Scopus scientific mapping production in industry 4.0 (2011–2018): a bibliometric analysis

Research in industry 4.0 is growing, driven by the innovations in production systems on a continuous basis. In this study, we identified the evolution of themes inherent in the industry 4.0 using a bibliometric software, namely SciMAT (Science Mapping Analysis Software Tool). The analyses included 1882 documents, 4231 keywords, and the relevant information was extracted based on frequency of co-occurrence of keywords. The clusters were plotted in two-dimensional strategic diagrams and analysed using the bibliometric indicators such as the number of publications, number of associated documents, and h-index. The results revealed that 2017 had the largest number of publications. Expert authors in the field and the periodicals that published the most were identified. The science mapping presented 31 clusters in which the most representative motor themes were CPS (Cyber-Physical System), IoT (Internet of Things), and Big Data. In addition, it was possible to identify fields with high investment of efforts by the scientific community such as the union between lean production and industry 4.0, production-centered CPS (CPPS), IoT (Industrial Internet of Things - IIoT), among others. The overlapping map showed an increase in the number of keywords from 338 to 1231 over the period of data. The map of scientific developments supported by an exhaustive research, it was possible to show the state of the art, the main challenges and perspectives for future research in the field of industry 4.0 such as Technology, Collaboration/Integration, Management and Implementation.     

Nanoencapsulation mechanism of fragrant oil: effect of formaldehyde − melamine molar ratio

Encapsulation of essential oils by in situ polymerization is commonly used to contain the oil and thus ensure its controlled release. Melamine resin formaldehyde is one of the most widely used shell materials due to its thermal and chemical stability. One of the factors that influences the properties of the capsules is the molar relationship between monomers. The effect of formaldehyde ? melamine (F/M) molar ratios 3, 4 and 6 on the nanoencapsulation, morphology and properties of nanocapsules was investigated. The morphology and particle size were investigated by the scanning electron microscopy and atomic force microscopy techniques. The composition of the formaldehyde ? melamine resins was determined by Fourier transform infrared spectroscopy, and the thermal stability of the nanocapsules was analysed by differential scanning calorimetry and thermogravimetric analysis. Increasing the formaldehyde content reduced the nanocapsules' chemical stability. The capsule sizes obtained were nanometric at all melamine ? formaldehyde ratios studied, with a non‐significant variation in particle size and shape. © 2017 Society of Chemical Industry     

On the Use of Ruthenium Dioxide in 1-n-Butyl-3-Methylimidazolium Ionic Liquids as Catalyst Precursor for Hydrogenation Reactions

The H₂ reduction of RuO₂ hydrate “dissolved” in 1-n-butyl-3-methylimidazolium ionic liquids with different counterions, hexafluorophosphate (BMI ? PF₆), tetrafluoroborate (BMI ? BF₄) and trifluoromethane sulfonate (BMI ? SO₃CF₃), is a simple and reproducible method for the preparation of ruthenium nanoparticles of 2.0–2.5?nm diameter size and with a narrow size distribution. The Ru nanoparticles were characterized by TEM and XRD. The isolated Ru nanoparticles are reoxidized in air, whereas they are less prone to oxidation when imbibed in the ionic liquids. These nanoparticles are active catalysts for the solventless or liquid–liquid biphasic hydrogenation of olefins under mild reaction conditions (4 atm, 75°C). The catalytic system composed of nanoparticles dispersed in BMI ? PF₆ ionic liquid is very stable and can be reused several times without any significant loss in the catalytic activity. Total turnover numbers greater than 110 000 (based on total Ru) or 320 000 (corrected for exposed Ru atoms) were attained within 80?h for the hydrogenation of 1-hexene.     

Facile recycling approach for waste minimization of silica-coated magnetite nanoparticles synthesis

The negative environmental impacts of industrial activity have been felt day-to-day, encouraging global actions to reduce the waste generation of harmful and persistent pollutants. Microemulsion synthesis of silica-coated iron oxide magnetic nanoparticles offers a high potential for several applications; however the process generates hazardous wastes that are difficult to treat and dispose of. In this study, cyclohexane and methanol were separated using phase decantation, distillation, and temperature reduction. The recovered solvents were reused in the same synthesis more than 20 times and the recovered surfactant IGEPAL® CO-520 was reused twice, suggesting the method applied has potential for continuous recycling.     

The kinetics and mechanisms of amorphous calcium carbonate (ACC) crystallization to calcite, via vaterite

The kinetics and mechanisms of nanoparticulate amorphous calcium carbonate (ACC) crystallization to calcite, via vaterite, were studied at a range of environmentally relevant temperatures (7.5-25 °C) using synchrotron-based in situ time-resolved Energy Dispersive X-ray Diffraction (ED-XRD) in conjunction with high-resolution electron microscopy, ex situ X-ray diffraction and infrared spectroscopy. The crystallization process occurs in two stages; firstly, the particles of ACC rapidly dehydrate and crystallize to form individual particles of vaterite; secondly, the vaterite transforms to calcite via a dissolution and reprecipitation mechanism with the reaction rate controlled by the surface area of calcite. The second stage of the reaction is approximately 10 times slower than the first. Activation energies of calcite nucleation and crystallization are 73±10 and 66±2 kJ mol(-1), respectively. A model to calculate the degree of calcite crystallization from ACC at environmentally relevant temperatures (7.5-40 °C) is also presented.     

Characterization of electron beam irradiated polypropylene: Influence of irradiation temperature on molecular and rheological properties

The aim of the investigations was to analyze the influence of the temperature during the irradiation process of polypropylene on the molar mass, the formation of long chain branching and the final branching topology. A linear isotactic polypropylene homopolymer was modified by electron beam irradiation at different temperatures, with two irradiation doses to insert long chain branching. The samples were analyzed by size exclusion chromatography coupled with a multiangle laser light scattering detector, by differential scanning calorimetry, and by shear and elongational rheology. The shear and elongational flow behavior is discussed in terms of the influence of molecular parameters and used to analyze the topology of the irradiated samples. With increasing temperature, a slight reduction of the molar mass, an increase of long chain branching and an increase of crystallization temperature were found. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2770–2780, 2006     

“那么，为什么是多西？”

正黄鸟在自己的树上歌唱,使我的心喜舞。我们两人住在一个村子里,这是我们的一份快乐。她心爱的一对小羊,到我园树的荫下吃草。它们若走进我的麦地,我就把它们抱在臂里。我们的村子名叫康遮那,人们管我们的小河叫安遮那。我的名字村人都知道,她的名字是软遮那。罗宾德拉纳特·泰戈尔,《园丁集》,1913年——冰心译     

Elucidating Mechanisms of Diffusion‐Based Calcium Carbonate Synthesis Leads to Controlled Mesocrystal Formation

Aggregation‐based crystal growth often gives rise to crystals with complex morphologies which cannot be generated via classical growth processes. Despite this, understanding of the mechanism is rather poor, particularly when organic additives or amorphous precursor phases are present. In this work, advantage is taken of the observation that aggregation‐based growth of calcium carbonate, and indeed many other minerals, is most often observed using diffusion‐based synthetic methods. By fully characterizing the widely used ammonia diffusion method (ADM)–which is currently used as a “black box”–the solution and supersaturation conditions which accompany CaCO₃ precipitation using this method are identified and insight is gained into the nucleation and growth processes which generate calcite mesocrystals. This reveals that the distinguishing feature of the ADM is that the initial nucleation burst consumes only a small quantity of the available ions, and the supersaturation then remains relatively constant, and well above the solubility of amorphous calcium carbonate (ACC), until the reaction is almost complete. New material is thus generated over the entire course of the precipitation, a feature which appears to be fundamental to the formation of complex, aggregation‐based morphologies. Finally, the importance of this understanding is demonstrated using the identified carbonate and supersaturation profiles to perfectly replicate CaCO₃ mesocrystals through slow addition of reagents to a bulk solution. This approach overcomes many of the inherent problems of the ADM by offering excellent reproducibility, enabling the synthesis of such CaCO₃ structures in large‐scale and continuous‐flow systems, and ultimately facilitating in situ studies of assembly‐based crystallization mechanisms.