Hard nanodiamonds in soft rubbers: Past,present and future – A review

Conventional fillers used in rubber matrices include carbon black (CB), silica, and clay. However, the new demands on reinforced rubbers, especially the need to significantly enhance the overall performance while reducing the amount of filler, is currently expected to be met only through intelligent use of nano-sized fillers. Among carbon-based nanomaterials, such as fullerenes, carbon nanotubes (CNTs), graphene and nanodiamonds (NDs), nanodiamonds are a good candidate due to their nano-scale size, stable diamond core, highly reactive outer shell, biocompatibility, and potential for chemical functionalization. Here we review the state of the art and current research on nanodiamonds produced by laser ablation and detonation techniques with a special focus on their application in elastomers. The current understanding about structure and synthesis of nanodiamonds indicates some possible methods for their functionalization and dispersion in soft rubber matrix. We also discuss the effect of nanodiamonds on the various properties of elastomeric materials.     

A fuzzy AHP evaluation model for buyer–supplier relationships with the consideration of benefits,opportunities, costs and risks

With increasingly fierce global competition, firms in various industries need to build a cooperative buyer–supplier relationship to survive and to acquire reasonable profit. Even though the literature on various types of collaboration between firms is abundant and the works on supplier selection models are numerous, the research that provides a mathematical model for the selection of the most appropriate form of buyer–supplier relationship is very limited. Existing buyer–supplier evaluation models usually only consider the benefits from the relationship, but not the opportunities, costs and risks that may need to be confronted. The main objective of this study is to propose an analytical approach to evaluate the forms of buyer–supplier relationship between a manufacturer and its supplier. A fuzzy analytic hierarchy process (AHP) model, which applies fuzzy set theory and the benefits, opportunities, costs and risks (BOCR) concept, is constructed to deal with uncertainty and to consider various aspects of alternatives. Multiple factors that affect the success of the relationship are analysed by incorporating experts’ opinions on their priority of importance, and a performance ranking of the buyer–supplier forms is obtained. A case study of selecting the most appropriate buyer–supplier form between a TFT-LCD manufacturer and its colour filter supplier is presented, and the proposed model is applied to facilitate the decision process. The proposed model is a general form that can be tailored and applied by firms that are making decisions on buyer–supplier relationship.     

A framework for defining both qualitative and quantitative supplier selection criteria considering the buyer–supplier integration strategies

Previous research has reported that the decision criteria used to evaluate suppliers differ by product category. This paper presents a framework for defining the supplier selection criteria by investigating possible quantitative and qualitative criteria reported by earlier studies according to the levels of buyer–supplier relationship, the company's competitive situation and its corporate strategies, rather than investigating these criteria in respect of product category. The solution proposed in this study not only assists decision makers to define selection criteria, but also supports determining the buyer–supplier integration level. An actual case in Audio Electronics, a Turkish electronics business, demonstrates the feasibility of applying the proposed framework in practice.     

Sustainable supplier management – a review of models supporting sustainable supplier selection,monitoring and development

In the last two decades, pressure from various stakeholders has forced many companies to establish environmental and social improvements both in their company and their supply chains. The growing number of journal publications and conference proceedings confirms this change also in academia. The aim of this paper is to analyse and review scientific literature on sustainable supplier management (SSM) with a focus on formal models supporting decision-making in sustainable supplier selection, monitoring and development. For this purpose, a framework on SSM is proposed and a comprehensive content analysis including a criteria analysis is carried out. Beyond this, in total 143 peer-reviewed publications between 1997 and 2014 have been analysed to identify both established and overlooked research fields. Major findings are the rapidly growing interest of this topic in academia in recent years, the predominance of Analytic Hierarchy Process, Analytic Network Process and fuzzy-based approaches, the focus on the final evaluation and selection process step and the rare investigation of social and quantitative metrics. This review may be useful for practitioners and scientists as it outlines major characteristics in this field, which can serve as a basis for further research.     

Developing environmental and social performance: the role of suppliers’ sustainability and buyer–supplier trust

We explore how environmental and social performance of manufacturing firms can be improved as sustainable supply chain management (SSCM) develops and evolves within a firm from internal to external practices. Importantly, this study considers how key suppliers’ sustainability performance and buyer–supplier trust mediate and moderate such a development. A conceptual framework is developed which relies on resource-based theories and emerging empirical evidence. Then, partial least square methodology is applied on survey data from a sample of Italian manufacturing firms. Results show that manufacturing firms’ sustainability performance improves as SSCM develops; however, while internal practices have a direct impact on performance, the effect of external practices on a manufacturing firm’s sustainability performance is fully mediated by key suppliers’ sustainability performance. Yet, buyer–supplier trust significantly influences the scope of such gains. Since evidence suggests that manufacturing firms are still struggling with how to leverage supply chain innovation potential for sustainable development, this study provides a timely and valuable contribution.     

Human factors and ergonomics in manufacturing in the industry 4.0 context – A scoping review

Industry 4.0 revolution has brought rapid technological growth and development in manufacturing industries. Technological development enables efficient manufacturing processes and brings changes in human work, which may cause new threats to employee well-being and challenge their existing skills and knowledge. Human factors and ergonomics (HF/E) is a scientific discipline to optimize simultaneously overall system performance and human well-being in different work contexts. The aim of this scoping review is to describe the state-of-the-art of the HF/E research related to the industry 4.0 context in manufacturing. A systematic search found 336 research articles, of which 37 were analysed utilizing a human-centric work system framework presented in the HF/E literature. Challenges related to technological development were analysed in micro- and macroergonomics work system frameworks. Based on the review we frame characteristics of an organisation level maturity model to optimize overall sociotechnical work system performance in the context of rapid technological development in manufacturing industries.     

A review on the temporal pattern of deer–vehicle accidents: Impact of seasonal,diurnal and lunar effects in cervids

The increasing number of deer–vehicle-accidents (DVAs) and the resulting economic costs have promoted numerous studies on behavioural and environmental factors which may contribute to the quantity, spatiotemporal distribution and characteristics of DVAs. Contrary to the spatial pattern of DVAs, data of their temporal pattern is scarce and difficult to obtain because of insufficient accuracy in available datasets, missing standardization in data aquisition, legal terms and low reporting rates to authorities. Literature of deer–traffic collisions on roads and railways is reviewed to examine current understanding of DVA temporal trends. Seasonal, diurnal and lunar peak accident periods are identified for deer, although seasonal pattern are not consistent among and within species or regions and data on effects of lunar cycles on DVAs is almost non-existent. Cluster analysis of seasonal DVA data shows nine distinct clusters of different seasonal DVA pattern for cervid species within the reviewed literature. Studies analyzing the relationship between time-related traffic predictors and DVAs yield mixed results. Despite the seasonal dissimilarity, diurnal DVA pattern are comparatively constant in deer, resulting in pronounced DVA peaks during the hours of dusk and dawn frequently described as bimodal crepuscular pattern. Behavioural aspects in activity seem to have the highest impact in DVAs temporal trends. Differences and variations are related to habitat-, climatic- and traffic characteristics as well as effects of predation, hunting and disturbance. Knowledge of detailed temporal DVA pattern is essential for prevention management as well as for the application and evaluation of mitigation measures.     

Horizontal cooperation and information sharing between suppliers in the manufacturer–supplier triad

In this paper, we analyse a collusion and information-sharing problem between two suppliers in a manufacturer–supplier triad. The manufacturer treats one supplier as a strategic supplier and the other as a backup. While the strategic supplier offers modules of good quality but longer lead times, the backup supplier offers modules with inferior quality but shorter lead times. If there are urgent orders, the manufacturer must turn to the backup supplier. However, it is difficult for the manufacturer to estimate whether the urgent supplier has put extra effort into their production. We formulate this problem by assuming that the urgent supplier has either low or high production costs. To take advantage of the competition between two suppliers, the manufacturer can design a contract menu that defines total payment and lead times, under which both suppliers may be worse off. Meanwhile, it is possible for the suppliers to tacitly form a coalition, and to even share the private cost information. We study this problem by formulating it as a three-stage game. Furthermore, we investigate the variation of profits for each part of the supply chain. We find that the manufacturer is worse off when suppliers cooperate or share private information. Both suppliers, however, can benefit from cooperation and information sharing.     

A review on the interfacial intermetallic compounds between Sn–Ag–Cu based solders and substrates

The objective of this review is to study the interfacial intermatallic compounds (IMCs) between Sn–Ag–Cu based solders and common substrates, which play a crucial role in solder joints typically present in Pb-free electronics manufacturing. The microstructural evolution of IMCs at the solder/substrate interfaces is analyzed, while the models and theories describing the formation/growth mechanism of interfacial IMCs are also introduced. We focus on the influence of a variety of factors that have been reported recently, including substrates, minor alloying, mechanical stress, electromigration and thermomigration etc., as full understanding of the mechanisms that determine the formation and growth of interfacial IMCs is important to reach for developing high reliability solder joints. In the end of this review, the characteristics of the IMCs are compared and illustrated, which have marked effect on the mechanical properties and fracture behavior as well as reliability of solder joints.     

Fe–Al–Mn–C lightweight structural alloys: a review on the microstructures and mechanical properties

Abstract

Adding a large amount of light elements such as aluminum to steels is not a new concept recalling that several Fe–Al–Mn–C alloys were patented in 1950s for replacement of nickel or chromium in corrosion resistance steels. However, the so-called lightweight steels or low-density steels were revisited recently, which is driven by demands from the industry where steel has served as a major structural material. Strengthening without loss of ductility has been a triumph in steel research, but lowering the density of steel by mixing with light elements will be another prospect that may support the competitiveness against emerging alternatives such as magnesium alloys. In this paper, we review recent studies on lightweight steels, emphasizing the concept of alloy design for microstructures and mechanical properties. The influence of alloying elements on the phase constituents, mechanical properties and the change of density is critically reviewed. Deformation mechanisms of various lightweight steels are discussed as well. This paper provides a reason why the success of lightweight steels is strongly dependent on scientific achievements even though alloy development is closely related to industrial applications. Finally, we summarize some of the main directions for future investigations necessary for vitalizing this field of interest.     

Structure and evolution of innovation research in the last 60 years: review and future trends in the field of business through the citations and co-citations analysis

The field of innovation studies has grown considerably in the last four decades, which has led to the emergence of new approaches and theoretical aspects that need to be examined and considered. Therefore, this paper aims to understand what are the main theoretical pillars that support the structure of innovation theories and fields, how it evolved over the years and what are the directions that lead to future trends in innovation research. The procedure consists in a mix-methods using the citation and co-citation analysis associated with bibliometric methods, Social Network Analysis, and a systematic review of the literature. The results were validated by Delphi with academic specialists in innovation. Considering publications between 1956 and 2016 divided into four 15-years timespan, the longitudinal analysis results indicate the evolution of the main streams of thoughts that support the current innovation research fields and depict a research orientation for future works that can be developed to generate relevant contributions for the theoretical development of the area. This paper differentiates itself bringing results based on a large database, by the research methods employed, and by the perspective adopted provides solid contributions to the understanding of the past, present, and future of the scientific research in innovation to business administration field.     

An integrated producer–buyer relationship in the environment of EMQ and JIT production systems

The philosophy of this paper is to build up a strong bond between a producer and a buyer. In this respect, an integrated producer–buyer inventory model with constant demand and small lot size is framed in two different production environments: an EMQ (economic manufacturing quantity)-based production environment and a JIT (just-in-time)-based production environment. Imperfect production with rework is considered for the producer while shortage and backlogging are introduced for the buyer. The joint total cost of the producer and buyer is minimised to determine the optimum rate of production and optimum shortage period for both cases. A comparative study is performed between these two cases using the numerical results in order to make a decision concerning the choice of a more convenient production system for small lot sizes. Sensitivity analyses are carried out together for both cases.     

Re-visiting crash–speed relationships: A new perspective in crash modelling

Although speed is considered to be one of the main crash contributory factors, research findings are inconsistent. Independent of the robustness of their statistical approaches, crash frequency models typically employ crash data that are aggregated using spatial criteria (e.g., crash counts by link termed as a link-based approach). In this approach, the variability in crashes between links is explained by highly aggregated average measures that may be inappropriate, especially for time-varying variables such as speed and volume. This paper re-examines crash–speed relationships by creating a new crash data aggregation approach that enables improved representation of the road conditions just before crash occurrences. Crashes are aggregated according to the similarity of their pre-crash traffic and geometric conditions, forming an alternative crash count dataset termed as a condition-based approach. Crash–speed relationships are separately developed and compared for both approaches by employing the annual crashes that occurred on the Strategic Road Network of England in 2012. The datasets are modelled by injury severity using multivariate Poisson lognormal regression, with multivariate spatial effects for the link-based model, using a full Bayesian inference approach. The results of the condition-based approach show that high speeds trigger crash frequency. The outcome of the link-based model is the opposite; suggesting that the speed–crash relationship is negative regardless of crash severity. The differences between the results imply that data aggregation is a crucial, yet so far overlooked, methodological element of crash data analyses that may have direct impact on the modelling outcomes.     

Entrainment phenomenon in gas–liquid two-phase flow: A review

The gas–liquid separation equipments are aimed to be designed for maximum efficiency of phase separation. In order to maximize their capacity the flow rates are required to be optimized for the capital cost of equipment. This leads to the situation where the gas phase leaves the separation interface with high velocities and carry liquid phase along with it in the form of droplets reducing the equipment efficiency. This is known as entrainment or carryover. Depending on the nature of the separation interface i.e., turbulence intensity, bubble dynamics, the size and velocity distribution of liquid fragments, droplets at the separation interface varies. This is the main source of empiricism involved in the analysis of such equipments. The mechanics of motion of the dispersed liquid phase in bulk of gas is relatively well studied. In the present paper the various experimental, analytical and numerical investigations carried out to address the issues of entrainment/carryover are carefully analyzed. Further, a critical review has been presented for bringing out a coherent theme and a current status of the subject under reference.     

A fuzzy multi-criteria decision-making approach for managing performance and risk in integrated procurement–production planning

Nowadays in Supply Chain (SC) networks, a high level of risk comes from SC partners. An effective risk management process becomes as a consequence mandatory, especially at the tactical planning level. The aim of this article is to present a risk-oriented integrated procurement–production approach for tactical planning in a multi-echelon SC network involving multiple suppliers, multiple parallel manufacturing plants, multiple subcontractors and several customers. An originality of the work is to combine an analytical model allowing to build feasible scenarios and a multi-criteria approach for assessing these scenarios. The literature has mainly addressed the problem through cost or profit-based optimisation and seldom considers more qualitative yet important criteria linked to risk, like trust in the supplier, flexibility or resilience. Unlike the traditional approaches, we present a method evaluating each possible supply scenario through performance-based and risk-based decision criteria, involving both qualitative and quantitative factors, in order to clearly separate the performance of a scenario and the risk taken if it is adopted. Since the decision-maker often cannot provide crisp values for some critical data, fuzzy sets theory is suggested in order to model vague information based on subjective expertise. Fuzzy Technique for Order of Preference by Similarity to Ideal Solution is used to determine both the performance and risk measures correlated to each possible tactical plan. The applicability and tractability of the proposed approach is shown on an illustrative example and a sensitivity analysis is performed to investigate the influence of criteria weights on the selection of the procurement–production plan.     

The effect of high-pressure torsion on the behaviour of intermetallic particles present in Al–1Mg and Al–3Mg

The effect of severe plastic deformation on intermetallic particles was investigated using high-pressure torsion on an Al–1Mg–0.2Si–0.2Fe–0.3Mn alloy and an Al–3Mg–0.2Si–0.2Fe–0.3Mn (wt%) alloy. Extensive optical microscopy and scanning electron microscopy was performed to analyse the intermetallic particles using image analysis software. It was found that all the intermetallic particles decreased in size with increasing strain whilst their spatial distribution was homogenised. A greater decrease in size was found for the intermetallic particles present in Al–1Mg alloy and the possible causes are discussed. Even though the strain near the centre of the sample is close to zero, refinement of intermetallic particles is substantial at this location.