Direct Mode Research Articles

Direct Mail or Bonded Warehouse? Logistics Mode Selection in Cross-Border E-Commerce under Exchange Rate Risk

The rapid development of cross-border e-commerce (CBEC) has enabled more suppliers to expand into overseas markets, meeting increasingly diverse consumer demands. Selecting an effective logistics mode is a crucial issue for suppliers, yet uncertainty in demand and exchange rate fluctuations make this problem challenging. This paper considers a supply chain consisting of a supplier and a CBEC platform. Using a distributionally robust optimization approach, we provide optimal overseas warehousing strategies and logistics mode selection for suppliers, given partial distribution information of market demand and exchange rate, such as means, variances, and covariances. It is found that when demand and exchange rate fluctuations are small, the supplier chooses the bonded warehouse logistics mode to reduce costs. Conversely, when demand and exchange rate fluctuations increase, the supplier opts for the direct mail mode to respond flexibly to market risk. The correlation between exchange rate and demand also affects the choice of logistics mode. Specifically, with low correlation, the preference is for the bonded warehouse mode, whereas high correlation leads suppliers to choose the direct mail mode. In addition, the impact of demand and exchange rate fluctuations on suppliers’ overseas warehousing volumes depends on the product’s profit margin. These findings provide guidance for the selection of CBEC logistics under exchange rate risk.

Electrodeposition of Silicon in the Low-Temperature LiCl-KCl-CsCl-K2SiF6 Melt Under Direct and Pulse Current

In this work, the effect of electrolysis modes and their parameters on the morphology of the silicon deposits on glassy carbon were studied. In direct current mode it was found that an increase in current density and deposition time changes the morphology of the silicon from a coating to a deposit with a complex surface. Scanning electron microscopy showed that silicon films produced at low current densities and a short deposition time are represented by spherical particles with a diameter of less than 1 μm. The pulse current mode made it possible to increase the cathode density of the deposition current, and the pulse current density to an average of ≈250 mA cm−2 does not lead to the formation of a large amount of dendritic deposit. It was found that a low frequency makes it possible to obtain higher-quality silicon coatings, because when the frequency increases, the coating most often does not cover the entire electrode. The high value of the duty cycle, even at low pulse current densities, always leads to the formation of dendrites. An increase in the total deposition time also leads to an increase in the amount of deposit and the formation of dendrites.

Performance assessment of deep borehole heat exchanger heating system under different heating modes

Abstract With the transition towards renewable energy sources, particularly as we move away from fossil fuels, there has been a constant evolution of deep borehole heat exchanger (DBHE) coupled heat pump heating technology. On the basis of the heat-exchanging properties of circulating fluid in the DBHE heating system, this paper clarifies the setup forms of this system, and elucidates the influence of heat extraction performance. After analysis and research, it can be concluded that the direct supply mode shows a more prominent decline in water temperature compared to the coupled heat pump and coupled plate heat exchanger modes. The imported and exported water temperatures when heating ends were recorded as 9.98°C and 16°C, respectively. The imported and exported water temperatures for both the direct supply and the coupled plate heat exchanger modes tend to be similar at 19.6°C and 25.5°C at a temperature of 7°C. Heat pump not only enhances the heat exchange features of ground source heat pump (GSHP) heating system, but also defines the configuration of heat extraction performance of DBHE. The system power consumption in the coupled plate heat exchanger mode is lower than that in the heat pump mode which is conducive to stable operation. Therefore, the best design form of the DBHE Heating System is the heat pump coupled plate exchange mode.

Performance evaluation of interfacial evaporation assisted solar still with patterned floating absorber and external reflectors

The rapid decrease in global freshwater sources, caused by industrialization, population growth and other unforeseen circumstances, demands the necessity of effective desalination strategies. Solar stills, which provide potable drinking water by utilizing abundantly available solar energy and a direct mode of desalination, are viable solutions. However, lower productivity limits the wide range acceptability of the conventional solar stills (CSS). This work experimentally investigates the effectiveness of interfacial evaporation in solar stills by incorporating the floating absorbers. The floating absorber solar still (FSS) is compared with CSS as a benchmark. FSS involves different absorber configurations such as bare, patterned, and multiple absorbers. Further, the effect of top and bottom reflectors (external) on the FSS performance is analyzed. The application of patterned FSS enhances the productivity by 146 % and 46 % compared to CSS and bare FSS. The use of external top and bottom reflectors in patterned FSS (FSS-P-R) enhances productivity by 28 %. The accumulated water yield per day for FSS-P-R configuration is 4.46 L/m2 with energy and exergy efficiency of 70.35 % and 5.9 %, respectively. The cost analysis estimates the cost of the produced freshwater for FSS-P-R as 0.018 $/L, recommending the deployment of the FSS with suitable modifications in remote and hot arid regions with abundant sunshine as a promising approach for alleviating the freshwater scarcity.

Rapid CU Partitioning and Joint Intra-Frame Mode Decision Algorithm

H.266/Versatile Video Coding (VVC) introduces new techniques that build upon previous standards, proposing a nested multi-type tree quadtree (QTMT). The introduction of this structure significantly enhances video coding efficiency; additionally, the number of directional modes in H.266 has increased by 32 compared to H.265, accommodating a greater variety of texture patterns. However, the changes in the related structures have also led to a significant increase in encoding complexity. To address the issue of excessive computational complexity, this paper proposes a targeted rapid Coding Units segmenting approach combined with decision-making for an intra-frame modes algorithm. In the first phase of the algorithm, we extract different features for CU blocks of various sizes and input them into the decision tree model’s classifier for classification processing, determining the CU partitioning mode to prematurely terminate the partitioning, thereby reducing the encoding complexity to some extent. In the second phase of the algorithm, we put forward an intra-frame mode decision strategy grounded in gradient descent techniques with a bidirectional search mode. This maximizes the approach to the global optimum, thereby obtaining the optimal intra-frame mode and further reducing the encoding complexity. Experimentation has demonstrated that the algorithm achieves a 54.53% reduction in encoding time. In comparison, the BD-BR (Bitrate-Distortion Rate) only increases by 1.38%, striking an optimal balance between the fidelity of video and the efficacy of the encoding process.

A D2D user pairing algorithm based on motion prediction and power control

AbstractUser pairing plays an important role in device‐to‐device (D2D) relay communication, contributing significantly to maintaining low energy consumption, high throughput, and overall energy efficiency in the communication system. To achieve these purposes, an attention‐based long short‐term memory motion prediction model (AT‐LSTM) and propose a joint power control algorithm. Leveraging these techniques, we also propose a D2D user pairing algorithm, distance–power–SINR pairing algorithm (DPSPA), which comprehensively considers factors such as D2D communication distances, transmit power, and signal‐to‐interference‐plus‐noise ratio. Initially, the AT‐LSTM model is utilized to predict the location of users. Subsequently, the distance between the user terminal device and each communication point and the base station, filtering cache points, and non‐cache points within the D2D communication radius are calculated. Then, based on the distance, required transmission power, and signal‐to‐interference‐plus‐noise ratio of each point, the evaluation index (the best matching product) is obtained. Finally, the point with the maximum best matching product is selected for D2D direct communication mode, D2D relay communication mode, or cellular communication mode. Simulation results demonstrate that DPSPA effectively reduces system energy consumption, enhances system throughput, and improves overall energy efficiency.

Distributed photovoltaic supportability consumption method considering energy storage configuration mode and random events

In order to improve the control capability of distributed photovoltaic support, a distributed photovoltaic support consumption method based on energy storage configuration mode and random events is proposed. A networked and constrained parameter analysis model for distributed photovoltaic power supply control was constructed. Based on the direct flexible mode of optical storage, an AC/DC voltage level control model for distributed solar power supply control was constructed. In the operation mode of DC hybrid distribution network, the demand response tracking identification method was used to analyze the uncertain characteristic parameters of distributed solar power supply load, and combined with the planned energy storage capacity parameters, the distributed solar power supply load and photovoltaic output were estimated. By configuring the optimal energy storage capacity, adjusting the power distribution of the microgrid, and integrating the analysis of uncertain factors and random events in the energy storage configuration mode, the design of distributed photovoltaic support consumption has been achieved. The experimental results show that the distributed photovoltaic absorption control using this method has lower load requirements, can effectively reduce the exchange power of the interconnection line, and improve the configuration scale, system reliability, and economy of the photovoltaic energy storage system.

Fabrication and characterization of multifunctional, asymmetric bilayer films based on chitosan/gelatin/mesoporous bioactive glass nanoparticles for guided bone regeneration

AbstractTwo-faced GBR membranes were fabricated by electrophoretic deposition (EPD) using a combination of biopolymers and mesoporous bioactive glass nanoparticles (MBGNs). The membrane design was aimed at leveraging the advantageous properties of both biopolymers and MBGNs. The dense composite layer consisted of chitosan (CS) incorporating MBGNs and it was functionalized with a phytotherapeutic drug, naringin (Nar). The porous layer consisted of CS-gelatin (Gel)- MBGNs as well as copper chelated chitosan (Cu(II)-CS)-Gel-MBGNs composites. EPD was conducted in direct current mode. The antibacterial activity of the membranes as a result of the presence of Cu(II) and Nar was confirmed. The films were cytocompatible when tested with MC3T3-E1 (pre-osteoblastic) and MG-63 (osteoblast like) cell lines. However, a slight cytotoxic effect of the releasing Cu(II) ions was determined. In contrast, Nar-loaded films revealed improved cell viability. The results indicate the high potential of EPD to fabricate bilayer structures for GBR applications. Graphical abstract

Modal Decomposition of Internal Tides in the Luzon Strait through Two-Dimensional Fourier Bandpass Filtering

Internal tides are pivotal dynamic processes enhancing the mixing of oceanic waters and facilitating energy transfer across various scales within the ocean. In recent years, the proliferation of satellite altimetry observations has enabled global predictions of the elevation and phase of internal tides. This study, leveraging the advanced global internal tide prediction model known as the Multivariate Inversion of Ocean Surface Topography-Internal Tide Model (MIOST-IT), employs a two-dimensional Fourier bandpass filtering approach to decompose the internal tides in the Luzon Strait, thereby addressing the east–west directional blind zones inherent in along-track satellite altimetry-based modal decomposition. To further elucidate the propagation trajectories of individual tidal modes in different directions, we introduce the directional Fourier filter method to characterize the spatial distribution features of each modal internal tide in the vicinity of the Luzon Strait. This work significantly enhances the accuracy and reliability of extracting parameters for distinct modal internal tides, furnishing a scientific basis for subsequent studies on internal tide dynamics and model refinement.

Vibration mitigation of a model aircraft with high-aspect-ratio wings using two-dimensional nonlinear vibration absorbers

High-aspect-ratio (HAR) airplane wings have higher energy efficiency and present an economical alternative to standard airplane wings. HAR wings have a high span and a high lift-to-drag ratio, allowing the wing to require less thrust during flight. However, due to their length and construction, HAR wings exhibit low-frequency, high-amplitude vibrations in both vertical (yaw axis) and longitudinal (roll axis) directions. To combat these unwanted vibrations, a two-dimensional nonlinear vibration absorber (2D-NVA) is constructed and attached to a model HAR-wing airplane to verify its effectiveness at reducing vibrational motion. The 2D-NVA design, which was presented in a previous study, consists of two low-mass, rigid bodies namely the housing and the impactor. The housing consists of a ring-like rigid body in the shape of an ellipse, while the impactor is a solid cylindrical mass which resides inside the cavity of the housing. The 2D-NVA is designed such that the impactor can contact the inner surface of the housing under both impacts and constrained sliding motion. The present study focuses on the use of the 2D-NVA to mitigate multiple modes of vibration excited by impulsive loading of a model airplane with HAR wings in both vertical and longitudinal directions. The effectiveness of a single 2D-NVA is investigated computationally using a finite element model of the model airplane. These results are verified experimentally and the performance of two 2D-NVAs (one on each wing) is also investigated. The contributions of this work are that: 1) the 2D-NVA alters the global response of the model aircraft by mitigating all relevant modes in both directions simultaneously; 2) a single 2D-NVA is optimal for mitigating motion in the vertical direction, while two active 2D-NVAs are optimal for the longitudinal direction; and 3) the performance of the 2D-NVA is robust to changes in the frequency content of the parent structure.

Electrospray ionisation suppression in aquatic dissolved organic matter studies – Investigation via liquid chromatography–mass spectrometry

Ionisation suppression is a persistent issue in electrospray ionisation mass spectrometry, which decreases the signal of co-eluting analytes. In non-targeted analysis, where analyte and organic matrix identity is unknown, this poses a very challenging analytical problem when it comes to quantitatively assessing differences between samples, including in a compositional sense. In this study, I demonstrate the problems that arise due to ionisation suppression using a very simple sample mixing scheme between a fresh, metabolite rich sample (a leaf leachate) and a forest pond water. Samples were analysed after solid phase extraction on Agilent PPL and using high performance liquid chromatography coupled to electrospray ionisation – Orbitrap mass spectrometry, charged aerosol detector and diode array detector, the latter two allowing quantification of eluting material. I found that more than half of the well-resolved analytes expected to be present (at equal concentration) were completely lost from detection after mixing with pond water DOM. The average recovery of analytical signal (i.e., the signal weighted average), was about 50%, and was highly variable between analytes. Ionisation suppression also affected the signal obtained from the geochemical background DOM, and material recovery decreased slightly when mixing samples and extracting at a higher volume on PPL. Overall, the results showed that ionisation suppression is an extremely important problem for comparison of biogeochemical samples, even when only considering presence and absence of detected features. A multi detector approach and liquid chromatographic separation adds great value in comparison to use of only high resolution mass spectrometry (in direct infusion mode).

A Fuzzy Logic-Based Directional Charging Scheme for Wireless Rechargeable Sensor Networks.

Wireless Power Transfer (WPT) has become a key technology to extend network lifetime in Wireless Rechargeable Sensor Networks (WRSNs). The traditional omnidirectional recharging method has a wider range of energy radiation, but it inevitably results in more energy waste. By contrast, the directional recharging mode enables most of the energy to be focused in a predetermined direction that achieves higher recharging efficiency. However, the MC (Mobile Charger) in this mode can only supply energy to a few nodes in each direction. Thus, how to set the location of staying points of the MC, its service sequence and its charging orientation are all important issues related to the benefit of energy replenishment. To address these problems, we propose a Fuzzy Logic-based Directional Charging (FLDC) scheme for Wireless Rechargeable Sensor Networks. Firstly, the network is divided into adjacent regular hexagonal grids which are exactly the charging regions for the MC. Then, with the help of a double-layer fuzzy logic system, a priority of nodes and grids is obtained that dynamically determines the trajectory of the MC during each round of service, i.e., the charging sequence. Next, the location of the MC's staying points is optimized to minimize the sum of charging distances between MC and nodes in the same grid. Finally, the discretized charging directions of the MC at each staying point are adjusted to further improve the charging efficiency. Simulation results show that FLDC performs well in both the charging benefit of nodes and the energy efficiency of the MC.

In vivo redox imaging of plasma-induced skin-inflammation in mice

Cold atmospheric plasma (CAP) generates reactive oxygen species (ROS) which induce biological effects on living cells. CAP has potential applications in medicine, but its highly reactive nature can lead to adverse skin complications. A noninvasive technique to examine redox changes in skin is needed for monitoring the treatment process. This study was conducted to develop a skin-inflammation model triggered by CAP-derived ROS and to monitor its progression noninvasively by in vivo dynamic nuclear polarization-MRI (DNP-MRI). The model was successfully developed by exposing the skin to both direct and remote modes of CAP. In vivo DNP-MRI imaging revealed faster reduction rates of TEMPOL in plasma-irradiated skin-inflammation areas, particularly in the remote mode plasma-irradiated skin. MRI revealed high-intensity areas in both the superficial and deep layers of the plasma-irradiated skin. The study highlights the potential importance of DNP-MRI in imaging skin-inflammation models and could improve the use of CAP in medical treatments.

“I See Super-Rich (Versus Poor) People, Therefore I Spend”: Effects of Social Comparison and Donation Mode on Egoistic Spending versus Altruistic Giving

ABSTRACT Digital platforms present consumers with contrasting visual narratives, from images of opulence to depictions of poverty. This study delves into the strategic implications of such dichotomous exposures, anchored in Social Comparison Theory. Three experiments (∑ N = 1665) investigated how portrayals of affluence and deprivation influence audience behaviors, specifically egoistic luxury spending versus altruistic charitable giving. Experiment 1a employed a 2 (exposure to photos of poverty versus affluence) x 2 (luxury spending versus charitable giving scenario as the within-subjects factor) mixed factorial design. Experiment 1b employed a 2 (poverty versus affluence) x 2 (luxury spending versus charitable giving) between-subjects factorial design. Experiment 2 employed a 3 (poverty versus affluence versus neutral photos) x 2 (anonymized versus publicized donation) between-subjects factorial design to further examine the interaction effects of social comparison direction and donation mode. Empirical findings highlight that downward social comparison (exposure to poverty) can amplify charitable inclinations, while upward comparison (exposure to affluence) can enhance conspicuous consumption. Individual difference factors such as materialism, need for status, social comparison orientation, and greed play pivotal roles in moderating these effects. This research contributes to the understanding of digital portrayal influences on consumers’ spending behavior, offering both theoretical insights and practical implications for strategic communication.

Visualization study on the flame propagation and distribution characteristics and exploration of optimal injection strategy in ammonia/diesel dual direct injection mode

With the increasing shortage of fossil fuels and the worsening carbon emission problems, ammonia has been attracted widely to alleviate the current challenges faced by internal combustion engines. Igniting direct injection of liquid ammonia by diesel may be a measure to achieve effective ammonia application, while the research on the characteristics of combustion and the unburned ammonia emission is little. Therefore, this paper studies the effects of ambient parameters and injection parameters on the characteristics of diesel ignition and flame propagation and distribution based on a constant volume combustion chamber, through the shadow method. The results indicate that the premise to ensure that ammonia can fully participate in combustion is that the flame can backpropagate to the junction of the two sprays. The current optimal injection strategy is the simultaneous injection of diesel and ammonia combined with a complete ammonia injection before the maintained flame. At a low temperature and high diesel injection pressure, ammonia will participate in combustion after a delay, which may result in a relatively low heat release rate and high unburned ammonia emissions. Overall, the paper can provide important references for professional researchers which is of great significance for the development of diesel/ammonia engines.

Impact of Gate Voltage on Mobility of Charge Carriers in Conductive Channel of Organic Molecular Semiconductors: Transport Landscape Assessed by Alternating and Direct Current Mode Techniques

AbstractThe gate voltage dependence of the charge carrier mobility is investigated by the microwave resonance technique in transport channels at various organic semiconductors‐insulator interfaces. Although the microwave based measurement is free from the Schottky‐barrier, the vertical charge transport, and the minority carrier trapping, which have been regarded as the origin of the nonlinearity in field effect transistor (FET) measurements, the obtained charge carrier mobility is impacted significantly by the applied gate bias. Atomic force microscopy (AFM) and X‐ray diffractometry (XRD) measurements revealed that the observed nonlinearity indeed originates from the surface disorder in even polycrystalline materials including conjugated polymers. The concerted assessment of the microwave resonance and the FET measurements reveals that 1) injected carriers below the threshold voltage are not trapped despite of the absence of the drain current, 2) the only charge carrier mobility at the 1st layer is assessed by FET measurements, and 3) the threshold voltage of conjugated polymers is relatively low due to the intra‐domain connection through tie molecules.

Viscoelastic Fluid Flow Model for Hydrodynamic Behaviour of Magnetorheological Fluid in Valve and Shear Modes for a Damper System

In this present study, the flow behaviour of magnetorheological fluid in valve and shear modes for damping system is modelled and analysed. The fluid is modelled as viscoelastic fluid flowing between two parallel plates in pressure driven flow mode, and also as direct shear mode. In the work, the post-yield shear thinning or thickening behaviour of magnetorheological fluids are accounted for. The velocity and pressure distributions in the unsteady magnetorheological fluid flow between the electrodes of the damper are obtained by solving the momentum equation of the magnetorheological fluid flow using the Laplace transform method. There is an excellent agreement between the results of the present model and the results of the experimental studies. The adopted viscoelastic flow model describes that the rheological behaviour of the fluid is separated into distinct pre-yield and post-yield regimes. The fluid flow velocity, velocity gradient, and shear stresses have all been shown to be enhanced by an increase in the pressure drop. The viscosity of the fluid increases with an increase in the volume fraction of particles in the fluid, which causes the resistance of the fluid to flow to increase and thereby, reduces the fluid flow velocity. Fluid flow velocity is decreased as a result of increasing magnetic field strength. The design of clutches, rotary brakes, dampers, shock absorbers, prosthetic devices, polishing and grinding tools, etc. will all benefit greatly from the adoption of the current model.

Differential eco-toxicological responses toward Eisenia fetida exposed to soil contaminated with naphthalene and typical metabolites.

Naphthalene (NAP) was frequently detected in polycyclic aromatic hydrocarbons (PAHs)-contaminated soil, and its residues may pose an eco-toxicological threat to soil organisms. The toxic effects of NAP were closely tied to phenolic and quinone metabolites in biological metabolism. However, the present knowledge concerning the eco-toxicological impacts of NAP metabolites at the animal level is scanty. Here, we assessed the differences in the eco-toxicological responses of Eisenia fetida (E. fetida) in NAP, 1-naphthol (1-NAO) or 1,4-naphthoquinone (1,4-NQ) contaminated soils. NAP, 1-NAO, and 1,4-NQ exposure triggered the onset of oxidative stress as evidenced by the destruction of the antioxidant enzyme system. The lipid peroxidation and DNA oxidative damage levels induced by 1-NAO and 1,4-NQ were higher than those of NAP. The elevation of DNA damage varied considerably depending on differences in oxidative stress and the direct mode of action of NAP or its metabolites with DNA. All three toxicants induced different degrees of physiological damage to the body wall, but only 1, 4-NQ caused the shedding of intestinal epithelial cells. The integrated biomarker response for different exposure times illustrated that the comprehensive toxicity at the animal level was 1,4-NQ > 1-NAO > NAP, and the time-dependent trends of oxidative stress responses induced by the three toxicants were similar. At the initial stage, the antioxidant system of E. fetida responded positively to the provocation, but the ability of E. fetida to resist stimulation decreased with the prolongation of time resulting in provocation oxidative damage. This study would provide new insights into the toxicological effects and biohazard of PAHs on soil animals.

In-situ monitoring of an offshore wind turbine blade using acceleration and strain measurements

One of the most critical components of wind turbines is the blades. As blades are constantly exposed to weather and high loads, they can wear and become damaged. Performing in-situ continuous monitoring can help detect sudden damages and prevent further degradation, which is imperative to avoid economic losses and fatal accidents. However, monitoring a rotating rotor blade presents some challenges. One challenge is the consideration of lightning protection. Hence, a non-conductor measurement system must be used. Another challenge is system identification and modal tracking considering environmental and operational conditions (EOCs). Furthermore, vibration-based monitoring results from actual and operational rotor blades are scarce in the existing literature. This study centres on operational modal analysis (OMA) using covariance- driven stochastic subspace identification (SSI-COV) of an offshore wind turbine blade in operation employing eight months of data from fibre optic accelerometers (FOA) and fibre Bragg grating (FBG) strain gauges. The identification focuses on the first two bending modes in flapwise and edgewise directions and the first torsional mode. The study aims to determine which fibre optic sensor delivers better results. Furthermore, it addresses the effect of EOCs on the modal parameters, where system identification and modal tracking are discussed. It was found that tracked modes showed similar trends with respect to time, and a high connection was observed between wind speed, rotor speed, and pitch angle with frequency and damping. Additionally, acceleration and strain measurements deliver the same frequency and damping values. FBG better identified the first flapwise mode. On the other hand, FOA was superior in almost all other modes. This study points towards employing FOA for vibration-based monitoring of wind turbine blades using modal parameters.

Towards the use of control systems with variable autonomy levels in tasks of extreme robotics

Increasing the level of robot autonomy in scenarios of extreme robotics allows, on the one hand, to reduce the load on the operator due to the sharing of labor between man and machine, and on the other, to increase the safety and efficiency of performing complex and critical tasks, such as search and rescue operations, monitoring of hazard-ous environments, disposal or neutralization of dangerous objects and many others. Such robots are characterized by the predominant use of teleoperation. However, recently there appeared a trend towards increasing of robot’s autonomy levels even for those types of robots that worked exclusively in direct teleoperation mode of control [1]. This article focuses on the consideration of control strategies for ground-based mobile robots with variable levels of autonomy when performing various types of work in extreme situations.