Material Stack Research Articles

Optimization and analysis of Si/SiGe strained vertically stacked heterostructure on insulator FeFinFET for high performance analog and RF applications

As semiconductor technology advances, the exploration of novel materials and device architectures becomes imperative to meet the growing demands of integrated circuits for analog and radio-frequency (RF) applications. In this paper, various advanced technologies have been amalgamated such as integration of ferroelectric layer in multigate FinFET along with the adaptation of SOI technology. Further strain technology is also used which employs a tri-layered strained-silicon channel system with the help of SiGe to form Vertically Stacked Heterostructure on Insulator Ferroelectric based FinFET (VS-HOI-FeFinFET) and on comparison with baseline FeFinFET, it is found to show remarkable improvements in terms of various measured parameters such as drain current, switching ratio, threshold voltage and subthreshold swing. Subsequently, gate stacking architecture is incorporated in VS-HOI-FeFinFET to further optimize the device performance. The four different configurations C1 to C4 are taken in terms of four different combinations of gate stack materials considered for gate oxide such as C1(SiO2+Al2O3), C2(SiO2+HfO2), C3(Al2O3), and C4(Al2O3+HfO2). It is found that the static and analog performance of VS-HOI-GS-FeFinFET enhance sequentially from configuration C1 to C4 such as switching ratio is enhanced upto around 5 times, DIBL and quality factor are improved by around 41% and 58% respectively along with significant improvement in device efficiency, early voltage, intrinsic gain, output conductance and output resistance. Subsequently performance optimization of VS-HOI-GS-FeFinFET with variation in mole fraction of germanium is also explored for various analog metrics. Further, several RF parameters are also explored and it is observed that the gain frequency product (GFP) and gain transconductance frequency product (GTFP) are augmented by around three times in magnitude along with 16% reduction in the unity gain cut off frequency in C4 configuration, exhibiting its ability of high frequency amplification with minimized noise distortion thus makes the device suitable for various high performance Analog and RF applications.

A flexible and fast digital twin for RRAM systems applied for training resilient neural networks

Resistive Random Access Memory (RRAM) has gained considerable momentum due to its non-volatility and energy efficiency. Material and device scientists have been proposing novel material stacks that can mimic the “ideal memristor” which can deliver performance, energy efficiency, reliability and accuracy. However, designing RRAM-based systems is challenging. Engineering a new material stack, designing a device, and experimenting takes significant time for material and device researchers. Furthermore, the acceptability of the device is ultimately decided at the system level. We see a gap here where there is a need for facilitating material and device researchers with a “push button” modeling framework that allows to evaluate the efficacy of the device at system level during early device design stages. Speed, accuracy, and adaptability are the fundamental requirements of this modelling framework. In this paper, we propose a digital twin (DT)-like modeling framework that automatically creates RRAM device models from device measurement data. Furthermore, the model incorporates the peripheral circuit to ensure accurate energy and performance evaluations. We demonstrate the DT generation and DT usage for multiple RRAM technologies and applications and illustrate the achieved performance of our GPU implementation. We conclude with the application of our modeling approach to measurement data from two distinct fabricated devices, validating its effectiveness in a neural network processing an Electrocardiogram (ECG) dataset and incorporating Fault Aware Training (FAT).

A methodical approach to design adiabatic waveguide couplers for heterogeneous integrated photonics

Abstract We present an elegant and effective approach for the design of adiabatic waveguide couplers tailored for the heterogeneous integration of photonic building blocks. This method empowers users to incorporate the shortest taper(s) in their designs, while upholding optimal coupling efficiency. The technique assesses mode overlap between a minimum of two waveguides within the cross-section of any heterogeneous material stack, determining the necessary waveguide cross-sectional dimension to achieve optimal coupling efficiency. Two illustrative design applications are showcased and compared to a linear, concave, and convex taper for reference: a SiN-to-polymer structure exhibiting a 40% coupling improvement and a Si-to-GeSi structure having a 2.2 up to 5 times shorter length.

Maneuverability and Processability of Molecular Crystals.

Crystal adaptronics, a burgeoning field at the intersection of materials science and engineering, focuses on harnessing the unique properties of organic molecular crystals to achieve unprecedented levels of maneuverability and processability in various applications. Increasingly, ordered stacks of crystalline materials are being endowed with fascinating mechanical compliance changes in response to external environments. Understanding how these crystals can be manipulated and tailored for specific functions has become paramount in the pursuit of advanced materials with customizable properties. Simultaneously, the processability of organic molecular crystals plays a pivotal role in shaping their utility in real-world applications. From growth methodologies to fabrication techniques, the ability to precisely machine these crystals opens new avenues for engineering materials with enhanced functionality. These processing methods enhance the versatility of organic crystals, allowing their integration into various devices and technologies, and further expanding the potential applications. This review aims to provide a concise overview of the current landscape in the study of dynamic organic molecular crystals, with an emphasis on the interconnected themes of operability and processability.

Synthesis, Modulation, and Application of Two-Dimensional TMD Heterostructures.

Two-dimensional (2D) transition metal dichalcogenide (TMD) heterostructures have attracted a lot of attention due to their rich material diversity and stack geometry, precise controllability of structure and properties, and potential practical applications. These heterostructures not only overcome the inherent limitations of individual materials but also enable the realization of new properties through appropriate combinations, establishing a platform to explore new physical and chemical properties at micro-nano-pico scales. In this review, we systematically summarize the latest research progress in the synthesis, modulation, and application of 2D TMD heterostructures. We first introduce the latest techniques for fabricating 2D TMD heterostructures, examining the rationale, mechanisms, advantages, and disadvantages of each strategy. Furthermore, we emphasize the importance of characteristic modulation in 2D TMD heterostructures and discuss some approaches to achieve novel functionalities. Then, we summarize the representative applications of 2D TMD heterostructures. Finally, we highlight the challenges and future perspectives in the synthesis and device fabrication of 2D TMD heterostructures and provide some feasible solutions.

Influence of Material Properties on Ruggedness Evaluation of Package Architectures for SiC Power Devices

Button shear tests at different temperatures between different mold compounds and Cu-leadframes have been performed to evaluate the adhesion of mold compounds to the inner surfaces of SiC-power devices. The results at different temperatures show the behavior of different material and layer stack combinations under storage at room temperatures as well as under operating conditions with elevated temperatures, where adhesion and thus the hermeticity of the device against moisture is significantly lowered. It has been shown that different thermomechanical properties of the mold compounds as well as the usage of different adhesion promoter materials have a significant effect on the adhesion properties of the mold compound to the leadframe surface of the SiC power devices, which have direct impact on the ruggedness and lifetime stability. Furthermore, these results have been correlated to thermomechanical simulations of the package architecture of SiC power devices under stress. Different wire bond architectures have been evaluated in simulations with and without die top delamination taken into account, showing that EMC delamination may play a major role in the lifetime stability of SiC power devices under thermomechanical stress like simulated in TCT- , IOL- and PTC-testing.

Based on size-exclusion effect of selective removal of organic pollutants in complex water quality by low temperature plasma: Degradation behavior and selective mechanism analysis

The presence of natural organic matters (NOMs) will have a negative effect on the removal of small molecule organic contaminants in complex water quality, therefore, it’s very important to design a catalyst with size-exclusion function to achieve the selective removal of targeted pollutant. Herein, a novel ZIF-L catalyst precursor with lamellar stack structure is designed, and iron as heteroatom is doped in ZIF-L gaps named ZIF-L@Fe. After pyrolysis, Fe ions are transformed into Fe nanoparticles, and act as the active sites of catalyst. In order to verify the selective removal ability of resulted NSC@Fe in dielectric barrier discharge (DBD), tetracycline hydrochloride (TTCH) and humic acid (HA) is selected as the target pollutant and coexistence macromolecular interferent, respectively. In the presence of HA (50 mg/L), the degradation rate of TTCH in the system is not significantly affected (with HA, k = 0.037 min−1; without HA, k 0.036 min−1), which is mainly due to the layered material stacking characteristics (size-exclusion). The degradation mechanism and pathway are further confirmed by radical quenching experiments and liquid chromatography−mass spectrograph (LC−MS), respectively. This study is believed to shed new light on how to rationally design catalyst with selective removal of organic pollutants in complex water quality for water remediation.

Maneuverability and Processability of Molecular Crystals

AbstractCrystal adaptronics, a burgeoning field at the intersection of materials science and engineering, focuses on harnessing the unique properties of organic molecular crystals to achieve unprecedented levels of maneuverability and processability in various applications. Increasingly, ordered stacks of crystalline materials are being endowed with fascinating mechanical compliance changes in response to external environments. Understanding how these crystals can be manipulated and tailored for specific functions has become paramount in the pursuit of advanced materials with customizable properties. Simultaneously, the processability of organic molecular crystals plays a pivotal role in shaping their utility in real‐world applications. From growth methodologies to fabrication techniques, the ability to precisely machine these crystals opens new avenues for engineering materials with enhanced functionality. These processing methods enhance the versatility of organic crystals, allowing their integration into various devices and technologies, and further expanding the potential applications. This review aims to provide a concise overview of the current landscape in the study of dynamic organic molecular crystals, with an emphasis on the interconnected themes of operability and processability.

Increasing of efficiency of hydrogen energy storage system by the use of high-pressure electrolyser with metal hydride electrode

The article describes the electrochemical process of hydrogen and oxygen generation by a membrane-less electrolyser having a passive electrode made of Ni and a gas absorption electrode made of metal hydride (LaNi5Hx). Such composition of the electrode stack materials (Ni - LaNi5Hx) makes it possible to generate hydrogen and oxygen during the half-cycles separately in time while maintaining the time intervals of the corresponding half-cycles. The last one indicates the stable capacitive characteristics of the LaNi5Hx metal hydride electrode. During the oxygen half-cycle, hydrogen is absorbed in the metal hydride electrode while oxygen is released at the nickel electrode and then removed into the oxygen storage system. During the subsequent half-cycle, the hydrogen absorbed by the metal hydride electrode is removed into the hydrogen storage system. We have studied the above electrolysis process with help of the laboratory experimental membrane-less electrolyser giving the possibility for generating, storing and compressing hydrogen in it. The use of a chemically active LaNi5Hx electrode will make it possible to implement a hydrogen energy storage system (electrolyser-storage system-consumer) and accordingly to increase the efficiency of the power plant by ≈ 8–10 %. It would be effective to use such high-pressure membrane-less electrolyser as an energy storage system element of an energy complex that receives electricity from the renewable energy sources (sun, wind).

An Integrated New Method for the Characterisation of Thickness Changes in Battery Active Materials during Cyclisation Under Pressure

Measuring thickness-changes in a battery stack (dilation) during cyclisation is paramount for the characterisation of chemo-mechanical properties of battery materials. A variety of approaches to achieve these measurements is available, either for measuring the whole stack or individual active materials. Another topic of great interest is the cyclisation of batteries under an applied pressure. These pressures range from a few kPa to hundreds of MPa. Especially the research of solid-state battery materials requires measurements of electrochemical properties under pressure.In light of this, characterising chemo-mechanical properties under an applied pressure is a natural demand. However, to the best of our knowledge, no commercially available integrated solution to measure the dilation in a battery stack under any significant amount of applied pressure has been reported yet.We therefore present a convenient and reproducible method to derive thickness changes of a whole cell stack under defined pressures during cycling. For that, the commercially available PAT-Cell-Force was used (Image 1, left). The PAT-Cell-Force allows the application of a force of up to 1500 N on a cell stack of a diameter of 18 mm. This translates to a pressure of up to ~6 MPa. Additionally, the PAT-Cell-Force is equipped with a strain gauge sensor, allowing the measurement of the force during the experiment. While cycling, periodic fluctuations in the force signal are observed that are correlated to the cell voltage (Image 1, right).Through technical modifications of the PAT-Cell-Force, the dilation of the cell-stack Δd has been derived from the amplitude of the force signal ΔF, reproducibly and in very good agreement to the expected values. This has been achieved for applied forces of up to F0 ~ 100 N, corresponding to Pressures of approximately P0 ~ 400 kPa. Tests for higher pressures are currently pending. Figure 1

(Invited) Challenges and Successes of an Industrial Start-up to Global Electrolyzer Company

Hydrogen generation via electrolysis has gained much attention internationally as not only a sustainable source of fuel for the transportation, but as a carrier of energy to capture stranded renewable energy due to the carbon-free chemical cycle and response characteristics of the technology. The barrier to entry preventing this technology from being widely adopted is the overall cost associated with both the upfront capital expense as well as the operating cost incurred over the product life. The majority of this cost is driven by 1) low electrical efficiencies due to the high ohmic resistance of thicker membranes required by electrolysis systems to electrochemically compress generated hydrogen for storage and the overpotential associated with the water splitting oxygen evolution reaction (OER) catalysts typically used, 2) high cost of system and cell stack materials, which need to be durable for up to 100,000hrs at potentials approaching 2V in both reducing and oxidizing environments, and 3) the lack of a robust supply chain for high volume manufacturing to further drive down cost through economies of scale.Nel Hydrogen has worked to commercialize this technology, originally developed for aerospace and miliary applications where cost and efficiency were not the drivers. Since the founding of Proton Energy Systems in 1996 and to the present as Nel Hydrogen we have worked to address these problem areas in an attempt to develop products that can serve cost sensitive markets, such as energy capture and storage. During this talk, I will look back on the challenges we faced as an industrial start-up dealing with uninterested suppliers, creating relationships, and establishing partnerships, all while developing our first 28cm2 products to the point today, where we are producing and siting multi-MW systems.

Engineering High-K Switching Devices for in-Memory Computing

Selecting and processing of appropriate stack materials for HfO2-based RRAM devices significantly influences the distribution of defects and oxygen vacancies (Vo) within the switching layer, thereby playing an important role in their switching behavior (1). Controlling this distribution to have more oxygen vacancies near the top electrode (TE) while reducing them near the bottom electrode (BE) results in reduced switching power and enhanced multilevel cell characteristics (MLC) of RRAM devices (2) and that makes them as promising options for in-memory computing. Since RRAM devices fabricated as metal-insulator-metal stack, exploring the impact of each layer remains an active area of research.In this work, we compared different devices by varying the materials of each layer. The first comparison is by varying the oxide layer with same TE (Ru) and BE (TiN) by (i) using stoichiometric HfO2 and (ii) employing HfO2 treated with hydrogen plasma at the midpoint. The device treated with hydrogen plasma consumed nanowatts power compared to the stoichiometric device that consumed hundreds of microwatts to be switched. The introduction of hydrogen plasma treatment at the midpoint of the HfO2layer redirects more Vo towards the TE, explaining the reduction in the switching power (1). While applying pulse SET operation, the hydrogen plasma-treated device exhibited excellent conductance quantization, whereas the stoichiometric device quickly saturated and remaining stuck in a low-resistance state (LRS) due to a lack of Vo (3). Introducing a bilayer Al2O3/HfO2 dielectric significantly decreased switching power consumption to a few microwatts range compared to the stoichiometric device. This reduction is attributed to the rapid formation of Vo within the Al2O3 layer, subsequently stimulating Vo formation within the HfO2layer (4). However, the hydrogen plasma-treated device still maintains the lowest power consumption.Further investigation involved in changing the TE material, Ru and TiN to understand the impact of the TE, given its working function and interface barriers significantly affect the distribution of Vonear the TE. The device using Ru as the TE switched with a 3nA compliance current (1). Introducing nitrogen plasma treatment to the bottom electrode of the TiN device improved its switching behavior due to the reduction Vo near the BE because of formation of the Hf-N bond and led to increase the Vo near the TE (5). This enhancement was marked by a reduction in switching power to picowatts and stabilization of the conductive filament within the oxide. This device demonstrated improved conductance quantization.REFERENCES Patel, Y.; Misra, D.; Triyoso, D.; Clark, R.; Tapily, K.; Consiglio, S.; Wajda, C.; and Leusink, G., "RRAM devices with plasma treated hfo2 with Ru as top electrode for in-memory computing hardware," ECS Transactions, 104(3), p. 35, 2021, DOI: 10.1149/10403.0035ecst.Wong, H.-S. P.; Lee, H. Y.; Yu, Sh.; Chen,Y.; Wu, Y.; Chen, P. Ch.; Lee, B.; Chen, F.T.; Tsai, M. G., "Metal–Oxide RRAM," Proceedings of the IEEE, 2012, DOI: 10.1109/JPROC.2012.2190369.Zeinati, A., Misra, D., Triyoso, D.H., Clark, R.D., Tapily, K., Consiglio, S., Wajda, C.S., Leusink, G.J. "Process Optimization to Reduce Power in hfo2-Based RRAM Devices for in-Memory Computing," ECS Meeting s, vol. MA2022-02, 806 (2022). Doi: 10.1149/MA2022-0215806mtgabsMisra, D.; Zhao, P.; Triyoso, D.; Clark, R.; Tapily, K.; Consiglio, S.; Wajda, C.; Leusink, G., "Dielectrics and Metal Stack Engineering for Multilevel Resistive Random-Access Memory," ECS Journal of Solid-State Science and Technology, 9, 05300, 2020. DOI: 10.1149/2162-8777/ab9dc5.Wang, M.-H.; Chang, T.-Ch.; Shih, Ch.-Ch., "Performance improvement after nitridation treatment in hfo2-based resistance random-access memory," Applied Physics Express, 2018. DOI: 10.7567/APEX.11.084101.

On the benefit of attention in inverse design of thin films filters

Abstract Attention layers are a crucial component in many modern deep learning models, particularly those used in natural language processing and computer vision. Attention layers have been shown to improve the accuracy and effectiveness of various tasks, such as machine translation, image captioning, etc. Here, the benefit of attention layers in designing optical filters based on a stack of thin film materials is investigated. The superiority of Attention layers over fully-connected Deep Neural Networks is demonstrated for this task.

Burst pressure performance comparison of type V hydrogen tanks: Evaluating various shapes and materials

Hydrogen, as a clean energy carrier, presents a significant step toward sustainable energy solutions but faces challenges in storage due to its low energy density and high volatility. This study addresses the optimization of Type V hydrogen storage tanks by investigating the burst pressure performance of spherical, cylindrical, and toroidal shapes. Using finite element analysis (FEA) and first-order shear deformation theory, we examined how these geometries impact burst pressure outcomes across a range of composite materials and layup configurations. The materials tested included carbon T700/epoxy, Kevlar/epoxy, E-glass fiber/epoxy, and basalt/epoxy. Results demonstrate that the toroidal shape significantly outperforms spherical and cylindrical designs in stress distribution and burst pressure, with basalt/epoxy composites exhibiting superior burst pressure performance (12.7 MPa) compared to Kevlar/epoxy (10.8 MPa), E-glass fiber/epoxy (11.4 MPa), and carbon T700/epoxy (8.9 MPa). Kevlar/epoxy toroidal tanks outperform other materials in weight performance, having a structural performance index of 0.0305 Mpa.m3/kg and hydrogen density per unit mass of 0.0251 kg H2/kg. The stacking sequence [-45/45]s optimized stress distribution for the toroidal shape across all materials. The findings highlight that toroidal designs offer significant advantages for high-pressure hydrogen storage, providing efficient stress management and improved safety. This paper underlines the potential of toroidal vessels for enhancing hydrogen storage efficiency and emphasizes the importance of material selection and stacking sequences in achieving optimal burst pressure performance for international organization for standardization (ISO) certification.

Epitaxial growth of c-axis inclined Sr3YCo4O10.5+ δ thin film: Insights into laser-induced voltage signals arising from magnetic anisotropy

We report the laser-induced voltage (LIV) signals in cubic phase Sr3YCo4O10.5+δ (CP-SYCO) thin films with a c-axis tilted and discuss the relationship between the LIV signals and magnetic anisotropy. CP-SYCO thin films were epitaxially deposited on 0°, 5°, 10°, 15°, and 20° miscut LaAlO3 (001) substrates using pulsed laser deposition (laser energy of 200 mJ, post-annealed at 760 °C). The peak voltage of the LIV for the 15° tilted CP-SYCO film is 310 mV (under laser energy of 400 mJ/pulse), with a rising edge of 26 ns. Compared with G-type antiferromagnetic ordered tetragonal phase Sr3YCo4O10.5+δ(OT-SYCO, deposited at a laser energy of 300 mJ, post-annealed at 790 °C) film, the CP-SYCO exhibits much stronger magnetization anisotropy along in-plane and out-plane due to the possible A-type antiferromagnetic moment arrangement. CP-SYCO films also demonstrate significant thermoelectric anisotropy, supporting the transverse thermoelectric effect, which is partially attributed to the contribution of spin entropy. This study provides an understanding of the anisotropic behavior in atomic layer thermoelectric stack materials and explores magnetic anisotropic material systems.

The selection mechanism of mineral bridges at the interface of stacked biological materials for a strength-toughness tradeoff

The strength-toughness tradeoff in biological materials such as nacre and bone is essentially due to their stacked microstructures formed by hard and soft phases. In some of these materials, purely soft phase acts as interface layers linking hard phases (platelets), while in some others, hard-phase bridges exist in the soft phase to form a hybrid interface. In order to disclose the selection mechanism of such different interface structures in biological materials, a novel shear-lag model with an interface consisting of alternatively distributed elasto-plastic (soft) and brittle-elastic (hard) segments is proposed. Using this model, solutions of tensile stress and tensile displacement in hard platelets and shear stresses in soft and hard interfacial segments are analytically achieved. Effects of the hybrid interface on the effective mechanical performances of the composite are analyzed, the results of which are well consistent with the existing experimental observations in biocomposites and bio-inspired composites. The most important finding is that the fracture strain of the soft phase has a decisive effect on the selection of a purely soft-phase interface or a hybrid interface of hard and soft phases in stacked biological materials in order to realize a tradeoff between strength and toughness. When the failure strain of the soft phase is relatively small, such as nacre, the purely soft-phase interface is too weak to transfer enough load to the platelet, and hard bridges are necessarily required to reinforce the interface and guarantee an efficient load transfer. When the soft phase has a sufficiently large failure strain, such as bone, the purely soft-phase interface is tough enough to sustain a large shear deformation, realizing an efficient load transfer and adequate utilization of all constituents, while an additional hard bridge is not conducive to the composite toughness due to its reducing effect on the interfacial shear deformation. The results not only help people gain a deeper understanding of the secrets behind the construction of different interfaces in biological materials, but also provide useful guidance for interface optimization design in strong and tough artificial materials.

Topology optimization of orthotropic multi-material microstructures with maximum thermal conductivity based on element-free Galerkin method

A topology optimization model for periodic heat transfer microstructure with orthotropic multi-material is established by using the element-free Galerkin method (EFGM) and alternating active-phase algorithm (AAPA). The maximum thermal conductivity is chosen as the opposite number of objective function, and the 3-D printing of the microstructure and heat transfer analysis are performed to validate the proposed model. The effects of the number of multi-material categories, the initial distributions of multi-material, the thermal conductivity factor, and the multi-material off-angle on the topological configuration with maximum thermal conductivity are studied. The results show that the multi-material topological configuration is comprised the material with a higher thermal conductivity as the primary frame and surrounded by the material with the lower thermal conductivity. The initial distribution of multi-material has a little impact on the maximum thermal conductivity. The alteration of the thermal conductivity factor will contribute to the accumulating of materials in the direction of the higher thermal conductivity, and the material stacking direction is more inclined to the direction of multi-material off-angle. The reasonable values of multi-material thermal conductivity factor is suggested to be 2–4 and multi-material off-angle is suggested to be 0°–30° and 60°–90°.

The Bacau (Romania) phosphogypsum stacks as a source of radioactive threat: a case study

ABSTRACT For a detailed characterization of the 5.7 106 mt phosphogypsum (PG) stack in the vicinity of Bacau city, Romania, the air dose rate (ADR) was measured in 72 points covering the stack surface, while 10 samples of stack material were collected for future analysis. Radiometric determinations showed for the ADR values varying between 364 ± 53 and 489 ± 8 nSv/h, with some extreme values of 2775 ± 734 nSv/h, significantly exceeding 90 nSv/h, the average value reported for the Romanian territory. High-resolution gamma-ray spectroscopy (HRGS), performed on 10 samples collected from the entire PG stack evidenced only the presence of 226Ra as the major radioactive element with a specific activity varied between 820 ± 150 and 5278 ± 264 Bq/kg for hot spots. Further analysis performed on a similar number of samples by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX), evidenced, beside gypsum as the main component, traces of brushite (CaHPO4·2H2O) and ardealite (Ca2(PO3OH)(SO4)·4H2O), as well as the presence of small acicular celestine (SrSO4) agglomerates. XRF determinations of the mass fractions of major elements evidenced values such as SiO2 (2.31 ± 0.73 %), TiO2 (0.07 ± 0.01 %), Al2O3 (0.17 ± 0.04 %), Fe2O3 (0.87 ± 0.18 %), MnO (0.01 ± 0.01 %), MgO (0.17 ± 0.02 %), CaO (32.5 ± 0.82 %), Na2O (0.04 ± 0.04 %), K2O (0.05 ± 0.01 %), P2O5 (2.12 ± 0.51 %), LOI (20.2 ± 0.3 %), i.e. closer to literature reported data for PG of different provenience while the data concerning the distribution of 20 trace elements, including incompatible Sc, La, Ce, and Th were relatively closer to the upper continental crust (UCC).

Uniform or demand-driven allocation? Optimal management of social donations distribution in response to sudden outbreaks

PurposeThis study aims to address challenges in the distribution of social donations during epidemic emergencies, focusing on issues such as uneven distribution and material stacking. The goal is to propose optimized strategies that enhance equity and efficiency in the allocation of donated resources.Design/methodology/approachFirstly, the satisfaction function is constructed from two perspectives of the designated hospital and the Red Cross. On this basis, the fairness perception level of the two is portrayed. Then, we set the time weights, and construct a multi-objective programming model by combining the resource constraints in the social donation distribution process. The combined algorithm of NSGA-II and TOPSIS is also designed for model solving. Finally, an example of social donation distribution of the Red Cross Society of China Wuhan Branch is conducted for numerical analysis.FindingsNumerical analysis reveals that timely transmission of demand information favors a demand-oriented distribution strategy for optimal efficiency. However, in scenarios with poor demand information transmission, an equal distribution of social donations proves to be a more effective strategy. Equal distribution ensures rapid allocation while minimizing perceived unfairness at designated hospitals, ultimately improving overall satisfaction levels and emergency response effectiveness.Practical implicationsThe findings provide practical insights for emergency response planners. These include translating the developed methods into guiding principles, establishing real-time monitoring systems, enhancing training for relevant departments, and implementing evaluation mechanisms. Practitioners can utilize this knowledge to optimize the efficiency of social donation distribution during sudden outbreaks.Social implicationsThe equitable distribution of social donations ensures efficient resource allocation and minimizes perceived unfairness, contributing to improved social satisfaction levels. This has broader implications for community resilience and support during emergencies.Originality/valueThis research contributes to the field by proposing a comprehensive model for optimizing social donation distribution in emergencies. The integration of fairness perception, time weights, and a multi-objective planning approach, along with the application of the combined algorithm of NSGA-II and TOPSIS, adds novelty and practical value to the existing literature. The study serves as a decision-making reference for enhancing emergency response theories in sudden event.

A new novel recognition and positioning system of black light-absorbing volute for automation depalletizing development

Abstract In the application of vision measurement, the black light-absorbing object is difficult to reflect the structured light from infrared emitter of the RGB-D camera. Therefore, an image recognition algorithm based on reference environment information is proposed to acquire the spatial positioning information of black volutes in the depalletizing system. The hardware system of the depalletizing system is mainly constructed of an upper computer, a six-axis industrial robot, an RGB-D camera and an end adsorption device. Firstly, the horizontal position information of each volute placed on the cardboard is obtained by the depth differences between the cardboard and the volute. Then, the depth information of the volute is obtained by the upper cardboard depth through collecting the position of the end vacuum suction cup triggered by feedback signal from vacuum generator. Secondly, a regional planar hand-eye calibration method is developed to improve the calibration accuracy in two-dimensional coordinates. The regional calibration method divides the robot working area into four regions: upper left, lower left, upper right, and lower right. The transformation matrix of each region is calculated separately. Finally, the depalletizing experiment is conducted on the three types of volutes. It is concluded that the average positioning error of the grasping center point of each volute obtained by our method is 3.795 mm, and its standard deviation is 1.769 mm. The average value of regional planar hand-eye calibration error is 4.044 mm, and its standard deviation is 1.501 mm. Under a stack of materials with dimensions of 1350 mm × 1350 mm × 1500 mm, the maximum error is controlled within 15 mm. Additionally, when combined with the end feedback compensation mechanism, the success rate for grasping all three volutes reaches 100%.