bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Zinc Hydride Cations [ZnH]+: Synthesis, Structure, and CO2 Hydrosilylation Catalysis
Authors: Ritter Florian , Spaniol Thomas P. , Douair Iskander , Maron Laurent , Okuda Jun 
Published: September 2020

AbstractProtonolysis of [ZnH2]n with the conjugated Brønsted acid of the bidentate diamine TMEDA (N,N,N′,N′‐tetramethylethane‐1,2‐diamine) and TEEDA (N,N,N′,N′‐tetraethylethane‐1,2‐diamine) gave the zinc hydride cation [(L2)ZnH]+, isolable either as the mononuclear THF adduct [(L2)ZnH(thf)]+[BArF4]− (L2=TMEDA; BArF4−=[B(3,5‐(CF3)2‐C6H3)4]−) or as the dimer [{(L2)Zn)}2(μ‐H)2]2+[BArF4]−2 (L2=TEEDA). In contrast to [ZnH2]n, the cationic zinc hydrides are thermally stable and soluble in THF. [(L2)ZnH]+ was also shown to form di‐ and trinuclear adducts of the elusive neutral [(L2)ZnH2]. All hydride‐containing cations readily inserted CO2 to give the corresponding formate complexes. [(TMEDA)ZnH]+[BArF4]− catalyzed the hydrosilylation of CO2 with tertiary hydrosilanes to give stepwise formoxy silane, methyl formate, and methoxy silane. The unexpected formation of methyl formate was shown to result from the zinc‐catalyzed transesterification of methoxy silane with formoxy silane, which was eventually converted into methoxy silane as well.
Isotope Effects in Plasmonic Photosynthesis
Authors: Yu Sungju , Jain Prashant K. 
Published: September 2020

AbstractThe photoexcitation of plasmonic nanoparticles has been shown to drive multistep, multicarrier transformations, such as the conversion of CO2 into hydrocarbons. But for such plasmon‐driven chemistry to be precisely understood and modeled, the critical photoinitiation step in the reaction cascade must be identified. We meet this goal by measuring H/D and 12C/13C kinetic isotope effects (KIEs) in plasmonic photosynthesis. In particular, we found that the substitution of H2O with D2O slows hydrocarbon production by a factor of 5–8. This primary H/D KIE leads to the inference that hole‐driven scission of the O−H bond in H2O is a critical, limiting step in plasmonic photosynthesis. This study advances mechanistic understanding of light‐driven chemical reactions on plasmonic nanoparticles.
Cold Plasma Treatment of Soybean Oil with Hydrogen Gas
Authors: Yepez Ximena V. , Baykara Haci , Xu Lei , Keener Kevin M. 
Published: September 2020

AbstractHigh‐voltage atmospheric cold plasma (HVACP) treatment generates reactive gas species that induce inter‐ and intramolecular reactions in soybean oil. The goal of this study is to analyze the effect of HVACP treatment on the chemical structure of soybean oil in a hydrogen gas environment at atmospheric pressure. HVACP was used to treat soybean oil (15 g) for up to 6 hours by triplicate. Plasma‐generated reactive gas species interact with the sample, producing three distinct fractions identified as a liquid, gel, and solid. Fatty acid profile, Fourier‐transform infrared spectroscopy, proton and carbon nuclear magnetic resonance, size‐exclusion chromatography, thermal properties, and peroxide value were used to characterize the chemical structure. Results indicated a lower content of polyunsaturated fatty acids, increased content of saturated fatty acids, and the presence of isomers. An insoluble portion was observed in the solid fraction and increased with treatment time up to 42% in the 6‐h treated samples. Plasma species may cause two main reactions: polymerization and hydrogenation.
Accurate Prediction of Kinematic Viscosity of Biodiesels and their Blends with Diesel Fuels
Authors: Mehrizadeh Masoud , Nikbin‐Fashkacheh Hadi , Zand Nima , Najafi‐Marghmaleki Adel 
Published: September 2020

AbstractViscosity of mixtures of biodiesels (admixtures) and mixtures of biodiesel/diesel (blends) is a important parameter for determining their combustion behavior. There is no universal and general model for prediction of viscosity of these systems at different conditions. Hence, developing simple, accurate, and general models for prediction of viscosity of these systems is of great importance. In this work, three computer‐based models named multilayer perceptron neural network (MLP‐NN), radial basis function optimized by particle swarm optimization (PSO‐RBF), and adaptive neuro fuzzy inference system optimized by hybrid approach (Hybrid‐ANFIS) were developed for prediction of viscosity of blends and admixtures. A number of 966 experimental data covering wide ranges of influencing parameters were utilized to develop the models. The accuracy of predictions of the developed models was examined by using different statistical quality measure approaches as well as comparing their results with the predictions of literature models. Results showed that the developed models present accurate predictions and are superior to the literature models. The predictions of PSO‐RBF model were also better than Hybrid‐ANFIS and MLP‐NN models.
Production and characterization of liquid biofuels from locally available nonedible feedstocks
Authors: Fadhil Abdelrahman B. 
Published: September 2020

AbstractMandarin (Citrus reticulata) seeds were exploited as possible nonedible feedstock for the synthesis of liquid biofuels, namely, biodiesel and bio‐oil via alkali–alcoholysis and pyrolysis routes, respectively. The alkali–alcoholysis reaction of mandarin seed oil with an equivalent mixture of methanol–ethanol alcohols was examined and optimized by analysis of variance (ANOVA). The best experimental yield of biodiesel (95.55 ± 1.55 wt.%) was comparable with the predicted yield (95.0 wt.%). Also, analysis by one‐way ANOVA showed that the selected variables were statistically significant. The 1H NMR spectroscopy asserted the transformation of the oil to biodiesel. Also, the evaluated properties of the biodiesel were in the range given by ASTM D6751 standards. The mandarin citrus seeds have also subjected to the thermal pyrolysis process in a fixed‐bed reactor to obtain bio‐oil and bio‐char. The influence of the pyrolysis temperature, time, feed particle size, and heating rate on the bio‐oil yield was optimized. The highest yield of bio‐oil (52.34 ± 1.25 wt.%) was attained at 475°C for 60 min using 70 mesh particle size of the feed with a heating rate of 20°C/min. The bio‐oil was analyzed by Fourier transform infrared spectroscopy (FTIR), 1H NMR spectroscopy, and ultimate analysis. The bio‐oil derived from MCS has an empirical formula of CH1.88 O0.16 N0.012 S0.0005 with 37.96 MJ/kg of heating value. The elevated carbon level, low oxygen content, and high calorific value (25.45 MJ/kg) of the attained bio‐char suggest its suitability as a solid fuel. Also, the obtained bio‐char can be utilized for preparing carbon adsorbent as a result of its good surface area.
Effect of phosphorus–nitrogen compound on flame retardancy and mechanical properties of polylactic acid
Authors: Hu Xu , Sun Jinhao , Li Xing , Qian Lijun , Li Juan 
Published: September 2020

AbstractA phosphorus‐nitrogen flame retardant (PN) was synthesized by using cytosine and diphenylphosphinic chloride. The flame retardancy and thermal stability of polylactic acid (PLA)/PN composites were investigated by the UL‐94 vertical burning test, limited oxygen index (LOI), cone calorimeter test, and thermogravimetric analysis. The PN performs efficiently on improving the flame retardancy of PLA. The PLA composite achieves the UL‐94 V‐0 rating and its LOI increases to 30.4 vol% by adding 0.5 wt% PN. The flame retardant mechanism analysis showed that PN catalyzes the degradation of PLA to improve the flame retardancy by melting‐away mode. Meanwhile PN reduces the release of flammable gasses during thermal degradation of PLA by promoting the transesterification of PLA, which is helpful for extinguishing flame. Moreover, triglycidyl isocyanurate (TGIC) was used as a micro‐crosslinking agent to reduce the loss of mechanical properties of PLA/PN composites caused by degradation. Adding 0.1 wt% TGIC and 1.0 wt% PN into PLA, the tensile strength and elongation at break of PLA/PN are increased to the same level as that of PLA. Therefore, PLA with excellent comprehensive performance can be obtained.
The effect of component addition order on the properties of epoxy resin/polyurethane resin interpenetrating polymer network structure
Authors: Cheng Hsien‐Tai , Lee Ya‐Shiuan , Liu Hsu‐Chen , Lee Wen‐Jau 
Published: September 2020

AbstractEpoxy resin (ER) is one of the most important synthetic resins, but it has the disadvantage of lacking impact resistance. However, it can be improved by mixing with polyurethane resin (PU). In this study, Epon 828, triethylenetetramine (TETA), polytetramethylene ether glycol (PTMG), isophorone diisocyanate (IPDI), and dibutyltin dilaurate (DBTDL) were used as raw materials to prepare ER/PU interpenetrating polymer network structures (IPNs) by three different blending processes. The results showed the reactivity between TETA and IPDI were greater than that between TETA and ER. When ER/TETA/PTMG/IPDI/DBTDL were mixed at the same time, or ER and PU resins were prepared separately and then mixed, the ER/PU composites produced had a phase separation inside the structure. The most appropriate blending method was to mix ER with PTMG, IPDI, DBTDL first, and then add TETA after 10 min. The composite formed had a uniform appearance, and had better physical, mechanical, and thermal properties than the others did.
The impact of intense types of effects on poly(N‐vinyl caprolactam) and composites in the system nanoscale anatase – poly(N‐vinyl caprolactam)
Authors: Chikhacheva Irina , Safyanova Lidiya , Timaeva Olesya , Kuz'micheva Galina , Kubrakova Irina , Komova Ninel 
Published: September 2020

AbstractFor the first time, the effects of microwave and ultrasonic treatments and an alternating electric field on poly(N‐vinyl caprolactam) (PVCL40) both in the original and in the composite with nanoscale anatase have been studied. Comparison of the results of studying the samples by X‐ray diffraction, IR spectroscopy, differential scanning calorimetry (DSC) before and after treatments allowed us to identify, and explain the response of objects to different types of effects with a change in their characteristics. Analysis and comparison of the results do not exclude the misorientation of the PVCL40 domains in thin films (microwave processing), which becomes flat‐ordered after their rubbing, the destruction of the PVCL40 and the disorder of the side substituent are found, accompanied by a change in the periodicity chains (microwave processing, electric field), a decrease in the water content in the system (microwave processing) and amorphization of nanoscale anatase (microwave processing, electric field) were revealed. The implementation of the revealed effects as response to microwave, ultrasonic, and electric field treatments on a similar type of polymers with a different composition and structure is not ruled out.
Reinforcement of polypropylene by cellulose microfibers modified with polydopamine and octadecylamine
Authors: Nagamine Shinsuke , Mizuno Yosuke , Hikima Yuta , Okada Kiyomi , Wang Long , Ohshima Masahiro 
Published: September 2020

AbstractCellulose microfibers (CMFs) having surfaces modified with polydopamine (PDPA) and octadecylamine (ODA) were prepared, and their reinforcing abilities for polypropylene (PP) were investigated. The PDPA coating was made via self‐polymerization of dopamine (P‐CMF), and subsequent alkylation was conducted by the reaction with ODA (OP‐CMF). The modified CMFs exhibited improved dispersibility in the PP matrix due to the reduced hydrophilicity. The OP‐CMF/PP composite prepared by batch mixing had a higher tensile modulus compared to that for the pure PP and composites with unmodified CMFs. However, excess alkylation lowered the tensile modulus, and the presence of an optimal degree of alkylation was demonstrated. The CMF/PP‐IM composites fabricated by injection molding exhibited improved tensile properties compared to those prepared by batch mixing. Both the tensile modulus and yield stress were increased by increasing the CMF content and improved by the surface modification of the CMFs.
Study on curing shrinkage and mechanism of DHOM‐modified epoxy‐acrylate‐based UV‐curing 3D printing materials
Authors: Li Songyi , Sun Dachao , Li Aqiang , Cui Yihua 
Published: September 2020

AbstractUV‐curing 3D printing technology is one of the technologies with the highest molding efficiency and accuracy in the field of 3D printing. At present, the main problems of UV‐curing 3D printing materials include the high curing shrinkage and the low toughness. In this work, free radical/cation hybrid curing system was developed, the effects of expansion monomer (DHOM, 3,9‐diethyl‐3′,9′‐dihydro‐xymethyl‐1,5,7,11‐tetraoxaspiro[5,5]undecanone) on the curing shrinkage, toughness, and other properties of the epoxy acrylate‐based UV‐curing 3D printing materials were investigated. The results showed that when the added amount of DHOM was 15 wt%, the best comprehensive performance of UV‐curing 3D printing materials was obtained. At this time, the curing shrinkage rate decreased from 6.13% to 3.47%. The main reason was that DHOM undergoes ring‐opening polymerization under the action of cationic photoinitiator, resulted in volume expansion. The impact strength increased from 9.61 to 12.13 KJ/m2, which was because that the ring‐opening reaction of DHOM reduced the curing shrinkage of the resin system and released the internal stress between the resin molecules.
Superior anticorrosion performance of epoxy‐based composites with well‐dispersed melamine modified graphene oxide
Authors: Li Yue , Yang Hui , Wang Fengqi , Huang Yong 
Published: September 2020

AbstractIn order to improve the dispersion of graphene in epoxy resin, the preparation of melamine modified graphene oxide (M‐rGO) is reported. The π‐π interaction between melamine and graphene oxide (GO) sheet is confirmed via ultraviolet–visible spectroscopy, Raman spectroscopy, and X‐ray photoelectron spectroscopy analysis, which endows M‐rGO with well dispersion. The dispersion concentration of M‐rGO in dimethyl sulfoxide is up to 9 mg/ml, and the stability of which keeps more than 18 months. The anticorrosion performance of M‐rGO/epoxy composite coatings was analyzed through electrochemical measurements and salt spray tests, these results indicate that M‐rGO has a good barrier effect on corrosive medium and even can replace zinc powder in zinc‐rich epoxy. In addition, the reinforced mechanical strength of M‐rGO/epoxy composite coatings is proved via mechanical strength tests.
Poly(imide‐siloxane) films with controlled thickness
Authors: Janegová Kristýna , Sysel Petr , Kulhánková Hana , Perfilov Viacheslav A. , Bernauer Milan , Fíla Vlastimil 
Published: September 2020

AbstractPolyimides containing siloxane moieties are used in some advanced applications. For example, these polymers can be employed as separation membranes in the form of self‐standing, thin films. These products are formed by components of different polarities that have the tendency, at least partly, to separate in the final materials, with an impact on their final, bulk, and/or surface properties. The aim of this work is to study the dependence of the composition of the polyimide, poly(imide‐siloxane) (PIS) and copolymeric PIS self‐standing films differing in thickness on their properties. The important finding is that there is a rather large difference observed in the water contact angle on the film side oriented toward the air atmosphere during film preparation and that oriented toward a hydrophobic Teflon surface. Nevertheless, the gas transport properties of carbon dioxide and methane for these membranes are more influenced by the membrane composition than by the surface properties.
Complex dynamics in psychosocial work with unaccompanied minor refugees with uncertain future prospects: A case study
Authors: Hettich Nora , Meurs Patrick 
Published: September 2020

AbstractThis case study explores the arriving process of an unaccompanied minor refugee in Germany and his perception of the psychosocial support he received. The aim is to elaborate possibilities to support refugee adolescents' arrival processes adequately. Two interviews—theme‐centered and narrative—were conducted and afterwards examined by a group of five researchers who used experts' validation as the analyzing tool. Four main dimensions were identified contributing to the complex dynamics in psychosocial work with unaccompanied minor refugees: (a) the distinct need for self‐determination and idealization, (b) the fight for state recognition as a legal refugee, (c) the attempt of achieving recognition by the society, and (d) the inability of building trusting and affective relationships with friends and caregivers in the host country. Thus, professionals working with unaccompanied minor refugees need to consider the adolescents' demand for self‐determination and perceive idealization not only as a defense mechanism but also as a coping strategy to survive in an unpredictable environment. Being a reliable object that can be used by the adolescent can help to establish a trusting basis for the relationship. This case study indicates that approaches of psychosocial support with unaccompanied minor refugees need to acknowledge and work with the interrelation between the inner world and the external reality of refugee adolescents.
Leaf Angle eXtractor: A high‐throughput image processing framework for leaf angle measurements in maize and sorghum
Authors: Kenchanmane Raju Sunil K. , Adkins Miles , Enersen Alex , Santana de Carvalho Daniel , Studer Anthony J. , Ganapathysubramanian Baskar , Schnable Patrick S. , Schnable James C. 
Published: September 2020

PremiseMaize yields have significantly increased over the past half‐century owing to advances in breeding and agronomic practices. Plants have been grown in increasingly higher densities due to changes in plant architecture resulting in plants with more upright leaves, which allows more efficient light interception for photosynthesis. Natural variation for leaf angle has been identified in maize and sorghum using multiple mapping populations. However, conventional phenotyping techniques for leaf angle are low throughput and labor intensive, and therefore hinder a mechanistic understanding of how the leaf angle of individual leaves changes over time in response to the environment.MethodsHigh‐throughput time series image data from water‐deprived maize (Zea mays subsp. mays) and sorghum (Sorghum bicolor) were obtained using battery‐powered time‐lapse cameras. A MATLAB‐based image processing framework, Leaf Angle eXtractor (LAX), was developed to extract and quantify leaf angles from images of maize and sorghum plants under drought conditions.ResultsLeaf angle measurements showed differences in leaf responses to drought in maize and sorghum. Tracking leaf angle changes at intervals as short as one minute enabled distinguishing leaves that showed signs of wilting under water deprivation from other leaves on the same plant that did not show wilting during the same time period.DiscussionAutomating leaf angle measurements using LAX makes it feasible to perform large‐scale experiments to evaluate, understand, and exploit the spatial and temporal variations in plant response to water limitations.
Hesperidin modulates the rhythmic proteomic profiling in Drosophila melanogaster under oxidative stress
Authors: Jayapalan Jaime J. , Subramanian Perumal , Kani Akshaya , Hiji Jumriah , Najjar Sara G. , Abdul‐Rahman Puteri S. , Hashim Onn H. 
Published: September 2020

AbstractThe circadian clock regulates vital aspects of physiology including protein synthesis and oxidative stress response. In this investigation, we performed a proteome‐wide scrutiny of rhythmic protein accrual in Drosophila melanogaster on exposure to rotenone, rotenone + hesperidin and hesperidin in D. melanogaster. Total protein from fly samples collected at 6 h intervals over the 24 h period was subjected to two‐dimensional gel electrophoresis and mass spectrometry. Bioinformatics tool, Protein ANalysis THrough Evolutionary Relationships classification system was used to the determine the biological processes of the proteins of altered abundance. Conspicuous variations in the proteome (151 proteins) of the flies exposed to oxidative stress (by rotenone treatment) and after alleviating oxidative stress (by hesperidin treatment) were observed during the 24 h cycle. Significantly altered levels of abundance of a wide variety of proteins under oxidative stress (rotenone treatment) and under alleviation of oxidative stress (rotenone + hesperidin treatment) and hesperidin (alone) treatment were observed. These proteins are involved in metabolism, muscle activity, heat shock response, redox homeostasis, protein synthesis/folding/degradation, development, ion‐channel/cellular transport, and gustatory and olfactory function of the flies. Our data indicates that numerous cellular processes are involved in the temporal regulation of proteins and widespread modulations happen under rotenone treatment and, action of hesperidin could also be seen on these categories of proteins.
Novel pyrazole‐clubbed thiophene derivatives via Gewald synthesis as antibacterial and anti‐inflammatory agents
Authors: Nayak Soukhyarani G. , Poojary Boja , Kamat Vinuta 
Published: September 2020

AbstractThe aim of this study was to synthesize newer potent Schiff bases by condensing 2‐amino‐5‐(2,4‐dichlorophenyl)thiophene‐3‐carbonitrile and 1,3‐disubstituted‐1H‐pyrazole‐4‐carbaldehydes, and to investigate their biological activity. The compounds were synthesized via Gewald synthesis and characterized by spectral data and elemental analyses. They were screened for their in vitro antibacterial and anti‐inflammatory activities. The synthesized compounds were also evaluated for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv using the microplate Alamar Blue assay. Compounds 8b, 8c, 8f, 8g, 8k, 8n, and 8o showed promising antibacterial activity. The interactions between the substituted pyrazoles and bovine protein showed promising anti‐inflammatory activity. The experimental results revealed compound 8a as a promising antitubercular agent. Hemolytic assays confirmed that the compounds are nontoxic, with percentage hemolysis ranging from 3.6 to 20.1, at a concentration of 1 mg/ml. The results suggest that the pyrazole ring and the substitution pattern on the heterocyclic moiety have an effect on the bioactivity.