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POLLINATION ROBOT
No full text본 출원 발명은 식물재배 시설에 사용하는 수분로봇에 관한 것으로 더욱 자세하게는 컨테이너형 재배시설에 설치되는 수직형 재배장치에 적합한 수분로봇을 제공하고자 하는 것이다. 컨테이너형 재배시설의 경우 공간이 협소하여 기존의 직교로봇을 사용하는 것이 매우 어렵기 때문에 새로운 형태의 수분로봇이 필요하다. 본 출원 발명은 상기와 같은 문제를 해결하기 위하여 공기를 압축하여 복수의 채널을 구비하여 고압의 공기를 공급하는 공기압축기 및 복수의 공기공급 전자밸브 및 상기 공기공급 전자밸브에서 공기를 공급차단 또는 공기 배출을 제어하는 공기공급제어부; 및 상기 복수의 공기공급 전자밸브 중 어느 하나 이상의 전자밸브와 연결되어 상기 고압의 공기가 유입 또는 배출함에 따라 그 길이가 신축하며 식물의 꽃을 수분하는 엔드이펙터를 일단에 구비하고 타단은 컨테이너형의 내부에 구비된 수형이송레일에 구비된 수평이송부에 고정되는 고무 또는 신축성이 있는 플라스틱 수지로 만들어진 수분로봇의 몸통; 및 상기 수분로봇의 몸통 측면에 몸통의 길이방향을 따라 2개 이상 마주보도록 상기 수분로봇의 몸통에 접착되어 상기 복수의 공기공급 전자밸브 중 어느 하나의 전자밸브에 연결되어 신축함으로써 상기 수분로봇의 몸통의 방향을 제어하는 것을 특징으로 하는 수분로봇를 제공한다. 상기와 같은 발명의 구성에 의하여 컨테이너와 같은 밀폐식 식물재배 시설에서 편리하게 사용할 수 있는 수분로봇을 제공하는 효과가 있다
Dual path biphasic column for highly selective and ultrafast organic solvent membrane extraction
No full textDespite significant advances in membrane technology, achieving efficient separation in organic solvent nanofiltration (OSN) remains a major challenge in the chemical and pharmaceutical industries, particularly when dealing with multicomponent molecular mixtures. To address this, in this study, we develop a biphasic column for organic solvent membrane extraction, which consists of closely packed micron-sized water droplets covered by sub-nanometer-thick ion-ligand complexes that serve as size-exclusive membranes. Molecular mixtures dissolved in an organic solvent can be selectively extracted into the droplets through the interfacial complexes based on their sizes, while the solvent flows through the micron-scale interstices between the droplets. This solute-solvent dual pathway design minimizes resistance in solvent convection, resulting in high productivity, while simultaneously achieving a high separation factor through the monodisperse nanopores of the interfacial complexes. Using aluminum ion-carboxylate terminated polydimethylsiloxane complexes as a representative, the column demonstrates a controllable, high separation factor of 600 with a productivity of 1100 L<middle dot>m-2<middle dot>hour-1<middle dot>bar-1 in cyclohexane, significantly outperforming conventional membrane OSN.
Robust Transmission Design for Active RIS-Aided Systems
No full textDifferent from conventional passive reconfigurable intelligent surfaces (RISs), incident signals and thermal noise can be amplified at active RISs. By exploiting the amplifying capability of active RISs, noticeable performance improvement can be expected when precise channel state information (CSI) is available. Since obtaining perfect CSI related to an RIS is difficult in practice, a robust transmission design is proposed in this paper to tackle the channel uncertainty issue, which will be more severe for active RIS-aided systems. To account for the worst-case scenario, the minimum achievable rate of each user is derived under a statistical CSI error model. Subsequently, an optimization problem is formulated to maximize the sum of the minimum achievable rate. Since the objective function is non-concave, the formulated problem is transformed into a tractable lower bound maximization problem, which is solved using an alternating optimization method. Numerical results show that the proposed robust design outperforms a baseline scheme that only exploits estimated CSI.
Impact of Phosphide-Phosphate Ratio on NiCoP Catalysts for Hydrogen Evolution in Anion Exchange Membrane Water Electrolysis
No full textAlkaline and anion exchange membrane water electrolysis (AEMWE) presents a promising approach for hydrogen production. However, the slow kinetics of the alkaline hydrogen evolution reaction (HER) remains a significant challenge. This study aimed to enhance HER activity by optimizing transition metal-phosphorus compound catalysts, including Ni, Co, NiCo, NiP, CoP, and NiCoP. Their surface structure, crystallinity, electrochemical properties, and HER performance were meticulously studied. Among the catalysts, Ni28Co62P10 exhibited exceptional HER performance, achieving a low overpotential of 48 mV at a current density of -10 mA cm-2 in 1 M KOH. X-ray photoelectron spectroscopy analysis revealed that an optimal 1:1 balance of phosphate to phosphide is critical for achieving efficient HER. These findings emphasize the importance of balancing phosphorus species for optimal alkaline HER catalysis. Moreover, Ni28Co62P10 demonstrated excellent durability, maintaining high performance after 5000 cycles. In AEMWE single-cell tests, the catalyst achieved a cell voltage of 1.88 V at 1 A cm-2, surpassing the performance of Ni/Co-based catalysts from previous studies. The NiCoP-based catalysts in this study presented considerable promise for AEMWE systems, paving the way to the development of more efficient and durable catalysts for hydrogen production and advancing hydrogen-based renewable energy technologies.
A nearby dark molecular cloud in the Local Bubble revealed via H2 fluorescence
No full textA longstanding prediction in interstellar theory posits that significant quantities of molecular gas, crucial for star formation, may be undetected due to being 'dark' in commonly used molecular gas tracers, such as carbon monoxide. We report the discovery of Eos, a dark molecular cloud located just 94 pc from the Sun. This cloud is identified using H2 far-ultraviolet fluorescent line emission, which traces molecular gas at the boundary layers of star-forming and supernova remnant regions. The cloud edge is outlined along the high-latitude side of the North Polar Spur, a prominent X-ray/radio structure. Our distance estimate utilizes three-dimensional dust maps, the absorption of the soft-X-ray background, and hot gas tracers such as O vi; these place the cloud at a distance consistent with the Local Bubble's surface. Using high-latitude CO maps we note a small amount (MH2 approximate to 20-40M circle dot\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}\end{document}) of CO-bright cold molecular gas, in contrast with the much larger estimate of the cloud's true molecular mass (MH2 approximate to 3.4x103M circle dot\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}M_{{{\rm{H}}}_{2}}\approx 3.4\times 1{0}<^>{3}\,M_{\odot }\end{document}), indicating that most of the cloud is CO dark. Combining observational data with novel analytical models and simulations, we predict that this cloud will photoevaporate in 5.7 Myr, placing key constraints on the role of stellar feedback in shaping the closest star-forming regions to the Sun.
Efficient Semitransparent Organic Solar Modules with Exceptional Diurnal Stability Through Asymmetric Interaction Induced by Symmetric Molecular Structure
No full textThe symmetry-breaking design strategy of nonfullerene acceptor can improve the performance of semitransparent organic solar cells (ST-OSCs). However, no report exists on the &quot;asymmetric molecular interaction&quot; induced by symmetric molecular structure in nonfullerene acceptors. Herein, we showcase that 2D fluorophenyl outer groups in symmetric 4FY promote dipole-driven self-assembly through asymmetric molecular interactions, resulting in a tighter packed structure than Y6 with the same symmetric geometry. Such unique properties lead to high-performance layer-by-layer OSCs, accompanied by simultaneously reduced energy and recombination losses and improved charge-related characteristics. ST-OSCs based on PCE10-2F/4FY achieve notable power conversion efficiency (PCE) of 10.81%, average visible transmittance of 45.43%, and light utilization efficiency (LUE) of 4.91%. Moreover, exceptional diurnal cycling stability is observed in the ST-OSCs based on PCE10-2F/4FY with much prolonged T80 up to 134 h, which is about 17 times greater than the reference PCE10-2F/Y6. Lastly, we fabricate highly efficient semitransparent organic solar modules based on PCE10-2F/4FY (active area of 18 cm2), which shows PCE of 6.78% and the highest LUE of 3.10% to date for all-narrow bandgap semitransparent organic solar modules. This work demonstrates that asymmetry-driven molecular interactions can be leveraged to fabricate large-area ST-OSCs that are efficient and stable under realistic operating conditions.
Angle- and Polarization-Tolerant Metasurface Designs Based on the Aperiodic Tiling
No full textMetasurfaces composed of subwavelength elements have garnered significant interest for their ability to manipulate electromagnetic waves in unique ways. However, their optical properties are often highly sensitive to incident angles and polarization states, which can limit practical applications. While introducing random perturbations helps alleviate this issue, it can complicate both the design and fabrication processes. Instead, a new class of metasurface designs based on aperiodic tiling is proposed, specifically 'Einstein' tiling, which systematically enhances angle and polarization tolerance. This method, retroactively applicable to many scatterer designs in previously reported metasurfaces as well, applies a single scatterer design across the entire surface, introducing aperiodicity and orientational diversity through predefined placement rules. This approach simplifies optimization and production. Our prototype, designed for structural color applications, shows tolerance to incident angles up to 45 degrees in both reflectance spectra and structural colors and accommodates arbitrary polarization states. The proposed metasurface maintains many of the advantages of periodic metasurfaces, such as easily designable colors and facile color mixing. This work highlights the potential of aperiodic metasurfaces for applications requiring robust performance under diverse lighting conditions, offering an interesting new route toward practical optical metasurfaces.
Prediction of edge crack initiation of low carbon steel based on stress-based failure model during hot rolling process
No full textLow-carbon steel plates play a crucial role in various industries such as automotive, energy, or structures. The hot rolling process to produce the steel plate may lead to the occurrence of edge cracks which requires to remove the affected edges, reducing the productivity in the manufacturing process. This study uses a stress-based fracture model considering the strain rate and temperature to predict the edge crack initiation of Si-added low-carbon steel during hot rolling. A new hardening model considering the strain rate and the temperature is proposed to model the target material including the softening behavior. Verification has been conducted by comparing finite element analysis with experiments from the hot rolling simulator under the same conditions. Using the strain-based fracture model led to an incorrect prediction of the edge crack initiation.
A Neuransistor with Excitatory and Inhibitory Neuronal Behaviors for Liquid State Machine
No full textA liquid state machine (LSM) is a spiking neural network model inspired by biological neural network dynamics designed to process time-varying inputs. In the LSM, maintaining a proper excitatory/inhibitory (E/I) balance among neurons is essential for ensuring network stability and generating rich temporal dynamics for accurate data processing. In this study, a &quot;neuransistor&quot; is proposed that implements the E/I neurons in a single device, allowing for the hardware implementation of the LSM. The device features a three-terminal transistor structure embodying TiO2-x/Al2O3 bi-layer, providing a two-dimensional electron electron gas (2DEG) channel at their interface. This device demonstrates hybrid excitatory and inhibitory dynamics with respect to the applied gate bias polarity, originating from the charge trapping/detrapping between the 2DEG and TiO2-x layers. Additionally, the three-terminal configuration allows masking capabilities by selecting terminal biases, realizing a reservoir behavior with superior reliability and durability. Its use in an LSM reservoir for time-series data prediction tasks using the Henon dataset and a chaotic equation solver for the Lorenz attractor is demonstrated. This benchmarking indicates that the LSM exhibits enhanced performance and efficiency compared to the conventional echo state network, underscoring its potential for advanced applications in reservoir computing.
GENERALIZED CONSISTENCY TRAJECTORY MODELS FOR IMAGE MANIPULATION
No full textDiffusion models (DMs) excel in unconditional generation, as well as on applications such as image editing and restoration. The success of DMs lies in the iterative nature of diffusion: diffusion breaks down the complex process of mapping noise to data into a sequence of simple denoising tasks. Moreover, we are able to exert fine-grained control over the generation process by injecting guidance terms into each denoising step. However, the iterative process is also computationally intensive, often taking from tens up to thousands of function evaluations. Although consistency trajectory models (CTMs) enable traversal between any time points along the probability flow ODE (PFODE) and score inference with a single function evaluation, CTMs only allow translation from Gaussian noise to data. This work aims to unlock the full potential of CTMs by proposing generalized CTMs (GCTMs), which translate between arbitrary distributions via ODEs. We discuss the design space of GCTMs and demonstrate their efficacy in various image manipulation tasks such as image-to-image translation, restoration, and editing. Code is available at https://github.com/1202kbs/GCTM