Structural composites for multifunctional applications: Current challenges and future trends

This review paper summarizes the current state-of-art and challenges for the future developments of fiber-reinforced composites for structural applications with multifunctional capabilities. After a brief analysis of the reasons of the successful incorporation of fiber-reinforced composites in many different industrial sectors, the review analyzes three critical factors that will define the future of composites. The first one is the application of novel fiber-deposition and preforming techniques together with innovative liquid moulding strategies. The second is the combination of these techniques by optimization tools based on novel multiscale modeling approaches, so fiber-reinforced composites with optimized properties can be designed and manufactured for each application. In addition, the third is the enhancement of composite applications by the incorporation of multifunctional capabilities. Among them, electrical conductivity, energy storage (structural supercapacitors and batteries) and energy harvesting (piezoelectric and solar energy) seem to be the most promising ones.     

Decision-making processes evaluation using two methodologies: field and simulation techniques

The study of information processing and human actions in complex environments requires the use of methodological tools that enable one to comprehend the complexity of context without sacrificing methodological accuracy, control of variables or results generalization. Research methods that allow the study of strategies that people use when they make decisions are, among others, field studies and simulated micro-worlds. The aim of this paper is to present the main theoretical and methodological conclusions obtained in two studies centred on decision-making processes. The authors were interested in evaluating the results obtained both in a previous field study developed with experts in process control tasks and in a simulated study with inexperienced people. In the field study, a verbal protocol technique was used, while in the simulated study a simulated dynamic task was developed which contained the main features of control process tasks. Among other factors, the authors are interested in exploring the effect of expertise with the task, the learning strategies and the ways of task solving. The results of these two studies indicate some characteristics of a good performance such as the importance of information searches; the taking into account of delays in the effects of the actions; the anticipation of possible system changes.     

Multi-sensors data fusion for monitoring of powdered and granule products: Current status and future perspectives

Process Analytical Technology (PAT) is a systematic approach for monitoring of process parameters and product quality attributes and nowadays is considered for continuous processing of many industrial products. It is a mechanism to design, analyse and control manufacturing processes through on-line, in-line, at-line and off-line configurations for monitoring Critical Quality Attributes (CQAs). PAT systems include a combination of reliable in-line sensors, spectroscopic instruments and Multivariate Statistical Methods (MSMs) to provide informative knowledge for quality assessment of powdered and granule products. Nevertheless, monitoring programs of advanced manufacturing processes based on PAT systems typically provide large sets of data which are complex to interpret. The application of appropriate data-driven modelling techniques could assist in the interpretation of complex data matrices to better control of processes. Data fusion is a data-driven approach that could increase performance and robustness of models used for data interpretation to generate more accurate knowledge about process conditions and performance by merging related outputs collected from several instruments and considering synergies from multiple sources. This paper aims at presenting the current state of the art regarding the application of multi-sensors data fusion for powdered and granule manufacturing processes and making a critical review of recent progress and future possible perspectives in this field.     

聚醚砜-环氧树脂共混体系相分离过程的数值模拟

在热塑性聚醚砜（PES）增韧改性热固性环氧树脂复合材料的制备过程中,通过控制PES-环氧树脂树脂共混体系相分离过程实现共混物相结构的调控,能够明显改善热固性环氧基体树脂的冲击强度。考虑PES-环氧树脂共混体系在相分离过程中PES应力松弛现象以及环氧树脂固化反应现象,采用黏弹性模型描述微观相形态的具体演化路径,揭示了树脂共混体系相分离过程的机制及动力学过程,分析了PES含量、PES分子量大小、PES与环氧树脂的动力学不对称程度以及固化工艺条件等材料及工艺参数对共混体系相结构演变过程以及最终相形态的影响规律及程度,从而为优化PES-环氧树脂树脂共混体系的微观相结构打下基础。     

Supported catalysts for heterogeneous electro-Fenton processes: Recent trends and future directions

Extremely low pH requirement and additional sludge management for the homogeneous electro-Fenton (EF) process necessitated the development of heterogeneous electro-Fenton (HEF) reactions that utilize solid catalysts that can be recovered and reused. In the recent decades, supported catalysts have immensely attracted researchers owing to the outstanding physical, chemical, and electronic properties of the supports that benefit the EF process by enhancing the removal efficiency, reducing reaction time, and extending the operational pH range. This review enlightens the readers about various materials that have been used for supporting the catalysts, their importance, method of impregnation, and optimum conditions required to attain maximum pollutant removal. From the wide array of catalysts reviewed, porous supports with a high surface area such as activated carbon, biochar and fibres adsorbs the pollutants near their surface facilitating enhanced Fenton reactions and degradation of pollutants. Alginate-based catalysts can be prepared by a simple procedure and exhibit good degradation efficiency when used in batch and continuous EF reactors. Zeolite-based catalysts are structurally stable and display promising results for successive cycles. The flexible and conductive nature of fibre-based supports performs the dual role as a catalyst and cathode. The highly stable and conductive properties of graphene and carbon nanotubes promote electron transfer, much required for continuous EF reactions.     

Traffic engineering in ATM networks: Current trends and future issues

In this survey we present an overview of the current state-of-the-art and the future issues to be resolved for the deployment of integrated communications networks based on the Asynchronous Transfer Mode (ATM) Our presentation is from the perspective of traffic and congestion control and management issues which hold the key to the successful achievement of this deployment since it is mainly in these aspects that ATM networks differ from conventional communication networks.     

气体分离膜应用的现状和未来

考虑了气体分离膜应用和气体传递机理的各种技术．现在商业气体分离膜应用的范围包括：富氮、富氧、氢回收、从天然气中除去酸性气体(CO2和H2S)、天然气脱水和有价值的挥发有机物(VOCs)的回收．讨论了每一个应用中可用膜材料的现状和限度，及有潜在力的若干新膜的应用，如乙烯／乙烷分离和燃料电池．     

Current and future trends of additive manufacturing for chemistry applications: a review

Three-dimensional (3-D) printing, also known as additive manufacturing, refers to a method used to generate a physical object by joining materials in a layer-by-layer process from a three-dimensional virtual model. 3-D printing technology has been traditionally employed in rapid prototyping, engineering, and industrial design. More recently, new applications continue to emerge; this is because of its exceptional advantage and flexibility over the traditional manufacturing process. Unlike other conventional manufacturing methods, which are fundamentally subtractive, 3-D printing is additive and, therefore, produces less waste. This review comprehensively summarises the application of additive manufacturing technologies in chemistry, chemical synthesis, and catalysis with particular attention to the production of general laboratory hardware, analytical facilities, reaction devices, and catalytically active substances. It also focuses on new and upcoming applications such as digital chemical synthesis, automation, and robotics in a synthetic environment. While discussing the contribution of this research area in the last decade, the current, future, and economic opportunities of additive manufacturing in chemical research and material development were fully covered.

Graphical abstract

     

Mechanical sub-cooling vapor compression systems: Current status and future directions

Using mechanical sub-cooling systems to increase COP of vapor compression cycles is a known method in literature to save energy and increase efficiency. Recently, much progress has been made with respect to investigation into its different aspects that can help to put it into practice. Numerical and experimental works are considered for the purpose of highlighting this progress. These can be categorized as: a) simulation of performance characteristics resulting from different refrigerant combinations in dedicated mechanical sub-cooling systems, b) variation in performance characteristics for a vapor compression cycle using integrated mechanical sub-cooling because of fouling, c) experimental study about consequences of employing a dedicated mechanical subcooling cycle with a simple vapor compression system, and d) experimental investigation about consequences of employing a subcooler in a two-stage refrigeration cycle. Some important results are discussed. Finally, some suggestions are made to provide direction into future research in this area to help put it into practice.     

Methods for fatigue-life estimation: A review of the current status and future trends

With the development of modern industry and ever more complex structural loads, the possibility of fatigue failure is increasing. Fatigue analysis can be used to evaluate the service life of components and reduce the probability of accidents. Therefore, the development and application of fatigue-analysis technology have important research significance. This paper collects information from a wide field of literature and summarizes the current status of fatigue-analysis research. It covers related...     

Acoustic chemometric prediction of total solids in bioslurry: A full-scale feasibility study for on-line biogas process monitoring

Dry matter is an important process control parameter in the bioconversion application field. Acoustic chemometrics, as a Process Analytical Technology (PAT) modality for quantitative characterisation of dry matter in complex bioslurry systems (biogas fermentation), has not been successful despite several earlier dedicated attempts. A full-scale feasibility study based on standard addition experiments involving natural plant biomass was conducted using multivariate calibration (Partial Least Squares Regression, PLS-R) of acoustic signatures against dry matter content (total solids, TS). Prediction performance of the optimised process implementation was evaluated using independent test set validation, with estimates of accuracy (slope of predicted vs. reference values) and precision (squared correlation coefficient, r²) of 0.94 and 0.97 respectively, with RMSEP of 0.32% w/w (RMSEP_rel = 3.86%) in the range of 5.8-10.8% w/w dry matter. Based on these excellent prediction performance measures, it is concluded that acoustic chemometrics has come of age as a full grown PAT approach for on-line monitoring of dry matter (TS) in complex bioslurry, with a promising application potential in other biomass processing industries as well.     

Existence and construction of translation models for stationary non-Gaussian processes

Translation models are memoryless transformations of Gaussian processes specified by their marginal distribution F and covariance function ξ. Iteration schemes are commonly used to find probability laws of Gaussian images of translation models, although these schemes may not converge since translation models do not exist for arbitrary functions F and ξ. Pairs (F,ξ) for which translation models exist are said to be consistent. Optimization algorithms are developed for constructing translation models that, for consistent pairs (F,ξ), match F and ξ, and, for inconsistent pairs (F,ξ), match F or ξ and approximate ξ or F. The resulting translation models can be used in Monte Carlo simulation studies.     

Addressing the slow corrosion rate of biodegradable Fe-Mn: Current approaches and future trends

The movement towards the commercialization of biodegradable Fe has been hampered by the perceived slow degradation rate of the metal in physiological environments. The introduction of Fe-Mn alloys offers promise due to its significantly improved biocorrosion rates, excellent biocompatibility, and non-magnetic properties. However, the issue of slow corrosion rates persists in this alloy and its future hinges on addressing this issue. This short review report presents the current approaches to address this problem, the challenges concerning Fe-Mn corrosion, and some future techniques that may improve the degradation rate of Fe-Mn alloys.     

Distributed supply chain network modelling and simulation: integration of agent-based distributed simulation and improved SCOR model

Agent-based distributed simulation is an efficient methodology for modelling and analysing such complex adaptive systems as dynamic supply chain networks. However, it lacks an acceptable generic standard. Supply chain operations reference (SCOR) model is a cross-functional framework widely accepted as an industry standard. It provides the standard processes, performance metrics, best practices and associated software functionalities for modelling, evaluating and improving supply chain networks. However, it is a static tool. Integration of agent-based distributed simulation and SCOR model can exploit their advantages to form a generic methodology for modelling and simulation of a wide range of supply chain networks. Therefore, this paper proposes a methodology for distributed supply chain network modelling and simulation by means of integration of agent-based distributed simulation and an improved SCOR model. The methodology contains two components: a hierarchical framework for modelling supply chain network based on the improved SCOR model and agent building blocks integrating the standard processes from the SCOR model. The hierarchical framework provides an approach for structure modelling in any level with different granularities based on the improved SCOR model, and allows rapidly mapping a supply chain network into the structure model of a multi-agent system; while agent building blocks are quite useful and convenient to fill the structure model to fulfil its function modelling. With the approach of structure modelling and function filling, not only can the process of agent-based supply chain network modelling be accelerated, but also the built models can be reused and expanded. Because the hierarchical framework is based on the conceptual framework of SCOR model and agent building blocks integrate the standard processes from SCOR model, the proposed methodology is more generic. In addition, the issues of sub-model synchronisation and data distribution management in the agent-based distributed simulation implementation are taken into consideration and the corresponding solutions for these issues are proposed. Finally, an example of a supply chain network is modelled and implemented to illustrate the proposed methodology and related solutions.     

隐身材料和隐身混凝土的研究现状与趋势

讨论了隐身材料的隐身机理，论述了雷达隐身材料、红外隐身材料、多频谱兼容的多功能隐身材料及隐身混凝土的研究状况，并提出了这几种隐身材料的发展趋势。     

Impact evaluation of supply chain initiatives: a system simulation methodology

To maintain enterprise competitiveness, enterprises require appropriate initiatives to efficiently manage the product, information and cash flows among different supply chain (SC) partners. Co-operation, postponement, vendor managed inventory, transhipment, logistic consolidation etc., are some of the typical initiatives for performance improvement in SC. In an industrial scenario, two or more of these SC initiatives are undertaken simultaneously for superior enterprise performance on multiple performance dimensions. These factors render the analytical SC models inapt and simulation modelling becomes a suitable methodology to study SC performance that can accommodate the complexities present. The impact studies of these initiatives are difficult because these require exploitation of flexible and dynamic modelling elements which are analytically complex and mathematically intractable. We address these issues in the present research by developing a simulation platform to undertake studies with an industrial SC scenario. The challenges to explore SC performance under multiple initiatives are the major motivations for the present research. The novelty of this research lies in the development of a multi-product, multi-echelon SC simulation platform for realistic and industrial SC scenario encompassing the capability to accommodate multiple SC initiatives simultaneously. It is based on the building block approach using Arena®. We undertake SC performance studies under the application of several important SC initiatives. The results are encouraging and they underline interesting research areas to explore further.     

Suitability of European climate for the Asian tiger mosquito Aedes albopictus: recent trends and future scenarios

The Asian tiger mosquito (Aedes albopictus) is an invasive species that has the potential to transmit infectious diseases such as dengue and chikungunya fever. Using high-resolution observations and regional climate model scenarios for the future, we investigated the suitability of Europe for A. albopictus using both recent climate and future climate conditions. The results show that southern France, northern Italy, the northern coast of Spain, the eastern coast of the Adriatic Sea and western Turkey were climatically suitable areas for the establishment of the mosquito during the 1960–1980s. Over the last two decades, climate conditions have become more suitable for the mosquito over central northwestern Europe (Benelux, western Germany) and the Balkans, while they have become less suitable over southern Spain. Similar trends are likely in the future, with an increased risk simulated over northern Europe and slightly decreased risk over southern Europe. These distribution shifts are related to wetter and warmer conditions favouring the overwintering of A. albopictus in the north, and drier and warmer summers that might limit its southward expansion.     

Manufacturing process analysis with support of workflow modelling and simulation

Process analysis is recognized as a major stage in business process reengineering that has developed over the last two decades. Manufacturing process analysis (MPA) is defined as performance analysis of the production process. A manufacturing process analysis framework is outlined with emphasis on linking a company's strategy to operational process. Two issues, namely process modelling and simulation based analysis, are investigated. A compound workflow model (CWM) is proposed to provide graphic presentation of the production process that can be easily understood. Also it can be used directly by simulation to study the impacts of scheduling policy and analyse the process performance. A two-stage simulation analysis method is provided to quantitatively and efficiently define cause-and-effect relations to identify drivers for improvement. The manufacturing environment, PSC (production planning, scheduling and control) factors and the process structure are three main concerns considered in the simulation. An example is discussed in the final part of the paper.     

金属韧性断裂准则的数值模拟和试验研究

对不同外形的45钢试件进行了拉伸、压缩和扭转等材料试验,对工程中常用的5个韧性断裂准则的适用范围进行了对比研究,并采用Gurson-Tvergaard(GT)多孔材料本构模型对试验过程进行了数值模拟.指出目前使用的断裂准则都不可能对材料在多种变形条件下给出一个固定临界值.根据金属成形工艺特点,综合考虑拉伸型和剪切型2种不同韧性断裂机制,提出一个统一的韧性断裂准则形式.试验和数值计算结果证明了该准则的有效性和普适性,进而利用单向拉伸和扭转试验确定的材料常数合理地预测压缩过程中的韧性断裂现象.