bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermo-Tunable Pores and Antibiotic Gating Properties of Bovine Skin Gelatin Gels Prepared with Poly(n-isopropylacrylamide) Network
Authors: Tsai Fang-Chang , Huang Chih-Feng , Chang Chi-Jung , Lu Chien-Hsing , Chen Jem-Kun
Published: September 2020

Polystyrene nanospheres (PNs) were embedded in bovine skin gelatin gels with a poly(N-isopropylacrylamide) (PNIPAAm) network, which were denoted as NGHHs, to generate thermoresponsive behavior. When 265 nm PNs were exploited to generate the pores, bovine skin gelatin extended to completely occupy the pores left by PNs below the lower critical solution temperature (LCST), forming a pore-less structure. Contrarily, above the LCST, the collapse of hydrogen bonding between bovine skin gelatin and PNIPAAm occurred, resulting in pores in the NGHH. The behavior of pore closing and opening below and above the LCST, respectively, indicates the excellent drug gating efficiency. Amoxicillin (AMX) was loaded into the NGHHs as smart antibiotic gating due to the pore closing and opening behavior. Accordingly, E. coli. and S. aureus were exploited to test the bacteria inhibition ratio (BIR) of the AMX-loaded NGHHs. BIRs of NGHH without pores were 48% to 46.7% at 25 and 37 °C, respectively, for E. coli during 12 h of incubation time. The BIRs of nanoporous NGHH could be enhanced from 61.5% to 90.4% providing a smart antibiotic gate of bovine skin gelatin gels against inflammation from infection or injury inflammation.
Design of Highly Adhesive and Water-Resistant UV/Heat Dual-Curable Epoxy–Acrylate Composite for Narrow Bezel Display Based on Reactive Organic–Inorganic Hybrid Nanoparticles
Authors: Lee Jun Hyup
Published: September 2020

To attain the narrow bezel characteristic of information displays, functional sealing composite materials should possess high adhesion strength and water barrier performance due to their narrow line widths. In this study, highly adhesive UV/heat dual-curable epoxy–acrylate composites with outstanding water-resistant performance have been proposed using photoreactive organic–inorganic hybrid nanoparticles that can react with an acrylate resin, creating a crosslinked nanoparticle network within the sealing composite. The hybrid nanoparticles consisted of reactive methacrylate groups as a shell and an inorganic core of silica or aluminum oxide, and were facilely synthesized through sol–gel reaction and chemisorption process. The curing characteristics, adhesive strength, and moisture permeability of the proposed sealing composite have been compared to those of a conventional epoxy–acrylate composite containing inorganic silica particles. The composites including hybrid nanoparticles exhibited high UV and heat curing ratios owing to the numerous methacrylate groups on the nanoparticle surface and high compatibility with organic resins. Moreover, the proposed sealing composite showed high adhesion strength and extremely low water permeability due to the creation of densely photocrosslinked network with matrix resins. In addition, the sealing composite exhibited excellent narrow dispensing width as well as relatively low viscosity, suggesting the potential application in narrow bezel display.
Polyvinyl Alcohol/Calcium Carbonate Nanocomposites as Efficient and Cost-Effective Cationic Dye Adsorbents
Authors: Jahani Davoud , Nazari Amin , Ghourbanpour Jaber , Ameli Amir
Published: September 2020

A novel polyvinyl alcohol (PVA)/calcium carbonate-based double-layer cationic dye adsorbent was developed. Polyvinyl alcohol (50 wt %) and calcium carbonate (50 wt %) were used together with borax as a cross-linking agent. The nanocomposite was prepared using only water, without the need for any toxic solvent or hazardous chemical. The final samples were obtained by the solvent casting method. The nanocomposite adsorbent was characterized using a Fourier transform infrared (FTIR) spectroscope and a scanning electron microscope (SEM). The adsorption performance on two cationic dyes, i.e., methylene blue and safranin was studied. Dye adsorption was quantified by measuring the nanocomposite swelling, contact time, and dye concentration. Pseudo first-order and pseudo second-order kinetic models as well as intraparticle diffusion model were used to model the adsorption kinetics. Moreover, the isotherm dye adsorption was investigated by Langmuir and Freundlich models. The results revealed that the developed nanocomposite has relatively high adsorption efficiency and short adsorption time and retains its performance after several successive absorption–desorption processes. The results also showed that the pseudo-second-order model best describes the adsorption kinetics, and the Freundlich isotherm model has a better compatibility with the experimental data. Finally, an adsorption mechanism was proposed for the dye removal process. The developed PVA/CaCO3 nanocomposite can be potentially used for efficient dye removal in wastewater treatments.
Fine-Structure Analysis of Perhydropolysilazane-Derived Nano Layers in Deep-Buried Condition Using Polarized Neutron Reflectometry
Authors: Akutsu-Suyama Kazuhiro , Kira Hiroshi , Miyata Noboru , Hanashima Takayasu , Miyazaki Tsukasa , Kasai Satoshi , Yamazaki Dai , Soyama Kazuhiko , Aoki Hiroyuki
Published: September 2020

A large background scattering originating from the sample matrix is a major obstacle for fine-structure analysis of a nanometric layer buried in a bulk material. As polarization analysis can decrease undesired scattering in a neutron reflectivity (NR) profile, we performed NR experiments with polarization analysis on a polypropylene (PP)/perhydropolysilazane-derived SiO2 (PDS)/Si substrate sample, having a deep-buried layer of SiO2 to elucidate the fine structure of the nano-PDS layer. This method offers unique possibilities for increasing the amplitude of the Kiessig fringes in the higher scattering vector (Qz) region of the NR profiles in the sample by decreasing the undesired background scattering. Fitting and Fourier transform analysis results of the NR data indicated that the synthesized PDS layer remained between the PP plate and Si substrate with a thickness of approximately 109 Å. Furthermore, the scattering length density of the PDS layer, obtained from the background subtracted data appeared to be more accurate than that obtained from the raw data. Although the density of the PDS layer was lower than that of natural SiO2, the PDS thin layer had adequate mechanical strength to maintain a uniform PDS layer in the depth-direction under the deep-buried condition.
Self-Assembly of Linear Amphiphilic Pentablock Terpolymer PAAx-PS48-PEO46-PS48-PAAxin Dilute Aqueous Solution
Authors: Gao Jia , An Kun , Lv Chao , Nie Jingjing , Xu Junting , Du Binyang
Published: September 2020

A series of linear amphiphilic pentablock terpolymer PAAx-b-PS48-b-PEO46-b-PS48-b-PAAx (AxS48O46S48Ax) with various lengths x of the PAA block (x = 15, 40, 60, and 90) were synthesized via a two-step atom transfer radical polymerization (ATRP) using Br-poly(ethylene oxide)-Br (Br-PEO46-Br) as the macroinitiator, styrene (St) as the first monomer, and tert-butyl acrylate (tBA) as the second monomer, followed with the hydrolysis of PtBA blocks. The AxS48O46S48Ax pentablock terpolymers formed micelles in dilute aqueous solution, of which the morphologies were dependent on the length x of the PAA block. Cryogenic transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), and zeta potential measurement were employed to investigate the morphologies, chain structures, size, and size distribution of the obtained micelles. The morphology of AxS48O46S48Ax micelles changed from spherical vesicles with ordered porous membranes to long double nanotubes, then to long nanotubes with inner modulated nanotubes or short nanotubes, and finally, to spherical micelles or large compound vesicles with spherical micelles inside when x increased from 15 to 90. The hydrophobic PS blocks formed the walls of vesicles and nanotubes as well as the core of spherical micelles. The hydrophilic PEO and PAA block chains were located on the surfaces of vesicle membranes, nanotubes, and spherical micelles. The PAA block chains were partially ionized, leading to the negative zeta potential of AxS48O46S48Ax micelles in dilute aqueous solutions.
The Study of the Degree of Crystallinity, Electrical Equivalent Circuit, and Dielectric Properties of Polyvinyl Alcohol (PVA)-Based Biopolymer Electrolytes
Authors: B. Aziz Shujahadeen , S. Marf Ayub , Dannoun Elham M. A. , Brza Mohamad A. , Abdullah Ranjdar M.
Published: September 2020

This report presents a facile and efficient methodology for the fabrication of plasticized polyvinyl alcohol (PVA):chitosan (CS) polymer electrolytes using a solution cast technique. Regarding characterizations of electrical properties and structural behavior, the electrochemical impedance spectroscopy (EIS) and X-ray diffraction (XRD) are used, respectively. Crystalline peaks appear in the XRD pattern of the PVA:CS:NH4I while no peaks can be seen in the XRD pattern of plasticized systems. The degree of crystallinity is calculated for all the samples from the deconvoluted area of crystalline and amorphous phases. Considering the EIS measurements, the most conductive plasticized system shows a relatively high conductivity of (1.37 × 10−4) S/cm, which is eligible for applications in energy storage devices. The analysis of the EIS spectra reveals a decrease in bulk resistance which indicates an increase in free ion carriers. The electrical equivalent circuit (EEC) model is used in the analysis of EIS plots. Dielectric properties are modified with the addition of glycerol as a plasticizer. It is proved that the addition of glycerol as a plasticizer lowers ion association. It also shows, at the low-frequency region, a large value of a dielectric constant which is correlated with electrode polarization (EP). The distribution of relaxation times is associated with conducting ions.
Characterization of Flaxseed Oil Bimodal Emulsions Prepared with Flaxseed Oil Cake Extract Applied as a Natural Emulsifying Agent
Authors: Drozłowska Emilia , Bartkowiak Artur , Łopusiewicz Łukasz
Published: September 2020

Currently, a majority of oilseeds plants are converted into byproducts and waste materials during processing. Press cakes are rich in valuable biopolymers, such as proteins and polysaccharides (fiber, lignans, etc.). In this study flaxseed oil cake extract (FOCE) was used to stabilize flaxseed oil-in-water emulsions. The effect of FOCE with various flaxseed oil concentrations (10–50% v/v) on several physicochemical properties of emulsions, such as stability, rheology, color and particle size was investigated. The rheological parameters suggested that all samples were non-Newtonian fluids, whereas particle size measurements and calculation SPAN index provided information about the broadness of emulsions particle size distribution. FOCE was able to efficiently stabilize oil/water interfaces with a high oil content. Results obtained for FOCE were compared with effects for synthetic emulsifier (Tween 80) and separated FOCE compounds (flaxseed gum and flaxseed protein). FOCE emulsifying activity is a result of different water-holding and oil-binding capacities of flaxseed gum and protein. This result is an intriguing conclusion regarding the necessity for using pure emulsifiers, showing the possibility of using a bio-based extract containing biopolymers, which is part of the principles of circular economy and the idea of zero-waste. The results give the opportunity to use FOCE as an ingredient in efficient flaxseed oil emulsions stabilizer for food applications.
Microbuckling Instability and the Second Yield during the Deformation of Semicrystalline Polyethylene
Authors: Bartczak Zbigniew , Vozniak Alina
Published: September 2020

Deformation instabilities, such as microbuckling or lamellar fragmentation due to slip localization, play a very important role in the deformation of semicrystalline polymers, although it still not well explored. Such instabilities often appear necessary to modify the deformation path and facilitate strain accommodation in an energy-minimizing manner. In this work, microbuckling instability was investigated using partially oriented, injection-molded (IM) samples of high-density polyethylene, deformed by a plane-strain compression. Deformed samples were probed by SEM, X-ray (small- and wide-angle X-ray scattering: SAXS, WAXS), and differential scanning calorimetry (DSC). It was found that microbuckling instability, followed quickly by the formation of lamellar kinks, occurred in high-density polyethylene (HDPE) at a true strain of about e = 0.3–0.4, mainly in those lamellar stacks which were initially oriented parallel to the compression direction. This phenomenon was observed with scanning electron microscopy, especially in the oriented skin layers of IM specimens, where a chevron morphology resulting from lamellae microbuckling/kinking was evidenced. Macroscopically, this instability manifested as the so-called “second macroscopic yield” in the form of a hump in the true stress–true strain curve. Microbuckling instability can have a profound effect on the subsequent stages of the deformation process, as well as the resulting structure. This is particularly important in deforming well-oriented lamellar structures—e.g., in drawing pre-oriented films of a semicrystalline polymer, a process commonly used in many technologies.
Mechanical, Physical and Thermal Properties of Sugar Palm Nanocellulose Reinforced Thermoplastic Starch (TPS)/Poly (Lactic Acid) (PLA) Blend Bionanocomposites
Authors: Nazrin A. , Sapuan S. M. , Zuhri M. Y. M.
Published: September 2020

In this paper, sugar palm nanocellulose fibre-reinforced thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend bionanocomposites were prepared using melt blending and compression moulding with different TPS concentrations (20%, 30%, 40%, 60%, and 80%) and constant sugar palm nanocellulose fibres (0.5%). The physical, mechanical, thermal, and water barrier properties were investigated. The SEM images indicated different TPS loading effects with the morphology of the blend bionanocomposites due to their immiscibility. A high content of TPS led to agglomeration, while a lower content resulted in the presence of cracks and voids. The 20% TPS loading reduced the tensile strength from 49.08 to 19.45 MPa and flexural strength from 79.60 to 35.38 MPa. The thermal stability of the blend bionanocomposites was reduced as the TPS loading increased. The thickness swelling, which corresponded to the water absorption, demonstrated an increasing trend with the increased addition of TPS loading.
Novel Method for the Manufacture of Complex CFRP Parts Using FDM-based Molds
Authors: Bere Paul , Neamtu Calin , Udroiu Razvan
Published: September 2020

Fibre-reinforced polymers (FRP) have attracted much interest within many industrial fields where the use of 3D printed molds can provide significant cost and time savings in the production of composite tooling. Within this paper, a novel method for the manufacture of complex-shaped FRP parts has been proposed. This paper features a new design of bike saddle, which was manufactured through the use of molds created by fused deposition modeling (FDM), of which two 3D printable materials were selected, polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS), and these molds were then chemically and thermally treated. The novel bike saddles were fabricated using carbon fiber-reinforced polymer (CFRP), by vacuum bag technology and oven curing, utilizing additive manufactured (AM) molds. Following manufacture the molded parts were subjected to a quality inspection, using non-contact three-dimensional (3D) scanning techniques, where the results were then statistically analyzed. The statistically analyzed results state that the main deviations between the CAD model and the manufactured CFRP parts were within the range of ±1 mm. Additionally, the weight of the upper part of the saddles was found to be 42 grams. The novel method is primarily intended to be used for customized products using CFRPs.
Synthesis, Structures, and Water Adsorption of Two Coordination Polymers Constructed by M(II) (M = Ni (1) and Zn (2)) with 1,3-Bis(4-Pyridyl)Propane (bpp) and 1,2,4,5-Benzenetetracarboxylate (BT4−) Ligands
Authors: Wang Chih-Chieh , Yi Wei-Cheng , Huang Zi-Ling , Chang Tsai-Wen , Chien Wen-Chi , Tseng Yueh-Yi , Chen Bo-Hao , Chuang Yu-Chun , Lee Gene-Hsiang
Published: September 2020

Two coordination polymers (CPs), with chemical formulas {[Ni2(bpp)2(BT)(H2O)6] 1.5(EtOH) 1.5H2O}n (1) and [Zn(bpp)(BT)0.5]·5H2O (2) (bpp = 1,3-bis(4-pyridyl)propane, and BT4− = tetraanion of 1,2,4,5-Benzenetetracarboxylic acid), have been synthesized and structurally characterized by single-crystal X-ray diffraction methods. In compound 1, the coordination environments of two crystallographically independent Ni(II) ions are both distorted octahedral bonded to two nitrogen donors from two bpp ligands and four oxygen donors from one BT4- ligand and three water molecules. Both bpp and BT4− act as bridging ligands with bis-monodentate and 1,4-bis-monodentate coordination modes, respectively, connecting the Ni(II) ions to form a 2D layered metal-organic framework (MOF). Adjacent 2D layers are then arranged orderly in an ABAB manner to complete their 3D supramolecular architecture. In 2, the coordination environment of Zn(II) ion is distorted tetrahedral bonded to two nitrogen donors from two bpp ligands and two oxygen donors from two BT4− ligands. Both bpp and BT4- act as bridging ligands with bis-monodentate and 1,2,4,5-tetrakis-monodentate coordination modes, respectively, connecting the Zn(II) ions to form a 3D MOF. The reversible water de-/adsorption behavior of 1 between dehydrated and rehydrated forms has been verified by cyclic Thermogravimetric (TG) analyses through de-/rehydration processes. Compound 1 also exhibits significant water vapor hysteresis isotherms.
Preparation of Hybrid Alginate-Chitosan Aerogel as Potential Carriers for Pulmonary Drug Delivery
Authors: Alnaief Mohammad , Obaidat Rana M. , Alsmadi Mo’tasem M.
Published: September 2020

This study aims to prepare hybrid chitosan-alginate aerogel microparticles without using additional ionic crosslinker as a possible pulmonary drug delivery system. The microparticles were prepared using the emulsion gelation method. The effect of the mixing order of the biopolymer within the emulsion and the surfactant used on final particle properties were investigated. Physicochemical characterizations were performed to evaluate particle size, density, morphology, surface area, surface charge, and the crystallinity of the preparation. The developed preparation was evaluated for its acute toxicity in adult male Sprague-Dawley rats. Measurements of zeta potential suggest that the surface charge depends mainly on the surfactant type while the order of biopolymer mixing has less impact on the surface charge. Chitosan amphiphilic properties changed the hydrophilic-lipophilic balance (HLB) of the emulsifying agents. The specific surface area of the prepared microparticles was in the range of (29.36–86.20) m2/g with a mesoporous pore size of (12.48–13.38) nm and pore volume of (0.09–0.29) cm3/g. The calculated aerodynamic diameter of the prepared particles was in the range of (0.17–2.29 µm). Toxicity studies showed that alginate-chitosan carrier developed herein caused mild lung inflammation with some renal and hepatic toxicities.
Effect of Prebiotic Polysaccharides on the Rheological Properties of Reduced Sugar Potato Starch Based Desserts
Authors: Gałkowska Dorota , Południak Monika , Witczak Mariusz , Juszczak Lesław
Published: September 2020

The aim of the study was to assess the possibility of using polysaccharides: inulin and polydextrose in combination with steviol glycosides as sucrose substitutes in starch-based desserts with reduced sugar content and to determine their influence on the rheological properties of these desserts. The samples (starch-milk desserts) were prepared from native potato starch, milk, dye, flavouring agent, and sucrose. The sucrose was partially or completely substituted with steviol glycosides and inulin or polydextrose. The rheological evaluation of the desserts was performed by determining pasting characteristics, viscosity curves, creep and recovery curves and mechanical spectra. Substitution of sucrose with prebiotic polysaccharides modified the rheological characteristics of the starch-milk desserts to a degree depending on the type and level of the substituting agent. Inulin reduced the peak viscosity of starch-milk paste, while it had no effect on the final viscosity of the product, contrary to polydextrose, which increased value of the latter parameter. The desserts exhibited a non-Newtonian, shear-thinning flow behaviour. The use of inulin, in both the highest and the lowest concentrations, significantly changed the consistency coefficient and the flow index values, while such a phenomenon was not observed in the case of polydextrose. The desserts with inulin showed increased values of the storage modulus and reduced susceptibility to stress, manifesting strengthened viscoelastic structure. The results indicate that the both prebiotic polysaccharides can serve as substitutes for sucrose in desserts with reduced sugar contents.
Synthesis and Properties of Thiophene and Aniline Copolymer Using Atmospheric Pressure Plasma Jets Copolymerization Technique
Authors: Jang Hyo Jun , Park Choon-Sang , Jung Eun Young , Bae Gyu Tae , Shin Bhum Jae , Tae Heung-Sik
Published: September 2020

This paper investigates the properties of thiophene and aniline copolymer (TAC) films deposited by using atmospheric pressure plasma jets copolymerization technique relative to various blending ratios of aniline and thiophene monomer for synthesizing the donor–acceptor conjugated copolymers. Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy are utilized to measure the surface morphology, roughness and film thickness of TAC films. Structural and chemical properties of TAC films are investigated by Fourier transforms-infrared spectroscopy (FT-IR), time of flight secondary ion mass spectrometry, and X-ray photoelectron spectroscopy. FE-SEM images show that the film thickness and nanoparticles size of the TAC films increase with an addition thiophene monomer in the aniline monomer. FE-SEM, FT-IR results show that TAC films are successfully synthesized on glass substrates in all cases. The iodine doped TAC film on the Si substrate with interdigitated electrodes shows the lowest electrical resistance at blending condition of thiophene of 25%.
Bifunctional Microcapsules with n-Octadecane/Thyme Oil Core and Polyurea Shell for High-Efficiency Thermal Energy Storage and Antibiosis
Authors: Wang Xianfeng , Li Chunhong , Wang Meihui , Zhao Tao , Li Wenyao
Published: September 2020

A new kind of bifunctional microcapsule containing a n-octadecane (OD) and thyme oil (TO) core based on polyurea shell designed for thermal energy storage and antibiosis was prepared successfully through interfacial polymerization. The scanning electron microscopic investigations reveal that the obtained composite microcapsules present the regular spherical morphology and the transmission electron microscopic observations confirm the clear core–shell structure. Morphological and chemical structure analyses prove the successful synthesis of bifunctional microcapsules. Thermogravimetric analysis indicates that the polyurea shell can protect the composite cores effectively. Differential scanning calorimetry examination shows that the bifunctional microcapsules can maintain high thermal storage capacity and the encapsulation efficiency of OD increases with the increase in TO. The supercooling crystallization can be notably suppressed by adding 7 wt.% of n-octadecanol. A study on the release behavior of TO from the bifunctional microcapsules reveals that the Higuchi kinetic model could better fit the TO release profile. The antibacterial results demonstrate that the bifunctional microcapsules can effectively inhibit the growth of Staphylococcus aureus and the inhibition rate can reach as high as 99.9% when the mass concentration of microcapsules is over 3 wt.%.
The Toxicological Testing and Thermal
Decomposition of Drive and Transport Belts Made
of Thermoplastic Multilayer Polymer Materials
Authors: Krawiec Piotr , Warguła Łukasz , Małozięć Daniel , Kaczmarzyk Piotr , Dziechciarz Anna , Czarnecka-Komorowska Dorota
Published: September 2020

The article presents the potential impact of flat drive and transport belts on people’s safety during a fire. The analysis distinguished belts made of classically used fabric–rubber composite materials reinforced with cord and currently used multilayer polymer composites. Moreover, the products’ multilayers during the thermal decomposition and combustion can be a source of emissions for unpredictable and toxic substances with different concentrations and compositions. In the evaluation of the compared belts, a testing methodology was used to determine the toxicometric indicators (WLC50SM) on the basis of which it was possible to determine the toxicity of thermal decomposition and combustion products in agreement with the standards in force in several countries of the EU and Russia. The analysis was carried out on the basis of the registration of emissions of chemical compounds during the thermal decomposition and combustion of polymer materials at three different temperatures. Moreover, the degradation kinetics of the polymeric belts by using the thermogravimetric (TGA) technique was evaluated. Test results have shown that products of thermal decomposition resulting from the neoprene (NE22), leder leder (LL2), thermoplastic connection (TC), and extra high top cower (XH) belts can be characterized as moderately toxic or toxic. Their toxicity significantly increases with the increasing temperature of thermal decomposition or combustion, especially above 450 °C. The results showed that the belts made of several layers of polyamide can be considered the least toxic in fire conditions. The TGA results showed that NBR/PA/PA/NBR belt made with two layers of polyamide and the acrylonitrile–butadiene rubber has the highest thermal stability in comparison to other belts.
Towards 3D Multi-Layer Scaffolds for Periodontal Tissue Engineering Applications: Addressing Manufacturing and Architectural Challenges
Authors: Porta Marta , Tonda-Turo Chiara , Pierantozzi Daniele , Ciardelli Gianluca , Mancuso Elena
Published: September 2020

Reduced periodontal support, deriving from chronic inflammatory conditions, such as periodontitis, is one of the main causes of tooth loss. The use of dental implants for the replacement of missing teeth has attracted growing interest as a standard procedure in clinical practice. However, adequate bone volume and soft tissue augmentation at the site of the implant are important prerequisites for successful implant positioning as well as proper functional and aesthetic reconstruction of patients. Three-dimensional (3D) scaffolds have greatly contributed to solve most of the challenges that traditional solutions (i.e., autografts, allografts and xenografts) posed. Nevertheless, mimicking the complex architecture and functionality of the periodontal tissue represents still a great challenge. In this study, a porous poly(ε-caprolactone) (PCL) and Sr-doped nano hydroxyapatite (Sr-nHA) with a multi-layer structure was produced via a single-step additive manufacturing (AM) process, as a potential strategy for hard periodontal tissue regeneration. Physicochemical characterization was conducted in order to evaluate the overall scaffold architecture, topography, as well as porosity with respect to the original CAD model. Furthermore, compressive tests were performed to assess the mechanical properties of the resulting multi-layer structure. Finally, in vitro biological performance, in terms of biocompatibility and osteogenic potential, was evaluated by using human osteosarcoma cells. The manufacturing route used in this work revealed a highly versatile method to fabricate 3D multi-layer scaffolds with porosity levels as well as mechanical properties within the range of dentoalveolar bone tissue. Moreover, the single step process allowed the achievement of an excellent integrity among the different layers of the scaffold. In vitro tests suggested the promising role of the ceramic phase within the polymeric matrix towards bone mineralization processes. Overall, the results of this study demonstrate that the approach undertaken may serve as a platform for future advances in 3D multi-layer and patient-specific strategies that may better address complex periodontal tissue defects.
Evaluation of Bead Geometry for Aluminum Parts Fabricated Using Additive Manufacturing-Based Wire-Arc Welding
Authors: Lee Hee-keun , Kim Jisun , Pyo Changmin , Kim Jaewoong
Published: September 2020

The wire arc additive manufacturing (WAAM) process used to manufacture aluminum parts has a number of variables. This study focuses on the effects of the heat input and the current and voltage ratio on the deposition efficiency. The effects of the heat input and current and voltage ratio (V/A) on the bead geometry were analyzed, depending on the cross-sectional geometry of the deposition layers, for nine different deposition conditions. The deposition efficiency was also analyzed by analyzing the cross-sectional geometry of the thin-wall parts made of aluminum. The heat input range was about 2.7 kJ/cm to 4.5 kJ/cm; the higher the heat input, the higher the deposition efficiency. The maximum deposition efficiency achieved in this study was 76%. The current and voltage ratio was used to quantify the portion of voltage (V) in the total heat input (Q), and the effect on the bead geometry was analyzed. As the portion of voltage in the quasi heat input decreased by about 10%, it was found that the deposition efficiency was decreased by 1% to 3%.
The Effects of Port Water Injection on Spark Ignition Engine Performance and Emissions Fueled by Pure Gasoline, E5 and E10
Authors: Salek Farhad , Babaie Meisam , Redel-Macias Maria Dolores , Ghodsi Ali , Hosseini Seyed Vahid , Nourian Amir , Burby Martin L , Zare Ali
Published: September 2020

It has been proven that vehicle emissions such as oxides of nitrogen (NOx) are negatively affecting the health of human beings as well as the environment. In addition, it was recently highlighted that air pollution may result in people being more vulnerable to the deadly COVID-19 virus. The use of biofuels such as E5 and E10 as alternatives of gasoline fuel have been recommended by different researchers. In this paper, the impacts of port injection of water to a spark ignition engine fueled by gasoline, E5 and E10 on its performance and NOx production have been investigated. The experimental work was undertaken using a KIA Cerato engine and the results were used to validate an AVL BOOST model. To develop the numerical analysis, design of experiment (DOE) method was employed. The results showed that by increasing the ethanol fraction in gasoline/ethanol blend, the brake specific fuel consumption (BSFC) improved between 2.3% and 4.5%. However, the level of NOx increased between 22% to 48%. With port injection of water up to 8%, there was up to 1% increase in engine power whereas NOx and BSFC were reduced by 8% and 1%, respectively. The impacts of simultaneous changing of the start of combustion (SOC) and water injection rate on engine power and NOx production was also investigated. It was found that the NOx concentration is very sensitive to SOC variation.
A Kraft Mill-Integrated Hydrothermal Liquefaction Process for Liquid Fuel Co-Production
Authors: Ong Benjamin H. Y. , Walmsley Timothy G. , Atkins Martin J. , Walmsley Michael R. W.
Published: September 2020

There is a growing awareness of the need to mitigate greenhouse gas emissions and the inevitable depletion of fossil fuel. With the market pull for the growth in sustainable and renewable alternative energy, the challenge is to develop cost-effective, large-scale renewable energy alternatives for all energy sectors, of which transport fuels are one significant area. This work presents a summary of novel methods for integrating kraft mills with a hydrothermal liquefaction process. The application of these methods has resulted in a proposed kraft mill-integrated design that produces a liquid fuel and could provide net mitigation of 64.6 kg CO2-e/GJ, compared to conventional petrol and diesel fuels, at a minimum fuel selling price of 1.12–1.38 NZD/LGE of fuel, based on the case study. This paper concludes that a hydrothermal liquefaction process with product upgrading has promising economic potential and environmental benefits that are significantly amplified by integrating with an existing kraft mill. At the current global kraft pulp production rate, if each kraft mill transforms into a biorefinery based on hydrothermal liquefaction, the biofuel production is an estimated 290 Mt (9.9 EJ).
On the Schott Term in the Lorentz-Abraham-Dirac Equation
Authors: Nakamura Tatsufumi
Published: September 2020

The equation of motion for a radiating charged particle is known as the Lorentz–Abraham–Dirac (LAD) equation. The radiation reaction force in the LAD equation contains a third time-derivative term, called the Schott term, which leads to a runaway solution and a pre-acceleration solution. Since the Schott energy is the field energy confined to an area close to the particle and reversibly exchanged between particle and fields, the question of how it affects particle motion is of interest. In here we have obtained solutions for the LAD equation with and without the Schott term, and have compared them quantitatively. We have shown that the relative difference between the two solutions is quite small in the classical radiation reaction dominated regime.
Muslim Community Organizations’ Perceptions of Islamophobia: Towards an Informed Countering Response
Authors: Cheikh Husain Sara
Published: September 2020

During the past two decades, Muslim Community Organizations (MCOs) in the West have increasingly become stakeholders in the public debates and the national consultations regarding the Muslim communities. MCO’s perception of Islamophobia is critical for understanding their collective response to the problem. Much of the Australian literature, nonetheless, tends to subsume Islamophobia within the dynamics of exclusion/inclusion within a social cohesion paradigm, and primarily through a focus on individuals. This article aims to contribute to the existing literature through a deeper contextual understanding of Australian MCOs’ framing of and engagement with Islamophobia in its various manifestations, in order to better cognize its impact on their agentic capacity. Deploying an expanded theoretical framework of agency structure, this article analyzes 25 interviews with representatives of Victorian MCOs, to explore their perceptions of Islamophobia across multiple domains of power—the social, discursive and the political. MCOs’ perceptions of the problem impact their responding anti-Islamophobia civic–political engagements towards soft grassroots connections and Muslims’ empowerment. In light of the findings, the article points for the need to enhance building inter-community solidarity, utilize supportive institutional multicultural schemes and establish a separate Muslim advocacy organization.
‘Beyond Boundaries or Best Practice’ Prayer in Clinical Mental Health Care: Opinions of Professionals and Patients
Authors: van Nieuw Amerongen-Meeuse Joke C. , Braam Arjan W. , Anbeek Christa , Schaap-Jonker Hanneke
Published: September 2020

The use of prayer in mental health care is controversial. Several scholars in the field have emphasized possibilities, whereas others have expressed clear disapproval. The aim of the current study was to describe opinions about prayer of mental health professionals (MHPs) and patients in a Christian (CC) and a secular (SC) mental health clinic. Content analysis was applied to 35 patient interviews and 18 interviews with MHPs. Most of the nurses in both clinics were open to the possible use of prayer, frequently argued by assisting patients in case of inability, but also by personal belief in its potency. Practitioners in both clinics were sometimes reticent or reluctant towards prayer. In the CC the nurses practiced prayer regularly, but all of them mentioned preconditions (like a similar outlook on life) and patients were stimulated to pray themselves. All patients in the CC and most of the patients in the SC had no objections against prayer and tended to focus on the benefits, like tranquility and relief. Prayer in mental health care could be practiced, especially by nurses, in cases of inability of patients, when considered beneficial and when a similar religious background is present.
Medieval Shiloh—Continuity and Renewal
Authors: Shcwartz Amichay , Shemesh Abraham Ofir
Published: September 2020

The present paper deals with the development of cult in Shiloh during the Middle Ages. After the Byzantine period, when Shiloh was an important Christian cult place, it disappeared from the written sources and started to be identified with Nebi Samwil. In the 12th century Shiloh reappeared in the travelogues of Muslims, and shortly thereafter, in ones by Jews. Although most of the traditions had to do with the Tabernacle, some traditions started to identify Shiloh with the tomb of Eli and his family. The present study looks at the relationship between the practice of ziyara (“visit” in Arabic), which was characterized by the veneration of tombs, and the cult in Shiloh. The paper also surveys archeological finds in Shiloh that attest to a medieval cult and compares them with the written sources. In addition, it presents testimonies by Christians about Jewish cultic practices, along with testimonies about the cult place shared by Muslims and Jews in Shiloh. Examination of the medieval cult in Shiloh provides a broader perspective on an uninstitutionalized regional cult.
Terrestrial Water Storage Change Retrieved by GRACE and Its Implication in the Tibetan Plateau: Estimating Areal Precipitation in Ungauged Region
Authors: Jia Yao , Lei Huimin , Yang Hanbo , Hu Qingfang
Published: September 2020

The Tibetan Plateau (TP) is referred to as the water tower of Asia, where water storage and precipitation have huge impacts on most major Asian rivers. Based on gravity recovery and climate experiment data, this study analyzed the terrestrial water storage (TWS) changes and estimated areal precipitation based on the water balance equation in four different basins, namely, the upper Yellow River (UYE), the upper Yangtze River (UYA), the Yarlung Zangbo River (YZ), and the Qiangtang Plateau (QT). The results show that the TWS change exhibits different patterns in the four basins and varies from −13 to 2 mm/year from 2003 to 2017. The estimated mean annual precipitation was 260 ± 19 mm/year (QT), 697 ± 26 mm/year (UYA), 541 ± 36 mm/year (UYE), and 1160 ± 39 mm/year (YZ) which performed better than other precipitation products in the TP. It indicates a potential method for estimating basin-scale precipitation through integrating basin average precipitation from the water balance equation in the poorly gauged and ungauged regions.
Assessment of the “Zero-Bias Line” Homogenization Method for Microwave Radiometers Using Sentinel-3A and Sentinel-3B Tandem Phase
Authors: Picard Bruno , Bennartz Ralf , Fell Frank , Frery Marie-Laure , Siméon Mathilde , Bordes Frank
Published: September 2020

The long-term stability of microwave radiometers (MWR) on-board altimetry missions is critical to reduce the uncertainty on the global mean sea level estimate. Harmonization and homogenization steps are applied to MWR observations in that perspective. The Sentinel-3 tandem phase provides a unique opportunity to quantify the uncertainties on the “zero-bias line” homogenization approach defined by Bennartz et al. (2020). Initially developed to improve the performance of the wet tropospheric correction retrieval, it is used here to provide a common reference for the inter-calibration between Sentinel-3A and Sentinel-3B MWR. A simplified version of the “zero-bias line” approach, a linear correction depending on brightness temperatures, allows to strongly reduce the bias between the two radiometers for both channels (about 0.5 K) and the standard deviation of the difference (0.3 K). The full version of the approach adding a dependency on wind speed has improved the quality of the WTC retrieval (Bennartz et al. 2020) but degrades the performance of the homogenization. It is thus recommended to apply the simplified version of this approach in the processing of fundamental data record. The quantification of the uncertainties on the homogenization approach is only possible due to the ideal configuration of the Sentinel-3 tandem phase. The same dataset and the same metrics could be used to assess other approaches.
Combining Multi-Sensor Satellite Imagery to Improve Long-Term Monitoring of Temporary Surface Water Bodies in the Senegal River Floodplain
Authors: Ogilvie Andrew , Poussin Jean-Christophe , Bader Jean-Claude , Bayo Finda , Bodian Ansoumana , Dacosta Honoré , Dia Djiby , Diop Lamine , Martin Didier , Sambou Soussou
Published: September 2020

Accurate monitoring of surface water bodies is essential in numerous hydrological and agricultural applications. Combining imagery from multiple sensors can improve long-term monitoring; however, the benefits derived from each sensor and the methods to automate long-term water mapping must be better understood across varying periods and in heterogeneous water environments. All available observations from Landsat 7, Landsat 8, Sentinel-2 and MODIS over 1999–2019 are processed in Google Earth Engines to evaluate and compare the benefits of single and multi-sensor approaches in long-term water monitoring of temporary water bodies, against extensive ground truth data from the Senegal River floodplain. Otsu automatic thresholding is compared with default thresholds and site-specific calibrated thresholds to improve Modified Normalized Difference Water Index (MNDWI) classification accuracy. Otsu thresholding leads to the lowest Root Mean Squared Error (RMSE) and high overall accuracies on selected Sentinel-2 and Landsat 8 images, but performance declines when applied to long-term monitoring compared to default or site-specific thresholds. On MODIS imagery, calibrated thresholds are crucial to improve classification in heterogeneous water environments, and results highlight excellent accuracies even in small (19 km2) water bodies despite the 500 m spatial resolution. Over 1999–2019, MODIS observations reduce average daily RMSE by 48% compared to the full Landsat 7 and 8 archive and by 51% compared to the published Global Surface Water datasets. Results reveal the need to integrate coarser MODIS observations in regional and global long-term surface water datasets, to accurately capture flood dynamics, overlooked by the full Landsat time series before 2013. From 2013, the Landsat 7 and Landsat 8 constellation becomes sufficient, and integrating MODIS observations degrades performance marginally. Combining Landsat and Sentinel-2 yields modest improvements after 2015. These results have important implications to guide the development of multi-sensor products and for applications across large wetlands and floodplains.
Designing a Validation Protocol for Remote Sensing Based Operational Forest Masks Applications. Comparison of Products Across Europe
Authors: Fernandez-Carrillo Angel , Franco-Nieto Antonio , Pinto-Bañuls Erika , Basarte-Mena Miguel , Revilla-Romero Beatriz
Published: September 2020

The spatial and temporal dynamics of the forest cover can be captured using remote sensing data. Forest masks are a valuable tool to monitor forest characteristics, such as biomass, deforestation, health condition and disturbances. This study was carried out under the umbrella of the EC H2020 MySustainableForest (MSF) project. A key achievement has been the development of supervised classification methods for delineating forest cover. The forest masks presented here are binary forest/non-forest classification maps obtained using Sentinel-2 data for 16 study areas across Europe with different forest types. Performance metrics can be selected to measure accuracy of forest mask. However, large-scale reference datasets are scarce and typically cannot be considered as ground truth. In this study, we implemented a stratified random sampling system and the generation of a reference dataset based on visual interpretation of satellite images. This dataset was used for validation of the forest masks, MSF and two other similar products: HRL by Copernicus and FNF by the DLR. MSF forest masks showed a good performance (OAMSF = 96.3%; DCMSF = 96.5), with high overall accuracy (88.7–99.5%) across all the areas, and omission and commission errors were low and balanced (OEMSF = 2.4%; CEMSF = 4.5%; relBMSF = 2%), while the other products showed on average lower accuracies (OAHRL = 89.2%; OAFNF = 76%). However, for all three products, the Mediterranean areas were challenging to model, where the complexity of forest structure led to relatively high omission errors (OEMSF = 9.5%; OEHRL = 59.5%; OEFNF = 71.4%). Comparing these results with the vision from external local stakeholders highlighted the need of establishing clear large-scale validation datasets and protocols for remote sensing-based forest products. Future research will be done to test the MSF mask in forest types not present in Europe and compare new outputs to available reference datasets.
Fusion of Spectral and Structural Information from Aerial Images for Improved Biomass Estimation
Authors: Banerjee Bikram Pratap , Spangenberg German , Kant Surya
Published: September 2020

Efficient, precise and timely measurement of plant traits is important in the assessment of a breeding population. Estimating crop biomass in breeding trials using high-throughput technologies is difficult, as reproductive and senescence stages do not relate to reflectance spectra, and multiple growth stages occur concurrently in diverse genotypes. Additionally, vegetation indices (VIs) saturate at high canopy coverage, and vertical growth profiles are difficult to capture using VIs. A novel approach was implemented involving a fusion of complementary spectral and structural information, to calculate intermediate metrics such as crop height model (CHM), crop coverage (CC) and crop volume (CV), which were finally used to calculate dry (DW) and fresh (FW) weight of above-ground biomass in wheat. The intermediate metrics, CHM (R2 = 0.81, SEE = 4.19 cm) and CC (OA = 99.2%, Κ = 0.98) were found to be accurate against equivalent ground truth measurements. The metrics CV and CV×VIs were used to develop an effective and accurate linear regression model relationship with DW (R2 = 0.96 and SEE = 69.2 g/m2) and FW (R2 = 0.89 and SEE = 333.54 g/m2). The implemented approach outperformed commonly used VIs for estimation of biomass at all growth stages in wheat. The achieved results strongly support the applicability of the proposed approach for high-throughput phenotyping of germplasm in wheat and other crop species.