Cycle Strategies Research Articles

Recovery of isolated lithium through discharged state calendar ageing.

Rechargeable Li-metal batteries have the potential to more than double the specific energy of the state-of-the-art rechargeable Li-ion batteries, making Li-metal batteries a prime candidate for next-generation high-energy battery technology1-3. However, current Li-metal batteries suffer from fast cycle degradation compared with their Li-ion battery counterparts2,3, preventing their practical adoption. A main contributor to capacity degradation is the disconnection of Li from the electrochemical circuit, forming isolated Li4-8. Calendar ageing studies have shown that resting in the charged state promotes further reaction of active Li with the surrounding electrolyte9-12. Here we discover that calendar ageing in the discharged state improves capacity retention through isolated Li recovery, which is in contrast with the well-known phenomenon of capacity degradation observed during the charged state calendar ageing. Inactive capacity recovery is verified through observation of Coulombic efficiency greater than 100% on both Li||Cu half-cells and anode-free cells using a hybrid continuous-resting cycling protocol and with titration gas chromatography. An operando optical setup further confirms excess isolated Li reactivation as the predominant contributor to the increased capacity recovery. These insights into a previously unknown pathway for capacity recovery through discharged state resting emphasize the marked impact of cycling strategies on Li-metal battery performance.

Upaya Meningkatkan Hasil Belajar Siswa Melalui Model Pembelajaran PAIKEM Pada Pembelajaran Bahasa Indonesia Di SD Negeri 054904 Lorong Bambuan

This research aims to improve student learning outcomes at SD Negeri 054904 Lorong Bambuan. This type of research is classroom action research (PTK). Classroom action research consists of two cycles. Each cycle consists of four stages that must be passed, namely planning, implementation, observation and reflection. This research was conducted at SDN 054904 Lorong Bambuan. The research was carried out from 18 October 2023 to 18 December 2023 for the 2023/2014 academic year. The research subjects were 19 class V students consisting of 11 female students and 8 male students. The research object is the PAIKEM method. Data collection techniques are observation, questionnaires and tests. Based on the research results, it can be concluded that: (1) Student learning outcomes before the action only achieved 21% completeness or as many as 4 students. (2) Student learning outcomes after implementing the Paikem Learning Strategy in cycle I were 47.4% or 9 students completed. Student learning outcomes in cycle II were 100% or 19 people completed.

WORKING CAPITAL MANAGEMENT STRATEGIES OF NIGERIAN MANUFACTURING FIRMS AND THE EFFECTS ON CORPORATE PERFORMANCE

The study examined the working capital management strategies of Nigerian Manufacturing Firms and effect on Corporate Performance. Working capital management was decomposed into five variables being account receivable management (ARM), account payable management (APM), inventory management (INVM), cash conversion cycle (CCC) and cash conversion efficiency (CCE) which serve as the explanatory variables of the study while Corporate Performance was proxied by Return on Assets (ROA). The data for the study were collected from the Financial Statement and Annual Accounts of the selected firms covering a data panel framework of 20 years period (2000 to 2020) and nine (9) firms specifically were selected. The analysis was based on the ARDL regression technique was used to estimate the regression model while the probability values of the ARDL regression estimates were used to test the hypotheses at 0.05 level of significance. The result showed that: Account receivable management strategy have long run and no short run effect on return on asset of quoted manufacturing firms in Nigeria; Account payable management strategy have long run and no short run effect on return on asset of quoted manufacturing firms in Nigeria; Inventory management strategy have long and short run effect on return on asset of quoted manufacturing firms in Nigeria; Cash conversion cycle strategy have long and short run effect on return on asset of quoted manufacturing firms in Nigeria; and Cash conversion efficiency strategy have no long and short run effect on return on asset of quoted manufacturing firms in Nigeria. Further analysis revealed that account receivable, account payable inventory management and cash conversion efficiency had causal effects on return on assets. However, there is no causal relationship between cash conversion cycle strategy and return on asset of quoted manufacturing firms in Nigeria. The study thus concluded that working capital management strategies have significant effect on the financial performance of firms, and that the degree of effect differs by period, type of strategy and financial performance indicator. It was recommended among others that management of firms should firms increase the supplies to customers and allow credit to its customers, and firms should also explore the use of short-term credit in financing their business. The study contributed to knowledge by employing long run panel technique in investigating the working capital and firm performance nexus in Nigeria.

Dinophysis, a highly specialized mixoplanktonic protist

Several Dinophysis species produce lipophilic toxins (diarrhetic shellfish poisoning, DSP and pectenotoxins PTX) which are transferred through the food web. Even at low cell densities (< 103 cell L-1), they can cause human illness and shellfish harvesting bans; toxins released into the water may kill early life stages of marine organisms. Dinophysis species are mixotrophs: they combine phototrophy (by means of kleptoplastids stolen from their prey) with highly selective phagotrophy on the ciliate Mesodinium, also a mixotroph which requires cryptophyte prey of the Teleaulax/Geminigera clade. Life cycle strategies, biological interactions and plastid acquisition and functioning in Dinophysis species make them exemplars of resilient holoplanktonic mixoplankters and of ongoing speciation and plastidial evolution. Nevertheless, 17 years after the first successful culture was established, the difficulties in isolating and establishing cultures with local ciliate prey, the lack of robust molecular markers for species discrimination, and the patchy distribution of low-density populations in thin layers, hinder physiological experiments to obtain biological measurements of their populations and slow down potential advances with next-generation technologies. The Omic’s age in Dinophysis research has only just started, but increased efforts need to be invested in systematic studies of plastidic diversity and culture establishment of ciliate and cryptophyte co-occurring with Dinophysis in the same planktonic assemblages.

МЕХАНИЗМ УПРАВЛЕНИЯ ОРГАНИЗАЦИЕЙ НА ОСНОВЕ ФОРМИРОВАНИЯ МАРКЕТИНГОВОЙ СТРАТЕГИИ

The purpose of the study is to develop the management of the organization through the application of marketing strategy. The article studies the fields of competitive strategy of the organization, including: leadership and minimization of costs; specialization in production, as well as fixation of market segment. Conceptual approaches to formation of marketing strategy have been systematized. It has been revealed that the variety of approaches to formation of marketing strategy is due to the plurality of researchers in this field. The step-by-step approach chosen covers all approaches to strategy formation to some extent. This provision defined the scientific basis for developing a marketing strategy by identifying the successive stages of strategy formation, taking into account the use of a digital approach to the formation of a marketing strategy. It presents consecutive main stages of formation of marketing strategy on the basis of analysis of consumer activity: preliminary; organizational and managerial; final. Each stage is a set of actions and possible tools for its implementation. The proposed organizational mechanism allows to use as a basis for formation of marketing strategy of the organization. Taking into account the obtained results, the role and place of formation of marketing strategy in the management cycle of the organization have been determined. The relevance of the study is proved by the formation of the marketing strategy of the organization, which affects the increase of the socio-economic potential of the organization as a whole. In the course of the study, an analysis of the scientific literature was conducted, the works of Russian and foreign scientists in the field of formation of marketing strategy were studied, as a result of which it is possible to conclude that that there are multiple approaches to the organizational mechanism of formation of marketing strategy. At the same time, the most developed step-by-step approach, which determined the further study of the organizational mechanism in the form of the phased formation of the marketing strategy, which can be attributed to: 1. planning the goals and activities of the organization (setting organizational goals; planning activities); 2. Implementation and monitoring of plans (decision-making and implementation of plans; monitoring of implementation); 3. Monitoring and analysis of results; 4. Adjustment of plans and /or objectives.

Fault-tolerant Hamiltonian cycle strategy for fast node fault diagnosis based on PMC in data center networks.

System-level fault diagnosis model, namely, the PMC model, detects fault nodes only through the mutual testing of nodes in the system without physical equipment. In order to achieve server nodes fault diagnosis in large-scale data center networks (DCNs), the traditional algorithm based on the PMC model cannot meet the characteristics of high diagnosability, high accuracy and high efficiency due to its inability to ensure that the test nodes are fault-free. This paper first proposed a fault-tolerant Hamiltonian cycle fault diagnosis (FHFD) algorithm, which tests nodes in the order of the Hamiltonian cycle to ensure that the test nodes are faultless. In order to improve testing efficiency, a hierarchical diagnosis mechanism was further proposed, which recursively divides high scale structures into a large number of low scale structures based on the recursive structure characteristics of DCNs. Additionally, we proved that $ 2(n-2){n^{k-1}} $ and $ (n-2){t_{n, k}}/{t_{n, 1}} $ faulty nodes could be detected for $ BCub{e_{n, k}} $ and $ DCel{l_{n, k}} $ within a limited time for the proposed diagnosis strategy. Simulation experiments have also shown that our proposed strategy has improved the diagnosability and test efficiency dramatically.

Experimental characterization of energy consumption in 5-axis milling machine and developing optimization strategy

The optimization of machining processes is of paramount significance because of its pivotal role in modern manufacturing. Efficient machining techniques not only enhance product quality but also reduce costs and environmental impacts. This study focuses on the experimental characterization of energy consumption in a 5-axis milling machine and the simulation of possible solutions to reduce it. The first step is to understand the key drivers of energy consumption which is crucial for enhancing energy management and optimization. This was achieved by developing a mathematical model that uses the most common machining parameters as input using a Response Surface Methodology experimental test plan and an analysis of the contributions of the auxiliary systems to the overall energy consumption. As a second step, the effectiveness of different solutions was simulated considering different application scenario, like the type of operations. Such solutions include the introduction of duty cycle strategies for some auxiliary systems and the optimization of process parameters.

Recent research in advanced fast reactors and fuel cycle strategies in Spain

One of the main drawbacks of current nuclear energy is the generation of high-level radioactive waste. On the other hand, the composition of the used nuclear fuel would still allow a very high amount of energy to be obtained from it. Advanced fuel cycles look for a better use of nuclear fuel while reducing the amount of waste generated by closing the fuel cycle, that is, reprocessing and recycling the useful elements. At the same time, this would increase the sustainability of the fuel cycle. For this to become a reality, research needs to be carried out in fields such as advanced fuel cycle scenarios, advanced nuclear reactors or advanced partitioning processes.Although with an official open fuel cycle policy, Spain remains interested in the reutilization of irradiated fuel and actively participates in the national and international R&D activities that pursue this objective. In this paper, we report on the main activities that are currently being performed and that had been performed in recent years in this field in Spain. The main lines of research followed, and projects in which Spain has participated or is currently participating will be outlined, together with the most relevant results and the knowledge transfer activities which are being carried.

Power and efficiency improvement of SI engine fueled with boosted producer gas-methane blends and LIVC-miller cycle strategy: Thermodynamic and optimization studies

An appealing alternative solution for lowering both reliance on power grid and pollution is by adopting decentralized power generation using gasifier-engine integrated systems. However, the utilization of gasification-derived producer gas (PG) leads to low engine power output and efficiency as compared to conventional fuels. This pertains to its low Calorific value(CV) and low flame-speed. Therefore, this simulation study aims to simulate and investigate the improvements in these parameters by inspecting various boosted-intake pressures and blends of high-CV methane with PG as inputs along with the implementation of Late inlet valve close(LIVC)-Miller cycle strategy on a 1500 RPM Dual-fuel(DF) SI engine model. Quasi-dimensional thermodynamic modelling (QDTM) was applied to simulate this performance and emission investigation by considering Sewage sludge-based PG (SSPG) as the PG variant. Best operational input settings were found using the Response Surface Methodology(RSM)-based multi-objective optimization. These optimal inputs were 3 bars of Pressure at intake valve closure (PIVC), 76.94 % SSPG-blend, and 77.32⁰ (ABDC) LIVC. The responses were correspondingly predicted as 40.46 % ITE, 21.35 bars IMEP, 16.8 kW BP, 20.04 bars BMEP, 9.48 MJ/kWh BSEC, with 0.08 V% CO and 3094 ppm NO emissions. Finally, with the ANOVA-based analysis, a 0.712 composite desirability was achieved with 95 % confidence level.

Leaf nitrogen and phosphorus resorption efficiencies are related to drought resistance across woody species in a Chinese savanna.

Leaf nutrient resorption and drought resistance are crucial for the growth and survival of plants. However, our understanding of the relationships between leaf nutrient resorption and plant drought resistance is still limited. In this study, we investigated the nitrogen and phosphorus resorption efficiencies (NRE and PRE), leaf structural traits, leaf osmotic potential at full hydration (Ψosm), xylem water potential at 50% loss of xylem-specific hydraulic conductivity (P50) and seasonal minimum water potential (Ψmin) for 18 shrub and tree species in a semiarid savanna ecosystem, in Southwest China. Our results showed that NRE and PRE exhibited trade-off against drought resistance traits (Ψosm and P50) across woody species. Moreover, this relationship was modulated by leaf structural investment. Species with low structural investment (e.g., leaf mass per area, leaf dry mass content and leaf construction cost [LCC]) tend to have high NRE and PRE, while those with high LCCs show high drought resistance, showing more negative Ψosm and P50.These results indicate that species with a lower leaf structural investment may have a greater need to recycle their nutrients, thus exhibiting higher nutrient resorption efficiencies, and vice versa. In conclusion, nutrient resorption efficiency may be a crucial adaptation strategy for coexisting plants in semiarid ecosystems, highlighting the importance of understanding the complex relationships between nutrient cycling and plant survival strategies.

Depth shapes microbiome assembly and network stability in the Mariana Trench.

Exploring microbial interactions and their stability/resilience from the surface to the hadal ocean is critical for further understanding of the microbiome structure and ecosystem function in the Mariana Trench. Vertical gradients did not destabilize microbial communities after long-term evolution and adaption. The uniform niche breadth, diversity, community complexity, and stability of microbiomes in both upper bathypelagic and hadal waters suggest the consistent roles of microbiomes in elemental cycling and adaptive strategies to overcome extreme environmental conditions. Compared with microeukaryotes, bacteria and archaea play a pivotal role in shaping the stability of the hadal microbiome. The consistent co-occurrence stability of microbiomes across vertical gradients was observed in the Mariana Trench. These results illuminate a key principle of microbiomes inhabiting the deepest trench: although distinct microbial communities occupy specific habitats, the interactions within microbial communities remain consistently stable from the upper bathypelagic to the hadal waters.

Exponential Stability of Switched Positive Systems With Unstable Subsystems Based on Digraphs

This paper addresses the transfer restricted switching problem for discrete-time switched positive linear systems with all unstable subsystems. To characterize the complex interaction between state components under subsystem switching, the switching digraph and state component digraph are conjoined and a novel switching walk approach is proposed to achieve the exponential stability of switched positive systems. By further deducing the relationship between the obtained decay rate of switched systems and the weight of the switching walk, an optimized stability result is presented and a switching cycle strategy is designed to make the decay rate of switched systems larger. Furthermore, a novel graph-based mode-dependent dwell time method is proposed, which allows subsystems to be activated at any integer multiple of a constant value. Finally, three simulation examples are provided to show the effectiveness of the proposed methods.

Efficiency improvement investigation through Miller cycle strategy for SI engine operating on stoichiometric producer gas and methane blends

Decentralized power generation through gasifier-engine system is an attractive alternative for reducing environmental impact and power grid dependency. For effective sewage sludge-waste to end-use electricity generation by engine integration, this work aims to simulate and investigate thermal efficiency enhancement in SI engine by employing late inlet valve close (LIVC) strategy with 12.0:1 geometrical compression ratio miller cycle and operating engine with sewage sludge-based producer gas (SSPG) by blending methane in various proportions. A quasi-dimensional thermodynamic model is simulated to explore SI engine performance, after validation from an experimental reference. Effects of blending SSPG to methane, varying LIVC and spark timing were analyzed respective to indicated thermal efficiency (ITE), indicated power (IP), brake thermal efficiency (BTE), brake power (BP), brake-specific energy consumption (BSEC) and emissions (CO and NO). Parametric results were found in trade-off nature of performance corresponding to engine efficiency and power. Thus, response surface methodology (RSM) was applied to find the best operating conditions for enhancing performance and diminishing emissions of the blended fuel SI engine. 64.7 % SSPG Blend, 70.33⁰ (ABDC) LIVC, and 34.03⁰ (BTDC) SOI were found as optimum operating parameters corresponding to the generated optimal responses of 35.47 % ITE, 5.18 kW IP, 27.95 % BTE, 4.08 kW BP, 12.671 MJ/kWh BSEC, and 0.688 V% CO, 1456.93 ppm NO emissions. The ANOVA-based regression model shows composite desirability of 0.8 with 95 % confidence level. In summary, the optimization method and optimal operation parameters offer significant reference for improving engine performance for high CR miller cycle-based LIVC approach.

Product life cycle techniques: SMEs maintenance strategies

The food and beverage subsector of the industry is expanding. As the opportunities available to businesses grow, competition to maintain market share intensifies as the loss of a product diminishes its competitiveness. This leads to accumulating unsold products in the inventory even though increased sales volume could generate cash. Because the product cannot compete until the market reacts, it is not sold. Product demand rises in response to capacity constraints but must still be fulfilled. Increased sales are necessary to retain consumers during market expansion or contraction periods. By evaluating the literature, this study ascertains the most effective courses of action for two business scenarios. This study identifies product life cycle strategies supported by mixed marketing techniques in research indexed at least SINA 3, Scopus, or WOS between 2013 and 2023. According to the study, a business can flourish by offering discounts or special services to customers willing to wait while sales capacity increases.

Analysis of variable system cost and maintenance strategy in life cycle considering different failure modes

Due to the complexity of multi-component systems, components failure modes are intricate. The failure modes lead to maintenance behavior combinations, which lead to a series of maintenance strategies. However, the failure modes of components are mixed in multi-component systems. Few researchers provide component failure modes comprehensively in life cycle, and integrate them into life cycle maintenance strategies for the selection schemes of different phases. In this paper, a variable system cost methodology in life cycle is studied, and maintenance strategies are developed by identifying components failure modes from a life cycle perspective to improve system reliability. One of the keys is determining maintenance behaviors for components in each phase of life cycle. The proposed four failure modes cover all possible failure scenarios of the components in different phases. Then, a selection scheme is developed to determine maintenance behaviors in life cycle. At last, a case of Huaneng wind farm in China is given to demonstrate the proposed method by comparing with a baseline maintenance strategy.

Big Data Analytics-based life cycle sustainability assessment for sustainable manufacturing enterprises evaluation

Recently, governments and organizations have repeatedly pressed manufacturing enterprises to promote the ethical and transparent use of natural resources, lessen their negative effects on national and international ecosystems, and safeguard people and the environment. In this context, enhancing the various stages of the product/service life cycle to fulfill sustainability requirements and foster sustainable value creation is a key area of interest for researchers and professionals. This emphasis reflects the growing recognition of the importance of minimizing the environmental impact of products and services, while also maximizing their positive contributions to society, economy, and environment. To this end, this research work addresses how manufacturing enterprises benefit from life cycle sustainability assessment (LCSA) thinking to incorporate the environmental and social criteria into the product/service life cycle strategies. To do so, a novel approach based on environmental priority strategy (EPS) as an LCSA method for impacts monetization coupling with Big Data Analytics (BDA) techniques and tools is developed to evaluate and analyze the manufacturing enterprises’ impacts on the environment and society. Moreover, the developed approach evaluates manufacturing enterprises’ progress toward sustainable development goals (SDGs). Finally, to demonstrate the applicability of the developed approach, a case study from the corporate environmental impact database is used, and the obtained numerical results are analyzed showing its efficiency and added value.

Yard space allocation of container port based on dual cycle strategy

The dual-cycle operation in loading and unloading operations is widely adopted by container ports around the world. This study addresses the storage space allocation problem of the container yard based on the dual-cycle operation mode, and a mixed integer programming model for storage space allocation in the container yard is established. The container transportation distance is taken as the objective of the optimization model, and practical constraints such as ship operating time demand in ports and yard loading cluster limitations are added. The results of the numerical experiments reveal that the dual-cycle of internal trucks in the yard area can decrease transportation distance of containers, and the space allocation method based on it is more effective than traditional methods. The scenario analysis also provides several management insights for practitioners in container ports and puts forward effective reference suggestions to further solve the bottleneck problem often faced by container ports.

A Security-constrained Unit Commitment-based Optimal Battery Usage Pattern Model

This paper discusses multiple strategies of security-constrained unit commitment (SCUC)-based optimal battery usage pattern models to drive the charging and discharging of different batteries and help the operation cycles satisfy their preferences according to battery characteristics. Previous studies mainly focus on either battery storage integration as a controllable resource into the grid with high penetration of renewable energy, or battery degradation costs as additional terms in the objective function of SCUC. In comparison, this paper first considers whether battery operation cycles satisfy their preferences according to specific battery characteristics. It discusses a full charging/discharging strategy for Ni-Cd batteries, which have a memory effect and prefer deep cycles. Then, the paper explores a shallow cycle strategy for Lithium-ion, lead acid, and Ni-H batteries, which have no memory effect and prefer shallow cycles for long service life. Subsequently, it is extended to a hybrid strategy when batteries with/without memory effects are at the same node. The proposed model minimizes the total operation cost of SCUC while including the penalties for battery usage strategies. The original problem is a mixed integer non-linear programming (MINLP) one, and then it can be mathematically converted into a mixed integer linear programming (MILP) one. Consequently, the models with multiple strategies are tested through IEEE 6-node power system. Computational results show that, compared to the base case without any strategy, the proposed optimal battery usage pattern approaches have an advantage in driving Ni-Cd batteries toward deep cycles, guiding Lithium-ion batteries towards shallow cycles, and improving the flexibility of performance with hybrid applications.

Evaluation of Laser Lap Weldability between the Titanium Alloy Ti-6Al-4V and Aluminum Alloy 6060-T6

This work investigates laser weldability between non-ferrous dissimilar metallic materials, specifically the aluminum 6060-T6 alloy and titanium Ti-6Al-4V. These materials are used in several engineering applications, including aerospace. In a simple lap joint configuration, these were welded with a pulsed Nd:YAG laser, with direct incidence on the titanium piece. Preheating and post-weld heating were introduced to mitigate cracking issues. Based on the primary experiments, the main variables were the peak laser power, which varied between 60 and 70%, and the number of beads (a single bead and double beads). The quality of the welds was assessed via uniaxial tensile tests, subjecting the joint to shear loading. Additionally, SEM micrographs were obtained to analyze the quality of the fusion between the dissimilar alloys. The higher strength of the welded samples achieved was 90 MPa, which is close to the reported value for the aluminum base material. A fracture occurred near the weld bead in the heat-affected zone (HAZ). The observed microporosities and cracks explain the lower value as compared to the base material. Although these were mitigated through the thermal cycle strategy employed and the shielding gas, they were not entirely avoided.

Sensitive photoelectrochemical detection of Hg2+ with low background noise

Herein, a sensitive photoelectrochemical (PEC) biosensor with low background noise for the detection of the potential heavy metal pollutant mercury ion (Hg2+) was developed based on the Nb.BtsI-assisted Hg2+ cycle strategy as the signal amplification channel and the methylene blue (MB)-double stranded DNA (dsDNA) intercalation complex as the PEC signal indicator. When a trace of target Hg2+ was present, a multitude of output DNA (S2) were released from the preformed reaction platform Au@Fe3O4-H1 through the process of Nb.BtsI-assisted Hg2+ cycling, which greatly amplified the input signal of Hg2+ and thus significantly improved the detection sensitivity of this PEC biosensor. The released S2 could be captured by the 1-hexanethiol (HT)/S1/gold nanoparticles (Au NPs)-engineered biosensing interface to generate steady dsDNA (S1/S2) for embedding numerous photoactive substance MB by π-π stacking, giving rise to the formation of the MB-dsDNA intercalation complex. As a unique PEC signal indicator, the MB-dsDNA intercalation complex could produce significant PEC signals for quantitative determination of Hg2+ from 100 fM to 100 nM. Notably, the introduction of photoelectric signal indicator made the PEC biosensor embrace low background noise and negligible false positive signal, thereby producing the highly enhanced of sensitivity and accuracy. With the assistant of the Nb.BtsI-assisted Hg2+ cycle strategy and the MB-dsDNA intercalation complex, the developed biosensor possessed high sensitivity and excellent accuracy for Hg2+ with a low detection limit of 33.3 fM, demonstrating that the proposed sensing platform was provided with a great application prospect in the field of monitoring and control of environmental pollution concerning Hg2+.