bluuebunny/crossref_metadata_2025 huggingface dataset:
In Situ Electrospun Porous MIL-88A/PAN Nanofibrous Membranes for Efficient Removal of Organic Dyes
Authors: Wu Hao , Xu Le , Jia Jiao , Dong Fengchun , Jia Yongtang , Liu Xi
Published: January 2023

In recent years, metal–organic framework (MOF)-based nanofibrous membranes (NFMs) have received extensive attention in the application of water treatment. Hence, it is of great significance to realize a simple and efficient preparation strategy of MOF-based porous NFMs. Herein, we developed a direct in situ formation of MOF/polymer NFMs using an electrospinning method. The porous MOF/polymer NFMs were constructed by interconnecting mesopores in electrospun composite nanofibers using poly(vinylpolypyrrolidone) (PVP) as the sacrificial pore-forming agent. MOF (MIL-88A) particles were formed inside the polyacrylonitrile (PAN)/PVP nanofibers in situ during electrospinning, and the porous MIL-88A/PAN (pMIL-88A/PAN) NFM was obtained after removing PVP by ethanol and water washing. The MOF particles were uniformly distributed throughout the pMIL-88A/PAN NFM, showing a good porous micro-nano morphological structure of the NFM with a surface area of 143.21 m2 g−1, which is conducive to its efficient application in dye adsorption and removal. Specifically, the dye removal efficiencies of the pMIL-88A/PAN NFM for amaranth red, rhodamine B, and acid blue were as high as 99.2, 94.4, and 99.8%, respectively. In addition, the NFM still showed over 80% dye removal efficiencies after five adsorption cycles. The pMIL-88A/PAN NFM also presented high adsorption capacities, fast adsorption kinetics, and high cycling stabilities during the processes of dye adsorption and removal. Overall, this work demonstrates that the in situ electrospun porous MOF/polymer NFMs present promising application potential in water treatment for organic dyestuff removal.
Head-to-Head Comparison of High-Performance Liquid Chromatography versus Nuclear Magnetic Resonance for the Quantitative Analysis of Carbohydrates in Yiqi Fumai Lyophilized Injection
Authors: Xie Yuesheng , Zheng Dayong , Yang Ting , Zhang Zhenzhen , Xu Wenwu , Liu Houru , Li Wei
Published: January 2023

Carbohydrate analysis can be used as a standard analysis for quality control of industries of plants, foods and pharmaceuticals. Quantitative 1H NMR spectroscopy (qNMR) is an excellent alternative to chromatography-based mixture analysis. However, the application of qNMR in sugar analysis has rarely been reported. In this study, the performance of qNMR in sugar analysis was investigated and compared with the results from HPLC analysis. A head-to-head comparison of qNMR (internal and external standard methods) versus HPLC (PMP pre-column derivatization HPLC, HPLC-RID and HPLC-ELSD) based on quantitative analysis of four carbohydrates (fructose, glucose, sucrose and maltose) in Yiqi Fumai lyophilized injection (YQFM) is presented. Both assays showed similar performance characteristics, including linearity range, accuracy, precision and recovery, and analysis times of less than 30 min/sample. After methodological validation, both qNMR and HPLC have good accuracy, precision and stability. Indeed, the qNMR method is simple, sensitive and rapid in quantifying the four sugars. By analysis of variance (ANOVA) for sugar content with HPLC and qNMR methods, we demonstrated that the two analytical methods had no significant difference and could be used interchangeably for the quantitative analysis of carbohydrates.
Conformations of Steroid Hormones: Infrared and Vibrational Circular Dichroism Spectroscopy
Authors: Yang Yanqing , Krin Anna , Cai Xiaoli , Poopari Mohammad Reza , Zhang Yuefei , Cheeseman James R. , Xu Yunjie
Published: January 2023

Steroid hormone molecules may exhibit very different functionalities based on the associated functional groups and their 3D arrangements in space, i.e., absolute configurations and conformations. Infrared (IR) and vibrational circular dichroism (VCD) spectra of four different steroid hormones, namely dehydroepiandrosterone (DHEA), 17α-methyltestosterone (MTTT), (16α,17)-epoxyprogesterone (Epoxy-P4), and dehydroepiandrosterone acetate (AcO-DHEA), were measured in deuterated dimethyl sulfoxide and some also in carbon tetrachloride. Extensive conformational searches were carried out using the recent developed conformer-rotamer ensemble sampling tool (CREST) which also accounts for solvent effects using an implicit solvation model. All the CREST conformational candidates were then reoptimized at the B3LYP-D3BJ/def2-TZVPD with the PCM of solvent. The good agreements between the experimental IR and VCD spectra and the theoretical simulations provide a conclusive information about their conformational distribution and absolute configurations. The experimental and theoretical IR and VCD spectra of AcO-DHEA in the carbonyl and alkene stretching region showed some discrepancies, and the possible causes related to solvent effects, large amplitude motions and levels of theory used in the modelling were explored in detail. As part of the investigation, additional calculations at the B3LYP-D3BJ/6-31++G (2d,p) and B3LYP-D3BJ/cc-pVTZ levels, as well as some ‘mixed’ calculations with the double-hybrid functional B2PLYP-D3 were also carried out. The results indicate that the double-hybrid functional is important for predicting the correct IR band pattern in the carbonyl and alkene stretching region.
The Halogen Bond in Weakly Bonded Complexes and the Consequences for Aromaticity and Spin-Orbit Coupling
Authors: Cunha Ana V. , Havenith Remco W. A. , van Gog Jari , De Vleeschouwer Freija , De Proft Frank , Herrebout Wouter
Published: January 2023

The halogen bond complexes CF3X⋯Y and C2F3X⋯Y, with Y = furan, thiophene, selenophene and X = Cl, Br, I, have been studied by using DFT and CCSD(T) in order to understand which factors govern the interaction between the halogen atom X and the aromatic ring. We found that PBE0-dDsC/QZ4P gives an adequate description of the interaction energies in these complexes, compared to CCSD(T) and experimental results. The interaction between the halogen atom X and the π-bonds in perpendicular orientation is stronger than the interaction with the in-plane lone pairs of the heteroatom of the aromatic cycle. The strength of the interaction follows the trend Cl < Br < I; the chalcogenide in the aromatic ring nor the hybridization of the C–X bond play a decisive role. The energy decomposition analysis shows that the interaction energy is dominated by all three contributions, viz., the electrostatic, orbital, and dispersion interactions: not one factor dominates the interaction energy. The aromaticity of the ring is undisturbed upon halogen bond formation: the π-ring current remains equally strong and diatropic in the complex as it is for the free aromatic ring. However, the spin-orbit coupling between the singlet and triplet π→π* states is increased upon halogen bond formation and a faster intersystem crossing between these states is therefore expected.
Effect of Nanoscale W Coating on Corrosion Behavior of Diamond/Aluminum Composites
Authors: Zhu Ping , Zhang Qiang , Xia Yixiao , Sun Kai , Lin Xiu , Gou Huasong , Shil’ko Serge , Wu Gaohui
Published: January 2023

The stability of diamond/aluminum composite is of significant importance for its extensive application. In this paper, the interface of diamond/aluminum composite was modified by adding nanoscale W coating on diamond surface. We evaluated the corrosion rate of nanoscale W-coated and uncoated diamond/aluminum composite by a full immersion test and polarization curve test and clarified the corrosion products and corrosion mechanism of the composite. The introduction of W nanoscale coating effectively reduces the corrosion rate of the diamond/aluminum composite. After corrosion, the bending strength and thermal conductivity of the nanoscale W-coated diamond/aluminum composite are considerably higher than those of the uncoated diamond/aluminum composite. The corrosion loss of the material is mainly related to the hydrolysis of the interface product Al4C3, accompanied by the corrosion of the matrix aluminum. Our work provides guidance for improving the life of electronic devices in corrosive environments.
Dynamics of Vacancy Formation and Distribution in Semiconductor Heterostructures: Effect of Thermally Generated Intrinsic Electrons
Authors: Shamirzaev Timur S. , Atuchin Victor V. , Zhilitskiy Vladimir E. , Gornov Alexander Yu.
Published: January 2023

The effect of thermally generated equilibrium carrier distribution on the vacancy generation, recombination, and mobility in a semiconductor heterostructure with an undoped quantum well is studied. A different rate of thermally generated equilibrium carriers in layers with different band gaps at annealing temperatures forms a charge-carrier density gradient along a heterostructure. The nonuniform spatial distribution of charged vacancy concentration that appears as a result of strong dependence in the vacancy formation rate on the local charge-carrier density is revealed. A model of vacancy-mediated diffusion at high temperatures typical for post-growth annealing that takes into account this effect and dynamics of nonequilibrium vacancy concentration is developed. The change of atomic diffusivity rate in time that follows on the of spatial vacancy distribution dynamics in a model heterostructure with quantum wells during a high-temperature annealing at fixed temperatures is demonstrated by computational modeling.
Fully Atomistic Molecular Dynamics Simulation of a TIPS-Pentacene:Polystyrene Mixed Film Obtained via the Solution Process
Authors: Suzuki Tomoka , De Nicola Antonio , Okada Tomoharu , Matsui Hiroyuki
Published: January 2023

Organic thin-film transistors using small-molecule semiconductor materials such as 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-P) have been recently studied for the production of flexible and printed electronic devices. Blending a semiconductor with an insulating polymer, such as polystyrene, is known to improve the device performance; however, its molecular-level structure remains unknown. In this study, we performed molecular dynamics (MD) simulations on a mixed system of TIPS-P and atactic polystyrene (aPS) with fully atomistic models to understand the structure of the mixed thin film at the molecular level and the influence on the device properties. To reproduce the deposition from the solution, we gradually reduced the number of toluene molecules in the simulation. The dynamic characteristics of the system, mean squared displacement, diffusion coefficient, density profile, and P2 order parameter were analyzed. Some of the simulated systems reached the equilibrium state. In these systems, the simulated structures suggested the presence of more TIPS-P molecules on the surface than inside the bulk, even at the low molecular weight of aPS, where phase separation was not observed experimentally. The results of the fully atomistic MD simulations are also a basis for the coarse-grained model to increase the speed of the MD simulation.
Phonon Dominated Thermal Transport in Metallic Niobium Diselenide from First Principles Calculations
Authors: Contreras René , Celentano Diego , Luo Tengfei , Liu Zeyu , Morales-Ferreiro J. O.
Published: January 2023

Niobium diselenide (NbSe2) is a layered transition metal dichalcogenide material which possesses unique electrical and superconducting properties for future nanodevices. While the superconducting, electrical, and bulk thermal transport properties of NbSe2 have been widely studied, the in-plane thermal transport property of NbSe2, which is important for potential thermoelectric applications, has not been thoroughly investigated. In this report, we study the lattice in-plane thermal transport of 2D NbSe2 by solving the phonon Boltzmann transport equation with the help of the first principles calculation. The thermal conductivity obtained at room temperature is 12.3 W/mK. A detailed analysis shows that the transverse acoustic phonon dominates the lattice thermal transport, and an anomalously small portion of electron contribution to the total thermal conductivity is observed for this metallic phase. The results agree well with experimental measurements and provide detailed mode-by-mode thermal conductivity contribution from different phonon modes. This study can provide useful information for integrating NbSe2 in nanodevices where both electrical and thermal properties are critical, showing great potential for integrating monolayer NbSe2 to thermoelectric devices.
Trilayered Gires–Tournois Resonator with Ultrasensitive Slow-Light Condition for Colorimetric Detection of Bioparticles
Authors: Kang Jiwon , Yoo Young Jin , Ko Joo Hwan , Mahmud Abdullah Al , Song Young Min
Published: January 2023

Over the past few decades, advances in various nanophotonic structures to enhance light–matter interactions have opened numerous opportunities for biosensing applications. Beyond the successful development of label-free nanophotonic biosensors that utilize plasmon resonances in metals and Mie resonances in dielectrics, simpler structures are required to achieve improved sensor performance and multifunctionality, while enabling cost-effective fabrication. Here, we present a simple and effectual approach to colorimetric biosensing utilizing a trilayered Gires–Tournois (GT) resonator, which provides a sensitive slow-light effect in response to low refractive index (RI) substances and thus enables to distinguish low RI bioparticles from the background with spatially distinct color differences. For low RI sensitivity, by impedance matching based on the transmission line model, trilayer configuration enables the derivation of optimal designs to achieve the unity absorption condition in a low RI medium, which is difficult to obtain with the conventional GT configuration. Compared to conventional bilayered GT resonators, the trilayered GT resonator shows significant sensing performance with linear sensitivity in various situations with low RI substances. For extended applications, several proposed designs of trilayered GT resonators are presented in various material combinations by impedance matching using equivalent transmission line models. Further, comparing the color change of different substrates with low RI NPs using finite-difference time-domain (FDTD) simulations, the proposed GT structure shows surpassing colorimetric detection.
High-Performance n-Type Bi2Te3 Thermoelectric Fibers with Oriented Crystal Nanosheets
Authors: Sun Min , Zhang Pengyu , Tang Guowu , Chen Dongdan , Qian Qi , Yang Zhongmin
Published: January 2023

High-performance thermoelectric fibers with n-type bismuth telluride (Bi2Te3) core were prepared by thermal drawing. The nanosheet microstructures of the Bi2Te3 core were tailored by the whole annealing and Bridgman annealing processes, respectively. The influence of the annealing processes on the microstructure and thermoelectric performance was investigated. As a result of the enhanced crystalline orientation of Bi2Te3 core caused by the above two kinds of annealing processes, both the electrical conductivity and thermal conductivity could be improved. Hence, the thermoelectric performance was enhanced, that is, the optimized dimensionless figure of merit (ZT) after the Bridgman annealing processes increased from 0.48 to about 1 at room temperature.
The Prevalence of Orthorexia Nervosa among Greek Professional Dancers
Authors: Athanasaki Dafni , Lakoumentas John , Feketea Gavriela , Vassilopoulou Emilia
Published: January 2023

The aim of this study was to determine the prevalence of orthorexia nervosa (ON) among professional dancers in Greece, as well as its relationship with nutrition, body mass index (BMI), body image flexibility, and parental bonding. The participants were 96 professional dancers, with a mean age of 23.41 ± 5.13 years, who completed a battery of questionnaires recording sociodemographic, clinical, and anthropometric characteristics; adherence to the Mediterranean diet (MedDiet); indications of ON, as determined by the ORTHO-15 questionnaire; body image flexibility, using the body image-acceptance and action questionnaire (BI-AAQ-5); and their recollection of their parents’ attitudes towards them during the first 16 years of life, with the parental bonding instrument (PBI). The study population was classified into two groups, based on BMI: normal weight, and underweight. ON was shown to be significantly correlated with BMI (p = 0.006)-present in normal weight subjects- and body image inflexibility (p < 0.001). Parental body image inflexibility was significantly correlated with a low bonding relationship as perceived in childhood. In conclusion, disordered eating attitudes and body shape concerns are prevalent among professional dancers and appear to be associated with their parental relationship during childhood. Identification of potential ON and development of preventive mechanisms could help to eliminate such concerns and improve the nutrition of professional dancers.
Sociodemographic and Healthcare Factors Associated with Stunting in Children Aged 6–59 Months in the Urban Area of Bali Province, Indonesia 2018
Authors: Kusumajaya Anak Agung Ngurah , Mubasyiroh Rofingatul , Sudikno Sudikno , Nainggolan Olwin , Nursanyoto Hertog , Sutiari Ni Ketut , Adhi Kadek Tresna , Suarjana I Made , Januraga Pande Putu
Published: January 2023

Stunting is a worldwide public health concern, including in Indonesia. Even when living in an urban area with urban characteristics, it is still possible for children to be at risk of stunting. The aim of this study was to determine the sociodemographic and healthcare factors associated with stunting in a province experiencing tourism growth, namely, Bali. Cross-sectional data on Bali Province from the Indonesian Basic Health Research Survey (Riskesdas, 2018) were used as the basis for the research analysis. A total of 846 respondents under five years of age were analyzed, indicating a stunting prevalence of 19.0%. Multivariate logistic regression demonstrated low maternal educational attainment (adjustedOR = 1.92; 95% Confidence Interval = 1.24–2.97), the inadequate consumption of iron tablets during pregnancy (adjustedOR = 1.56; 95% Confidence Interval = 1.08–2.24), and no extended family (adjustedOR = 1.55; 95% Confidence Interval = 1.07–2.26) as being significantly associated with stunting. According to these findings, sociodemographic and healthcare factors are associated with stunting in urban Bali. Improving women’s education, ensuring sufficient iron tablets are consumed during pregnancy, and encouraging the involvement of the extended family in childcare are recommended.
Coffee Pulp: A Natural Alternative for Control of Resistant Nematodes in Small Ruminants
Authors: López-Rodríguez Gabino , Zaragoza-Bastida Adrian , Reyes-Guerrero David Emanuel , Olmedo-Juárez Agustín , Valladares-Carranza Benjamín , Vega-Castillo Luis Fernando , Rivero-Perez Nallely
Published: January 2023

Goat production in Mexico is an important economic activity that is affected by different gastrointestinal nematode (GIN) species. GINs resistant to commercial anthelmintics have been reported. Plant extracts or agro-industrial by-products, such as coffee pulp, have been proposed as control alternatives, given their secondary metabolite content. The aim of the present study was to determine the anthelmintic activity of the hydroalcoholic extract of coffee pulp against benzimidazole-resistant GINs. Stool samples were collected from goats, from which GIN eggs were identified and quantified. Molecular techniques confirmed the genus of GINs and their benzimidazole resistance profile. The percentage of egg hatching inhibition (% EHI) and larval mortality (% LM) with the hydroalcoholic extract of coffee pulp was determined at concentrations from 200 to 0.39 mg/mL. The genera Haemonchus spp. and Trichostrongylus spp. were identified, and the presence of the β-tubulin gene mutation, associated with benzimidazole (BZ) resistance, was determined. Hydroalcoholic extract of coffee pulp inhibited 100% of egg hatching at 200 and 100 mg/mL, with no larvicidal effect at the evaluated concentrations.
Formulation and In Vitro Evaluation of Mucoadhesive Sustained Release Gels of Phytoestrogen Diarylheptanoids from Curcuma comosa for Vaginal Delivery
Authors: Limpongsa Ekapol , Tabboon Peera , Tuntiyasawasdikul Sarunya , Sripanidkulchai Bungorn , Pongjanyakul Thaned , Jaipakdee Napaphak
Published: January 2023

Diarylheptanoids (DAs) characterized by a 1,7-diphenylheptane structural skeleton are considered a novel class of phytoestrogens. The DAs available in Curcuma comosa Roxb. (C. comosa) extract demonstrated significant estrogenic activities both in vitro and in vivo. This study aimed to develop and comprehensively evaluate a mucoadhesive vaginal gel for the sustained release of DAs. Different mucoadhesive polymers as gelling agents were investigated. C. comosa ethanolic crude extract was used as a source of DAs. All C. comosa gels were light brown homogeneous with pH within 4.4–4.6. Their flow behaviors were pseudoplastic with a flow behavior index of 0.18–0.38. The viscosity at a low shear rate varied from 6.2 to 335.4 Pa·s. Their mechanical and extrudability properties were associated well with rheological properties. Polycarbophil (PCP):hydroxypropyl methylcellulose (HPMC) blends had a higher mucoadhesiveness to porcine vaginal mucosa than those of PCP-based or HPMC-based gels. All C. comosa gels exhibited a sustained, zero-order DA release pattern over 72 h. Korsmeyer and Peppas equation fitting indicated a non-Fickian, case II transport release mechanism. C. comosa gels had good physical and chemical stability under low-temperature storage for up to 12 months. PCP:HPMC-based mucoadhesive gels could be a proper delivery system for vaginal administration of DAs.
Development of a Positive Psychology Well-Being Intervention in a Community Pharmacy Setting
Authors: Ward Jennifer Louise , Sparkes Alison , Ricketts Marie , Hewlett Paul , Prior Amie-Louise , Hallingberg Britt , James Delyth Higman
Published: January 2023

Background: Community pharmacies are well-placed to deliver well-being interventions; however, to date, nothing has been produced specifically for this setting. The aim of this study was to develop a positive psychology intervention suitable for a community pharmacy setting with the goal of increasing the well-being of community members. Methods: Intervention development consisted of three steps: Step 1—identify the evidence-base and well-being model to underpin the basis of the intervention (Version 1); Step 2—model the intervention and gather user feedback to produce Version 2, and Step 3—revisit the evidence-base and refine the intervention to produce Version 3. Results: Findings from nine studies (seven RCTs, one cross-sectional, one N-1 design plus user feedback were applied to model a 6-week ‘Prescribing Happiness (P-Hap)’ intervention, underpinned by the PERMA model plus four other components from the positive psychology literature (Three Good Things, Utilising Your Signature Strengths in New Ways, Best Possible Selves and Character Strengths). A PERMA-based diary was designed to be completed 3 days a week as part of the intervention. Conclusions: This work is an important development which will direct the future implementation of interventions to support well-being in this novel setting. The next stage is to gain the perspectives of external stakeholders on the feasibility of delivering the P-Hap for its adoption into community pharmacy services in the future.
Physiological and Ultrastructural Responses to Excessive-Copper-Induced Toxicity in Two Differentially Copper Tolerant Citrus Species
Authors: Li Xin-Yu , Lin Mei-Lan , Lu Fei , Zhou Xin , Xiong Xing , Chen Li-Song , Huang Zeng-Rong
Published: January 2023

Over-applied copper (Cu)-based agrochemicals are toxic to citrus trees. However, less information is available discussing the ultrastructural alterations in Cu-stressed citrus species. In the present study, seedlings of Citrus sinensis and Citrus grandis that differed in Cu-tolerance were sandy-cultured with nutrient solution containing 0.5 µM Cu (as control) or 300 µM Cu (as Cu toxicity) for 18 weeks. At the end of the treatments, the physiological parameters and ultrastructural features of the citrus leaves and roots were analyzed. The results indicate that Cu toxicity significantly decreased the ratio of shoot biomass to dry weight, the Cu translocation factor and the total chlorophyll of two citrus species. The anatomical and ultrastructural alterations verified that excessive Cu resulted in starch granules accumulated in the leaves and roots of the two citrus species. Under Cu toxicity, increased root flocculent precipitate and thickened root cell wall might reduce the Cu translocation from citrus roots to the shoots. Compared with C. sinensis, C. grandis maintained a relatively integral root cellular structure under Cu toxicity, which provided a structural basis for a higher Cu tolerance than C. sinensis. The present results increase our understanding of the physiological and ultrastructural responses to Cu toxicity in citrus species.
Characterization and Transcriptome Analysis of Maize Small-Kernel Mutant smk7a in Different Development Stages
Authors: Wang Jing , Wang Hongwu , Li Kun , Liu Xiaogang , Cao Xiaoxiong , Zhou Yuqiang , Huang Changling , Peng Yunling , Hu Xiaojiao
Published: January 2023

The kernel serves as a storage organ for various nutrients and determines the yield and quality of maize. Understanding the mechanisms regulating kernel development is important for maize production. In this study, a small-kernel mutant smk7a of maize was characterized. Cytological observation suggested that the development of the endosperm and embryo was arrested in smk7a in the early development stage. Biochemical tests revealed that the starch, zein protein, and indole-3-acetic acid (IAA) contents were significantly lower in smk7a compared with wild-type (WT). Consistent with the defective development phenotype, transcriptome analysis of the kernels 12 and 20 days after pollination (DAP) revealed that the starch, zein, and auxin biosynthesis-related genes were dramatically downregulated in smk7a. Genetic mapping indicated that the mutant was controlled by a recessive gene located on chromosome 2. Our results suggest that disrupted nutrition accumulation and auxin synthesis cause the defective endosperm and embryo development of smk7a.
Amino Acids as Bio-Based Curing Agents for Epoxy Resin: Correlation of Network Structure and Mechanical Properties
Authors: Rothenhäusler Florian , Ruckdaeschel Holger
Published: January 2023

Bio-based alternatives for petroleum-based thermosets are crucial for implementing sustainable practices in fiber-reinforced polymer composites. Therefore, the mechanical properties of diglycidyl ether of bisphenol a (DGEBA) cured with either l-arginine, l-citrulline, γ-aminobutyric acid, l-glutamine, l-tryptophan, or l-tyrosine were investigated to determine the potential of amino acids as bio-based curing agents for epoxy resins. Depending on the curing agent, the glass transition temperature, Young’s modulus, tensile strength, and critical stress intensity factor range from 98.1 ∘C to 188.3 ∘C, 2.6 GPa to 3.5 GPa, 39.4 MPa to 46.4 MPa, and 0.48 MPam0.5 to 1.34 MPam0.5, respectively. This shows that amino acids as curing agents for epoxy resins result in thermosets with a wide range of thermo-mechanical properties and that the choice of curing agent has significant influence on the thermoset’s properties. After collecting the results of dynamic mechanical analysis (DMA), tensile, flexural, compression, and compact tension tests, the functionality f, cross-link density νC, glass transition temperature Tg, Young’s modulus ET, compression yield strength σCy, critical stress intensity factor in mode I KIC, fracture energy GIC, and diameter of the plastic zone dp are correlated with one another to analyze their inter-dependencies. Here, the cross-link density correlates strongly positively with Tg, ET, and σCy, and strongly negatively with KIC, GIC, and dp. This shows that the cross-link density of DGEBA cured with amino acids has a crucial influence on their thermo-mechanical properties and that the thermosets considered may either be stiff and strong or tough, but hardly both at the same time.
Fused Deposition Modeling and Characterization of Heat Shape Memory Poly(lactic) Acid-Based Porous Vascular Scaffold
Authors: Zhang Li , Hanif Muhammad , Li Jiacheng , Shah Abdul Hakim , Hussain Wajid , Zhang Guotao
Published: January 2023

Shape memory polymers have received widespread attention from researchers because of their low density, shape variety, responsiveness to the environment, and transparency. This study deals with heat-shape memory polymers (SMPs) based on polylactic acid (PLA) for designing and fabricating a novel porous vascular scaffold to treat vascular restenosis. The solid isotropic material penalization method (SIMP) was applied to optimize the vascular scaffolds. Based on the torsional torque loading of Hyperworks Optistruct and the boundary conditions, the topological optimization model of a vascular scaffold unit was established. Forward and reverse hybrid modeling technology was applied to complete the final stent structure’s assembly. The glass transition temperature for the present SMPs is 42.15 °C. With the increase in temperature, the ultimate tensile strength of the SMPs is reduced from 29.5 MPa to 11.6 MPa. The maximum modulus at room temperature was around 34 MPa. Stress relaxation curves show that the material classification is a “thermoset” polymer. The superb mechanical properties, the transition temperature of the SMPs, and the recovery ratio made it a feasible candidate for a vascular scaffold. A circular tube based on the shape memory polymers was presented as an example for analyzing the recovery ratio in an unfolding state. A higher recovery ratio was obtained at a temperature of 65 °C with a tube thickness of 2 mm. Finally, the proposed porous vascular scaffold was successfully fabricated, assessed, and compared with the original and previously developed vascular scaffolds. The proposed scaffold structure regains its initial shape with a recovery ratio of 98% (recovery temperature of 47 °C) in 16 s. The tensile strength, Young’s modulus, and bending strength of the proposed scaffold were 29.5 MPa, 695.4 MPa, and 6.02 MPa, respectively. The results showed that the proposed scaffold could be regarded as a potential candidate for a vascular implantation.
Influence of Alkali Treatment of Jatropha Curcas L. Filler on the Service Life of Hybrid Adhesive Bonds under Low Cycle Loading
Authors: Kolář Viktor , Hrabě Petr , Müller Miroslav , Hromasová Monika , Herák David , Sutanto Hadi
Published: January 2023

The aim of this research was to evaluate the effect of untreated and 5% aqueous NaOH solution-treated filler of the plant Jatropha Curcas L. on the mechanical properties of adhesive bonds, especially in terms of their service life at different amplitudes of cyclic loading. As a result of the presence of phorbol ester, which is toxic, Jatropha oilseed cake cannot be used as livestock feed. The secondary aim was to find other possibilities for the utilization of natural waste materials. Another use is as a filler in polymer composites, that is, in composite adhesive layers. The cyclic loading of the adhesive bonds was carried out for 1000 cycles in two amplitudes, that is, 5–30% of the maximum force and 5–50% of the maximum force, which was obtained by the static tensile testing of the adhesive bonds with unmodified filler. The static tensile test showed an increase in the shear strength of the adhesive bonds with alkali-treated filler compared to the untreated filler by 3–41%. The cyclic test results did not show a statistically significant effect of the alkaline treatment of the filler surface on the service life of the adhesive bonds. Positive changes in the strain value between adhesive bonds with treated and untreated filler were demonstrated at cyclic stress amplitudes of 5–50%. SEM analysis showed the presence of interlayer defects in the layers of the tested materials, which are related to the oil-based filler used.
Incorporating Graphene Nanoplatelets and Carbon Nanotubes in Biobased Poly(ethylene 2,5-furandicarboxylate): Fillers’ Effect on the Matrix’s Structure and Lifetime
Authors: Kourtidou Dimitra , Karfaridis Dimitrios , Kehagias Thomas , Vourlias George , Bikiaris Dimitrios N. , Chrissafis Konstantinos
Published: January 2023

Poly(ethylene 2,5-furandicarboxylate) (PEF) nanocomposites reinforced with Graphene nanoplatelets (GNPs) and Carbon nanotubes (CNTs) were in situ synthesized in this work. PEF is a biobased polyester with physical properties and is the sustainable counterpart of Polyethylene Terephthalate (PET). Its low crystallizability affects the processing of the material, limiting its use to packaging, films, and textile applications. The crystallization promotion and the reinforcement of PEF can lead to broadening its potential applications. Therefore, PEF nanocomposites reinforced with various loadings of GNPs, CNTs, and hybrids containing both fillers were prepared, and the effect of each filler on their structural characteristics was investigated by X-ray Diffraction (XRD), Fourier transform infrared spectroscopy—attenuated total reflectance (FTIR–ATR), and X-Ray Photoelectron Spectroscopy (XPS). The morphology and structural properties of a hybrid PEF nanocomposite were evaluated by Transmission Electron Microscopy (TEM). The thermo-oxidative degradation, as well as lifetime predictions of PEF nanocomposites, in an ambient atmosphere, were studied using Thermogravimetric Analysis (TGA). Results showed that the fillers’ incorporation in the PEF matrix induced changes in the lamellar thickness and increased crystallinity up to 27%. TEM analysis indicated the formation of large CNTs aggregates in the case of the hybrid PEF nanocomposite as a result of the ultrasonication process. Finally, the presence of CNTs caused the retardation of PEF’s carbonization process. This led to a slightly longer lifetime under isothermal conditions at higher temperatures, while at ambient temperature the PEF nanocomposites’ lifetime is shorter, compared to neat PEF.
Applications and Challenges of Supercritical Foaming Technology
Authors: Zhou Yujin , Tian Yingrui , Peng Xiaowei
Published: January 2023

With economic development, environmental problems are becoming more and more prominent, and achieving green chemistry is an urgent task nowadays, which creates an opportunity for the development of supercritical foaming technology. The foaming agents used in supercritical foaming technology are usually supercritical carbon dioxide (ScCO2) and supercritical nitrogen (ScN2), both of which are used without environmental burden. This technology can reduce the environmental impact of polymer foam production. Although supercritical foaming technology is already in production in some fields, it has not been applied on a large scale. Here, we present a detailed analysis of the types of foaming agents currently used in supercritical foaming technology and their applications in various fields, summarizing the technological improvements that have been made to the technology. However, we have found that today’s supercritical technologies still need to address some additional challenges to achieve large-scale production.
Progression of Quantum Dots Confined Polymeric Systems for Sensorics
Authors: Ahirwar Ranjana Choudhary , Mehra Swati , Reddy Sanjeev Machindra , Alshamsi Hassan Abbas , Kadhem Aseel A. , Karmankar Smita Badur , Sharma Alka , Poushali
Published: January 2023

The substantial fluorescence (FL) capabilities, exceptional photophysical qualities, and long-term colloidal stability of quantum dots (QDs) have aroused a lot of interest in recent years. QDs have strong and wide optical absorption, good chemical stability, quick transfer characteristics, and facile customization. Adding polymeric materials to QDs improves their effectiveness. QDs/polymer hybrids have implications in sensors, photonics, transistors, pharmaceutical transport, and other domains. There are a great number of review articles available online discussing the creation of CDs and their many uses. There are certain review papers that can be found online that describe the creation of composites as well as their many different uses. For QDs/polymer hybrids, the emission spectra were nearly equal to those of QDs, indicating that the optical characteristics of QDs were substantially preserved. They performed well as biochemical and biophysical detectors/sensors for a variety of targets because of their FL quenching efficacy. This article concludes by discussing the difficulties that still need to be overcome as well as the outlook for the future of QDs/polymer hybrids.
Improving the Shelf Life and Quality of Minced Beef by Cassia Glauca Leaf Extracts during Cold Storage
Authors: Ghoneim Shaymaa , Saleh Ebeed , Hussein Mohamed , Sadek Kadry , Shukry Mustafa , Ghamry Heba I. , Fericean Liana Mihaela , Ali Eman
Published: January 2023

Minced beef is a popular meat product due to its low price and superior nutritional value. The contamination of minced beef is a significant risk for the worldwide meat market. Both natural and synthetic preservatives are used to expand the shelf life and improve the quality properties of meat. The harmful effects of synthetic preservatives make natural preservatives more appealing. Therefore, this research was performed to study the impact of different concentrations of Cassia glauca leaf extract (CGE) on increasing the shelf life of minced beef. Seventy-two minced beef samples were divided into control, 0.25, 0.5, and 1% w/w CGE treated groups. The control and treated samples were kept at 3 ± 1 °C in the refrigerator for 15 days. Minced beef samples’ sensory, chemical, and microbiological properties were assessed every three days. The gained results showed that the CGE addition effectively decreased the microbial count and maintained the minced beef’s sensory and chemical quality. Additionally, CGE extended the shelf life of minced meat up to 15 days under the proper refrigeration condition compared to the control group, which decomposed after the sixth day of refrigeration. Our study suggested that CGE could be used as a natural preservative for refrigerated minced meat.
Incorporation of Substrates and Inoculums as Operational Strategies to Promote Lignocellulose Degradation in Composting of Green Waste—A Pilot-Scale Study
Authors: Oviedo-Ocaña Edgar Ricardo , Soto-Paz Jonathan , Sanchez-Torres Viviana , Sánchez Antoni
Published: January 2023

Composting is a sustainable alternative for green waste (GW) valorization contributing to the circular bioeconomy. However, the processing time must be reduced and the end-product quality must be improved. This study determined the effect of the incorporation of processed food waste (PFW), unprocessed food (UPFW), sawdust (SW), phosphate rock (PR) and a specific bacterial inoculum on GW-composting process parameters and product quality. Three treatments were evaluated in 120 kg piles: (i) TA: (GW + UPFW + PFW + inoculum), (ii) TB (GW + UPFW + PFW), and (iii) TC (GW). An inoculum of Bacillus sp. and Paenibacillus sp. was incorporated in the cooling phase for TA. On the other hand, the effect of the inoculum at the laboratory scale (20 kg reactors) was compared with that found at the pilot scale (120 kg piles). The incorporation of FW, SW, PR and the inoculum increased the amount of lignocellulose biodegradation (TA: 29.1%; TB: 22.7%; TC: 18.2%), which allowed for a reduction of up to 14 days of processing time. The product obtained for TA had a similar quality to the other two treatments, although a lower phytotoxicity was determined according to the germination index (TA: 95%; TB: 85%; and TC: 83%). The final product of TA showed the best agricultural characteristics with pH 8.3, TOC of 24.8%, TN of 1.32%, and GI of 98.8%. Finally, the scaling effect with the bacterial inoculum was shown to affect parameters such as the TOC, TN, GI, and, to a lesser extent, temperature and pH. The results obtained in this paper highlight the importance of optimizing the composting of GW, specifically with the use of co-substrates and specific inocula, which can be of interest for composting materials with a high content of lignocellulose such as GW.
Performance of a Combined Bacteria/Zeolite Permeable Barrier on the Rehabilitation of Wastewater Containing Atrazine and Heavy Metals
Authors: Silva Bruna , Pimentel Cassia Z. , Machado Bruna , Costa Filomena , Tavares Teresa
Published: January 2023

Several chemicals, such as pesticides and heavy metals, are frequently encountered together in environment matrices, becoming a priority concerning the prevention of their emissions, as well as their removal from the environment. In this sense, this work aimed to evaluate the effectiveness of a permeable biosorbent bio-barrier reactor (PBR) on the removal of atrazine and heavy metals (copper and zinc) from aqueous solutions. The permeable bio-barrier was built with a bacterial biofilm of R. viscosum supported on 13X zeolite. One of the aims of this work is the investigation of the toxic effects of atrazine, copper and zinc on the bacterial growth, as well as the assessment of their ability to adapt to repeated exposure to contaminants and to degrade atrazine. The growth of R. viscosum was not affected by concentrations of atrazine bellow 7 mg/L. However, copper and zinc in binary solutions were able to inhibit the growth of bacteria for all the concentrations tested (5 to 40 mg/L). The pre-acclimation of the bacteria to the contaminants allowed for an increase of 50% of the bacterial growth. Biodegradation tests showed that 35% of atrazine was removed/degraded, revealing that this herbicide is a recalcitrant compound that is hard to degrade by pure cultures. The development of a PBR with R. viscosum supported on zeolite was successfully performed and the removal rates were 85% for copper, 95% for zinc and 25% for atrazine, showing the potential of the sustainable and low-cost technology herein proposed.
Do Countries Need Religious and Educational Freedoms to Achieve Prosperity?
Authors: Khan Khatib Ahmad , Aigerim Danabekova , Wu Yansheng
Published: January 2023

This study examines the impact of religious and educational freedoms on prosperity. The system GMM model is applied by using the data of 45 lower-, middle-, and high-income countries from 2009 to 2018. The results show that religious and academic freedoms are positively and statistically significantly associated with prosperity. It is revealed from the results that the lagged impact of both religious and education freedoms has a higher impact on prosperity than the current level of both variables. Interestingly, the interaction term between academic and religious freedom is also positive and statistically significant, indicating that their combined effect further increases prosperity. Further, the interaction term between government effectiveness and gross fixed capital formation is introduced. Its impact is positive and significant, indicating that capital investment positively affects prosperity in the case of higher government effectiveness. This study uses gross fixed capital formation and trade openness as control variables and these variables have a positive impact on prosperity, but the impact of trade openness on prosperity is insignificant. Thus, this study recommends religious and education freedom to achieve prosperity, especially in low-income countries that are already lagging.
FAANG Stocks, Gold, and Islamic Equity: Implications for Portfolio Management during COVID-19
Authors: Saleem Kashif , AlHares Osama , Khan Haroon , Farooq Omar
Published: January 2023

During the COVID-19 pandemic, technology stocks, such as FAANG stocks (Facebook, Amazon, Apple, Netflix, and Google), attracted the attention of global investors due to the vast use of technology in daily business. However, technology stocks are generally considered risky stocks; hence, efficient risk management is required to construct an optimal portfolio. In this study, we investigate the volatility spillovers and dynamic conditional correlations among the daily returns of FAANG company stocks, gold, and sharia-compliant equity to construct the optimal portfolio weights and hedge ratios during the COVID-19 pandemic period by utilizing a multivariate GARCH framework. The dynamic conditional correlations reveal that both gold and sharia-compliant equities exhibit lower correlations with FAANG stocks during the COVID-19 pandemic, implying opportunities for portfolio diversification. The findings indicate that gold and shariah-compliant equity are good candidates to hedge FAANG stocks. These findings are highly relevant for international investors, asset managers, hedgers, and portfolio managers.
Automatic Registration of Homogeneous and Cross-Source TomoSAR Point Clouds in Urban Areas
Authors: Pang Lei , Liu Dayuan , Li Conghua , Zhang Fengli
Published: January 2023

Building reconstruction using high-resolution satellite-based synthetic SAR tomography (TomoSAR) is of great importance in urban planning and city modeling applications. However, since the imaging mode of SAR is side-by-side, the TomoSAR point cloud of a single orbit cannot achieve a complete observation of buildings. It is difficult for existing methods to extract the same features, as well as to use the overlap rate to achieve the alignment of the homologous TomoSAR point cloud and the cross-source TomoSAR point cloud. Therefore, this paper proposes a robust alignment method for TomoSAR point clouds in urban areas. First, noise points and outlier points are filtered by statistical filtering, and density of projection point (DoPP)-based projection is used to extract TomoSAR building point clouds and obtain the facade points for subsequent calculations based on density clustering. Subsequently, coarse alignment of source and target point clouds was performed using principal component analysis (PCA). Lastly, the rotation and translation coefficients were calculated using the angle of the normal vector of the opposite facade of the building and the distance of the outer end of the facade projection. The experimental results verify the feasibility and robustness of the proposed method. For the homologous TomoSAR point cloud, the experimental results show that the average rotation error of the proposed method was less than 0.1°, and the average translation error was less than 0.25 m. The alignment accuracy of the cross-source TomoSAR point cloud was evaluated for the defined angle and distance, whose values were less than 0.2° and 0.25 m.