Leveraging Flow Regeneration in Individual Energy-Efficient Hydraulic Drives

The current demand for energy efficiency in hydraulics directs towards the replacement of centralized, valve-controlled actuators with individual, throttleless drives. The resulting solutions often require an undesirable sizing of the key components to expand the system’s operating region. Using flow regeneration (i.e., shortcutting the actuator’s chambers) mitigates this issue. Such an option, already stated for individual drives, lacks an in-depth analysis from the control perspective since the dynamic properties are changed (e.g., the natural frequency is decreased to about 60% of the original value). Therefore, this research paper studies a representative single-pump architecture arranged in a closed-circuit configuration. Linear control techniques are used to understand the system dynamics and design a PI-control algorithm that also adds active damping. The outcomes are validated via high-fidelity simulations referring to a single-boom crane as the study case. The results encompassing diverse scenarios indicate that flow regeneration is only interesting in those applications where the dynamic response is not demanding. In fact, the lower natural frequency reduces the system’s bandwidth to about 69% of the original value and affects the closed-loop position tracking drastically. This poor performance becomes evident when medium-to-high actuation velocity is commanded with respect to the maximum value.

Circuit Optimization Method to Reduce Disturbances in Poly-Si 1T-DRAM

A capacitorless one-transistor dynamic random-access memory device (1T-DRAM) is proposed to resolve the scaling problem in conventional one-transistor one-capacitor random-access memory (1T-1C-DRAM). Most studies on 1T-DRAM focus on device-level operation to replace 1T-1C-DRAM. To utilize 1T-DRAM as a memory device, we must understand its circuit-level operation, in addition to its device-level operation. Therefore, we studied the memory performance depending on device location in an array circuit and the circuit configuration by using the 1T-DRAM structure reported in the literature. The simulation results show various disturbances and their effects on memory performance. These disturbances occurred because the voltages applied to each device during circuit operation are different. We analyzed the voltage that should be applied to each voltage line in the circuit to minimize device disturbance and determine the optimized bias condition and circuit structure to achieve a large sensing margin and realize operation as a memory device. The results indicate that the memory performance improves when the circuit has a source line and the bias conditions of the devices differ depending on the write data at the selected device cell. Therefore, the sensing margin of the 1T-DRAM used herein can expectedly be improved by applying the proposed source line (SL) structure.

Extrasynaptic signaling enables an asymmetric juvenile motor circuit to produce a symmetric mature gait.

Bilaterians generate motor patterns with symmetries that correspond to their body plans. This is thought to arise from wiring symmetries in their motor circuitries. We show that juvenile C. elegans larva has an asymmetrically wired motor circuit, but they still generate bending pattern with dorsal-ventral symmetry. In this juvenile circuit, wiring between excitatory and inhibitory motor neurons drives and coordinates contraction of dorsal muscles with relaxation of ventral muscles, producing dorsal bends. Ventral bending is not driven by its own circuitry. Instead, ventral muscles are excited uniformly by premotor interneurons through extrasynaptic signaling, and ventral bends occur in entrainment to the activity of motor neurons for dorsal bends. During maturation, the juvenile motor circuit is replaced by two homologous motor circuits that separately generate dorsal and ventral bending. Our modeling reveals that the juvenile circuit configuration provides an adequate solution for an immature motor circuit to drive functional gait long before the animal matures.

Recovery of Rare Erath Oxides from Flotation Concentrates of Bastnaesite Ore by Ultra-Fine Centrifugal Concentration

Historically, the ability to effectively separate carbonate gangue from bastnaesite via flotation has frequently proven to be challenging without sacrificing significant rare earth oxide (REO) grade or recovery. However, in light of the fact that the rare earth bearing minerals often exhibit higher specific gravities than the carbonate gangue, the possibility exists that the use of gravity separation could be used to achieve such a selective separation. This however is complicated by the fact that, in cases such as this study when the liberation size is finer than 50 microns, most traditional gravity separation methods become increasingly challenging. The aim of this study is to determine the applicability of centrifugal concentrators to beneficiate ultra-fine (UF) bastnaesite and calcite bearing flotation concentrates. By using a UF Falcon, it was possible to achieve initial gravity REO recoveries exceeding 90% while rejecting on the order of 25% to 35% of the total calcium from an assortment of rougher and cleaner flotation concentrates. Additionally, when additional stages of cleaner UF Falcon gravity separation were operated in an open circuit configuration, it was possible, from an original fine feed of 35 microns containing 50.5% REO and 5.5% Ca, to upgrade up to approximately 59% REO and 2.0% calcium. While not the goal of this study, these results also support previous limited data to suggest that UF Falcons are potentially capable of treating a wider range of materials than they were originally designed for, including feeds rich in heavy mineral content.

Research and proposal the configuration of the booster circuit in the grid connected solar cell system and MPPT simulation in the partially shaded conditions

This paper proposes a new turbocharger configuration that uses fewer semiconductor locks, fewer reactor coils, and a higher turbidity factor than conventional turbocharger configurations. This allows for easier control, less component loss, high efficiency, reduced circuit size and weight, and low cost. A booster circuit configuration with recommended neutral is required and is suitable for T-shaped and NPC 3-order inverters. In addition, the article also applies the maximum power point tracking algorithm for PV systems working in partially shaded conditions to improve the working efficiency of PV systems, to meet the requirements of the PV systems. grid-connected large capacity PV system.