Limited Capacity Research Articles

Synthesis of GN/ MnO2 nanocomposite materials for photo-assisted supercapacitor with enhanced capacities

Supercapacitors with the advantages of high power density and rapid discharging rate have widespread applications in energy storage. Nevertheless, their development is hindered by the limitation of low specific capacity. Traditional approaches to enhance specific capacity primarily involve incorporating foreign atoms and blending with additional reactive substances. Herein, a photo-assisted supercapacitor electrode material (GN/MnO2 nanocomposite) with excellent capacity is developed. As a photoactive material, graphene generates electrons and holes with photoirradiation. As the photogenerated carriers increase, electrons are separated from the holes and stored as charges. Photoirradiation is the driving force that promotes the energy storage and conversion of supercapacitors. Although there are many reports on GN/MnO2 composites, there are still few reports on the photo-assisted energy storage of this composite material. The specific capacity of this photo-assisted GN/MnO2 electrode materials could reach 210 F/g with photoirradiation. It was higher than that without photoirradiation (170 F/g). The development of this study provides important theoretical guidance and practical significance for the research of photo-assisted energy storage materials, and plays a significant role in advancing the progress of energy storage devices with high specific capacity.

Isoreticular Curves: A Theory of Capillary Condensation To Model Water Sorption within Microporous Sorbents.

Metal-organic frameworks have gained traction as leading materials for water sorption applications due to precise chemical tunability of their well-ordered pores. These applications include atmospheric water capture, heat pumps, desiccation, desalination, humidity control, and thermal batteries. However, the relationships between the framework pore structure and the measurable water sorption properties, namely critical relative humidity for condensation, maximal capacity, and pore size or temperature for the onset of hysteresis, have not been clearly delineated. Herein, we precisely formulate these relationships by application of the theory of capillary condensation and macroscopic thermodynamic models to a large data set of MOF water isotherms. These relationships include a concept termed isoreticular curves that relates the critical pressure for pore condensation (α), gravimetric capacity (Qmax), and hydrophilicity (the Gibbs free energy for binding water, ΔG) as Qmax = a1(ΔG/ln α)2 + a2(ΔG/ln α), with constants a1 and a2 dependent upon the density and volume occupied by the linker and secondary building unit, and framework topology. Through this analysis, we propose guidelines for the maximization of sorption capacity at a given relative humidity with minimal hysteresis and discuss the theoretical limits for capacity at low relative humidity. This model provides an explanation for the lack of high-capacity frameworks at low relative humidity, as increasing pore size also causes an increase in relative humidity. We propose a loose upper bound of Qmax = -0.25(1/ln α)2 - 1.75(1/ln α) for the limit of maximal capacity at a given relative humidity in the dry regime. These guidelines are consequential for the design of new materials for water sorption applications.

Novel mirror-flipped mode permutation technique for long-haul 6-mode transmission

Mode-division multiplexing based on few-mode fibers is expected to overcome capacity limits of current single-mode fiber communications. Mode permutation as an approach for extending transmission reach has attracted great attention. In this paper, we propose a mirror-flipped mode permutation (MFMP) scheme based on newly developed fibers with symmetric differential mode delay (DMD). We demonstrate a 28-GBaud transmission over a 1542-km 6-mode fiber link, which suppresses modal-dispersion impact by 36% and mitigates mode-dependent-loss effect with 3.1-dB Q-factor improvement, compared with the traditional cyclic mode permutation at 1233 km. Then, we experimentally verify that the proposed MFMP works well even using a fiber with a not exactly symmetric group delay distribution. Benefiting from a low DMD in this fiber, we demonstrate a 6-mode PM-QPSK transmission at 25 GBaud with 16-λ channels, extending the transmission distance to 3000 km.

A multi-ship power sharing strategy: Using two-stage robust optimization and Shapley value approach

In recent years, the use of cold ironing (CI) has effectively reduced the carbon emissions of ships in port areas. However, due to the limitation of port CI quantity and power supply capacity, the power demand of some ships cannot be met. To solve this problem, this paper proposes a multi-ship power sharing strategy based on two-stage robust optimization and improved Shapley value method. Firstly, considering the uncertainty of ship photovoltaic power generation, a multi-ship power sharing model based on two-stage robust optimization is established. This model is a three-level optimization model with mixed integer variables, which is a NP-hard problem. In this paper, the nested column-and-constraint generation algorithm combined with duality theory and big-M method is used to obtain the optimal scheduling strategy of ship shared power, CI power and load demand response power. Secondly, an improved Shapley value method considering berth and remaining berthing time is proposed to realize the cost allocation in the process of ship power sharing. Finally, the effectiveness of the multi-ship power sharing strategy in reducing berthing costs and carbon emissions is verified by simulation. This method is expected to provide a new idea for the development of green ports.

Ensuring Sustainable Grid Stability through Effective EV Charging Management: A Time and Energy-Based Approach

The rise of electric vehicles (EVs) has significantly transformed transportation, offering environmental advantages by curbing greenhouse gas emissions and fossil fuel dependency. However, their increasing adoption poses challenges for power systems, especially distribution systems, due to the direct connection of EVs with them. It requires robust infrastructure development, smart grid integration, and effective charging solutions to mitigate issues like overloading and peak demand to ensure grid stability, reliability, and sustainability. To prevent local equipment overloading during peak load intervals, the management of EV charging demand is carried out in this study, considering both the time to deadline and the energy demand of EVs. Initially, EVs are prioritized based on these two factors (time and energy)—those with shorter deadlines and lower energy demands receive higher rankings. This prioritization aims to maximize the number of EVs with their energy demands met. Subsequently, energy allocation to EVs is determined by their rankings while adhering to the transformer’s capacity limits. The process begins with the highest-ranked EV and continues until the transformer nears its limit. To this end, an index is proposed to evaluate the performance of the proposed method in terms of unserved EVs during various peak load intervals. Comparative analysis against the earliest deadline first approach demonstrates the superior ability of the proposed method to fulfill the energy demand of a larger number of EVs. By ensuring sustainable energy management, the proposed method supports the widespread adoption of EVs and the transition to a cleaner, more sustainable transportation system. Comparative analysis shows that the proposed method fulfills the energy needs of up to 33% more EVs compared to the earliest deadline method, highlighting its superior performance in managing network loads.

How middle-skilled workers adjust to immigration: the role of occupational skill specificity

PurposeOur study explores the effects of immigration on the employment of native middle-skilled workers, focusing on how this effect varies with the specificity of their occupational skill bundles.Design/methodology/approachExploiting the 2002 opening of the Swiss labor market to EU workers and using register data on the location and occupation of these workers, our findings provide novel results on the labor market effects of immigration.FindingsWe show that the inflow of EU workers led to an increase in the employment of native middle-skilled workers with highly specific occupational skills. This finding could be attributed to immigrant workers reducing existing skill gaps, enhancing the quality of job-worker matches, and alleviating firms' capacity restrictions. This allowed firms to create new jobs, thereby providing increased employment options for middle-skilled workers with highly specialized skills.Originality/valuePrevious literature has predominantly highlighted the disadvantages of specific occupational skills compared to general skills in the context of labor market shocks. However, our findings reveal that workers with specific occupational skills can benefit from an immigration-driven labour market shock. These results suggest that policy conclusions regarding the role of specific occupational skills should be more nuanced.

Ultrasound Controllable Release of Proteolysis Targeting Chimeras for Triple-Negative Breast Cancer Treatment.

Triple-negative breast cancer (TNBC) is a special subtype of breast cancer, which is highly aggressive and incurable. Here, we proposed an ultrasound activatable bromodomain-containing protein 4 (BRD4) proteolysis targeting chimera (PROTAC) release strategy for the first time for precisely controlled protein degradation in preclinical TNBC model. Through combination of PROTAC and ultrasound-targeted microbubble destruction (UTMD) technology, the present strategy also aims to concurrently solve the major limitations of poor loading capacity of microbubbles and undesirable targeting and membrane permeability of PROTAC. PROTAC (ARV-825)-encapsulated microbubbles, ARV-MBs, were developed for the efficacious treatment of TNBC invitro and invivo. The microbubbles we synthesized showed ultrasound-responsive drug release ability, which could effectively promote the penetration of PROTAC into tumor site and tumor cell. Under ultrasound, ARV-MBs could play an effective antitumor effect by potentiating the ubiquitination and degradation of BRD4 in tumor. The current study may provide a new idea for promoting clinical translation of drug-loaded microbubbles and PROTAC, and offer a new efficacious therapeutic modality for TNBC.

О грузоперевозках на существующем главном ходу Октябрьской железной дороги после ввода в эксплуатацию ВСМ Москва — Санкт-Петербург

Objective: to study the change of passenger and freight traffic on the Oktyabrskaya Railway “main route — the way around” and to show the need to continue research, taking into account the construction in 2028 high-speed railway Moscow — St. Petersburg (HSR). Methods: analysis of published research results, study of the main regulatory documents, reports and other sources taking into account the reflection of the key tasks of the development of railway transport, including the HSR network, according to the Transport Strategy of the Russian Federation until 2030 with a forecast until 2035. Results: it was found that after switching cargo traffic from the main route to the way around in Russia, tariffs and the delivery time of goods by rail have increased. With the growth of the total volume of container traffic towards the ports of the North-West, the goods are transported by road. There is a strong competition between Sapsan trains and air transport in the fight for passengers on the Moscow — St. Petersburg route. The upgraded railway track for the Sapsan speed service is operating at the capacity limit. This confirms the relevance of the construction of HSR in this route and makes it important of research of passenger and freight traffic on the Oktyabrskaya Railway “main route — the way around”. Practical importance: the use of research results will increase the competitiveness of railways in comparison with auto and airtransport in the Oktyabrskaya Railway “main route — the way around”.

Coating-assisted picosecond laser ablation for microstructure fabrication of SiC ceramics

Silicon carbide (SiC) ceramics have emerged as critical materials in the production of high-precision components. Ultrafast laser processing is deemed the optimal technique for micro-nano manufacturing of SiC. However, the permanent deposition layer induced by laser ablation can critically impact the precision of the component. In this work, a coating-assisted picosecond laser ablation (CAPLA) method was proposed, in which sacrificial photoresist coating was utilized to improve surface quality without efficiency loss. The coating serves to prevent the uncooled plasma from contacting with the substrate, thereby preventing the formation of a permanent deposition layer. By comparing the CAPLA method with laser direct ablation, the influence of laser parameters and photoresist coating characteristics on the deposition layer was investigated systematically. A processed surface devoid of deposition layers can be achieved by CAPLA with low pulse energy and a high number of scans. The uniformity is critical to ensure the transmission of the laser beam, and a larger thickness can improve the processing efficiency by increasing the limit of pulse energy capacity. Pin arrays and vacuum grooves for SiC ceramic vacuum chucks were fabricated to demonstrate the superiority of the CAPLA method. These results suggest that this method can be a novel and promising approach for high-precision component manufacturing.

Quantum computer-enabled receivers for optical communication

Optical communication is the standard for high-bandwidth information transfer in today’s digital age. The increasing demand for bandwidth has led to the maturation of coherent transceivers that use phase- and amplitude-modulated optical signals to encode more bits of information per transmitted pulse. Such encoding schemes achieve higher information density, but also require more complicated receivers to discriminate the signaling states. In fact, achieving the ultimate limit of optical communication capacity, especially in the low light regime, requires coherent joint detection of multiple pulses. Despite their superiority, such joint detection receivers are not in widespread use because of the difficulty of constructing them in the optical domain. In this work we describe how optomechanical transduction of phase information from coherent optical pulses to superconducting qubit states followed by the execution of trained short-depth variational quantum circuits can perform joint detection of communication codewords with error probabilities that surpass all classical, individual pulse detection receivers. Importantly, we utilize a model of optomechanical transduction that captures non-idealities such as thermal noise and loss in order to understand the transduction performance necessary to achieve a quantum advantage with such a scheme. We also execute the trained variational circuits on an IBM-Q device with the modeled transduced states as input to demonstrate that a quantum advantage is possible even with current levels of quantum computing hardware noise.

Rigid-flexible mediated Co-polyimide enabling stable silicon anode in lithium-ion batteries

Silicon is considered as a promising electrode materials for the next generation of lithium-ion batteries. However, it’s commercial applications are hindered by significant volume changes. In this study, copolyimide binders with adjustable rigidity and flexibility were synthesized through simple copolymerization. The rigid segments containing adenine groups (p-APA) provide excellent mechanical strength and interface interaction, while flexible segments containing siloxane bonds and alkane chains (DS-NH2) can buffer volume changes through enhanced mobility and topological entanglement of molecular segments. Optimizing the copolymerization ratio helps minimize damage to the silicon electrode structure and stabilizes solid electrolyte interphase (SEI) growth. Compared to the rigid polyimide binders, rigid-flexible coupling strategy improves cycling stability, remaining a capacity of 2170 mAh/g at 2 A/g after 200 cycles and exhibiting stable cycling for over 750 cycles with a capacity limitation of 1500 mAh/g. The high mass loading silicon anodes, micron-sized silicon oxide electrodes and the full cells also exhibit favorable electrochemical performance. This research provides valuable insights for designing high-performance aromatic polymer binders for high energy density lithium-ion batteries.

Time efficiency and match optimization in scheduling Pencak Silat matches: a case study of the Sleman Regency Student Pencak Silat Championship in 2023

The issue of this research is that many pencak silat matches in Indonesia still use manual calculations in several dis-tricts/regencys, then the calculation data is inputted into the system. This will take a lot of time, so the pencak silat match schedule spends a lot of time. The data used is the number of parties at the Sleman Regency Student Pencak Silat Championship in 2023. This research aims to find calculations to maximize the number of parties/matches/match numbers per day in a martial arts match. The method that can be used is the Preemptive Multiple Bounded Knapsack Problem (PMBKP). PMBKP involves distributing the quanti-ty of different types of items to a group of knapsacks with their respective priorities and capacity limits. The PMBKP results obtained in the 2023 Sleman District Pencak Silat Championship problem using the Branch and Bound algorithm are 175 parties on the first day, 133 parties on the second day, 128 parties on the third day, 127 parties on the fourth day, and 72 parties on the fifth day. These results can be said to be effective if applied to pencak silat matches that aim to nurture achievements, such as introductions and district/regency level matches. Keywords: Pencak Silat, Competition, Sports Schedule

Reading a graph is like reading a paragraph.

Vision provides rapid processing for some tasks, but encounters strong constraints from others. Although many tasks encounter a capacity limit of processing four visual objects at once, some evidence suggests far lower limits for processing relationships among objects. What is our capacity limit for relational processing? If it is indeed limited, then people may miss important relationships between data values in a graph. To test this question, we asked people to explore graphs of trivially simple 2 × 2 data sets and found that half of the viewers missed surprising and improbable relationships (e.g., a child's height decreasing over time). These relationships were spotted easily in a control condition, which implicitly directed viewers to prioritize inspecting the key relationships. Thus, a severe limit on relational processing, combined with a cascade of other capacity-limited operations (e.g., linking values to semantic content), makes understanding a graph more like slowly reading a paragraph then immediately recognizing an image. These results also highlight the practical importance of "data storytelling" techniques, where communicators design graphs that help their audience prioritize the most important relationships in data. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Augmentation of the tubular distiller performance via hot air injection from a parabolic trough collector, nanocoating, and nanofluid

Nowadays, due to freshwater scarcity intensifying, researchers are actively seeking to improve solar desalination, a technology with immense potential, but there are still limitations in production capacity. This study investigated the integration of various additives in tubular solar still (TSS) at three configurations. In Case I, a V-corrugated basin and an air parabolic trough collector (PTC) equipped with evacuated tubes were integrated. Then, with the same attachments, CuO nanocoating was applied to the basin surface in Case II, aiming to enhance heat absorption. Finally, in Case III, CuO nanofluid was used in the presence of all previous enhancers. The system was studied during summer days with weather parameters having average ranges (minimum – peak) of 32.5–37.5 °C (ambient temperature), 318.5–1000 W/m2 (solar radiation), and 1.1–2.3 m/s (wind speed). The results were very acceptable and competitive. All modified configurations of the advanced TSS (ATSS) significantly increased distillate production compared to the classic TSS (CTSS), with a range of 49.84–79.88 %. Case III stood out as the most successful configuration, achieving outstanding gains in both energy and exergy efficiencies. Compared to the CTSS, Case III boasted an impressive 83.69 % improvement in energy efficiency and a staggering 242.45 % increase in exergy efficiency. This refers to a system that not only produces more desalinated water but also does so with significantly less wasted energy, making it a more environmentally sustainable solution. Case III also offered a good economic advantage with a 13.51 % cost reduction compared to CTSS.

Experimental Study of the Flexural Performance of GFRP-Reinforced Seawater Sea Sand Concrete Beams with Built-In GFRP Tubes.

The use of seawater sea sand concrete (SSSC) and fiber-reinforced polymer (FRP) has broad application prospect in island and coastal areas. However, the elastic modulus of FRP reinforcement is obviously lower than that of ordinary steel reinforcement, and the properties of SSSC are different from that of ordinary concrete, which results in a limit in the bearing capacity and stiffness of structures. In order to improve the flexural performance of FRP-reinforced SSSC beams, a novel SSSC beam with built-in glass FRP (GFRP) tubes was proposed in this study. Referring to many large-scale beam experiments, one specimen was used for one situation to illustrate the study considering costs and feasibility. Firstly, flexural performance tests of SSSC beams with GFRP tubes were conducted. Then, the effects of the GFRP tubes' height, the strength grades of concrete inside and outside the GFRP tubes, and the GFRP reinforcement ratio on the flexural behaviors of the beams were investigated. In addition, the concept of capacity reserve was proposed to assess the ductility of the beams, and the interaction between the concrete outside the GFRP tube, the GFRP tube and concrete inside the tube was discussed. Finally, the formulas for the normal section bearing capacity of beams with built-in GFRP tubes were derived and verified. Compared to the beam without GFRP tubes, under the same conditions, the ultimate bearing capacities of the SSSC beam with 80 mm, 100, and 200 mm height GFRP tubes were increased by 17.67 kN, 24.52 kN, and 144.42 kN, respectively.

The Evaluation of Water Loss in The Western North Tarum Irrigation Channel

The Western North Tarum Irrigation channel plays a crucial role in supplying water to irrigated agricultural areas. However, it encounters challenges in ensuring adequate water delivery to all channel segments. This research assesses water loss during the distribution process in the Western North Tarum Irrigation channel, focusing on the evaluation of channel capacity and the impact of suboptimal water management on water loss. The study employs the HEC-RAS model, a hydraulic system analysis tool, to evaluate the channel’s capacity and simulates its behavior under various discharge conditions. The evaluation reveals that two channel segments, B.TUB 13 and B.TUB 25, have exceeded their capacity limits, resulting in overflow. Sedimentation downstream, particularly in these segments, exacerbates the issue by altering the channel slope and impeding water flow. This research identifies poor water distribution management as a significant factor contributing to water loss in the irrigation channel. Inadequate scheduling and the absence of proper water measurement tools result in instances of overwatering or underwatering in some areas. The lack of monitoring and control in the irrigation system hampers the detection of uncontrolled flow in the channels, leading to substantial water loss and inefficient water use. This research underscores the importance of evaluating and maintaining irrigation channel capacity to prevent overflow and water loss. Furthermore, it emphasizes the significance of effective water management to achieve more efficient water distribution and irrigation. Addressing these challenges is crucial for ensuring the long-term sustainability of irrigated agriculture in the Western North Tarum Irrigation area.Keywords: HEC-RAS, Irrigation Channel, Water Distribution, Water Loss, Western North Tarum

Research on optimization of multimodal hub-and-spoke transport network under uncertain demand

In the cargo transportation system, the hub-and-spoke transport network can make full use of the scale effect between logistics hubs and reduce logistics costs. Joint transportation of multiple modes of transportation can give full play to the advantages of different modes of transportation, which not only reduces logistics costs but also improves transportation efficiency. Therefore, this paper combines the advantages of multimodal transportation and hub-and-spoke network, and establishes an optimization model of multimodal hub-and-spoke transport network under demand uncertainty. The model takes into account hub capacity constraints and customer satisfaction with respect to transportation time, and to facilitate the model solution, we utilize the fuzzy expected value method and the fuzzy chance constraints based on credibility to clarify the uncertain variables in the model. We use mixed coding to describe the selection of hubs, assignment of nodes, and choice of transportation modes in this study and use the NSGA-II algorithm with local reinforcement to solve the problem. Finally, numerical experiments are designed to verify the validity of the model and algorithm through sensitivity analysis of relevant parameters, determine the reasonable number of hubs and confidence level, and obtain the influence of the change of hub capacity limit and the ratio of single and double hub transit on the research objectives. The results show that: the NSGA-II algorithm with local reinforcement can significantly improve the convergence speed of the algorithm; There is benefit inversion between economic cost and time cost, and the pursuit of economic cost minimization and time cost minimization, respectively, will lead to different choices of the number of hubs; Increasing the ratio of goods transfer between hubs is beneficial for fully utilizing the scale effect between hubs, achieving the goal of reducing economic costs, but at the same time, it will increase time costs.

Shaping the future: Improvements in the EV charging Infrastructure: A comparative analysis of Germany and India

The shift towards sustainable transportation has accelerated the deployment of electric vehicles (EVs), demanding advancements in EV charging infrastructure. [1] This thesis, "Shaping the Future: Improvements in EV Charging Infrastructure," explores the critical role of enhancing charging networks to boost EV adoption and usage. It delves into the status, challenges, technological innovations, regulatory frameworks, and evaluates the collective impact on future mobility. In-depth investigations reveal the challenges facing the existing EV charging infrastructure, such as grid capacity limitations, interoperability issues, and regulatory complexities. [2] It also compares global strategies from countries like Germany and India to evaluate the impact of government policies, subsidies, and incentives on infrastructure deployment. The research identifies emerging trends, including wireless charging, bidirectional capabilities, and smart, connected charging stations, emphasizing their potential to revolutionize the EV charging experience. It assesses the economic and environmental sustainability of integrating renewable energy sources into charging networks, as well as the scalability and adaptability of the infrastructure to evolving demands. [3] By synthesizing these findings, the thesis provides insights into future directions for the development of EV charging infrastructure. It offers recommendations for overcoming current barriers, fostering technological innovation, and harmonizing regulations to create a seamless, sustainable, and universally accessible EV charging environment.

A digital twin for parallel liquid-state nuclear magnetic resonance spectroscopy

One approach to increasing nuclear magnetic resonance measurement sample throughput is to implement multiple, independent detection sites. However, the presence of radio frequency interference poses a challenge in multi-detector systems, particularly in unshielded coil arrays lacking sufficient electrical isolation. This issue can lead to unwanted coupling of inductive coils, resulting in excitation pulse interference and signal transfer among multiple detection sites. Here we propose a theoretical framework that combines electromagnetic simulation with spin-dynamic calculations. This framework enables the evaluation of coil coupling effects, the design of parallel pulse sequences to mitigate inter-channel coupling, and the separation of composite free induction decays obtained from multiple detectors. The parallel pulse compensation scheme was validated by a 2-channel parallel spectroscopy experiment. These results provide valuable insights for the design of parallel nuclear magnetic resonance hardware and for exploring the limits of parallelization capacity within a fixed magnet system.

Forecast Analysis of Fruit Supply Using Time-Series Method: A Study at PT Aerofood Indonesia

PT Aerofood Indonesia is an entity operating in the aviation logistics industry, specifically as a partner of the Garuda Indonesia airline. The main problem faced is the tendency to have excessive supplies of raw materials, especially in the aspect of purchasing fruit because it is susceptible to damage. This phenomenon often recurs and peaks beyond dry goods capacity limits, especially the availability of papaya fruit which often exceeds capacity by more than 50%. Therefore, this research aims to identify the optimal forecasting method for papaya fruit to overcome the problem of excessive stock. In this research, four forecasting approaches were tested, namely Trend Analysis, Single Average Exponential, Double Average Exponential, and Holt's Winter Method. Forecasting calculations were carried out using a manual approach and supported by Minitab 18 software. The research results showed that the Holt's Winter method with a multiplicative approach produced the lowest Mean Absolute Percentage Error (MAPE), namely 16%. The Holt's Winter method with a multiplicative approach has proven to be effective in producing accurate forecasts. By implementing this recommended forecasting method, it is hoped that companies can be more efficient in managing inventory and reduce the impact of losses due to excess stock.