bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling of Environmental Ageing of Polymers and Polymer Composites—Modular and Multiscale Methods
Authors: Krauklis Andrey E. , Karl Christian W. , Rocha Iuri B. C. M. , Burlakovs Juris , Ozola-Davidane Ruta , Gagani Abedin I. , Starkova Olesja
Published: January 2022

Service lifetimes of polymers and polymer composites are impacted by environmental ageing. The validation of new composites and their environmental durability involves costly testing programs, thus calling for more affordable and safe alternatives, and modelling is seen as such an alternative. The state-of-the-art models are systematized in this work. The review offers a comprehensive overview of the modular and multiscale modelling approaches. These approaches provide means to predict the environmental ageing and degradation of polymers and polymer composites. Furthermore, the systematization of methods and models presented herein leads to a deeper and reliable understanding of the physical and chemical principles of environmental ageing. As a result, it provides better confidence in the modelling methods for predicting the environmental durability of polymeric materials and fibre-reinforced composites.
Catalytic Polymerization of Phthalonitrile Resins by Carborane with Enhanced Thermal Oxidation Resistance: Experimental and Molecular Simulation
Authors: Jia Yuxiang , Bu Xiaojun , Dong Junyu , Zhou Quan , Liu Min , Wang Fang , Wang Maoyuan
Published: January 2022

Biphenyl phthalonitrile (BPh) resins with good thermal and thermo-oxidative stability demonstrate great application potential in aerospace and national defense industries. However, BPh monomer has a high melting point, poor solubility, slow curing speed and high curing temperature. It is difficult to control the polymerization process to obtain the resins with high performance. Here, a BPh prepolymer (BPh-Q) was prepared by reacting 1,7-bis(hydroxymethyl)-m-carborane (QCB) with BPh monomers. The BPh-Q exhibited much better solubility, faster curing speed and lower curing temperature compared with pure BPh and BPh modified with bisphenol A (BPh-B, a common prepolymer of BPh). Thus, the polymerization process of BPh was greatly accelerated at a low temperature, resulting in a BPh resin with enhanced thermostability and oxidation resistance. The experimental and theoretical models revealed the promotion effect of B-H bond on the curing reaction of phthalonitrile via Markovnikov addition reaction due to the special steric structure of carborane. This study provided an efficient method to obtain low-temperature curing phthalonitrile resins with high thermal and thermo-oxidative resistance, which would be potentially useful for the preparation of high-performance cyanide resin-based composites.
Deep Eutectic Solvents for Starch Treatment
Authors: Skowrońska Dorota , Wilpiszewska Katarzyna
Published: January 2022

In this review, the application of deep eutectic solvents (DESs) as starch solvents, plasticizers and for other treatment has been described. Starch, as one of the most abundant biopolymers, is considered for forming new biodegradable materials. This new approach, referring to applying deep eutectic solvents for dissolving starch, its plasticization and other modifications, was presented. A DES could be a good alternative for common starch plasticizers (e.g., glycerol, urea) as well as recently considered ionic liquids. The high variety of DES component combinations makes it possible to obtain materials with the properties specific for given applications.
Hydrothermal Ageing Effect on Reinforcement Efficiency of Nanofibrillated Cellulose/Biobased Poly(butylene succinate) Composites
Authors: Starkova Olesja , Platnieks Oskars , Sabalina Alisa , Gaidukovs Sergejs
Published: January 2022

Nanofibrillated cellulose (NFC) is a sustainable functional nanomaterial known for its high strength, stiffness, and biocompatibility. It has become a key building block for the next-generation of lightweight, advanced materials for applications such as consumer products, biomedical, energy storage, coatings, construction, and automotive. Tunable and predictable durability under environmental impact is required for high performance applications. Bio-based poly (butylene succinate) (PBS) composites containing up to 50% NFC content were designed and aged in distilled water or at high relative humidity (RH98%). PBS/NFC composites are characterized by up to 10-fold increased water absorption capacity and diffusivity and the data are correlated with model calculations. Aged samples exhibited decreased crystallinity and melting temperature. Incorporation of NFC into PBS showed up to a 2.6-fold enhancement of the elastic modulus, although accompanied by a loss of strength by 40% and 8-fold reduction in the strain at failure of maximally loaded composites. Hydrothermal ageing had almost no influence on the tensile characteristics of PBS; however, there were considerable degradation effects in PBS/NFC composites. Altered reinforcement efficiency is manifested through a 3.7-fold decreased effective elastic moduli of NFC determined by applying the Halpin–Tsai model and a proportional reduction of the storage moduli of composites. The adhesion efficiency in composites was reduced by hydrothermal ageing, as measured Puckanszky’s adhesion parameter for the strength, which decreased from 3 to 0.8. For the loss factor, Kubat’s adhesion parameter was increased by an order. PBS filled with 20 wt.% NFC is identified as the most efficient composition, for which negative environmental degradation effects are counterbalanced with the positive reinforcement effect. The PBS matrix can be used to protect the NFC network from water.
Enhanced Low-Frequency Sound Absorption of a Porous Layer Mosaicked with Perforated Resonator
Authors: Li Xin , Liu Bilong , Wu Qianqian
Published: January 2022

A composite structure composed of a porous-material layer mosaicked with a perforated resonator is proposed to improve the low-frequency sound absorption of the porous layer. This structure is investigated in the form of a porous-material matrix (PM) and a perforated resonator (PR), and the PR is a thin perforated plate filled with porous material in its back cavity. Theoretical and numerical models are established to predict the acoustic impedance and sound absorption coefficient of the proposed structure, and two samples made of polyurethane and melamine, respectively, are tested in an impedance tube. The predicted results are consistent with that of the measured. Compared with a single porous layer with the same thickness, the results show that the designed structure provides an additional sound absorption peak at low frequencies. The proposed structure is compact and has an effective absorption bandwidth of more than two octaves especially below the frequency corresponding to 1/4 wavelength. A comparison is also made between the sound absorption coefficients of the proposed structure and a classical micro-perforated plate (MPP), and the results reveal equivalent acoustic performance, suggesting that it can be used as an alternative to the MPP for low–mid frequency sound absorption. Moreover, the influences of the main parameters on the sound absorption coefficient of PPCS are also analyzed, such as the hole diameter, area ratio, flow resistance, and porous-material thickness in the PR. The mechanism of sound absorption is discussed through the surface acoustic impedance and the distributions of particle velocity and sound pressure at several specific frequencies. This work provides a new idea for the applications of the thin porous layer in low- and medium-frequency sound absorption.
A Flexible Sandwich Structure Carbon Fiber Cloth with Resin Coating Composite Improves Electromagnetic Wave Absorption Performance at Low Frequency
Authors: Liu Yuanjun , Lu Qianqian , Wang Jing , Zhao Xiaoming
Published: January 2022

In order to improve the electromagnetic wave absorbing performance of carbon fiber cloth at low frequency and reduce the secondary pollution caused by the shielding mechanism, a flexible sandwich composite was designed by a physical mixing coating process. This was composed of a graphene layer that absorbed waves, a carbon fiber cloth layer that reflected waves, and a graphite layer that absorbed transmitted waves. The influence of the content of graphene was studied by a control variable method on the electromatic and mechanical properties. The structures of defect polarization relaxation and dipole polarization relaxation of graphene, the interfacial polarization and electron polarization of graphite, the conductive network formed in the carbon fiber cloth, and the interfacial polarization of each part, combined together to improve the impedance matching and wave multiple reflections of the material. The study found that the sample with 40% graphene had the most outstanding absorbing performance. The minimum reflection loss value was −18.62 dB, while the frequency was 2.15 GHz and the minimum reflection loss value compared to the sample with no graphene increased 76%. The composites can be mainly applied in the field of flexible electromagnetic protection, such as the preparation of stealth tent, protective covers of electronic boxes, helmet materials for high-speed train drivers, etc.
Ultrahigh and Tunable Electromagnetic Interference Shielding Performance of PVDF Composite Induced by Nano-Micro Cellular Structure
Authors: Yang Yang , Zeng Shuiping , Li Xiping , Hu Zhonglue , Zheng Jiajia
Published: January 2022

Lightweight and efficient electromagnetic interference (EMI) shielding materials play a vital role in protecting high-precision electronic devices and human health. Porous PVDF/CNTs/urchin-like Ni composites with different cell sizes from nanoscale to microscale were fabricated through one-step supercritical carbon dioxide (CO2) foaming. The electrical conductivity and electromagnetic interference (EMI) shielding performance of the composites with different cell sizes were examined in detail. The results indicated that the nanoscale cell structure diminishes the EMI shielding performance of the composite, whereas the microscale cell structure with an appropriate size is beneficial for improving the EMI shielding performance. A maximum EMI shielding effectiveness (SE) of 43.4 dB was achieved by the composite foams which is about twice that of the solid composite. Furthermore, as the supercritical CO2 foaming process reduces the density of the composite by 25–50%, the EMI SSE (specific shielding effectiveness)/t(thickness) of the composite reaches 402 dB/(g/cm2), which is the highest value of polymer foam obtained to the best of the authors’ knowledge. Finally, compression tests were performed to show that the composites still maintained excellent mechanical properties after the supercritical CO2 foaming process.
Immobilization of Air-Stable Copper Nanoparticles on Graphene Oxide Flexible Hybrid Films for Smart Clothes
Authors: Huang Peng-Yang , Huang Chen-Yang , Li Jia-Wun , Shen Sheng-Yen , Cheng Chih-Chia , Chiu Chih-Wei , Jeng Ru-Jong , Lin Jiang-Jen
Published: January 2022

Through the use of organic/inorganic hybrid dispersants—which are composed of polymeric dispersant and two-dimension nanomaterial graphene oxide (GO)—copper nanoparticles (CuNPs) were found to exhibit nano stability, air-stable characteristics, as well as long-term conductive stability. The polymeric dispersant consists of branched poly(oxyethylene)-segmented esters of trimellitic anhydride adduct (polyethylene glycol−trimethylolpropane−trimellitic anhydride, designated as PTT). PTT acts as a stabilizer for CuNPs, which are synthesized via in situ polymerization and redox reaction of the precursor Cu(CH3COO)2 within an aqueous system, and use graphene oxide to avoid the reduction reaction of CuNPs. The results show that after 30 days of storage the CuNPs/PTT/GO composite film maintains a highly conductive network (9.06 × 10−1 Ω/sq). These results indicate that organic/inorganic PTT/GO hybrid dispersants can effectively maintain the conductivity stability of CuNPs and address the problem of CuNP oxidation. Finally, the new CuNPs/PTT/GO composite film was applied to the electrocardiogram (ECG) smart clothes. This way, a stable and antioxidant-sensing electrode can be produced, which is expected to serve as a long-term ECG monitoring device.
Macromolecular Insights into the Altered Mechanical Deformation Mechanisms of Non-Polyolefin Contaminated Polyolefins
Authors: Demets Ruben , Grodent Marie , Van Kets Karen , De Meester Steven , Ragaert Kim
Published: January 2022

Current recycling technologies rarely achieve 100% pure plastic fractions from a single polymer type. Often, sorted bales marked as containing a single polymer type in fact contain small amounts of other polymers as contaminants. Inevitably, this will affect the properties of the recycled plastic. This work focuses on understanding the changes in tensile deformation mechanism and the related mechanical properties of the four dominant types of polyolefin (PO) (linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP)), contaminated with three different non-polyolefin (NPO) polymers (polyamide-6 (PA-6), polyethylene terephthalate (PET), and polystyrene (PS)). Under the locally elevated stress state induced by the NPO phase, the weak interfacial adhesion typically provokes decohesion. The resulting microvoids, in turn, initiate shear yielding of the PO matrix. LLDPE, due to the linear structure and intercrystalline links, is well able to maintain high ductility when contaminated. LDPE shows deformation similar to the pure material, but with decreasing ductility as the amount of NPO increases. Addition of 20 wt% PA-6, PET, and PS causes a drop in strain at break of 79%, 63%, and 84%, respectively. The typical ductile necking of the high-crystalline HDPE and PP is strongly disturbed by the NPO phase, with a transition even to full brittle failure at high NPO concentration.
The Effects of Three-Dimensional Ligand Immobilization on Kinetic Measurements in Biosensors
Authors: Chiodi Elisa , Marn Allison M. , Bakhshpour Monireh , Lortlar Ünlü Nese , Ünlü M. Selim
Published: January 2022

The field of biosensing is in constant evolution, propelled by the need for sensitive, reliable platforms that provide consistent results, especially in the drug development industry, where small molecule characterization is of uttermost relevance. Kinetic characterization of small biochemicals is particularly challenging, and has required sensor developers to find solutions to compensate for the lack of sensitivity of their instruments. In this regard, surface chemistry plays a crucial role. The ligands need to be efficiently immobilized on the sensor surface, and probe distribution, maintenance of their native structure and efficient diffusion of the analyte to the surface need to be optimized. In order to enhance the signal generated by low molecular weight targets, surface plasmon resonance sensors utilize a high density of probes on the surface by employing a thick dextran matrix, resulting in a three-dimensional, multilayer distribution of molecules. Despite increasing the binding signal, this method can generate artifacts, due to the diffusion dependence of surface binding, affecting the accuracy of measured affinity constants. On the other hand, when working with planar surface chemistries, an incredibly high sensitivity is required for low molecular weight analytes, and furthermore the standard method for immobilizing single layers of molecules based on self-assembled monolayers (SAM) of epoxysilane has been demonstrated to promote protein denaturation, thus being far from ideal. Here, we will give a concise overview of the impact of tridimensional immobilization of ligands on label-free biosensors, mostly focusing on the effect of diffusion on binding affinity constants measurements. We will comment on how multilayering of probes is certainly useful in terms of increasing the sensitivity of the sensor, but can cause steric hindrance, mass transport and other diffusion effects. On the other hand, probe monolayers on epoxysilane chemistries do not undergo diffusion effect but rather other artifacts can occur due to probe distortion. Finally, a combination of tridimensional polymeric chemistry and probe monolayer is presented and reviewed, showing advantages and disadvantages over the other two approaches.
Preparation of Electrochemical Supercapacitor Based on Polypyrrole/Gum Arabic Composites
Authors: Ullah Rizwan , Khan Nadia , Khattak Rozina , Khan Mehtab , Khan Muhammad Sufaid , Ali Omar M.
Published: January 2022

The current research focused on the super capacitive behavior of organic conducting polymer, i.e., polypyrrole (PPy) and its composites with gum arabic (GA) prepared via inverse emulsion polymerization. The synthesized composites material was analyzed by different analytical techniques, such as UV-visible, FTIR, TGA, XRD, and SEM. The UV-Vis and FTIR spectroscopy clearly show the successful insertion of GA into PPy matrix. The TGA analysis shows high thermal stability for composites than pure PPy. The XRD and SEM analysis show the crystalline and amorphous structures and overall morphology of the composites is more compact and mesoporous as compared to the pure PPy. The electrochemical properties of modified solid state supercapacitors established on pure polypyrrole (PPy), polypyrrole/gum arabic (PPy/GA) based composites were investigated through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge (GCD). The specific capacitance of the PPy modified gold electrode is impressive (~168 F/g). The specific capacitance of PPy/GA 1 electrode has been increased to 368 F/g with a high energy density and power density (~73 Wh/kg), and (~599 W/kg) respectively.
Improving the Mould and Blue-Stain-Resistance of Bamboo through Acidic Hydrolysis
Authors: Yu Zixuan , Zhang Xiaofeng , Zhang Rong , Yu Yan , Sun Fengbo
Published: January 2022

Bamboo is much more easily attacked by fungus compared with wood, resulting in shorter service life and higher loss in storage and transportation. It has been long accepted that the high content of starch and sugars in bamboo is mainly responsible for its low mould resistance. In this paper, acetic acid, propionic acid, oxalic acid, citric acid, and hydrochloric acid were adopted to hydrothermally hydrolyze the starch in bamboo, with the aims to investigate their respective effect on the mould and blue-stain resistance of bamboo, and the optimized citric acid in different concentrations were studied. The starch content, glucose yields, weight loss, and colour changes of solid bamboo caused by the different acidic hydrolysis were also compared. The results indicated that weak acidic hydrolysis treatment was capable of improving mould-resistant of bamboo. The mould resistance increased with the increased concentration of citric acid. Bamboo treated with citric acid in the concentration of 10% could reduce the infected area ranging to 10–17%, the growth rating of which could reach 1 resistance. The content of soluble sugar and starch remained in bamboo decreased significantly from 43 mg/g to 31 mg/g and 46 mg/g to 23 mg/g, respectively, when the citric acid concentration varied from 4% to 10%. Citric acid treatments of 10% also caused a greatest surface colour change and weight loss. The results in this study demonstrated citric acid treatment can effectively reduce the starch grain and soluble sugars content and improve mould resistance of bamboo, which can be attributed to the reduction of starch grain and soluble carbohydrates (such as glucose, fructose, and sucrose, etc.) in bamboo.
Effect of Stretching on Thermal Behaviour of Electro-Conductive Weft-Knitted Composite Fabrics
Authors: Repon Md. Reazuddin , Laureckiene Ginta , Mikucioniene Daiva
Published: January 2022

This experiment presents a study carried out on the electric charge passing textiles for heat production in compression weft-knitted composite fabrics used for medical purposes. The aim was to flourish compression support of knitted structure with integrated highly sensitive metal (silver) coated polyamide multifilament yarns and to evaluate its heat origination attributes after stretching in different levels as well as changes of the temperature during the time. A flat double needle-bed knitting machine was utilized to fabricate the selected specimens together with elastomeric inlay-yarn incorporated into the structure for compression generation and silver coated polyamide yarn laid as ground yarn in a plated structure for heat generation. Six different variants depending on the metal coated yarn amount used and the fabric structure along with two types of the conductive yarn linear density were fabricated for this research work. Scanning electron microscope (SEM) images were preoccupied to show the morphology of conductive yarn and thermal pictures were captured to study the evenness of the heat over the surface of composite fabrics depending on conductive yarn distribution in the pattern repeat. The temperature profile of fabricated composite fabrics and comparison of the heat generation by specimens after stretching in different levels was studied
Changes in the Local Conformational States Caused by Simple Na+ and K+ Ions in Polyelectrolyte Simulations: Comparison of Seven Force Fields with and without NBFIX and ECC Corrections
Authors: Lukasheva Natalia , Tolmachev Dmitry , Martinez-Seara Hector , Karttunen Mikko
Published: January 2022

Electrostatic interactions have a determining role in the conformational and dynamic behavior of polyelectrolyte molecules. In this study, anionic polyelectrolyte molecules, poly(glutamic acid) (PGA) and poly(aspartic acid) (PASA), in a water solution with the most commonly used K+ or Na+ counterions, were investigated using atomistic molecular dynamics (MD) simulations. We performed a comparison of seven popular force fields, namely AMBER99SB-ILDN, AMBER14SB, AMBER-FB15, CHARMM22*, CHARMM27, CHARMM36m and OPLS-AA/L, both with their native parameters and using two common corrections for overbinding of ions, the non-bonded fix (NBFIX), and electronic continuum corrections (ECC). These corrections were originally introduced to correct for the often-reported problem concerning the overbinding of ions to the charged groups of polyelectrolytes. In this work, a comparison of the simulation results with existing experimental data revealed several differences between the investigated force fields. The data from these simulations and comparisons with previous experimental data were then used to determine the limitations and strengths of these force fields in the context of the structural and dynamic properties of anionic polyamino acids. Physical properties, such as molecular sizes, local structure, and dynamics, were studied using two types of common counterions, namely potassium and sodium. The results show that, in some cases, both the macroion size and dynamics depend strongly on the models (parameters) for the counterions due to strong overbinding of the ions and charged side chain groups. The local structures and dynamics are more sensitive to dihedral angle parameterization, resulting in a preference for defined monomer conformations and the type of correction used. We also provide recommendations based on the results.
Polysaccharides from Basidiocarps of the Polypore Fungus Ganoderma resinaceum: Isolation and Structure
Authors: Bleha Roman , Třešnáková Lucie , Sushytskyi Leonid , Capek Peter , Čopíková Jana , Klouček Pavel , Jablonský Ivan , Synytsya Andriy
Published: January 2022

In this study, we focused on the isolation and structural characterization of polysaccharides from a basidiocarp of polypore fungus Ganoderma resinaceum. Polysaccharide fractions were obtained by successive extractions with cold water at room temperature (20 °C), hot water under reflux (100 °C), and a solution of 1 mol L−1 sodium hydroxide. The purity of all fractions was controlled mainly by Fourier transform infrared (FTIR) spectroscopy, and their composition and structure were characterized by organic elemental analysis; neutral sugar and methylation analyses by gas chromatography equipped with flame ionization detector (GC/FID) and mass spectrometry detector (GC/MS), respectively; and by correlation nuclear magnetic resonance (NMR) spectroscopy. The aqueous extracts contained two main polysaccharides identified as a branched O-2-β-d-mannosyl-(1→6)-α-d-galactan and a highly branched (1→3)(1→4)(1→6)-β-d-glucan. Mannogalactan predominated in the cold water extract, and β-d-glucan was the main product of the hot water extract. The hot water soluble fraction was further separated by preparative anion exchange chromatography into three sub-fractions; two of them were identified as branched β-d-glucans with a structure similar to the corresponding polysaccharide of the original fraction. The alkaline extract contained a linear (1→3)-α-d-glucan and a weakly branched (1→3)-β-d-glucan having terminal β-d-glucosyl residues attached to O-6 of the backbone. The insoluble part after all extractions was identified as a polysaccharide complex containing chitin and β-d-glucans.
Preparation of Transparent Fast-Growing Poplar Veneers with a Superior Optical Performance, Excellent Mechanical Properties, and Thermal Insulation by Acetylation Modification Using a Green Catalyst
Authors: He Wen , Wang Rui , Guo Feiyu , Cao Jizhou , Guo Zhihao , Qiang Han , Liang Shuang , Pang Qunyan , Wei Bairen
Published: January 2022

There has been growing interest in transparent conductive substrates due to the prevailing flexible electron devices and the need for sustainable resources. In this study, we demonstrated a transparent fast-growing poplar veneers prepared by acetylated modification, followed by the infiltration of epoxy resin. The work mainly focused on the effect of acetylation treatment using a green catalyst of 4-Dimethylpyridine on the interface of the bulk fast-growing poplar veneer, and the result indicated that the interface hydrophobicity was greatly enhanced due to the higher substitute of acetyl groups; therefore, the interface compatibility between the cell wall and epoxy resin was improved. The obtained transparent fast-growing poplar veneers, hereafter referred to as TADPV, displayed a superior optical performance and flexibility, in which the light transmittance and haze were 90% and 70% at a wavelength of 550 nm, respectively, and the bending radius and bending angle parallel to grain of TADPV were 2 mm and 130°, respectively. Moreover, the tensile strength and tensile modulus of the TADPV were around 102 MPa and 198 MPa, respectively, which is significantly better than those of the plastic substrates used in flexible electron devices. At the same time, the thermal conductivity tests indicated that TADPV has a low coefficient of thermal conductivity of 0.34 Wm−1 K−1, which can completely meet the needs of transparent conductive substrates. Therefore, the obtained TADPV can be used as a candidate for a flexible transparent substrate of electron devices.
Enzymatic Conversion of Lignosulfonate into Wood Adhesives: A Next Step towards Fully Biobased Composite Materials
Authors: Hellmayr Raphaela , Bischof Sabrina , Wühl Jasmin , Guebitz Georg M. , Nyanhongo Gibson S. , Schwaiger Nikolaus , Liebner Falk , Wimmer Rupert
Published: January 2022

This study investigates the effect of the enzymatic polymerization of lignosulfonate for the formulation of a lignosulfonate-based adhesive. For this, beech lamellas were glued together and tested according to the EN 302-1 standard. The results showed that the laccase-polymerized lignosulfonate-based wood adhesives (LS-p) had similar mechanical properties as a standard carpenter’s glue (PVAc-based D3 class white glue), as no significant difference in tensile shear strength between these two adhesive types was found. However, carpenter’s glue showed almost 100% wood failure, while with the lignosulfonate-based wood glue, the samples failed, mainly in the glueline. Pre-polymerization of LS-p is the most critical factor to achieve the required viscosity, which is also connected to the wetting properties and the resulting tensile shear strength. The longer the pre-polymerization, the higher the viscosity of the LS-p adhesive, with the tensile shear strength reaching a plateau. The presented data show the potential of using enzymatically pre-polymerized lignosulfonate as a well-performing wood adhesive. Further development and optimization of the pre-polymerization process is required, which is also important to push towards upscaling and practical applications.
Experimental Investigation of Polypropylene Composite Drawn Fibers with Talc, Wollastonite, Attapulgite and Single-Wall Carbon Nanotubes
Authors: Tsioptsias Costas , Leontiadis Konstantinos , Messaritakis Stavros , Terzaki Aikaterini , Xidas Panagiotis , Mystikos Kyriakos , Tzimpilis Evangelos , Tsivintzelis Ioannis
Published: January 2022

Isotactic polypropylene (PP) composite drawn fibers were prepared using melt extrusion and high-temperature solid-state drawing at a draw ratio of 7. Five different fillers were used as reinforcement agents (microtalc, ultrafine talc, wollastonite, attapulgite and single-wall carbon nanotubes). In all the prepared samples, antioxidant was added, while all samples were prepared with and without using PP grafted with maleic anhydride as compatibilizer. Material characterization was performed by tensile tests, differential scanning calorimetry, thermogravimetric analysis and Fourier transform infrared spectroscopy. Attapulgite composite fibers exhibited poor results in terms of tensile strength and thermal stability. The use of ultrafine talc particles yields better results, in terms of thermal stability and tensile strength, compared to microtalc. Better results were observed using needle-like fillers, such as wollastonite and single-wall carbon nanotubes, since, as was previously observed, high aspect ratio particles tend to align during the drawing process and, thus, contribute to a more symmetrical distribution of stresses. Competitive and synergistic effects were recognized to occur among the additives and fillers, such as the antioxidant effect being enhanced by the addition of the compatibilizer, while the antioxidant itself acts as a compatibilizing agent.
The Effect of Sulfated Zirconia and Zirconium Phosphate Nanocomposite Membranes on Fuel-Cell Efficiency
Authors: Sigwadi Rudzani , Mokrani Touhami , Msomi Phumlani , Nemavhola Fulufhelo
Published: January 2022

To investigate the effect of acidic nanoparticles on proton conductivity, permeability, and fuel-cell performance, a commercial Nafion® 117 membrane was impregnated with zirconium phosphates (ZrP) and sulfated zirconium (S-ZrO2) nanoparticles. As they are more stable than other solid superacids, sulfated metal oxides have been the subject of intensive research. Meanwhile, hydrophilic, proton-conducting inorganic acids such as zirconium phosphate (ZrP) have been used to modify the Nafion® membrane due to their hydrophilic nature, proton-conducting material, very low toxicity, low cost, and stability in a hydrogen/oxygen atmosphere. A tensile test, water uptake, methanol crossover, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to assess the capacity of nanocomposite membranes to function in a fuel cell. The modified Nafion® membrane had a higher water uptake and a lower water content angle than the commercial Nafion® 117 membrane, indicating that it has a greater impact on conductivity. Under strain rates of 40, 30, and 20 mm/min, the nanocomposite membranes demonstrated more stable thermal deterioration and higher mechanical strength, which offers tremendous promise for fuel-cell applications. When compared to 0.113 S/cm and 0.013 S/cm, respectively, of commercial Nafion® 117 and Nafion® ZrP membranes, the modified Nafion® membrane with ammonia sulphate acid had the highest proton conductivity of 7.891 S/cm. When tested using a direct single-cell methanol fuel cell, it also had the highest power density of 183 mW cm−2 which is better than commercial Nafion® 117 and Nafion® ZrP membranes.
Polysaccharides in Agro-Industrial Biomass Residues
Authors: Souza Márcio Araújo de , Vilas-Boas Isis Tavares , Leite-da-Silva Jôse Maria , Abrahão Pérsia do Nascimento , Teixeira-Costa Barbara E. , Veiga-Junior Valdir F.
Published: January 2022

The large-scale industrial use of polysaccharides to obtain energy is one of the most discussed subjects in science. However, modern concepts of biorefinery have promoted the diversification of the use of these polymers in several bioproducts incorporating concepts of sustainability and the circular economy. This work summarizes the major sources of agro-industrial residues, physico-chemical properties, and recent application trends of cellulose, chitin, hyaluronic acid, inulin, and pectin. These macromolecules were selected due to their industrial importance and valuable functional and biological applications that have aroused market interests, such as for the production of medicines, cosmetics, and sustainable packaging. Estimations of global industrial residue production based on major crop data from the United States Department of Agriculture were performed for cellulose content from maize, rice, and wheat, showing that these residues may contain up to 18%, 44%, and 35% of cellulose and 45%, 22%, and 22% of hemicellulose, respectively. The United States (~32%), China (~20%), and the European Union (~18%) are the main countries producing cellulose and hemicellulose-rich residues from maize, rice, and wheat crops, respectively. Pectin and inulin are commonly obtained from fruit (~30%) and vegetable (~28%) residues, while chitin and hyaluronic acid are primarily found in animal waste, e.g., seafood (~3%) and poultry (~4%).
Study of Wax Deposition Pattern of High Wax-Bearing Crude Oil Based on Cold Finger Experiment
Authors: Wei Lixin , Li Da , Liu Chao , He Zhaojun , Ge Yang
Published: January 2022

In order to solve the problem of wax deposition in waxy crude oil from the Daqing oilfield, cold fingers were used in the experimentation. Compared with other methods, the cold finger method is simple, easy to operate, and takes little space. Measurements of wax deposition with temperature, temperature differences between the crude oil and the wall, deposition time, and cold finger rotation rate were made. The results showed that the deposition rate is up to 0.35 g/h at 8–24 h. The maximum deposition rate at 90 rotations/min was 0.26 g/h, which is 3% higher than the minimum deposition rate.
The Incorporation of Cultural and Religious Diversity in LGBT Policies: Experiences of Queer Migrants from Muslim Backgrounds in Catalonia, Spain
Authors: Coll-Planas Gerard , García-Romeral Gloria , Masi Belén
Published: January 2022

This article reflects on the biases in sexual and gender diversity policies in relation to the axis of cultural and religious diversity in Catalonia (Spain), where these policies have experienced an enormous boost since 2014. The paper aims to analyse the articulation between the experiences of queer migrants from Muslim backgrounds living in Catalonia and the LGBT and intercultural policies. Based on interviews both with queer migrants and people involved in developing public policies, we analyse how these two axes intersect. The approach of policies is mainly monofocal and assimilationist, failing to acknowledge the hybridity of queer migrant experiences. However, we also find examples of policy programmes that adopt an intersectional perspective and embrace hybridity by advancing more inclusive LGBT equality policies. The conclusions highlight two axes of tensions that have emerged in the analysis of the policies: the construction of the figure of the queer person from a Muslim background and the role of the state regarding sexual and gender diversity.
No Country for Muslims? The Invention of an Islam Républicain in France and Its Impact on French Muslims
Authors: Käsehage Nina
Published: January 2022

Since the beheading of the French teacher Samuel Paty on 16 October 2020, the call for a fight against the so-called ‘Political Islam’ has been heard once again, not only in France, but all over Europe (EU). The politicization of Islam is held to be responsible for the increasing attacks by radical Islamic actors within European metropoles, and the EU states’ call for action and revenge in response to this ideology and its adherents, in order to guarantee public security and democratic values. Starting from the major terrorist attacks in France in the last few years, this paper seeks to compare the interlinking between domestic policy and religious radicalization and its impact on neighboring states. With regard to the attacks on 13 November 2015 in France, the attackers were traced back to radical networks in Belgium and Germany. Based on selected interviews that have been conducted by the author with female adherents of jihadist milieus within the years 2015 and 2016 in France and social media examples of Muslim reactions on the current French law enforcement, the tension between domestic policy and religious freedom related to Islam in France will be highlighted in this article. Among other reasons, the interview quotations and social media reactions can be seen as a result of a specific religious understanding and practice related to Islam by some actors. In addition, the ongoing othering of Muslims by France and other European societies can be seen to be in sum to be responsible for the increasing interest of young Muslims in radical Islamic thought that led to jihadist attacks within France in the not-so-distant past. With respect to the aforementioned development, this article will conceptualize the problematique of a (politically motivated) category formation related to one religion that is currently practiced in France, as seen from the perspective of a religious studies scholar.
Confucian Identification, Ancestral Beliefs, and Ancestral Rituals in Korea
Authors: Kim Jibum , Shim Jae-Mahn , Kim Sori
Published: January 2022

Since Koreans do not consider Confucianism to be part of religion, conventional religious identification questions cannot accurately capture the number of Confucians in Korea. Using the Korean General Social Survey and other data sources, we aim to describe the identification, beliefs, and practices related to Confucianism, especially ancestral rituals, and to examine whether these beliefs and practices differ across religious groups. Contrasted with 0.2% of the adult population identifying their religion as Confucianism in the 2015 Korean Census, 51% considered themselves as Confucians when asked, “(Regardless of your religious affiliation) do you consider yourself a Confucian?” If we consider those who think that rites for deceased family members are Confucian, the proportion was 44%. Considering those who conduct ancestral rites at a gravesite as Confucians, the proportion was 86%, but was only 70% when we count those who perform ancestral rites at home as Confucians. We also found substantial differences among religious groups. In general, Buddhists were most likely and Protestants were least likely to identify with Confucianism, believe in the power of ancestors, and perform ancestral rites. Perhaps most telling is the result of religious none falling in the middle between Buddhists and Protestants in terms of identification, beliefs, and rituals of Confucianism. The differences of religious groups appear to reflect religious syncretism and the exclusivity of religion. It is overstating to declare a revival of Confucianism, but it is reasonable to say that Confucianism is not a dying tradition in Korean society.
Cyprus and Sardinia at the Transition from the Bronze to the Iron Age: A Sacred Landscape Approach
Authors: Papantoniou Giorgos , Depalmas Anna
Published: January 2022

In the framework of this contribution, and taking a macro-historic sacred landscapes approach, we established a comparative project analysing in parallel the development of sacred landscapes of two mega-islands, Cyprus and Sardinia, at the transition from the Bronze to the Iron Age. In both Cyprus and Sardinia, the period between the 12th and 8th centuries BC seems to have been a time when re-negotiations of individual, societal, and political identities took place, and this is clearly reflected on the construction of the sacred landscapes of the two islands. We first present our ‘landscape/macro-historic approach’; we then define the chronological horizon and the socio-historical contexts under discussion for each island, exploring at the same time how the hierarchical arrangement of ritual sites appearing at this transitional phase seems to be related with articulated social order or linked with shifting relations of power and cultural influence. Finally, we proceed to a discussion addressing the following three questions: (1) what is the relation between individual insularities and the construction of sacred landscapes on these two mega-islands?; (2) how can a ‘landscape/macro-historic approach’ assist us in better formulating microscopic approaches on both islands at the transition from the Bronze to the Iron Age?; and (3) is a comparative approach viable?
Existential Dimension and Spiritual Assistance in the “A. Gemelli” University Hospital in Rome: A Cross-Disciplinary and Sacramental Enhanced Dynamical Approach in Palliative Care
Authors: Mantini Alessandro , Ricciotti Maria , Meloni Eleonora , Tummolo Anita , Dispenza Sabrina , Barillaro Christian
Published: January 2022

In the A. Gemelli university hospital in Rome, the presence of highly specialized inter-professional palliative care teams and spiritual assistants who are dedicated to their role in the service of inpatients is valuable to person-centered healthcare. Spiritual needs are commonly experienced by patients with sudden illness, chronic conditions, and life-limiting conditions, and, consequently, spiritual care is an intrinsic and essential component of palliative care. This paper focuses on the sacrament of the Anointing of the Sick to demonstrate the importance of spiritual care as an integral part of palliative care and highlights the need for all interdisciplinary team members to address spiritual issues in order to improve the holistic assistance to the patient. Over a 3-year period (October 2018–September 2021), data about the sacrament of the Anointing of the Sick administered by the hospitaller chaplaincy were collected. A total of 1541 anointings were administered, with an average of 514 anointings per year, excluding reductions related to the COVID-19 pandemic. In 98% of cases, the sacrament was requested by health personnel, and in 96% of cases, the same health personnel participated in the sacrament. These results demonstrate that, at the A. Gemelli polyclinic in Rome, the level of training that the care team has received in collaboration with the chaplains has generated a good generalized awareness of the importance of integrating the spiritual needs of patients and their families into their care, considering salvation as well as health, in a model of dynamic interprofessional integration.
Ritual, Legend, and Metaphor: Narratives of the Willow in Yuan Zaju
Authors: Wang Qian , Yang Qiong
Published: January 2022

Narratives of willow trees in Yuan zaju 雜劇, or variety play, largely come in three types, namely, the ritual performance of shooting willows; the deliverance of willow spirits by Lü Dongbin, one of the Eight Immortals of Daoism; and the use of the word willow to refer to women. The willow shooting ritual depicted in Yuan zaju was highly reminiscent of the willow shooting ritual popular throughout the Song (960–1279), Liao (916–1125), Jin (1115–1234), and Yuan (1271–1368) dynasties, with its conceptual origins traceable to the ancient shamanic belief in the willow as a sacred tree prevalent among the Khitans and Jurchens who lived in what is now northeastern China. The legend of Lü Dongbin delivering a willow spirit to immortality is a recurring motif in Han Chinese folklore and Daoist hagiography, which also finds expression in the iconic image of Guanyin Pusa or Bodhisattva Avalokitesvara holding a willow branch with which they cure diseases for people and bring fulfillment to their wishes. The frequent use of “willow leaf-shaped eyebrows” (liumei 柳眉) and “willow-like waist” (liuyao 柳腰) in Yuan zaju as metaphorical references to women can be seen as a continuation of the great literary tradition of Shijing 詩經 (The Book of Songs) and also as a dramatic enactment of the fertility cult of the willow and women in Chinese folk religion. Evidence abounds that the narratives about the willow in Yuan zaju were not a new creation but an artistic manifestation of centuries-old folk belief and literary tradition.
The Cruelty of Supersessionism: The Case of Dietrich Bonhoeffer
Authors: Phelan John E.
Published: January 2022

The impact of the Shoah on Christian biblical and theological studies has been significant. The Christian doctrine of supersessionism, the replacement of the Jews and Judaism by the Christian church, has come in for particular criticism. Some more traditional scholars have either ignored these critiques or suggested that they were shaped not by critical study of the biblical text but by Christian guilt. It is also argued that the supersessionist argument is so thoroughly woven into the Christian story that extracting it would destroy the story itself. For some, it appears that there is no Christianity without supersessionism. This paper argues not only that this challenge to supersessionism was indeed the result of post-Shoah reflection, but that such challenges were appropriate and necessary. It does this in part by considering the case of German pastor and theologian Dietrich Bonhoeffer whose early citations of the “teachings of contempt” were challenged by the violence of Nazis and the clarity of their intent to destroy both the Jews and, eventually, the church. A non-supersessionist Christianity is both possible and necessary, not simply to preserve the relationship between Christians and Jews, but to enable both communities to engage in the work of “consummation” and “redemption” that God has entrusted to them.
Estimating Visible Band Albedo from Aerial Orthophotographs in Urban Areas
Authors: Hofierka Jaroslav , Onačillová Katarína
Published: January 2022

Albedo is an important parameter in many environmental and renewable energy models. Satellite sensors can be used to derive broadband or narrowband albedos. However, the spatial resolution of such data can be insufficient in urban areas with complex morphology and land cover diversity. In this study, we propose the use of widely available aerial orthophotographs to derive visible band albedo in urban surfaces that can be effectively used in high-resolution applications. The solution is based on the estimation of the reflected irradiance captured by an RGB sensor and approximated by the brightness component in the hue-saturation-brightness (HSB) color model and incident solar irradiance modelled by the r.sun module in GRASS GIS. The visible band albedo values are calibrated by published reference values for selected land cover classes or, alternatively, by a spectroradiometer. The method is applied to the central part of Košice and compared to visible band albedo derived from the Landsat 8 OLI and Sentinel 2A sensors and previously published typical albedo values for various land cover classes, resulting in reasonable agreement. The proposed methodology is implemented using standard GIS tools that are easily applicable to any high-resolution urban data.