bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Phosphorus-Containing Polyanilines by Electrochemical Copolymerization
Authors: Martínez-Sánchez Beatriz , Quintero-Jaime Andrés Felipe , Huerta Francisco , Cazorla-Amorós Diego , Morallón Emilia
Published: May 2020

In this study, the phosphonation of a polyaniline (PANI) backbone was achieved in an acid medium by electrochemical methods using aminophenylphosphonic (APPA) monomers. This was done through the electrochemical copolymerization of aniline with either 2- or 4-aminophenylphosphonic acid. Stable, electroactive polymers were obtained after the oxidation of the monomers up to 1.35 V (reversible hydrogen electrode, RHE). X-ray photoelectron spectroscopy (XPS) results revealed that the position of the phosphonic group in the aromatic ring of the monomer affected the amount of phosphorus incorporated into the copolymer. In addition, the redox transitions of the copolymers were examined by in situ Fourier-transform infrared (FTIR) spectroscopy, and it was concluded that their electroactive structures were analogous to those of PANI. From the APPA monomers it was possible to synthesize, in a controlled manner, polymeric materials with significant amounts of phosphorus in their structure through copolymerization with PANI.
3D Direct Printing of Silicone Meniscus Implant Using a Novel Heat-Cured Extrusion-Based Printer
Authors: Luis Eric , Pan Houwen Matthew , Sing Swee Leong , Bajpai Ram , Song Juha , Yeong Wai Yee
Published: May 2020

The first successful direct 3D printing, or additive manufacturing (AM), of heat-cured silicone meniscal implants, using biocompatible and bio-implantable silicone resins is reported. Silicone implants have conventionally been manufactured by indirect silicone casting and molding methods which are expensive and time-consuming. A novel custom-made heat-curing extrusion-based silicone 3D printer which is capable of directly 3D printing medical silicone implants is introduced. The rheological study of silicone resins and the optimization of critical process parameters are described in detail. The surface and cross-sectional morphologies of the printed silicone meniscus implant were also included. A time-lapsed simulation study of the heated silicone resin within the nozzle using computational fluid dynamics (CFD) was done and the results obtained closely resembled real time 3D printing. Solidworks one-convection model simulation, when compared to the on-off model, more closely correlated with the actual probed temperature. Finally, comparative mechanical study between 3D printed and heat-molded meniscus is conducted. The novel 3D printing process opens up the opportunities for rapid 3D printing of various customizable medical silicone implants and devices for patients and fills the current gap in the additive manufacturing industry.
Large, Rapid Swelling of High-cis Polydicyclopentadiene Aerogels Suitable for Solvent-Responsive Actuators
Authors: Chriti Despoina , Raptopoulos Grigorios , Brandenburg Benjamin , Paraskevopoulou Patrina
Published: May 2020

High-cis polydicyclopentadiene (PDCPD) aerogels were synthesized using ring opening metathesis polymerization (ROMP) of dicyclopentadiene (DCPD) with a relatively air-stable ditungsten catalytic system, Na[W2(μ-Cl)3Cl4(THF)2]·(THF)3 (W2; (W3W)6+, a′2e′4), and norbornadiene (NBD)as a co-initiator. These aerogels are compared in terms of chemical structure and material properties with literature PDCPD aerogels obtained using well-established Ru-based alkylidenes as catalysts. The use of NBD as a co-initiator enhances the degree of crosslinking versus the more frequently used phenylacetylene (PA), yielding materials with a controlled molecular structure that would persist solvent swelling. Indeed, those PDCPD aerogels absorb selected organic solvents (e.g., chloroform, tetrahydrofuran) and swell rapidly, in some cases up to 4 times their original volume within 10 min, thus showing their potential for applications in chemical sensors and solvent-responsive actuators. The advantage of aerogels versus xerogels or dense polymers for these applications is their open porosity, which provides rapid access of the solvent to their interior, thus decreasing the diffusion distance inside the polymer itself, which in turn accelerates the response to the solvents of interest.
Relationship between the Ionization Degree and the Inter-Polymeric Aggregation of the Poly(maleic acid-alt-octadecene) Salts Regarding Time
Authors: Reyes Isabella , Palacio Maria M. , Yarce Cristhian J. , Oñate-Garzón Jose , Salamanca Constain H.
Published: May 2020

Alternating amphiphilic copolymers are macromolecular systems with a polarity duality in their structure, since they are generally formed by alternating segments corresponding to a potential electrolyte group and an alkyl (aliphatic or aromatic) group. These systems, depending on the ionization degree, as well as the time, may form different types of intra and interpolymeric aggregates in aqueous media. Therefore, this study, which in fact is the continuation of a previously reported work, is focused on establishing how the ionization degree of the sodium and potassium salts of the poly(maleic acid-alt-octadecene) affect zeta potential, pH, electrical conductivity, particle size, polydispersity index, and surface tension over time. The results showed that polymeric salts with a high ionization degree in aqueous media formed homogeneous systems with bimodal sizes and high zeta potential values, which tended to quickly become less negative, lowering the pH and slightly increasing the electrical conductivity; while systems with low ionization degree lead to the opposite, forming heterodispersed systems with several populations of particle sizes, high polydispersity, low zeta potential values, neutral and invariable pH values, and high electrical conductivity values. Consequently, these results suggest that the values of particle size, polydispersity index, zeta potential, pH, and electrical conductivity change regarding the polymeric ionization degree, as well as the time. Therefore, such variables should be considered and controlled when working with this kind of polymeric materials.
Fabrication of High-Quality Polymer Composite Frame by a New Method of Fiber Winding Process
Authors: Mlýnek Jaroslav , Petrů Michal , Martinec Tomáš , Rahimian Koloor Seyed Saeid
Published: May 2020

Polymer composite frame has been frequently used in the main structural body of vehicles in aerospace, automotive, etc., applications. Manufacturing of complex curved composite frame suffer from the lack of accurate and optimum method of winding process that lead to preparation of uniform fiber arrangement in critical location of the curved frame. This article deals with the fabrication of high-quality polymer composite frame through an optimal winding of textile fibers onto a non-bearing core frame using a fiber-processing head and an industrial robot. The number of winding layers of fibers and their winding angles are determined based on the operational load on the composite structure. Ensuring the correct winding angles and thus also the homogeneity of fibers in each winding layer can be achieved by using an industrial robot and by definition of its suitable off-line trajectory for the production cycle. Determination of an optimal off-line trajectory of the end-effector of a robot (robot-end-effector (REE)) is important especially in the case of complicated 3D shaped frames. The authors developed their own calculation procedure to determine the optimal REE trajectory in the composite manufacturing process. A mathematical model of the winding process, matrix calculus (particularly matrices of rotations and translations) and an optimization differential evolution algorithm are used during calculation of the optimal REE trajectory. Polymer composites with greater resistance to failure damage (especially against physical destruction) can be produced using the above mentioned procedure. The procedure was successfully tested in an experimental composite laboratory. Two practical examples of optimal trajectory calculation are included in the article. The described optimization algorithm of REE trajectory is completely independent of the industrial robot type and robot software tools used and can also be used in other composite manufacturing technologies.
Deformation Properties of Concentrated Metal-in-Polymer Suspensions under Superimposed Compression and Shear
Authors: Malkin Alexander Ya. , Kulichikhin Valery G. , Mityukov Anton V. , Kotomin Sergey V.
Published: May 2020

Concentrated metal-in-polymer suspensions (55 vol.% and 60 vol.%) of aluminum powder dispersed in low molecular weight polyethylene glycol) demonstrate elastoplastic properties under compression and shear. The rheological behavior of concentrated suspensions was studied in a rotational rheometer with uniaxial compression (squeezing), as well as shearing superimposed on compression. At a high metal concentration, the elasticity of the material strongly increases under strain, compared with the plasticity. The elastic compression modulus increases with the growth of normal stress. Changes in the shear modulus depend on both normal and shear stresses. At a low compression force, the shear modulus is only slightly dependent on the shear stress. However, high compression stress leads to a decrease in the shear modulus by several orders with the growth of the shear stress. The decrease in the modulus seems to be rather unusual for compacted matter. This phenomenon could be explained by the rearrangement of the specific organization of the suspension under compression, leading to the creation of inhomogeneous structures and their displacement at flow, accompanied by wall slip. The obtained set of rheological characteristics of highly loaded metal-in-polymer suspensions is the basis for understanding the behavior of such systems in the powder injection molding process.
Preparation of Nanocomposite Alginate Fibers Modified with Titanium Dioxide and Zinc Oxide
Authors: Borkowski Dominik , Krucińska Izabella , Draczyński Zbigniew
Published: May 2020

Active dressings based on natural polymers are becoming increasingly popular on the market. One of such polymers is alginate, which is characterized by biodegradability, resorbability, has no carcinogenic properties, does not have allergenic or hemostatic properties, and has a confirmed lack of toxicity. However, this polymer does not show biocidal and biostatic properties, therefore the purpose of this research was to select the appropriate conditions for the production of calcium alginate fibers modified with nano titanium dioxide and nano zinc oxide. It was assumed that the presence of nano metal oxide fillers will give antibacterial properties to formed fibers, which were used to form nonwovens. The following article presents a comparative analysis of nonwovens made of alginate fibers, without nano additives, with nonwovens made of alginate fibers containing in their structure 7% titanium dioxide and nonwovens made of alginate fibers containing 2% ZnO. The selection of the nano additive content was determined by the spinning ability of the developed polymer solutions. Based on the results contained in the article, it was found that the introduction of modifiers in the structure of fibers increases the diameter of the fiber pores, which improves the sorption and retention properties of the obtained fibers, and also gives differentiated antibacterial properties to the obtained nonwovens depending on the type of nano additive used. Greater activity against Escherichia coli, Staphylococcus aureus strains and Aspergillus Niger molds was shown in nonwovens made of 2% ZnO modified fibers compared to nonwovens made from TiO2 modified fibers.
Enhancing the Mechanical Performance of Bleached Hemp Fibers Reinforced Polyamide 6 Composites: A Competitive Alternative to Commodity Composites
Authors: Alonso-Montemayor Francisco J. , Tarrés Quim , Oliver-Ortega Helena , Espinach F. Xavier , Narro-Céspedes Rosa Idalia , Castañeda-Facio Adali O. , Delgado-Aguilar Marc
Published: May 2020

Automotive and industrial design companies have profusely used commodity materials like glass fiber-reinforced polypropylene. These materials show advantageous ratios between cost and mechanical properties, but poor environmental yields. Natural fibers have been tested as replacements of glass fibers, obtaining noticeable tensile strengths, but being unable to reach the strength of glass fiber-reinforced composites. In this paper, polyamide 6 is proposed as a matrix for cellulosic fiber-based composites. A variety of fibers were tensile tested, in order to evaluate the creation of a strong interphase. The results show that, with a bleached hardwood fiber-reinforced polyamide 6 composite, it is possible to obtain tensile strengths higher than glass-fiber-reinforced polyolefin. The obtained composites show the existence of a strong interphase, allowing us to take advantage of the strengthening capabilities of such cellulosic reinforcements. These materials show advantageous mechanical properties, while being recyclable and partially renewable.
Polycaprolactone Films Modified by L-Arginine for Mesenchymal Stem Cell Cultivation
Authors: Nashchekina Yuliya , Chabina Alina , Nashchekin Alexey , Mikhailova Natalia
Published: May 2020

This article describes the modification conditions and properties of polymer films obtained using a solution of poly(ε-caprolactone) modified with arginine. We investigated the effects on the surface and biological properties of films created using various arginine concentrations and temperature conditions during the modification process. We found that both increasing the arginine concentration of the treatment solution or the temperature of the treatment reaction increased the arginine content of the film. Following a cellular cultivation period of 3 days, greater levels of cell proliferation were observed on all modified poly(ε-caprolactone) films compared to unmodified polymer films. Experiments using fluorescence microscopy showed that the modification conditions also had a significant effect on cellular spreading and the organization of the actin cytoskeleton following 2 h of cultivation. The degree of spreading and actin cytoskeleton organization observed in cells on these modified polymer films was superior to that of the control films.
Effect of Fabric Architecture on Tensile Behaviour of the High-Molecular-Weight Polyethylene 3-Dimensional Interlock Composite Reinforcements
Authors: Li Mengru , Wang Peng , Boussu François , Soulat Damien
Published: May 2020

As promising fibrous reinforcements in the thick composites manufacturing, 3-dimensional warp interlock fabrics (3DWIFs) are recognised more and more in the industry for their outstanding mechanical properties compared to the 2D laminates. The present work shows the influence of the fabric’s architecture on the tensile behaviour of 3DWIFs. Five kinds of 3D fabrics with different interlock structures have been designed according to the main category of binding warp yarn evolution. These five 3DWIFs, containing both binding and stuffer warp yarns and produced with the same warp and weft densities, are experimentally tested via uniaxial tensile tests. The experimental results of the different 3DWIFs have been compared to find the optimal solution based on several mechanical performances. Fabric structures have an impact on tensile properties both in the warp and weft directions. Furthermore, other influential factors, for example, the yarn crimps during the weaving process and the crimp angles of binding warp yarns in 3DWIFs, are investigated and discussed in the paper. The influence of the total crimp angles related to the binding path on the tensile properties of 3DWIFs via the inter yarns friction is summarised.
Preparation of Nanocomposite-Based High Performance Organic Field Effect Transistor via Solution Floating Method and Mechanical Property Evaluation
Authors: Kim Youn , Kwon Yeon Ju , Ryu Seungwan , Lee Cheol Jin , Lee Jea Uk
Published: May 2020

We demonstrate that using nanocomposite thin films consisting of semiconducting polymer, poly(3-hexylthiophene) (P3HT), and electrochemically exfoliated graphene (EEG) for the active channel layer of organic field-effect transistors (OFETs) improves both device performances and mechanical properties. The nanocomposite film was developed by directly blending P3HT solution with a dispersion of EEG at various weight proportions and simply transferring to an Si/SiO2 substrate by the solution floating method. The OFET based on P3HT/EEG nanocomposite film showed approximately twice higher field-effect mobility of 0.0391 cm2·V−1·s−1 and one order of magnitude greater on/off ratio of ~104 compared with the OFET based on pristine P3HT. We also measured the mechanical properties of P3HT/EEG nanocomposite film via film-on-elastomer methods, which confirms that the P3HT/EEG nanocomposite film exhibited approximately 2.4 times higher modulus (3.29 GPa) than that of the P3HT film (1.38 GPa), while maintaining the good bending flexibility and durability over 10.0% of bending strain and bending cycles (1000 cycles). It was proved that the polymer hybridization technique, which involves adding EEG to a conjugated polymer, is a powerful route for enhancing both device performances and mechanical properties while maintaining the flexible characteristics of OFET devices.
Model Progress for Tensile Power of Polymer Nanocomposites Reinforced with Carbon Nanotubes by Percolating Interphase Zone and Network Aspects
Authors: Zare Yasser , Rhee Kyong Yop
Published: May 2020

In the present work, a simple simulation is advanced based on a Callister equation considering the impacts of interphase and carbon nanotube (CNT) nets on the strength of nanocomposites after percolation onset. The advanced model can analyze the strength of nanocomposite by filler aspect ratio (α), percolation beginning ( φ p ), interphase depth (t), interphase power (σi), net density (N), and net power (σN). The empirical consequences of several samples agree with the estimations of the industrialised model. The nanocomposite strength straightly depends on “α”, “t”, “σi”, “N”, and “σN”, while the radius and percolation onset of CNT play the inverse characters. The reasonable impacts of net and interphase possessions on the nanocomposite strength rationalise the accurate progress of the Callister equation.
Ecological Design of New Efficient Energy-Performance Construction Materials with Rigid Polyurethane Foam Waste
Authors: Briones-Llorente Raúl , Barbosa Ricardo , Almeida Manuela , Montero García Eduardo Atanasio , Rodríguez Saiz Ángel
Published: May 2020

An ecological mortar is designed from industrial sub-products, with the objective of utilizing both the slag residues, generated during steel manufacturing processes, and the waste from Polyurethane Foam (PF) panels, generated during refrigerator chamber manufacturing processes. The ecological mortar design involves the dosing of Electric Arc Furnace (EAF) slag, together with finely ground Polyurethane Foam, cement, and additives. An energy efficient prefabricated block is designed with the mortar, for use in construction, and its energy performance is assessed as a material inserted within the envelope of a service sector (hospital) building, either as an exterior skin, or as an enclosing component within the façade interior. The main contribution of this research is the characterization of the thermo-physical and mechanical properties of a new prefabricated panel made with recycled materials. The full characterization of the properties of these new materials is presented and discussed. The new prefabricated panel demonstrates adequate thermo-mechanical characteristics as a substitute for traditional materials, while improving the sustainability of the building. As a secondary objective, the energy behaviour of the new panels when integrated in a real building is presented by means of a case study simulation. The use of computational thermal simulation confirmed that the properties of the prefabricated block influenced the annual thermal demand of the building for heating and cooling. Improvements to the thermal inertia of the building envelope were also confirmed with the inclusion of PF waste, giving the mortar an energy performance that was similar to conventional materials, in such a way that its use in façade construction may be validated, in addition to its environmental benefits, due to it having been manufactured with critical recycled industrial waste such as EAF slag and PF, thereby contributing to both the circular economy and sustainable development.
Characterisation of Hybrid Polymersome Vesicles Containing the Efflux Pumps NaAtm1 or P-Glycoprotein
Authors: Rottet Sarah , Iqbal Shagufta , Beales Paul A. , Lin Anran , Lee Jiwon , Rug Melanie , Scott Colin , Callaghan Richard
Published: May 2020

Investigative systems for purified membrane transporters are almost exclusively reliant on the use of phospholipid vesicles or liposomes. Liposomes provide an environment to support protein function; however, they also have numerous drawbacks and should not be considered as a “one-size fits all” system. The use of artificial vesicles comprising block co-polymers (polymersomes) offers considerable advantages in terms of structural stability; provision of sufficient lateral pressure; and low passive permeability, which is a particular issue for transport assays using hydrophobic compounds. The present investigation demonstrates strategies to reconstitute ATP binding cassette (ABC) transporters into hybrid vesicles combining phospholipids and the block co-polymer poly (butadiene)-poly (ethylene oxide). Two efflux pumps were chosen; namely the Novosphingobium aromaticivorans Atm1 protein and human P-glycoprotein (Pgp). Polymersomes were generated with one of two lipid partners, either purified palmitoyl-oleoyl-phosphatidylcholine, or a mixture of crude E. coli lipid extract and cholesterol. Hybrid polymersomes were characterised for size, structural homogeneity, stability to detergents, and permeability. Two transporters, NaAtm1 and P-gp, were successfully reconstituted into pre-formed and surfactant-destabilised hybrid polymersomes using a detergent adsorption strategy. Reconstitution of both proteins was confirmed by density gradient centrifugation and the hybrid polymersomes supported substrate dependent ATPase activity of both transporters. The hybrid polymersomes also displayed low passive permeability to a fluorescent probe (calcein acetomethoxyl-ester (C-AM)) and offer the potential for quantitative measurements of transport activity for hydrophobic compounds.
Electrochemically-Obtained Polysulfonic-Acids Doped Polyaniline Films—A Comparative Study by Electrochemical, Microgravimetric and XPS Methods
Authors: Lyutov Vladimir , Kabanova Varvara , Gribkova Oxana , Nekrasov Alexander , Tsakova Vessela
Published: May 2020

Polyaniline (PANI) layers are electrochemically obtained in the presence of four polysulfonic acids with different rigidities of the polymer backbone-iso-(and tere-)poly-(4,4′-(2,2′-disulfonic acid)-diphenylene-iso(tere)-phthalamide (i-PASA and t-PASA), polystyrenesulfonic acid (PSSA) and poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA). Combined microgravimetric (EQCM) and electrochemical measurements are carried out in the course of polymerization and repetitive redox switching. It is found that after synthesis PASA-doped PANIs shows good stability with low exchange of mass in the course of voltammetric scans, while PAMPSA-doped PANI contains a large amount of water that gradually becomes expelled in the repetitive redox switching. PANI obtained in the presence of PSSA takes an intermediate position with respect to mass exchanged in the electrochemical redox process. XPS studies are used to obtain data for the extent of doping of the different PANI materials. The results show high doping level (about 0.5) for PASA- and PAMPSA- and lower level (0.32) for PSSA-doped PANI layers. Repeated electrochemical studies carried out with the specimens investigated by XPS after long-term storage in the dry state give evidence for structural rearrangement, perfect recuperation of the initial electrochemical activity and high stability of the electrochemical response.
X-ray-Based Spectroscopic Techniques for Characterization of Polymer Nanocomposite Materials at a Molecular Level
Authors: Son Dongwan , Cho Sangho , Nam Jieun , Lee Hoik , Kim Myungwoong
Published: May 2020

This review provides detailed fundamental principles of X-ray-based characterization methods, i.e., X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, and near-edge X-ray absorption fine structure, and the development of different techniques based on the principles to gain deeper understandings of chemical structures in polymeric materials. Qualitative and quantitative analyses enable obtaining chemical compositions including the relative and absolute concentrations of specific elements and chemical bonds near the surface of or deep inside the material of interest. More importantly, these techniques help us to access the interface of a polymer and a solid material at a molecular level in a polymer nanocomposite. The collective interpretation of all this information leads us to a better understanding of why specific material properties can be modulated in composite geometry. Finally, we will highlight the impacts of the use of these spectroscopic methods in recent advances in polymer nanocomposite materials for various nano- and bio-applications.
Extreme Foaming Modes for SCF-Plasticized Polylactides: Quasi-Adiabatic and Quasi-Isothermal Foam Expansion
Authors: Zimnyakov Dmitry , Zdrajevsky Roman , Minaev Nikita , Epifanov Evgeniy , Popov Vladimir , Ushakova Olga
Published: May 2020

The experimental evidence on depressurization foaming of the amorphous D,L-polylactide, which is plasticized by subcritical (initial pressures below the critical value) or supercritical (initial pressures above the critical value) carbon dioxide at a temperature above the critical value, relates to two extreme cases: a slow quasi-isothermal foam expansion, and a rapid quasi-adiabatic expansion. Under certain conditions, the quasi-isothermal mode is characterized by the non-monotonic dependencies of the foam volume on the external pressure that are associated with the expansion-to-shrinkage transition. The quasi-adiabatic and quasi-isothermal expansions are characterized by a significant increase in the degree of foam expansion under conditions where the CO2 initial pressure approaches the critical value. The observed features are interpreted in terms of the energy balance in the foam volume and the phenomenological model based on the equation of the foam state. The expansion-to-shrinkage condition is based on the relationship between the average bubble radius and the pressure derivative of the surface tension for the plasticized polylactide. The maximum expansion ratio of the rapidly foamed polylactide in the vicinity of the critical point is interpreted in terms of the maximum decrement of the specific internal energy of the foaming agent (carbon dioxide) in the course of depressurization.
The Effect of Modification on the Properties of Polyetherimide and Its Carbon-Filled Composite
Authors: Slonov Azamat , Musov Ismel , Zhansitov Azamat , Rzhevskaya Elena , Khakulova Diana , Khashirova Svetlana
Published: May 2020

The effect of oligophenylene sulfone (OPSU) and polycarbonate (PC) on the rheological, mechanical and thermal properties of polyetherimide (PEI) and a carbon-filled composite based on it was studied. It is shown that the introduction of OPSU and PC leads to a decrease in the melt viscosity of PEI and a carbon-filled composite based on it with the preservation of their mechanical properties and heat resistance at a sufficiently high level. It was found that composites with OPSU have higher mechanical and thermal properties compared with composites with PC. Samples from modified carbon-filled PEI were printed by the fused deposit modeling (FDM) method. Three-dimensionally printed samples from carbon-filled PEI modified by OPSU showed significantly higher mechanical properties than composites with PC.
Controlling the Skin Barrier Quality through the Application of Polymeric Films Containing Microspheres with Encapsulated Plant Extract
Authors: Kozlowska Justyna , Tylkowski Bartosz , Stachowiak Natalia , Prus-Walendziak Weronika
Published: May 2020

Human skin has protective functions and it is a barrier that protects the interior of the body from harmful environmental factors and pathogen penetration. An important role of the skin is also to prevent the loss of water from the body and if the skin barrier is damaged, the amount of water emitted from the internal environment is increased. Therefore, it is crucial to recovery and maintenance of epidermal barrier integrity. The aim of the current work was to encapsulate Calendula officinalis flower extract in gelatin microspheres and then incorporation microspheres into thin polymeric films made from sodium alginate or mixture of sodium alginate and starch. Such materials may find applications in the cosmetic field for example in the preparation of masks for skin, according to the Calendula officinalis flower extract wide influence on skin condition. Thus, the release profile of this extract from the materials was tested under conditions corresponding to the skin (pH 5.4, 37 °C). The mechanical properties, surface free energy, and moisture content of obtained films were measured. To determine the barrier quality of the stratum corneum, transepidermal water loss (TEWL) and skin color measurements were performed. The loaded microspheres were successfully incorporated into polymeric films without affecting its useful properties. Although the values of Young’s modulus and the moisture content were decreased after film modification by microspheres addition, the skin parameters were much better after application of films with microspheres. The results confirmed that obtained materials can be potentially used in cosmetics to improve the skin barrier quality.
Intelligent Setting Method of Reagent Dosage Based on Time Series Froth Image in Zinc Flotation Process
Authors: Tang Zhaohui , Tang Liyong , Zhang Guoyong , Xie Yongfang , Liu Jinping
Published: May 2020

It is well known that the change of the reagent dosage during the flotation process will cause the froth image to change continuously with time. Therefore, an intelligent setting method based on the time series froth image in the zinc flotation process is proposed. Firstly, the sigmoid kernel function is used to estimate the cumulative distribution function of bubble size, and the cumulative distribution function shape is characterized by sigmoid kernel function parameters. Since the reagent will affect the froth image over a period of time, the time series of bubble size cumulative distribution function is processed by the ELMo model and the dynamic feature vectors are output. Finally, XGBoost is used to establish the nonlinear relationship modeling between reagent dosage and dynamic feature vectors. Industrial experiments have proved the effectiveness of the proposed method.
Utilization of Steel-Making Dust in Drilling Fluids Formulations
Authors: Magzoub Musaab I. , Ibrahim Mohamed H. , Nasser Mustafa S. , El-Naas Muftah H. , Amani Mahmood
Published: May 2020

Steelmaking is an energy-intensive process that generates considerable amounts of by-products and wastes, which often pose major environmental and economic challenges to the steel-making industry. One of these by-products is steel dust that is produced during the separation of impurities in the smelting and refining of metals in steel-making furnaces. In this study, electric arc furnace (EAF) dust has been evaluated as a potential, low-cost additive to increase the viscosity and weight of drilling muds. Currently, the cost of drilling operations typically accounts for 50 to 80% of the exploration costs and about 30 to 80% of the subsequent field development costs. Utilization of steelmaking waste in drilling fluids formulations is aimed to produce new and optimized water-based drilling formulations, which is expected to reduce the amount of bentonite and other viscosifier additives used in the drilling formulations. The results showed that in a typical water-based drilling fluid of 8.6 ppg (1030.51 kg/m3), the amount of standard drilling grade bentonite could be reduced by 30 wt.% with the addition of the proposed new additive to complete the required mud weight. The mixture proved to be stable with no phase separation.
Well-Defined Conjugated Macromolecules Based on Oligo(Arylene Ethynylene)s in Sensing
Authors: Krywko-Cendrowska Agata , Szweda Dawid , Szweda Roza
Published: May 2020

Macromolecules with well-defined structures in terms of molar mass and monomer sequence became interesting building blocks for modern materials. The precision of the macromolecular structure makes fine-tuning of the properties of resulting materials possible. Conjugated macromolecules exhibit excellent optoelectronic properties that make them exceptional candidates for sensor construction. The importance of chain length and monomer sequence is particularly important in conjugated systems. The oligomer length, monomer sequence, and structural modification often influence the energy bang gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the molecules that reflect in their properties. Moreover, the supramolecular aggregation that is often observed in oligo-conjugated systems is usually strongly affected by even minor structural changes that are used for sensor designs. This review discusses the examples of well-defined conjugated macromolecules based on oligo(arylene ethynylene) skeleton used for sensor applications. Here, exclusively examples of uniform macromolecules are summarized. The sensing mechanisms and importance of uniformity of structure are deliberated.
Striving for a Safer and More Ergonomic Workplace: Acceptability and Human Factors Related to the Adoption of AR/VR Glasses in Industry 4.0
Authors: Sik Lanyi Cecilia , Withers John Dermott Alexander
Published: May 2020

The word smart is very popular these days, as a result of nearly everything being digital today. Background information: In this digital world, everything is interconnected by smart devices. The driving force behind this is today’s Industry 4.0 environment, which is affected by many factors, including the ergonomic and safe design of new technology, ensuring the safety of factory operators, whilst increasing productivity and profits. The authors answer the following research questions: Are AR/VR systems or devices proposed for industrial use capable of meeting the needs of the industry (including sustainability)? Are these AR/VR devices designed to ensure easy use and efficient training of factory operators? Do the proposals of the reviewed research papers place sufficient emphasis on creating ergonomic workplaces? These publications were categorized into three subcategories based on the used key technology, research or application area, and their main purposes. Conclusion: Virtual reality, augmented reality, and IoT are becoming increasingly more suitable for industrial use, despite facing scrutiny and criticism.
An Approach to Health and Safety Assessment in Industrial Parks
Authors: García-Gómez Fco. Javier , González-Gaya Cristina , Rosales-Prieto Víctor Fco.
Published: May 2020

Safety is a fundamental aspect to take into account in the design, construction and operation of industrial parks. Therefore, it is important to know how to deal with safety in this type of facility, and how to deal with risk analysis. This document provides information related to the industrial park risk assessment process to improve the health and safety of workers in these places. A search and consultation of references related to occupational health and safety management systems is carried out, and it is found that, although there is adequate protection, both in relation to the safety of workers in industrial parks and the safety of personnel outside the facilities, it is helpful to establish a health and safety risk assessment to identify hazards and hazardous events, evaluate associated risks, and select techniques or strategies (opportunities) to manage those risks after prioritization. Following the implementation of the selected techniques, their effectiveness can then be monitored in order to avoid incidents. This document can be a model for future implementation of a health and safety management system based in ISO 45001:2018.
The Evolutionary Game for Collaborative Innovation of the IoT Industry under Government Leadership in China: An IoT Infrastructure Perspective
Authors: Hou Jie , Li Baizhou
Published: May 2020

Since the United States, the European Union, China, and other countries put forward the development strategy of Internet of Things (IoT), it has been growing rapidly, leading to industrial restructuring and the sustainable development of various industries. Not only can collaborative innovation of the IoT industry accelerate R&D efficiency and product substitution frequency of IoT infrastructure, but also it can promote the construction of smart cities, the application of Big Data and Cloud Computing, and the development of 5G. In China, government is a leader and initiator of IoT infrastructure deployment. Therefore, in this paper, we construct an evolutionary game model of the IoT industry under government leadership represented by government, telecom equipment manufacturers, and telecom operators. Then, we analyze the asymptotic stability, equilibrium stability, and evolutionary stability strategy of the model. Finally, we carry out numerical simulation to investigate the effect of eight factors and four mechanisms on evolutionary behaviors of the three parties. The results show each factor has a different influence on them. Evolutionary game model offers ideas for government and industry subjects before the collaborative innovation of IoT infrastructure deployment in practice.
Evaluating the Traffic and Emissions Impacts of Congestion Pricing in New York City
Authors: Baghestani Amirhossein , Tayarani Mohammad , Allahviranloo Mahdieh , Gao H. Oliver
Published: May 2020

Traffic congestion is a major challenge in metropolitan areas due to economic and negative health impacts. Several strategies have been tested all around the globe to relieve traffic congestion and minimize transportation externalities. Congestion pricing is among the most cited strategies with the potential to manage the travel demand. This study aims to investigate potential travel behavior changes in response to cordon pricing in Manhattan, New York. Several pricing schemes with variable cordon charging fees are designed and examined using an activity-based microsimulation travel demand model. The findings demonstrate a decreasing trend in the total number of trips interacting with the central business district (CBD) as the price goes up, except for intrazonal trips. We also analyze a set of other performance measures, such as Vehicle-Hours of Delay, Vehicle-Miles Traveled, and vehicle emissions. While the results show considerable growth in transit ridership (6%), single-occupant vehicles and taxis trips destined to the CBD reduced by 30% and 40%, respectively, under the $20 pricing scheme. The aggregated value of delay for all vehicles was also reduced by 32%. Our findings suggest that cordon pricing can positively ameliorate transportation network performance and consequently, improve air quality by reducing particular matter inventory by up to 17.5%. The results might facilitate public acceptance of cordon pricing strategies for the case study of NYC. More broadly, this study provides a robust framework for decision-makers across the US for further analysis on the subject.
All-Day Energy Harvesting Power System Utilizing a Thermoelectric Generator with Water-Based Heat Storage
Authors: Kadohiro Yasuki , Cheng Shuo , Cross Jeffrey S.
Published: May 2020

Solar thermal systems, especially solar hot water household heating/storage systems, are considered the most cost-effective alternatives to fossil fuel hot water heating energy systems. Recently, solar hot water systems are combined with a thermoelectric generator, forming hybrid systems. However, these hybrid systems described in the literature cannot generate electricity from sunset to sunrise, or at night, when residential consumers use the most electricity. In this paper, an all-day energy harvesting power system utilizing a thermoelectric generator with water-based heat storage is presented to generate electricity all-day and also produce warm water. The experimental and theoretical analyses were conducted to evaluate and verify the performance of the systems. In the case study, the scaled-up system shows potential to provide 198.9 L of warm water per day, 0.912 kWh of electricity in the daytime, and 0.0332 kWh of electricity at nighttime for a typical house with 6.34 m2 of available surface area in Tokyo, Japan. Although the electric power at night is low, this novel lab-scale system shows the potential to be a viable source of electricity and warm water throughout the day, without emitting any greenhouse gas.
Novel Drying Methods for Sustainable Upcycling of Brewers’ Spent Grains as a Plant Protein Source
Authors: Pratap Singh Anubhav , Mandal Ronit , Shojaei Maryam , Singh Anika , Kowalczewski Przemysław Łukasz , Ligaj Marta , Pawlicz Jarosław , Jarzębski Maciej
Published: May 2020

Brewers’ spent grains (BSGs) are the most important by-product of the brewing industry and are rich in protein and fiber. However, abundant amounts of BSGs are discarded annually worldwide. This project aimed to employ and compare innovative drying techniques to introduce snacks with protein sources derived from leftover BSGs. This study explored the dehydration kinetics of BSGs and the effect of three different drying methods—oven drying (OD), freeze drying (FD), and vacuum microwave drying (VMD)—on their protein content and functionality. Then, an energy and exergy analysis for the drying methods was given. Accordingly, a snack product (baked chips) using the dehydrated BSGs was developed by a sensory panel study to assess consumer acceptability of the final products. It was found that the VMD process took less drying time (48 min) compared to OD (50 min), with higher effectiveness as a drying process. VMD-treated BSG also showed moderate protein functionality and the highest overall acceptability when used in baked chips. Thus, VMD might be used as a sustainable drying technology for thermal treatment and valorization of BSG. In addition to having implications for dietary health, findings can help improve the economy of the breweries and other industries that deal with the processing of grains by valorizing their process waste and contributing to sustainability.
Probabilistic Reliability Enhancement Strategies of Hydro Dominant Power Systems under Energy Uncertainty
Authors: Fang Fang , Karki Rajesh , Piya Prasanna
Published: May 2020

Climatic hydrological changes cause considerable seasonal and yearly energy variation in hydro dominant electric power systems. Extreme weather events are becoming more frequent in recent years causing dramatic impacts on energy availability in such systems. A significant amount of energy is often wasted due to reservoir overflow during wet seasons. By contrast, the scarcity of water in dry seasons results in inadequate power generation to meet the system demand, and therefore degrades overall system reliability. The high risks associated with an extreme dry hydrological condition should not be ignored in long term system adequacy planning of hydro dominant utilities. This paper presents a probabilistic method to incorporate diurnal, seasonal and yearly energy management strategies in run-of-river and storage type hydropower plant planning and operation in order to minimize the adverse impact of energy uncertainty and maintain long-term system adequacy. The impacts of reservoir capacity and demand side management on water utilization and system reliability are investigated with case studies illustrated using the IEEE Reliability Test System modified to create a hydro dominant system. The achieved benefits of reliability enhancement strategies are analyzed and compared in this paper.
Automated Locating Mining-Induced Microseismicity without Arrival Picking by Weighted STA/LTA Traces Stacking
Authors: Jiang Yuanjian , Peng Pingan , Wang Liguan , He Zhengxiang
Published: May 2020

The automatic location of the microseismic source is still a challenging endeavor in the microseismic field. Due to the complexity of the mining environment, the microseismic records collected by different channels vary, and generally have a low signal-to-noise ratio (SNR). Therefore, the automatic location algorithm is required to be robust and accurate. For microseismic records with low SNR, the stack-based method does not need to pick arrival, thus avoiding the large location error caused by picking arrival. However, the traditional stack-based method does not consider the influence of the waveform quality of different stations, which can bring some errors to the location result. In this paper, in order to improve the location accuracy of the traditional stack-based method, we propose a method for weighted STA/LTA traces stacking. First, we established evaluation indicators of waveform quality based on microseismic records. Then, the STA/LTA traces are given weight to stack according to the evaluation indicators. Finally, the maximum value of the stacking function is solved in the four-dimensional space to obtain the source coordinates. In the process of calculation, we use the weighted differential evolution (WDE) optimal algorithm instead of the full grid search method, which greatly improves the calculation efficiency. The blasting experiment and engineering application show that the proposed method is stable and effective, and the location accuracy is higher than the traditional stack-based method and the arrival-based method.
An Adapted Version of the Water Wave Optimization Algorithm for the Capacitated Vehicle Routing Problem with Time Windows with Application to a Real Case Using Probe Data
Authors: Tebaldi Letizia , Murino Teresa , Bottani Eleonora
Published: May 2020

Customers’ habits, as far as shipping requests are concerned, have changed in the last decade, due to the fast spread of e-commerce and business to consumer (B2C) systems, thus generating more and more vehicles on the road, traffic congestion and, consequently, more pollution. Trying to partially solve this problem, the operational research field dedicates part of its research to possible ways to optimize transports in terms of costs, travel times, full loads etc., with the aim of reducing inefficiencies and impacts on profit, planet and people, i.e., the well-known triple bottom line approach to sustainability, also thanks to new technologies able to instantly provide probe data, which can detail information as far as the vehicle behavior. In line with this, an adapted version of the metaheuristic water wave optimization algorithm is here presented and applied to the context of the capacitated vehicle routing problem with time windows. This latter one is a particular case of the vehicle routing problem, whose aim is to define the best route in terms of travel time for visiting a set of customers, given the vehicles capacity and time constraints in which some customers need to be visited. The algorithm is then tested on a real case study of an express courier operating in the South of Italy. A nearest neighbor heuristic is applied, as well, to the same set of data, to test the effectiveness and accuracy of the algorithm. Results show a better performance of the proposed metaheuristic, which could improve the journeys by reducing the travel time by up to 23.64%.