discontinuity at the bar ends all compromise the accuracy of the traditional strain measurement method in a Kolsky tension bar experiment. In this study, an improved three-channel splitting-beam laser extensometer technique was developed to directly and independently track the displacement of the incident and transmission bar interfaces. By adopting a dual-channel configuration on the incident bar side, the resolution and measurement range of this laser extensometer were coordinated between the two channels to provide highly precise measurement at both small and large strains under high strain-rate loading condition. On the transmission bar side an amplified channel, similar to that used on the incident bar side, was adopted to measure the transmission bar displacement with high resolution. With this novel design, a maximum resolution of approximately 500 nm can be obtained for the bar displacement measurement, which corresponds to a strain of 0.0079% for a specimen with 6.35 mm gage length. To further improve the accuracy, a pair of lock nuts were used to tighten the tensile specimen to the bars in an effort not only to prevent the specimen from potential pre-torsional deformation and damage during installation, but also to provide better thread engagement between the specimen and the bar ends. As a demonstration of this technique, dynamic tensile stress–strain response of a 304L stainless steel was characterized with high resolution in both elastic and plastic deformations.

Capillary Rise of Nanostructured Microwicks.

Capillarity refers to the driving force to propel liquid through small gaps in the absence of external forces, and hence enhanced capillary force has been pursued for various applications. In this study, flower like ZnO nanostructures are successfully deposited to enhance capillarity of microwick structures that are specially designed to augment boiling heat transfer performance. Microreactor-assisted nanomaterial deposition, MANDTM, is employed with a flow cell to deposit the ZnO nanostructures on a large sized microwick (4.3 cm × 10.7 cm) with dual-channel configuration. A capillary rise experiment based on the mass gain method is first performed using water and ethanol (EtOH) as the working liquids to demonstrate the enhanced capillary force induced by the ZnO nanostructure on the microwick structure. It is found that the coating of ZnO nanostructure effectively propels the working fluids through the nano- or micro pores created from the ZnO nanostructure and consequently improves the capillary force. In order to investigate the wicking mechanism of the ZnO coated microwick structure, the capillary rise result based on height measurement was compared with analytical models. It is found that the gravity effect and viscous force play an important role in wicking rise of the coated wick structure. This study aims at demonstrating the capability of the integrated MAND process with a flow cell for producing a large scaled nanostructured surface, which eventually has a great potential for enhanced boiling heat transfer.

Dual-channel microcantilever heaters for volatile organic compound detection and mixture analysis.

We report on novel microcantilever heater sensors with separate AlGaN/GaN heterostructure based heater and sensor channels to perform advanced volatile organic compound (VOC) detection and mixture analysis. Operating without any surface functionalization or treatment, these microcantilevers utilize the strong surface polarization of AlGaN, as well as the unique heater and sensor channel geometries, to perform selective detection of analytes based on their latent heat of evaporation and molecular dipole moment over a wide concentration range with sub-ppm detection limit. The dual-channel microcantilevers have demonstrated much superior sensing behavior compared to the single-channel ones, with the capability to not only identify individual VOCs with much higher specificity, but also uniquely detect them in a generic multi-component mixture of VOCs. In addition, utilizing two different dual channel configurations and sensing modalities, we have been able to quantitatively determine individual analyte concentration in a VOC mixture. An algorithm for complete mixture analysis, with unique identification of components and accurate determination of their concentration, has been presented based on simultaneous operation of an array of these microcantilever heaters in multiple sensing modalities.

An ARM-based Multi-channel CNC Solution for Multi-tasking Turning and Milling Machines

ARM-based CNC systems are used as a low-cost solution for controlling 2-3 axis machines. The increase of computing power of ARM processors facilitated their application to controlling multi-tasking and multi-axis machines with several independent control channels. The paper presents the results of the exploratory investigation of the transition from the PC-based to the ARM-based CNC solution. The cross-platform architecture of CNC systems, the porting of CNC kernel software to the single-board computers Raspberry Pi 2 with the Linux operating system and the control of servo drives and PLC I/O over EtherCAT fieldbus with cycle time of 2ms are investigated as well.The dual-channel configuration of ARM-based CNC designed to control the multi-tasking turning and milling machine with inclined layout is presented. The paper illustrates the kinematic scheme and the network architecture of NAKLON 535 machining center for ARM-based CNC solution.

Simultaneous evaluation of two branches of a multifunctional integrated optic chip with an ultra-simple dual-channel configuration

We propose an ultra-simple dual-channel configuration for simultaneously evaluating two branches of a multifunctional integrated optic chip (MFIOC). In the configuration, the MFIOC is employed as a beam splitter to construct the demodulation interferometer together with a 2×2 fiber coupler. Interference happens between polarization modes traveling through different channels of the MFIOC. The cross-couplings of each channel are respectively characterized by the interference peaks which distribute on opposite sides of the central interference peak. Temperature responses of the MFIOC are experimentally measured from −40°C to 80°C. Results show that the proposed configuration can achieve simultaneous dual-channel transient measurements with resolution of −90 dB and dynamic range of 90 dB. In addition, the two channels of the configuration have consistent measuring performance, and the two branches of the MFIOC have different responses to temperature variation.

Evaluation of in-channel amperometric detection using a dual-channel microchip electrophoresis device and a two-electrode potentiostat for reverse polarity separations.

In-channel amperometric detection combined with dual-channel microchip electrophoresis is evaluated using a two-electrode isolated potentiostat for reverse polarity separations. The device consists of two separate channels with the working and reference electrodes placed at identical positions relative to the end of the channel, enabling noise subtraction. In previous reports of this configuration, normal polarity and a three-electrode detection system were used. In the two-electrode detection system described here, the electrode in the reference channel acts as both the counter and reference. The effect of electrode placement in the channels on noise and detector response was investigated using nitrite, tyrosine, and hydrogen peroxide as model compounds. The effects of electrode material and size and type of reference electrode on noise and the potential shift of hydrodynamic voltammograms for the model compounds were determined. In addition, the performance of two- and three-electrode configurations using Pt and Ag/AgCl reference electrodes was compared. Although the signal was attenuated with the Pt reference, the noise was also significantly reduced. It was found that lower LOD were obtained for all three compounds with the dual-channel configuration compared to single-channel, in-channel detection. The dual-channel method was then used for the detection of nitrite in a dermal microdialysis sample obtained from a sheep following nitroglycerin administration.

Numerical modeling of flow boiling instabilities using TRACE

Dynamic flow instabilities in two-phase systems are a vitally important area of study due to their effects on a great number of industrial applications, including heat exchangers in nuclear power plants. Several next generation nuclear reactor designs incorporate once through steam generators which will exhibit boiling flow instabilities if not properly designed or when operated outside design limits. A number of numerical thermal hydraulic codes attempt to model instabilities for initial design and for use in accident analysis.TRACE, the Nuclear Regulatory Commission’s newest thermal hydraulic code is used in this study to investigate flow instabilities in both single and dual parallel channel configurations. The model parameters are selected as to replicate other investigators’ experimental and numerical work in order to provide easy comparison. Particular attention is paid to the similarities between analysis using TRACE Version 5.0 and RELAP5/MOD3.3. Comparison of results is accomplished via flow stability maps non-dimensionalized via the phase change and subcooling numbers.Results of this study show that TRACE does indeed model two phase flow instabilities, with the transient response closely mimicking that seen in experimental studies. When compared to flow stability maps generated using RELAP, TRACE shows similar results with differences likely due to the somewhat qualitative criteria used by various authors to determine when the flow is truly unstable.

Deep brain stimulation lead-contact heating during 3T MRI: single- versus dual-channel pulse generator configurations

Background: Magnetic resonance imaging (MRI) after deep brain stimulation (DBS) carries the risk of heating at the lead-contacts within the brain. Objective/Hypothesis: To compare the effect of single- and dual-channel DBS implantable pulse generator (IPG) configurations on brain lead-contact heating during 3T MRI. Methods: A phantom with bilateral brain leads and extensions connected to two single-channel IPGs or a dual-channel right or left IPG was utilized. Using a transmit/receive head coil, seven scan sequences were conducted yielding a range of head-specific absorption rates (SAR-H). Temperature changes (ΔT) at the bilateral 0 and 3 lead-contacts were recorded, and normalized temperatures (ΔT/SAR-H) and slopes defining the ΔT/SAR-H over the SAR-H range were compared. Results: Greater heating was strongly correlated with higher SAR-H in all configurations. For each scan sequence, the ΔT/SAR-H of single-channel left lead-contacts was significantly greater than the ΔT/SAR-H of either dual-channel configuration. The slope defining the relationship between ΔT and SAR-H for the single-channel left lead (1.68°C/SAR-H) was significantly greater (p < 0.0001) than the ΔT/SAR-H slope for the single-channel right lead (0.97°C/SAR-H), both of which were significantly greater (p < 0.0001) than the ΔT/SAR-H slopes of left or right leads (range 0.68 to 0.70°C/SAR-H) in the dual-channel configurations. There were no significant differences in ΔT/SAR-H slope values between the dual-channel configurations. Conclusion: DBS hardware configuration using bilateral single-channel versus unilateral dual-channel IPGs significantly affects DBS lead-contact heating during 3T MRI brain scanning.