Large-scale Applications Research Articles

Formulation optimization of oil shale semi-coke/lime/cement solidified loess based on ternary nephogram and establishment of elastic-plastic damage model

Oil shale semi-coke (OSS) is a industrial solid waste produced after the dry distillation refining of oil shale. Due to its internal enrichment of activity silico-aluminate minerals, it can be utilized to prepare low-carbon cementitious materials through alkali activation. In this study, a composite material for reinforcing loess was synthesized using OSS, lime, and cement. Drawing upon the ternary design method, the optimization of oil shale semi-coke/lime/cement stabilized loess (OLC-SL) formulation was explored. Through microscopic analysis, the enhancement mechanism of OLC-SL was probed. Furthermore, it comprehensively understood the stress-strain characteristics of OLC-SL by conducting triaxial experiments and developed an elastic-plastic damage model for OLC-SL through numerical. The outcomes of this study provide novel insights and theoretical support for the resource utilization of OSS waste, and hold crucial implications for promoting the large-scale application of OSS waste in the disposal of expansive loess.

Corrosion Resistance and Conductivity of Ta-Nb-N-Coated 316L Stainless Steel as Bipolar Plates for Proton Exchange Membrane Fuel Cells

The large-scale application of stainless steel (SS) bipolar plates (BPs) in proton exchange membrane fuel cells (PEMFCs) is mainly limited by insufficient corrosion resistance and electrical conductivity. In this work, Ta-Nb-N coatings were prepared on 316L SS substrates by unbalanced magnetron sputtering to improve corrosion resistance and conductivity. The Ta-Nb-N coatings had a dense structure without obvious defects. In simulated PEMFC cathode environments consisting of 0.5 M H2SO4 + 2 ppm HF at 70 ± 0.5 °C, which is harsher than the U.S. Department of Energy specification, the corrosion current density of Ta-Nb-N-coated BPs was reduced to 2.2 × 10−2 μA·cm−2. Ta-Nb-N-coated samples showed better electrical conductivity than 316L SS, which had an excellent interfacial contact resistance of 9.2 mΩ·cm2. In addition, the Ta-Nb-N-coated samples had a water contact angle of 100.7°, showing good hydrophobicity for water management. These results indicate that Ta-Nb-N coatings could be a promising material for BPs.

Wflow_sbm v0.7.3, a spatially distributed hydrological model: from global data to local applications

Abstract. The wflow_sbm hydrological model, recently released by Deltares, as part of the Wflow.jl (v0.7.3) modelling framework, is being used to better understand and potentially address multiple operational and water resource planning challenges from a catchment scale to national scale to continental and global scale. Wflow.jl is a free and open-source distributed hydrological modelling framework written in the Julia programming language. The development of wflow_sbm, the model structure, equations and functionalities are described in detail, including example applications of wflow_sbm. The wflow_sbm model aims to strike a balance between low-resolution, low-complexity and high-resolution, high-complexity hydrological models. Most wflow_sbm parameters are based on physical characteristics or processes, and at the same time wflow_sbm has a runtime performance well suited for large-scale high-resolution model applications. Wflow_sbm models can be set a priori for any catchment with the Python tool HydroMT-Wflow based on globally available datasets and through the use of point-scale (pedo)transfer functions and suitable upscaling rules and generally result in a satisfactory (0.4 ≥ Kling–Gupta efficiency (KGE) < 0.7) to good (KGE ≥ 0.7) performance for discharge a priori (without further tuning). Wflow_sbm includes relevant hydrological processes such as glacier and snow processes, evapotranspiration processes, unsaturated zone dynamics, (shallow) groundwater, and surface flow routing including lakes and reservoirs. Further planned developments include improvements on the computational efficiency and flexibility of the routing scheme, implementation of a water demand and allocation module for water resource modelling, the addition of a deep groundwater concept, and computational efficiency improvements through for example distributed computing and graphics processing unit (GPU) acceleration.

An experimental and theoretical investigation of NiO-rGO composites for hydrogen evolution reactions

Producing hydrogen (H2) as a sustainable energy carrier is most effectively achieved through the process of electrochemical water splitting. Although noble metals like Pt-based electrocatalysts are effective, their cost and availability limit large-scale application. Nickel-based materials excel in catalyzing hydrogen evolution reactions (HER), but their low electronic conductivity restricts scalability. Our study introduces a simple synthesis of NiO coupled with rGO, forming NiO-rGO composites with enhanced surface area, which shows remarkable electrocatalytic performance in HER. The NiO-rGO exhibits low overpotentials (176 mV) at a current density of 10 mA cm−2 in acidic solutions. The experimental studies are well supported by first-principles DFT methods.

Potential Strategy to Control the Organic Components of Condensable Particulate Matter: A Critical Review.

More and more attention has been paid to condensable particulate matter (CPM) since its emissions have surpassed that of filterable particulate matter (FPM) with the large-scale application of ultralow-emission reform. CPM is a gaseous material in the flue stack but instantly turns into particles after leaving the stack. It is composed of inorganic and organic components. Organic components are an important part of CPM, and they are an irritant, teratogenic, and carcinogenic, which triggers photochemical smog, urban haze, and acid deposition. CPM organic components can aggravate air pollution and climate change; therefore, consideration should be given to them. Based on existing methods for removing atmospheric organic pollutants and combined with the characteristics of CPM organic components, we provide a critical overview from the aspects of (i) fundamental cognition of CPM, (ii) common methods to control CPM organic components, and (iii) catalytic oxidation of CPM organic components. As one of the most encouraging methods, catalytic oxidation is discussed in detail, especially in combination with selective catalytic reduction (SCR) technology, to meet the growing demands for multipollutant control (MPC). We believe that this review is inspiring for a fuller understanding and deeper exploration of promising approaches to control CPM organic components.

The Cryoprotective Effect of an Antifreeze Collagen Peptide Complex Obtained by Enzymatic Glycosylation on Tilapia

Antifreeze peptides have become effective antifreeze agents for frozen products, but their low quantity of active ingredients and high cost limit large-scale application. This study used the glycosylation of fish collagen peptides with glucosamine hydrochloride catalyzed by transglutaminase to obtain a transglutaminase-catalyzed glycosylation product (TGP) and investigate its antifreeze effect on tilapia. Compared with the blank group, the freshness (pH value of 6.31, TVB-N value of 21.7 mg/100 g, whiteness of 46.28), textural properties (especially hardness and elasticity), and rheological properties of the TGP groups were significantly improved. In addition, the protein structures of the samples were investigated using UV absorption and fluorescence spectroscopy. The results showed that the tertiary structure of the TGP groups changed to form a dense polymer. Therefore, this approach can reduce the denaturation and decomposition of muscle fibers and proteins in fish meat more effectively and has a better protective effect on muscle structure and protein aggregation, improving the stability of fish meat. This study reveals an innovative method for generating antifreeze peptides by enzymatic glycosylation, and glycosylated fish collagen peptide products can be used as new and effective green antifreeze agents in frozen foods.

Цифровой переход и его правовые аспекты в реализации внешних компетенций Европейского союза

Digital transition is a key priority of the European Union strategic autonomy. The EU external competences serve as instrumental long-term trendsetters prompting third countries to follow suit in terms of a large-scale artificial intelligence systems application, ensuring cyber security, network infrastructure protection, using big data systems and other disruptive technologies. Treaty-based and legislative norms and principles, related to such phenomena, when enshrined in bilateral, interregional and international agreements, make an integral part of the incipient “Human-to-Smart Machine” interface ‘code of ethics’ that might largely fore-shadow the future. In a change-bound world order with a swelling importance of the power of states, their resource and military potential, the stability of interstate relations hinges on the will of major powers and the commitment of the parties to the international obligations they assumed. Fraught with legal conflicts, derogations, in fact, lead to direct confrontation. With fast-track refinement of its pivotal external competence tools well under way, the EU keeps abreast with the geopolitical dynamics in Europe. A dramatic shifting in “soft” and “hard” power equa-tion is manifest.

Significantly improved dehydrogenation of dodecyl-N-ethylcarbazole over supported PdFe bimetallic nanocatalysts via polydopamine surface modification of Al2O3

N-ethylcarbazole (NEC) has great application prospects in hydrogen storage due to its ability to dehydrogenate at lower energy and high hydrogen storage performance. Developing supported metal catalysts with high catalytic activity and stability is key to achieving large-scale application of LOHC hydrogen storage technology. In this paper, bimetallic FePd/Al2O3@PDA-GR catalysts used for the dehydrogenation process of 12H-NEC were prepared by stepwise reduction methods, including chemical reduction and galvanic replacement, using PDA-coated Al2O3 as the support. The characterization results showed that adding PDA could anchor the metal particles, improve the dispersion of metal particles on the support surface, and reduce the agglomeration phenomenon. The nanoparticles of bimetallic catalysts prepared by the galvanic replacement were small, with the particle size distribution of 0.86 nm-2.78 nm, and an average size of 1.52 nm. The large number of exposed active sites enabled the catalysts to reduce the dosage of Pd while still possessing excellent catalytic performance. And part of Pd was coated on Fe NPs in the Fe5Pd1/Al2O3@PDA-GR catalysts prepared by galvanic replacement, which improved the atom utilization of Pd. And there is an obvious electronic interaction between Fe and Pd. In the dehydrogenation process of 12H-NEC to NEC, The prepared FePd/Al2O3@PDA-GR catalyst exhibited excellent catalytic performance and had a significantly greater dehydrogenation efficiency than found in the literature, 95% for 1 h and 100% for 3 h at 180 °C. The temperature drop to 160 °C did not affect the dehydrogenation efficiency, which remained at 98.1% for 3 h. The prepared catalyst had good stability, and the dehydrogenation efficiency was 93.1% after five successive cycles.

Improving patient-centred counselling skills among lay healthcare workers in South Africa using the Thusa-Thuso motivational interviewing training and support program.

We developed a motivational interviewing (MI) counselling training and support program for lay counsellors in South Africa-branded "Thusa-Thuso-helping you help", commonly referred to as Thusa-Thuso. We present the results of a pilot study to determine the program's impact on MI technical skills and qualitatively assess the feasibility of a training-of-trainers (TOT) scale-up strategy among counselling staff of non-governmental (NGO) support partners of the human immunodeficiency virus (HIV) treatment program in South Africa. We enrolled adult (≥ 18 years) lay counsellors from ten primary healthcare clinics in Johannesburg (South Africa) selected to participate in the Thusa-Thuso training and support program. Counsellors attended the ten-day baseline and quarterly refresher training over 12 months (October 2018-October 2019). Each counsellor submitted two audio recordings of mock counselling sessions held during the ten-day baseline training and two additional recordings of sessions with consenting patients after each quarterly contact session. We reviewed the recordings using the MI treatment integrity (MITI) coding system to determine MI technical (cultivating change talk and softening sustain talk) and relational (empathy and partnership) competency scores before and after training. After 12 months of support with pilot site counsellors, we were asked to scale up the training to NGO partner team trainers in a once-off five-day Training of trainers (TOT) format (n = 127 trainees from November 2020 to January 2021). We report TOT training experiences from focus group discussions (n = 42) conducted six months after the TOT sessions. Of the 25 enrolled lay counsellors from participating facilities, 10 completed the 12-month Thusa-Thuso program. Attrition over the 12 months was caused by death (n = 3), site exclusion/resignations (n = 10), and absence (n = 2). MI competencies improved as follows: the technical skills score increased from a mean of 2.5 (standard deviation (SD): 0.8) to 3.1 (SD: 0.5), with a mean difference of 0.6 (95% confidence interval (CI): 0.04, 0.9). The MI relational skills score improved from a mean of 3.20 (SD: 0.7) to 3.5 (SD: 0.6), with a mean difference of 0.3 (95% CI: -0.3, 8.5). End-point qualitative data from the counsellors highlighted the value of identifying and addressing specific skill deficiencies and the importance of counsellors being able to self-monitor skill development using the MITI review process. Participants appreciated the ongoing support to clarify practical MI applications. The TOT program tools were valuable for ongoing on-the-job development and monitoring of quality counselling skills. However, the MITI review process was perceived to be too involved for large-scale application and was adapted into a scoring form to document sit-in mentoring sessions. The Thusa-Thuso MI intervention can improve counsellor motivation and skills over time. In addition, the program can be scaled up using an adapted TOT process supplemented with fidelity assessment tools, which are valuable for skills development and ongoing maintenance. However, further studies are needed to determine the effect of the Thusa-Thuso program on patient ART adherence and retention in care. Trial registration: Pan African Clinical Trials Registry No: PACTR202212796722256 (12 December 2022).

Suppressed Electrolyte Decomposition Behavior to Improve Cycling Performance of LiCoO2 under 4.6V through the Regulation of Interfacial Adsorption Forces.

Alleviating the decomposition of the electrolyte is of great significance to improving the cycle stability of cathodes, especially for LiCoO2 (LCO), its volumetric energy density can be effectively promoted by increasing the charge cutoff voltage to 4.6V, thereby supporting the large-scale application of clean energy. However, the rapid decomposition of the electrolyte under 4.6V conditions not only loses the transport carrier for lithium ion, but also produces HF and insulators that destroy the interface of LCO and increase impedance. In this work, the decomposition of electrolyte is effectively suppressed by changing the adsorption force between LCO interface and EC. Density functional theory illustrates the LCO coated with lower electronegativity elements has a weaker adsorption force with the electrolyte, the adsorption energy between LCO@Mg and EC (0.49eV) is weaker than that of LCO@Ti (0.73eV). Meanwhile, based on the results of time of flight secondary ion mass spectrometry, conductivity-atomic force microscopy, in situ differential electrochemical mass spectrometry, soft X-ray absorption spectroscopy, and nuclear magnetic resonance, as the adsorption force increases, the electrolyte decomposes more seriously. This work provides a new perspective on the interaction between electrolyte and the interface of cathode and further improves the understanding of electrolyte decomposition.

A parallel framework on hybrid architectures for raster-based geospatial cellular automata models

Geospatial cellular automata (Geo-CA) models have encountered challenges in computing efficiency and scalability when conducting large-scale land use change simulation applications. Parallel computing has proven to be effective to address these challenges. However, parallelization strategies for existing parallel Geo-CA models are always optimized for specific models and lack applicability to others. Besides, most parallel Geo-CA models focus on parallelizing land use change simulations, ignoring land use transition rule mining. Moreover, there is a lack of effective parallel strategies for demand-constrained land use change simulation on distributed heterogeneous architectures. This study proposes a parallel framework on hybrid parallel computing architectures applicable for raster-based Geo-CA models to enhance their computing efficiency and scalability while maintaining simulation accuracy. The framework provides parallelization strategies for both the land use transition rule mining for multiple land use types and the demand-constrained land use change simulation on distributed heterogeneous architectures. The framework was employed to parallelize two contemporary Geo-CA models, i.e., PLUS and MCCA. Experiments showed that the parallelized models achieved significant improvements in computing efficiency and scalability, confirming the effectiveness of the proposed framework for large-scale land use change simulation studies.

Large-Scale Integration of the Ion-Reinforced Phytic Acid Layer Stabilizing Magnesium Metal Anode.

Rechargeable magnesium batteries (RMBs) have garnered significant attention for their potential in large-scale energy storage applications. However, the commercial development of RMBs has been severely hampered by the rapid failure of large-sized Mg metal anodes, especially under fast and deep cycling conditions. Herein, a concept proof involving a large-scale ion-reinforced phytic acid (PA) layer (100 cm × 7.5 cm) with an excellent water-oxygen tolerance, high Mg2+ conductivity, and favorable electrochemical stability is proposed to enable rapid and uniform plating/stripping of Mg metal anode. Guided by even distributions of Mg2+ flux and electric field, the as-prepared large-sized PA-Al@Mg electrode (5.8 cm × 4.5 cm) exhibits no perforation and uniform Mg plating/stripping after cycling. Consequently, an ultralong lifespan (2400 h at 3 mA cm-2 with 1 mAh cm-2) and high current tolerance (300 h at 9 mA cm-2 with 1 mAh cm-2) of the symmetric cell using the PA-Al@Mg anode could be achieved. Notably, the PA-Al@Mg//Mo6S8 full cell demonstrates exceptional stability, operating for 8000 cycles at 5 C with a capacity retention of 99.8%, surpassing that of bare Mg (3000 cycles, 74.7%). Moreover, a large-sized PA-Al@Mg anode successfully contributes to the stable pouch cell (200 and 750 cycles at 0.1 and 1 C), further confirming its significant potential for practical utilization. This work provides valuable theoretical insights and technological support for the practical implementation of RMBs.

Nitrogen-Doped Graphene-Supported Nickel Nanoparticles Reveal Low Dehydrogenation Temperature and Long Cyclic Life of Magnesium Hydrides.

Magnesium hydride (MgH2) is a promising hydrogen storage candidate due to its large capacity; however, high dehydrogenation temperature and slow kinetic rates are the main bottlenecks. Herein, we proposed a strategy for designing nitrogen-doped graphene-supported Ni nanoparticles (NPs) (Ni@NC) to tackle these problems. The results showed that the MgH2 + 15 wt % Ni@NC nanocomposite reduced the on-set dehydrogenation temperature to 195 °C, which was 175 °C lower than pristine MgH2. In addition, MgH2 + 15 wt % Ni@NC achieved 1.7 and 6.5 wt % desorption capacities at 225 and 300 °C, respectively, while absorbing 5.5 wt % hydrogen at 100 °C. The MgH2 + 15 wt % Ni@NC nanocomposite showed high cyclic stability, achieving 98.0% capacity retention after 100 cycles at 270 °C with negligible loss in capacity. This remarkable hydrogen storage performance can be attributed to the homogeneous distribution of Ni NPs on N-doped graphene layers, in situ formed Mg2NiH2 NPs, and multiphasic regions, promoting the nucleation and growth process during hydrogenation/dehydrogenation, which stabilized and improved the cyclic stability. This strategy paves the way to developing high-performance MgH2 for large-scale applications.

Self-Supported WO3@RuO2 Nanowires for Electrocatalytic Acidic Water Oxidation.

Developing catalysts with high catalytic activity and stability in acidic media is crucial for advancing hydrogen production in proton exchange membrane water electrolyzers (PEMWEs). To this end, a self-supported WO3@RuO2 nanowire structure was grown in situ on a titanium mesh using hydrothermal and ion-exchange methods. Despite a Ru loading of only 0.098 wt %, it achieves an overpotential of 246 mV for the oxygen evolution reaction (OER) at a current density of 10 mA·cm-2 in acidic 0.5 M H2SO4 while maintaining excellent stability over 50 h, much better than that of the commercial RuO2. After the establishment of the WO3@RuO2 heterostructure, a reduced overpotential of the rate-determining step from M-O* to M-OOH* is confirmed by the DFT calculation. Meanwhile, its enhanced OER kinetics are also greatly improved by this self-supported system in the absence of the organic binder, leading to a reduced interface resistance between active sites and electrolytes. This work presents a promising approach to minimize the use of noble metals for large-scale PEMWE applications.

Solar driven integrated CO2 capture and CH4 dry reforming via FexMny/Ni/CaAl multi-function materials

Integrated CO2 capture and dry reforming of CH4 (ICCU-DRM) holds great promise in mitigating greenhouse gas emissions and producing value-added syngas simultaneously. However, the in-situ conversion is a highly endothermic process, which requires a large amount of energy to drive, making it very difficult for large-scale applications. The combination of solar energy in ICCU-DRM provide a potential solution to tackle the problem, but it needs to construct and evaluate multi-function materials (MFMs) with good features of CO2 adsorption, catalytic conversion and light absorption. Herein, we report a synthesis approach to prepare Fe5Mn5/Ni/CaAl for use in the solar driven ICCU-DRM, which directly utilize the solar energy for syngas production with excellent comprehensive performance. The material prepared demonstrates an average spectral absorbance of 85.81 %, and a CO2 capacity of 8.46 mmol·g−1 with up to 89 % conversion to syngas. We expect the synthesis strategy has good implications on the development of innovative materials for carbon reduction and energy storage applications.

Use of omic heating technology in the process of processing fruits and vegetables. Overview of the subject field

The modern consumer prefers natural products with minimal processing, which allows maximum preservation of the nutritional value of the product and fresh taste and aroma. The purpose of this article is to review the results of studies concerning the effect of ohmic heating on the product in comparison with heat treatment and considering the combined use of this method with non-thermal technologies in the production of canned fruit and vegetables. The material for this study was 105 scientific publications. A search for scientific literature in English and Russian on the use of the ohmic heating technology in the process of processing fruits and vegetables was carried out in the bibliographic databases Scopus, Web of Science, as well as in other sources. The period 2010–2023 was adopted as the time frame for the review of scientific publications. To review the subject field of the study, an algorithm was used in accordance with the PRISMA protocol. A scientific search and review of scientific publications on the research topic showed a limited number of studies assessing the ohmic heating (OH) technology in the processing of fruits and vegetables. In the process of using this technology, electric current is applied, ensuring uniform and rapid release of heat inside the food matrix. OH has a shorter processing time, which helps preserve the organoleptic quality of the product and its nutritional value. Compared to heat treatment, the OH technology not only inactivates microorganisms and food enzymes, but also prevents overheating, which reduces the negative impact of temperature on the chemical composition of the product. Evaporation/concentration, dehydration/drying of fruit juices or purees using OH resulted in higher energy efficiency and reduced processing time compared to traditional processing methods. Despite many advantages, there are limitations to large-scale industrial application of the OH method, including corrosion of the electrodes, which can have a negative impact on the product, as well as uneven heating of some types of fruit and vegetable raw materials during continuous processing. The results of this review can be used in the process of conducting further scientific research, which is advisable to continue in order to determine specific processing parameters and eliminate uneven heating of food raw materials.

Design and Application of a Credit Bank Based on Blockchain Technology

Credit banks are an important way to build a lifelong learning system and a learning society. At present, various types of credit banks in China generally have limitations such as low efficiency in learning achievement certification and conversion, difficulty in ensuring the quality of learning achievement certification, and vague identification of credit banks. Blockchain technology has the characteristics of openness, consensus, transparent transactions, anonymity, tamper resistance, and traceability, which can effectively solve the centralized governance problems faced by the current construction of credit banks. This article elaborates on the current development status and characteristics of credit banks at home and abroad, analyzes the feasibility of combining credit banks with blockchain, and designs a blockchain based credit bank system architecture and processing flow to address the challenges of inconsistent credit conversion standards, low conversion efficiency, and data security risks in traditional credit banks. It proposes using block structure design to achieve secure and tamper proof credit data, proposes a smart contract based credit recognition and conversion method to achieve decentralized governance of credit banks, and establishes a blockchain based credit bank certification, conversion, and other application design models, which can provide technical support for the large-scale application of credit banks in the future.

Recycling Waste Agricultural Nets as Cement Composites.

The advancement of agricultural mesh technology has contributed to its improved properties. As a result, agricultural nets are widely adopted in large-scale farming applications, for example, in cereal crop farming. However, a consequence of this increased use of agricultural nets is the accumulation of large amounts of waste. The current paper focuses on the recycling of agricultural nets used in wrapping straw bales to develop additives and fillers in cement composites. The research details an analysis of the use of waste agricultural meshes as an ingredient in cement composites. Six test series of different mixtures were conducted. In the first four series, agricultural waste was utilised as an additive in a composite comprising aggregate and cement slurry (the amounts of wasted nets were 20, 40, 60, and 80 kg/m3). In the last test series, the recyclate utilised comprised a mixture of cement slurry and waste only. The composites were subjected to standard tests and thermal resistance tests. The results showcased that that the addition of a net worsened the workability of the concrete mixture, and with increasing amounts of addition, the consistency of the mixture could change from liquid to dense plastic. The flexural strength of the composite decreased with increasing amounts of recyclate. In subsequent test series, the flexural strength value was lower than that of the control (3.93 MPa), from 7.38% (3.64 MPa) for the composite with 20 kg/m3 of recyclate to 37.66% (2.45 MPa) for the composite with of 80 kg/m3 recyclate. The flexural strength value of the net-filled composite without aggregate was very high (10.44 MPa), where the value obtained for the control composite was 62.36% lower. The results of the compressive strength test showed a decrease in this parameter with increasing amounts of additive. The value assessed for the control composite was 27.99 MPa. As expected, the composite that had no aggregate and consisted of only recycled filler had the lowest compressive strength. The value of this parameter was 13.07 MPa, and it was 53.31% lower than that of the control composite. The results of the tests of resistance to temperatures were similar to those recorded for the composites with polypropylene fibres. All composites demonstrated a significant decrease in their compressive and flexural strength after annealing. SEM imaging showed that the net fibres were closely bonded to the cement stone. Finally, it was concluded that recyclates performed best as fillers in lightweight composites with a low density, low absorption, high flexural strength, and satisfactory compressive strength.

Scalable multiscale-spectral GFEM with an application to composite aero-structures

In this paper, the first large-scale application of multiscale-spectral generalized finite element methods (MS-GFEM) to composite aero-structures is presented. The crucial novelty lies in the introduction of A-harmonicity in the local approximation spaces, which in contrast to Babuška and Lipton (2011) [30] is enforced more efficiently via a constraint in the local eigenproblems. This significant modification leads to excellent approximation properties, which turn out to be essential to capture accurately material strains and stresses with a low dimensional approximation space, hence maximizing model order reduction. The implementation of the framework in the Distributed and Unified Numerics Environment (DUNE) software package, as well as a detailed description of all components of the method are presented and exemplified on a composite laminated beam under compressive loading. The excellent parallel scalability of the method, as well as its superior performance compared to the related, previously introduced GenEO method are demonstrated on two realistic application cases, including a C-shaped wing spar with complex geometry. Further, by allowing low-cost approximate solves for closely related models or geometries this efficient, novel technology provides the basis for future applications in optimization or uncertainty quantification on challenging problems in composite aero-structures.

Optimization of culture medium to improve bio-cementation effect based on response surface method

The main challenge in the large-scale application of MICP lies in its low efficiency and promoting biofilm growth can effectively address this problem. In the present study, a prediction model was proposed using the response surface method. With the prediction model, optimum concentrations of nutrients in the medium can be obtained. Moreover, the optimized medium was compared with other media via bio-cementation tests. The results show that this prediction model was accurate and effective, and the predicted results were close to the measured results. By using the prediction model, the optimized culture media was determined (20.0 g/l yeast extract, 10.0 g/l polypeptone, 5.0 g/l ammonium sulfate, and 10.0 g/l NaCl). Furthermore, the optimized medium significantly promoted the growth of biofilm compared to other media. In the medium, the effect of polypeptone on biofilm growth was smaller than the effect of yeast extract and increasing the concentration of polypeptone was not beneficial in promoting biofilm growth. In addition, the sand column solidified with the optimized medium had the highest strength and the largest calcium carbonate contents. The prediction model represents a platform technology that leverages culture medium to impart novel sensing, adjustive, and responsive multifunctionality to structural materials in the civil engineering and material engineering fields.