13197 research outputs found
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Dye adsorption-assisted colloidal dispersion of single-walled carbon nanotubes in polar solvents
No full textMicellar surfactants with amphiphilic chemical structures are mostly used to disperse single-walled carbon nanotubes (SWCNTs) in water. However, there is little systematic knowledge regarding the use of low-molecular-weight nonmicellar adsorbates as efficient surfactants for colloidal SWCNT dispersions, which limits the number of available solvents. In this article, we present an empirical rule for adsorbate-based dispersants required for SWCNT dispersion in polar organic solvents and water. First, we demonstrate that SWCNTs can be dispersed in aqueous media with the aid of the non-aqueous stilbene backbone compound amsonic acid. The impact of nonmicellar physical adsorption on dispersion was systematically examined using low-molecular-weight compounds, including Fluorescent Brighteners 28 and 220. This discovery has increased the availability of solvents such as water, polar organic solvents such as alcohols, and surfactants such as widely used organic dyes. The results of our study indicate that effective nonmicellar dispersants should include acid$2013base-carrying structures. The present findings have elucidated the colloidal chemistry of nanocarbon materials with significant potential for application as low-molecular-weight adsorbate-enhanced multifunctional inks.journal articl
Monolingual Paraphrase Detection for Low Resource Pashto Language
Get PDF奈良先端科学技術大学院大学修士(工学)master thesi
Statistical Modeling of Within-Laboratory Precision Using a Hierarchical Bayesian Approach
Get PDF奈良先端科学技術大学院大学博士(理学)doctoral thesi
Capacitated Shortest Path Tour-Based Service Chaining Adaptive to Changes of Service Demand and Network Topology
No full textTo achieve sustainable networking, network service providers have expressed significant interest in employing automated network operations that integrate network functions virtualization (NFV), software-defined networking (SDN), and machine learning (ML). In the context of NFV/SDN, a certain network service is regarded as a sequence of virtual network functions (VNFs) forming a service chain. The service chaining (SC) problem aims at establishing an appropriate service path from an origin node to a destination node where the VNFs are executed at intermediate nodes in the required order under resource constraints on nodes and links. SDN enables programmable configurations on forwarding devices (i.e., switches and routers) for traffic forwarding between VNFs. In our previous work, we formulated the SC problem as an integer linear program (ILP) based on the capacitated shortest path tour problem (CSPTP), which is an extended version of SPTP with additional node and link capacity constraints. Furthermore, we developed Lagrangian heuristics to solve the problem by considering the balance between optimality and computational complexity. In this paper, we propose a deep reinforcement learning (DRL) framework coupled with the graph neural network (GNN) to realize CSPTP-based SC that adapts to changes of service demand and/or network topology. Numerical results show that the proposed framework achieves nearly optimal SC with higher learning speed compared to the conventional deep Q-Network based approach. Moreover, it performs well when confronted with variations in service demand and exhibits competitive performance compared to the ILP solutions across the majority of 243 real-world topologies.journal articl
Cytokinin signaling is involved in root hair elongation in response to phosphate starvation
No full textRoot hair, single-celled tubular structures originating from the epidermis, plays a vital role in the uptake of nutrients from the soil by increasing the root surface area. Therefore, optimizing root hair growth is crucial for plants to survive in fluctuating environments. Root hair length is determined by the action of various plant hormones, among which the roles of auxin and ethylene have been extensively studied. However, evidence for the involvement of cytokinins has remained elusive. We recently reported that the cytokinin-activated B-type response regulators, ARABIDOPSIS RESPONSE REGULATOR 1 (ARR1) and ARR12 directly upregulate the expression of ROOT HAIR DEFECTIVE 6-LIKE 4 (RSL4), which encodes a key transcription factor that controls root hair elongation. However, depending on the nutrient availability, it is unknown whether the ARR1/12$2013RSL4 pathway controls root hair elongation. This study shows that phosphate deficiency induced the expression of RSL4 and increased the root hair length through ARR1/12, though the transcript and protein levels of ARR1/12 did not change. These results indicate that cytokinins, together with other hormones, regulate root hair growth under phosphate starvation conditions.journal articl
Designing Heat-Resistant and Moldable Polyester Resin by the Integration of Machine Learning Models with Expert Knowledge
No full textPolyester resin has advantages in transparency and chemical resistance and is widely used in films and containers. In industrial applications, multiple conflicting properties of polyester resin must be optimized. Nevertheless, few reports have been found dealing with the design of polyester resins with machine learning (ML) models. Herein, we report a multiobjective design strategy of heat tolerant and moldable polyester resin, represented by the glass-transition temperature (Tg) and the softening point (SP). Our proposed workflow is an interplay between ML models and expert knowledge. Highly accurate interpretable linear regression models using chemical structural features were constructed for Tg and SP, which were utilized for evaluating previously uninvestigated monomers. Insights into substructures with which highly correlated properties (Tg and SP) were compromised were obtained by analyzing the regression coefficients of a linear model for SP/Tg. Based on the insight from the SP/Tg model, four dicarboxylic monomers consisting of untested molecular scaffolds were proposed and with which polyester resins were actually synthesized. The synthesized resins exhibited desired properties, consistent with prediction results by ML models. The reported workflow successfully proposed the dicarboxylic monomers with which polyester resins had desirable multiple properties.journal articl
Self-powered and speed-adjustable sensor for abyssal ocean current measurements based on triboelectric nanogenerators
No full textThe monitoring of currents in the abyssal ocean is an essential foundation of deep-sea research. The state-of-the-art current meter has limitations such as the requirement of a power supply for signal transduction, low pressure resistance, and a narrow measurement range. Here, we report a fully integrated, self-powered, highly sensitive deep-sea current measurement system in which the ultra-sensitive triboelectric nanogenerator harvests ocean current energy for the self-powered sensing of tiny current motions down to 0.022009MPa. A variable-spacing structure broadens the measuring range to 0.022009m/s, which is 67% wider than that of commercial alternatives. The system successfully operates at a depth of 4531$2009m in the South China Sea, demonstrating the record-deep operations of triboelectric nanogenerator-based sensors in deep-sea environments. Our results show promise for sustainable ocean current monitoring with higher spatiotemporal resolution.journal articl
Gathering in Carrier Graphs: Meeting via Public Transportation System
No full textThe gathering problem requires multiple mobile agents in a network to meet at a single location. This paper investigates the gathering problem in carrier graphs, a subclass of recurrence of edge class of time-varying graphs. By focusing on three subclasses of single carrier graphs - circular, simple, and arbitrary - we clarify the conditions under which the problem can be solved, considering prior knowledge endowed to agents and obtainable online information, such as the count and identifiers of agents or sites. We propose algorithms for solvable cases and analyze the complexities and we give proofs for the impossibility for unsolvable cases. We also consider general carrier graphs with multiple carriers and propose an algorithm for arbitrary carrier graphs. To the best of our knowledge, this is the first work that investigates the gathering problem in carrier graphs.conference pape
