Production Of Structures Research Articles

Facile preparation of Co-doped ZnIn2S4 nanosheets for highly efficient photocatalytic hydrogen peroxide production

Utilizing solar energy to produce hydrogen peroxide from oxygen and water offers an appealing and sustainable approach. In this work, Co-doped ZnIn2S4 nanosheets were effectively synthesized through a chemical precipitation method, and the morphological structure, band structure and pathways for hydrogen peroxide production were investigated. The results indicate that Co doping significantly enhances the photocatalytic efficiency of ZnIn2S4 in producing hydrogen peroxide. The sample with the 2 % doping concentration exhibited the highest rate, with a detected hydrogen peroxide concentration of 535.53 µM in the solution after 100 minutes of exposure to visible light, which is 4.29-fold higher than that of undoped ZnIn2S4. Further analysis revealed that the improved performance mainly originated from better spectral response, faster photogenerated carrier transport, and lower recombination frequency of photogenerated electron-hole pairs.

Drifting vessel statistics and emergency towing cases

Abstract Recent climate studies forecast violent weather events with impact on the safety of maritime transportation. For example, harsh weather may result in system failures such as blackouts or loss of steering capability. Problems met when performing planned maintenance at sea may lead to adverse events if the weather cause delays or makes it impossible to complete the planned work. A drifting vessel in general is a liability for collisions with offshore structures, groundings, and total loss due to capsizing. The increasing use of ocean structures for energy production at sea (coastal and deepwater windfarms) and the transfer of fish farming structures to more exposed locations increase the probability of collisions between drifting ships and ocean structures. To mitigate risks, several incidents and their consequences have been analysed by national administrations. In some cases, these analyses have recommended the use of dedicated emergency towing resources. The willingness of the national governments to fund such resources is directly related to the time since the last major incident in their territorial waters. This paper reviews some recent cases of emergency towing operations in Norwegian waters and highlights challenges interlinked to setting up an emergency towing connection between a drifting ship and an emergency towing vessel in harsh weather.

Salvinia natans-Based Hierarchical Structures for Solar Thermal Clean Water Production from High-Salinity Wastewater.

Biomaterial-based solar-driven evaporation has great potential for wastewater treatment and seawater desalination with a high energy conversion and utilization efficiency. However, technology gaps still exist for effectively and directly applying multiscale structures and intrinsic water transport channels of natural materials to enhance high-efficiency photothermal evaporation. In this study, a high-performance biomass-derived photothermal evaporative material was obtained using Salvinia natans, a common aquatic floating plant, together with simple poly(m-phenylenediamine) oxidation modification, building a hybrid biomass evaporator. With advantageous natural features of adequate water transport, microscale-nanoscale hierarchical structures, effective water activation, and antisalt-fouling function, the hybrid biomass evaporator achieves a high evaporation rate of 2.24 kg m-2 h-1 under one sun radiation (1 kW m-2). In addition, modified Salvinia natans also demonstrate certain ability to remove heavy metals during the photothermal evaporation of wastewater. This work offers a new perspective on the synthesis of an environmentally friendly and cost-effective solar-driven evaporator material, which has the advantages of low cost, simple process, and high photothermal conversion efficiency, and can be widely applied to seawater desalination and the treatment of wastewater with high salt concentrations.

Aided Porous Medium Emulsification for Functional Hydrogel Microparticles Synthesis.

Despite the substantial advancement in developing various hydrogel microparticle (HMP) synthesis methods, emulsification through porous medium to synthesize functional hybrid protein-polymer HMPs has yet to be addressed. Here, the aided porous medium emulsification for hydrogel microparticle synthesis (APME-HMS) system, an innovative approach drawing inspiration from porous medium emulsification is introduced. This method capitalizes on emulsifying immiscible phases within a 3D porous structure for optimal HMP production. Using the APME-HMS system, synthesized responsive bovine serum albumin (BSA) and polyethylene glycol diacrylate (PEGDA) HMPs of various sizes are successfully synthesized. Preserving protein structural integrity and functionality enable the formation of cytochrome c (cyt c) - PEGDA HMPs for hydrogen peroxide (H2O2) detection at various concentrations. The flexibility of the APME-HMS system is demonstrated by its ability to efficiently synthesize HMPs using low volumes (≈50µL) and concentrations (100µm) of proteins within minutes while preserving proteins' structural and functional properties. Additionally, the capability of the APME-HMS method to produce a diverse array of HMP types enriches the palette of HMP fabrication techniques, presenting it as a cost-effective, biocompatible, and scalable alternative for various biomedical applications, such as controlled drug delivery, 3D printing bio-inks, biosensing devices, with potential implications even in culinary applications.

Application of Numerical Modeling and Finite Element Analysis in Fused Filament Fabrication: A Review.

Additive manufacturing (AM) is not necessarily a new process but an advanced method for manufacturing complex three-dimensional (3D) parts. Among the several advantages of AM are the affordable cost, capability of building objects with complex structures for small-batch production, and raw material versatility. There are several sub-categories of AM, among which is fused filament fabrication (FFF), also commonly known as fused deposition modeling (FDM). FFF has been one of the most widely used additive manufacturing techniques due to its cost-efficiency, simplicity, and widespread availability. The FFF process is mainly used to create 3D parts made of thermoplastic polymers, and complex physical phenomena such as melt flow, heat transfer, solidification, crystallization, etc. are involved in the FFF process. Different techniques have been developed and employed to analyze these phenomena, including experimental, analytical, numerical, and finite element analysis (FEA). This study specifically aims to provide a comprehensive review of the developed numerical models and simulation tools used to analyze melt flow behavior, heat transfer, crystallization and solidification kinetics, structural analysis, and the material characterization of polymeric components in the FFF process. The strengths and weaknesses of these numerical models are discussed, simplifications and assumptions are highlighted, and an outlook on future work in the numerical modeling and FE simulation of FFF is provided.

Intercalation of V2O5 and Polypyrrole into a Graphene Oxide Layer: A Hybrid Multifunctional Photothermal Structure for Efficient Solar Evaporation, Water Purification, Disinfection, and Power Production.

Development of a hybrid multifunctional photothermal structure with multifunctional capabilities is deliberated as an effective approach for harvesting abundant solar energy for sustainable environmental applications. Achieving enhanced solar to thermal conversion efficiency utilizing a suitably designed, environmentally compatible thermal management structure however remains a significant challenge. Herein, we report the intercalation of V2O5 and polypyrrole into a graphene oxide layer to design a hybrid photothermal assembly (PPy-V2O5-GO) and its multifunctional proficiencies. The hybrid photothermal structure demonstrated synergistic photothermal conversion, buoyant porous structure sustaining water transmission, and efficient steam release. V2O5 and polypyrrole-intercalated optimized graphene oxide structure attained an evaporation rate of 1.9 kg m-2 h-1 with a conversion efficiency of 92% under 1 sun solar radiation. At maximum, the assembly's surface temperature hit 64 ± 2 °C, suggesting its suitability as a solar water purifier. Outdoor experiments suggest the evaporator assembly's capability to accumulate a total output of 15 kg m-2 over a single day. Cell viability investigations revealed strong antimicrobial properties of PPy-V2O5-GO against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria, eliminating nearly all under 1 sun, making it a potential candidate for photothermal therapy. Furthermore, when combined with a commercial thermoelectric module, the framework displayed exceptional photothermal conversion efficiency, hinting at its potential for electrical power generation. The integration of PPy-V2O5-GO with a Bi2Te3-based thermoelectric module significantly boosted the thermoelectric generator's performance, offering an enhanced power output of 2.8 mW and a high power density of 1.24 mW/cm2, making them suitable for off-grid or remote-area application. Overall, the PPy-V2O5-GO photothermal assembly's stability, lack of leaching, effectiveness in producing pure water from seawater, antimicrobial efficacies, and recyclability make it an excellent choice for sustainable water treatment and power generation.

Green Hydrogen, a Solution for Replacing Fossil Fuels to Reduce CO2 Emissions

The article examines the role of green hydrogen in reducing CO2 emissions in the transition to climate neutrality, highlighting both its benefits and challenges. It starts by discussing the production of green hydrogen from renewable sources and provides a brief analysis of primary resource structures for energy production in European countries, including Romania. Despite progress, there remains a significant reliance on fossil fuels in some countries. Economic technologies for green hydrogen production are explored, with a note that its production alone does not solve all issues due to complex and costly compression and storage operations. The concept of impure green hydrogen, derived from biomass gasification, pyrolysis, fermentation, and wastewater purification, is also discussed. Economic efficiency and future trends in green hydrogen production are outlined. The article concludes with an analysis of hydrogen-methane mixture combustion technologies, offering a conceptual framework for economically utilizing green hydrogen in the transition to a green hydrogen economy.

Emergency production of medical products: partial decentralization vs. complete decentralization

In the emergency production of medical products, the supplier with raw materials is often the leader in the game and has the advantage of determining the supply chain structure. Previous research on supply chain structure mostly focuses on how the leader uses this advantage to obtain the optimal profit, ignoring the strategic compensation of the follower under this disadvantage. This paper explores how the follower can get the optimal profit through contract design and production time in a supply chain composed of two buyers (integrated buyer and non-integrated buyer) and a supplier. In the case of shortage of medical products, firms form a completely decentralized or partially decentralized (the supplier and a buyer form a vertically integrated entity) structure for emergency production. The results show that the integrated buyer can obtain more profits in the partially decentralized structure. In addition, in the partially decentralized structure, the non-integrated buyer is more sensitive to production time. Surprisingly, in emergency production, the more purchases the non-integrated buyer makes, the higher the wholesale price of the supplier. However, under certain conditions, this abnormal phenomenon increases the possibility of the buyer obtaining the optimal profit, and weakens the influence of supply chain structure.

Auxetic textiles, composites and applications

Auxetic textiles are intriguing materials with unusual capabilities. These materials exhibit a negative Poisson’s ratio with extraordinary performance in toughness, resilience, shear resistance, and acoustic properties mainly due to their special structure and associated deformation mechanics. Auxetic materials can also have applications around energy absorption and can effectively be used for vibration damping and shock absorbency. The exceptional behaviour of auxetic textiles can be obtained by utilising specific fibrous materials and introducing auxetic geometry and structures differently during weaving, knitting, and nonwoven manufacturing. This issue of Textile Progress highlights the fundamental aspects of various auxetic structures and their properties in general and a detailed analysis of auxetic textile structures and composites, their manufacturing processes, modelling, characterisation, and applications. These materials can potentially revolutionise their applications in sports, automotive, construction industry, biomedical engineering, aerospace, marine, and defence personal protective equipment. Fundamental understanding of auxetic geometry, followed by developing and analysing these geometries by analytical and computational modelling, translating the geometry into appropriate textile structures for actual fabric production, characterisation of auxetic fabrics and their composites, and finally, some innovative applications in technical textiles are some of the fascinating issues addressed in this review.

Reticulated porous structures of La0.8Al0.2NiO3-δ perovskite for enhanced green hydrogen production by thermochemical water splitting

The preparation and optimisation of La0.8Al0.2NiO3-δ (LANi82) perovskite shaped as reticulated porous ceramic (RPC) structures for H2 production by thermochemical water splitting is presented for the first time. The perovskite was first synthesised in powder form following a modified Pechini method. The redox properties of the LANi82 were first tested under N2/air flow in a thermogravimetric analyser. After that, the sponge replica method for preparing RPCs was optimised in terms of slurry composition and final thermal treatment to obtain a LANi82-RPC structure with porosity and strength appropriate to enhance heat and mass transfer in further solar reactors. The optimised LANi82-RPC material showed an outstanding hydrogen production of 8.3 cm3 STP/gmaterial·cycle at isothermal conditions (800 °C). This production was increased up to 11.5 cm3 STP/gmaterial·cycle if the thermal reduction was performed at 1000 °C. Additionally, a stable activity with almost constant H2 production in consecutive cycles was obtained for the optimised LANi82-RPC in both cases. The structure of the reticulated porous materials, with open macroporosity and wide interconnected channels, enhances heat and mass transfer, leading to higher hydrogen productions of the LANi82-RPC as compared to the materials as powder form in the same experimental set-up. These facts reinforce the favourable prospects of LANi82-RPC for large-scale hydrogen production, improving the coupling to current solar thermal concentration technologies developed, such as concentrated solar power tower.

P‐254: Late‐News Poster: Design Optimization and Considering Mass Production of 2D Hole Arrayed Double Anode Structure for Improving Outcoupling Efficiency of OLEDoS

AR, VR Headset for “metaverse” is one of candidates to widen human life experiences with virtual reality. Display requirement for headset is the high resolution as to 3000ppi that needs to enhance outcoupling efficiency of OLED (OLEDoS). We optimized 2D hole arrayed double anode structure for mass production with materials, thickness of anode and interlayer, process variation of etching top anode, and particles in double anodes. Outcoupling efficiency of optimized structure is improved to 1.377 folds than conventional TE‐OLEDs. We hope that this study promotes more approaches to excite SPPs of anode.

Construction of Inverse-Opal ZnIn2S4 with Well-Defined 3D Porous Structure for Enhancing Photocatalytic H2 Production.

The conversion of solar energy into hydrogen using photocatalysts is a pivotal solution to the ongoing energy and environmental challenges. In this study, inverse opal (IO) ZnIn2S4 (ZIS) with varying pore sizes is synthesized for the first time via a template method. The experimental results indicate that the constructed inverse opal ZnIn2S4 has a unique photonic bandgap, and its slow photon effect can enhance the interaction between light and matter, thereby improving the efficiency of light utilization. ZnIn2S4 with voids of 200 nm (ZIS-200) achieved the highest hydrogen production rate of 14.32 μ mol h-1. The normalized rate with a specific surface area is five times higher than that of the broken structures (B-ZIS), as the red edge of ZIS-200 is coupled with the intrinsic absorption edge of the ZIS. This study not only developed an approach for constructing inverse opal multi-metallic sulfides, but also provides a new strategy for enriching efficient ZnIn2S4-based photocatalysts for hydrogen evolution from water.

MoS2@ZIF-8-based aerogel with multiscale biomimetic structure achieving all-day desalination and wastewater purification

In emerging freshwater generation strategy, solar driven evaporation technology has been brought into focus owing to its non-pollution and facile facilities. However, maintaining high freshwater yield remains a challenge under natural circumstances. Herein, MoS2@ZIF-8-based aerogel featuring a lotus root hourglass-shaped structure (denoted as LMZA) for efficient freshwater production via hybrid energy harvesting is ingeniously devised. After being integrated with metallic 1 T phase MoS2 and a vertically aligned porous structure, LMZA not only achieves an outstanding evaporation rate at different incident angles and intensities, but also utilizes wind or environmental energy for evaporation. More importantly, the proposed LMZA also achieved a fast evaporation rate of 8.47 kg m-2h−1 under 4.0 m s−1 without solar irradiation, which fully eliminated the impact of solar intermittency. Afterward, LMZA with a cross-scale hierarchical structure for desalination exhibits an evaporation rate of up to 2.08 kg m-2h−1 under one sun irradiation in 20 wt% brine, and possesses exceptional adaptability and stability. Besides, another advantage of LMZA is the effective purification of cadmium-containing wastewater through water evaporation and in situ adsorption. The removal efficiency is 74 % under one sun irradiation, and the condensed water with undetected Cd(II) heavy metal ions was obtained. More importantly, combined with ambient factors such as wind and ambient temperature in the natural environment, the home-made device achieves all-day freshwater generation with a daily yield of 27.08 kg m−2. The investigation of the device and LMZA pioneers a novel design concept for high yield freshwater generation in practical applications.

Impact of Cu complex anions on CuZnAl intercalated hydrotalcite-like catalysts for low-carbon alcohols synthesis from syngas

Elucidating the structure-performance relationship of catalysts for low-carbon alcohols synthesis from syngas is crucial for designing efficient catalysts. In this study, CuO particle size, reducibility, and the number of oxygen vacancies could be adjusted by changing intercalated Cu complex anions, thereby affecting the catalyst's performance. The characterization results indicated that the insertion of [Cu(C2O4)2]2- between ZnAl layered double hydroxide resulted in the largest CuO particles (26.5 nm), leading to an increase in the metallic copper surface area. Consequently, the highest CO conversion (13.0 %) was achieved without altering alcohol distribution. On the other hand, when [Cu(EDTA)]2- was inserted, the catalyst possessed the smallest CuO particle size (8.9 nm), more abundant oxygen vacancies, and enhanced interaction between Cu species and ZnO, which promoted carbon chain growth and resulted in a high C2+OH proportion of 75.8 %. Our study thus provides a new perspective on catalyst structures for the syngas production of low-carbon alcohols.

Hierarchical MPC‐based control structure for continuous biodiesel production

AbstractThis paper presents an advanced control strategy for a continuous biodiesel production plant based on a steady‐state optimizer and model predictive control (MPC). The proposed control system aims to optimize the production process and maintain product quality within required specifications. First, two steady‐state optimizers were developed with the aim of minimizing the steady‐state deviations of the manipulated and controlled variables and minimizing the biodiesel production cost. An MPC was then formulated to track the set points imposed by the steady‐state optimizers in real time and manipulate the control inputs accordingly. The scope of this work is limited to measured disturbances only. The effectiveness of the proposed control strategy is demonstrated through dynamic simulation studies performed using HYSYS and MATLAB. The results obtained using the proposed control methodology show significant improvements in performance compared to conventional control strategies. Furthermore, it avoids the quality problem reflected in the amount of water in the final product that the original plant presented due to an inadequate design of the control strategy. Overall, the results of this research indicate that the proposed advanced control strategy has the potential to improve the efficiency and profitability of continuous biodiesel production plants.

Characteristic Investigation on the Methanol Steam Reforming Microchannel Reactor with the Novel Catalytic Combustion Self-Heating Structure for Hydrogen Production

Characteristic Investigation on the Methanol Steam Reforming Microchannel Reactor with the Novel Catalytic Combustion Self-Heating Structure for Hydrogen Production

노작교육론 기반의 ‘공동체 역량’신장을 위한 침선 공예 프로그램 개발: 두루주머니형 파빌리온 제작 사례를 중심으로

As the untact culture spread due to post-COVID-19 and Edutech emerged as a spotlight industry, the craft program was developed while sympathizing with the reality that students' solidarity with the community was weakening. This study focuses on finding out the effectiveness of pavilion production classes using sewing crafts programs based on work-oriented education in cultivating community competence. This study aims to integrate sewing crafts and art programs, provide a place for students to learn to develop a sense of community and improve their abilities, analyze the educational value of sewing crafts as a medium for com-munity harmony, and propose a nine-session instructional plan using it. This plan encourages students to promote relationships, mutual reciprocity, empathy/care, which are elements of community competence by creating pavilions. Pavilion refers to a building made temporarily for special purposes at an exhibition hall or fair and is established as a meaningful outdoor project in the field of architecture and culture and arts. In this study, students must build structures for pavilion production, and the structures are wrapped by a material called Gwangmok through hand sewing. This study aims to suggest the necessity of effective edu-cational research in emphasizing the importance of promoting a sense of community and strengthening community ties by integrating work-oriented education into art education.

Evolutionary novelties underlie sound production in baleen whales.

Baleen whales (mysticetes) use vocalizations to mediate their complex social and reproductive behaviours in vast, opaque marine environments1. Adapting to an obligate aquatic lifestyle demanded fundamental physiological changes to efficiently produce sound, including laryngeal specializations2-4. Whereas toothed whales (odontocetes) evolved a nasal vocal organ5, mysticetes have been thought to use the larynx for sound production1,6-8. However, there has been no direct demonstration that the mysticete larynx can phonate, or if it does, how it produces the great diversity of mysticete sounds9. Here we combine experiments on the excised larynx of three mysticete species with detailed anatomy and computational models to show that mysticetes evolved unique laryngeal structures for sound production. These structures allow some of the largest animals that ever lived to efficiently produce frequency-modulated, low-frequency calls. Furthermore, we show that this phonation mechanism is likely to be ancestral to all mysticetes and shares its fundamental physical basis with most terrestrial mammals, including humans10, birds11, and their closest relatives, odontocetes5. However, these laryngeal structures set insurmountable physiological limits to the frequency range and depth of their vocalizations, preventing them from escaping anthropogenic vessel noise12,13 and communicating at great depths14, thereby greatly reducing their active communication range.

Oscillatory flow driven microdroplet breakup dynamics and microparticle formation in LMPA-water two phase flow system

This study presents a mathematical modeling and numerical investigation of oscillatory flow induced microdroplet breakup in low melting point alloy (LMPA)-in-water two-phase flow system in a microchannel. The effects of perturbation flow Weber number, and oscillating frequencies on the droplet breakup dynamics have been elucidated. Lowering the wall temperature will accelerate the solidification process of LMPA droplets, giving rise to the rapid formation of ultra-small particles with size down to 1 micron in less than 3 ms. The versatile approach combines oscillatory flow dominated droplet breakup process and phase change process, leading to the formation of LMPA microparticles with monodispersed size distribution and well-tailored properties by using a straight microchannel, which obviates the need for sophisticated design and complex fabrication process of microdevices. This work will provide a strategy to manipulating LMPA droplet size and structure for the massive production of ultra-small LMPA microparticles via a facile control over the flow conditions in the two-phase flow in a microfluidic system. It will open up for a diversity of applications of LMPA microparticles in various fields such as energy storage and thermal management.

TASK SCHEDULING OPTIMISATION OF DISTRIBUTED REAL-TIME COMPUTING SYSTEMS.

Distributed computing structures for production and special purposes represent the resources of soft or hard real-time systems. The problem of task planning is to determine the optimal distribution according to the generalized criterion of system utility. The article discusses the methods of building a schedule, based on the theory of planning. It is shown that the most effective step in this process is the optimisation of the activity of the enterprises or organizations at all levels - economic, technical, informational, etc., under the conditions of natural limitations on time resources. Since the optimisation of schedule planning occupies a fundamentally important place in the process of organizing the effective operation of a distributed multiprocessor computing system, the possibilities of using this theory in creating an optimal schedule based on the theory of queues with ordinary and marked applications are considered. The theoretical basis of the planning optimisation problem is a multistage system with M storage units and a set of N´M services. In order to organize the schedule optimality criteria to ensure ease of description, storage and software implementation, a conditional division of criteria into geographic, technical or transit categories with a description of the corresponding priority value is proposed. Taking into account these components, an expression for the average waiting time in the queue for a marked demand is derived. The scheme of the conceptual approach to the construction of a multi-core computer with the distribution of periodic and sporadic tasks is presented. The scheme of the real-time system (RTS) in hardware and software implementation is also presented. Background streams in RTS are activated by RT operating system (RT OS) commands and are embedded in primary streams. The above demonstrates the versatility of the proposed approach to scheduling a multiprocessor computing structure and its ability to meet the user's work requirements in real time.