bluuebunny/crossref_metadata_2025 huggingface dataset:
Probabilistic risk assessment of patulin in imported apple juice and apple‐containing beverages in Taiwan
Authors: Lien Keng‐Wen , Ling Min‐Pei , Pan Min‐Hsiung
Published: May 2020

BACKGROUND

In Taiwan, nearly 90% of apples and raw ingredients for apple‐based products are imported. Apple juices (137 samples) and apple‐containing beverages (35 samples) were collected in Taiwan from imported food and analyzed for patulin content.

RESULTS

The results revealed that the incidence levels of patulin for apple juice and apple‐containing beverages are 5.84% and 5.71%. The mean contamination levels were 1.7 and 1.4 μg kg−1 for apple juice and apple‐containing beverages. One sample exceeded 50 μg kg−1, the maximum permissible limit according to the Taiwan Sanitation Standard for the Tolerance of Mycotoxins in Foods. The estimated intake of patulin for consumers ranged from 5.4 to 18.0 ng kg−1 body weight per day for apple juice and between 6.1 and 11.2 ng kg−1 body weight for apple‐containing beverages. The highest average patulin intake was observed among infants aged 0–3 years, followed by children aged 4–12 years old. Finally, the hazard index (HI) for the 50th, 90th, and 95th percentiles are 0.0186, 0.1201, and 0.2048, respectively, for infants aged 0–3 years.

CONCLUSION

The dietary intake of patulin from imported apple juices and apple‐containing beverages is well below the safety levels and does not present a risk for adult and children consumers. However, it is important to point out that we only analyzed imported apple juices and apple‐containing beverages. More studies are necessary to establish if the HI for patulin will still remain below 1 when other foods and beverages are included in the risk calculations. © 2020 Society of Chemical Industry
Acceptability by sensory and visual analyses of meat from Nellore heifers fed with natural additives and finished in feedlots
Authors: de Oliveira Monteschio Jessica , Passetti Rodrigo Augusto Cortez , de Souza Kennyson Alves , Guerrero Ana , de Moraes Pinto Laura Adriane , Valero Maribel Velandia , Vital Ana Carolina Pelaes , Osório José Carlos Silveira , de Araújo Castilho Ricardo , Sañudo Carlos , do Prado Ivanor Nunes
Published: May 2020

BACKGROUND

This study evaluated the acceptability (by sensorial and visual analyses) of meat from 40 Nellore heifers (finished in feedlots for 73 days) fed with different diets supplemented with essential oils (EOs) and an active principle blend. The five diets tested were: CON – a diet without essential oil and active principle blend (eugenol, thymol, and vanillin); ROS – a diet supplemented with rosemary EO; BLE – supplemented with a blend; BCL – a diet with clove EO+ blend; and BRC – a diet with rosemary, clove EOs + blend. The acceptability of diet and aging time was evaluated by consumers.

RESULTS

Diet affected consumer acceptability and visual analysis (meat color). The diets with EO and the blend showed better sensory acceptance by the consumers; meat aged for 7 days received higher scores than meat aged for 1 day. Meat from heifers that received both EOs + blend (BCL, BRC) obtained the highest scores in the visual evaluation.

CONCLUSION

The use of natural compounds in ruminant diets improves the sensory characteristics of meat without damaging visual acceptability and may be an alternative to the conventional additive market. © 2020 Society of Chemical Industry
Quality assessment of raw and baked Aucklandia lappa Decne. by color measurement and fingerprint analysis
Authors: Xue Rong , Deng Chang , Cao Honghong , Zhang Kewei , Lu Tulin , Mao Chunqin
Published: May 2020

Aucklandia lappa Decne. has been used as a traditional Chinese herb for thousands of years in treating various kinds of disorders. According to the Chinese Pharmacopoeia, there are two kinds of processed products, raw and baked Aucklandia lappa Decne., which have different therapeutic effect in clinical application. In this study, based on color measurement and fingerprint analysis, the method to assess the quality of these two processed products was established. In color measurement, the reference ranges of color parameters (L*, a*, and b*), standard color difference values, and mathematical prediction functions of these two processed products were obtain after the color was measured by a spectrophotometer. Meanwhile, high‐performance liquid chromatography fingerprints of these two processed products were established, where there were 12 peaks recognized as the common peaks in both processed products, in which two peaks were identified as costunolide and dehydrocostus lactone, and these two processed products were classified with chemometrics analysis subsequently. Furthermore, the correlation between color parameters and sample compositions was explored and the contents of costunolide and dehydrocostus lactone were determined simultaneously by high‐performance liquid chromatography. Consequently, an integral method including color measurement, high‐performance liquid chromatography fingerprint with chemometrics analysis, and quantitative determination was established.
Density‐dependent mechanisms regulate spore formation in the diatom Chaetoceros socialis
Authors: Pelusi Angela , Margiotta Francesca , Passarelli Augusto , Ferrante Maria Immacolata , Ribera d'Alcalà Maurizio , Montresor Marina
Published: May 2020

Resting stages are reported for several unicellular eukaryotes including diatoms that can produce spores or resting cells. These stages represent a repository of diversity in sediments but the factors that induce their formation are elusive. We investigated spore formation in the marine diatom Chaetoceros socialis. Our results confirm that nitrogen starvation is an effective experimental trigger for spore formation. However, we observed that spores are also produced when the external pool of nutrients is not limiting, and by using a semicontinuous setup, we could show that they appear only when cell density is high. The presence of a chemical cue mediating spore formation was supported by experiments carried out incubating cells with culture media conditioned by both healthy and lysed cells. These findings shed new light on the mechanisms that regulate the transition between life cycle stages and represent an experimental baseline for the identification of the signaling molecules.
Guanidinylated Amphiphilic Polycarbonates with Enhanced Antimicrobial Activity by Extending the Length of the Spacer Arm and Micelle Self‐Assembly
Authors: Cho Chloe A. , Liang Chao , Perera Janesha , Brimble Margaret A. , Swift Simon , Jin Jianyong
Published: May 2020

Nine guanidinylated amphiphilic polycarbonates are rationally designed and synthesized. Each polymer has the same biodegradable backbone but different side groups. The influence of the hydrophobic/hydrophilic effect on antimicrobial activities and cytotoxicity is systematically investigated. The results verify that tuning the length of the spacer arm between the cationic guanidine group and the polycarbonate backbone is an efficient design strategy to alter the hydrophobic/hydrophilic balance without changing the cationic charge density. A spacer arm of six methylene units (CH2)6 shows the best antimicrobial activity (minimum inhibitory concentration, MIC = 40 µg mL−1 against Escherichia coli, MIC = 20 µg mL−1 against Staphylococcus aureus, MIC = 40 µg mL−1 against Candida albicans) with low hemolytic activity (HC50 > 2560 µg mL−1). Furthermore, the guanidinylated polycarbonates exhibit the ability to self‐assemble and present micelle‐like nanostructure due to their intrinsic amphiphilic macromolecular structure. Transmission electron microscopy and dynamic light scattering measurements confirm polymer micelle formation in aqueous solution with sizes ranging from 82 to 288 nm.
Perfluoropyridine as a Scaffold for Semifluorinated Thiol‐ene Networks with Readily Tunable Thermal Properties
Authors: Moore Levi M. J. , Greeson Kevin T. , Stewart Kevin A. , Kure Daniel A. , Corley Cynthia A. , Jennings Abby R. , Iacono Scott T. , Ghiassi Kamran B.
Published: May 2020

Two new trifunctional alkene monomers based on the highly modular perfluoropyridine scaffold are synthesized with an aliphatic and an aromatic moiety, 4‐penten‐1‐ol and eugenol, respectively. The monomers are the basis for thiol‐ene thermoset materials, formulated against a difunctional or trifunctional thiol. Systems based on these novel monomers have a wide range of thermal properties, with glass transition temperatures (Tgs) spanning from −42 to 21 °C. Mixed systems obey the Fox equation, and Tgs of the mixtures can be tuned to specific values in that range. Thermal degradation temperatures follow a similar trend, with decomposition temperatures ranging from 274 to 348 °C in nitrogen with varying compositions having tailorability therein. This new class of semifluorinated thermoset materials with tunable thermal properties has several potential applications within the aerospace industry, such as sealants and coatings, where stability and survivability at high temperatures in harsh environmental conditions are imperative.
Effect of Molecular Architecture on Conformational Relaxation of Polymer Chains at Interfaces
Authors: Nguyen Hung K. , Kawaguchi Daisuke , Tanaka Keiji
Published: May 2020

Dynamics of polymer chains near an interface with an inorganic material are believed to strongly affect the physical properties of polymers in nanocomposites and thin films. An effect of molecular architecture on the conformational relaxation behavior of polystyrene (PS) chains at the quartz interface using sum‐frequency generation spectroscopy is reported here. The relaxation dynamics of chains in direct contact with the quartz interface is slower with a star‐shaped architecture than that with its linear counterpart. The extent of the delay becomes more pronounced with increasing number of arms. This can be explained in terms of the superior interfacial activity to the quartz surface for the star‐shaped PS.
Hybrid Helical Polymer Nanochannels Constructed by Combining Aromatic Amide and Pyridine‐Oxadiazole Structural Sequences
Authors: Qi Shuaiwei , Zhang Chenyang , Yan Tengfei , Yang Feihu , Zhang Jing , Mao Shizhong , Dong Zeyuan
Published: May 2020

An effective method is reported to synthesize aromatic helical polymer nanochannels by combining both the well‐studied aromatic amide helical codons with pyridine‐oxadiazole helical codons into helical structure sequences. With this strategy, a type of helical polymer nanochannel that shows structure‐directed transmembrane transport functions is synthesized. Although such nanochannels show relatively weak selectivity for the transportation of alkali metal ions, accessible chemical mutation of helical structure sequences will provide a great chance for the design of desired channel property. The straightforward preparation of well‐established pyridine‐oxadiazole helical structure will significantly promote the synthesis of this kind of aromatic helical polymer nanochannels. With the development of aromatic amide foldamers, moreover, a number of “monomers” will be available for the preparation of helical polymer nanochannels.
Numerical solution of two‐dimensional time fractional cable equation with Mittag‐Leffler kernel
Authors: Kumar Sachin , Baleanu Dumitru
Published: May 2020

The main motive of this article is to study the recently developed Atangana‐Baleanu Caputo (ABC) fractional operator that is obtained by replacing the classical singular kernel by Mittag‐Leffler kernel in the definition of the fractional differential operator. We investigate a novel numerical method for the nonlinear two‐dimensional cable equation in which time‐fractional derivative is of Mittag‐Leffler kernel type. First, we derive an approximation formula of the fractional‐order ABC derivative of a function tk using a numerical integration scheme. Using this approximation formula and some properties of shifted Legendre polynomials, we derived the operational matrix of ABC derivative. In the author of knowledge, this operational matrix of ABC derivative is derived the first time. We have shown the efficiency of this newly derived operational matrix by taking one example. Then we solved a new class of fractional partial differential equations (FPDEs) by the implementation of this ABC operational matrix. The two‐dimensional model of the time‐fractional model of the cable equation is solved and investigated by this method. We have shown the effectiveness and validity of our proposed method by giving the solution of some numerical examples of the two‐dimensional fractional cable equation. We compare our obtained numerical results with the analytical results, and we conclude that our proposed numerical method is feasible and the accuracy can be seen by error tables. We see that the accuracy is so good. This method will be very useful to investigate a different type of model that have Mittag‐Leffler fractional derivative.
A coupled compressible flow and geomechanics model for dynamic fracture aperture during carbon sequestration in coal
Authors: Chen Min , Hosking Lee J. , Sandford Richard J. , Thomas Hywel R.
Published: May 2020

This paper presents the development of a discrete fracture model of fully coupled compressible fluid flow, adsorption and geomechanics to investigate the dynamic behaviour of fractures in coal. The model is applied in the study of geological carbon dioxide sequestration and differs from the dual porosity model developed in our previous work, with fractures now represented explicitly using lower‐dimensional interface elements. The model consists of the fracture‐matrix fluid transport model, the matrix deformation model and the stress‐strain model for fracture deformation. A sequential implicit numerical method based on Galerkin finite element is employed to numerically solve the coupled governing equations, and verification is completed using published solutions as benchmarks. To explore the dynamic behaviour of fractures for understanding the process of carbon sequestration in coal, the model is used to investigate the effects of gas injection pressure and composition, adsorption and matrix permeability on the dynamic behaviour of fractures. The numerical results indicate that injecting nonadsorbing gas causes a monotonic increase in fracture aperture; however, the evolution of fracture aperture due to gas adsorption is complex due to the swelling‐induced transition from local swelling to macro swelling. The change of fracture aperture is mainly controlled by the normal stress acting on the fracture surface. The fracture aperture initially increases for smaller matrix permeability and then declines after reaching a maximum value. When the local swelling becomes global, fracture aperture starts to rebound. However, when the matrix permeability is larger, the fracture aperture decreases before recovering to a higher value and remaining constant. Gas mixtures containing more carbon dioxide lead to larger closure of fracture aperture compared with those containing more nitrogen.
Early administration of imatinib mesylate reduces plexiform neurofibroma tumor burden with durable results after drug discontinuation in a mouse model of neurofibromatosis type 1
Authors: Armstrong Amy E. , Rhodes Steven D. , Smith Abbi , Chen Shi , Bessler Waylan , Ferguson Michael J. , Jiang Li , Li Xiaohong , Yuan Jin , Yang Xianlin , Yang Feng‐Chun , Robertson Kent A. , Ingram David A. , Blakeley Jaishri O. , Clapp D. Wade
Published: May 2020

Background

Neurofibromatosis type 1 (NF1) is a common genetic disorder characterized by plexiform neurofibromas (pNF), which are thought to be congenital tumors that arise in utero and enlarge throughout life. Genetic studies in murine models delineated an indispensable role for the stem cell factor (SCF)/c‐kit pathway in pNF initiation and progression. A subsequent phase 2 clinical trial using imatinib mesylate to inhibit SCF/c‐kit demonstrated tumor shrinkage in a subset of preexisting pNF; however, imatinib's role on preventing pNF development has yet to be explored.

Procedure

We evaluated the effect of imatinib dosed at 10‐100 mg/kg/day for 12 weeks to one‐month‐old Nf1flox/flox;PostnCre(+) mice, prior to onset of pNF formation. To determine durability of response, we then monitored for pNF growth at later time points, comparing imatinib‐ with vehicle‐treated mice. We assessed gross and histopathological analysis of tumor burden.

Results

Imatinib administered preventatively led to a significant decrease in pNF number, even at doses as low as 10 mg/kg/day. Tumor development continued to be significantly inhibited after cessation of imatinib dosed at 50 and 100 mg/kg/day. In the cohort of treated mice that underwent prolonged follow‐up, the size of residual tumors was significantly reduced as compared with age‐matched littermates that received vehicle control.

Conclusions

Early administration of imatinib inhibits pNF genesis in vivo, and effects are sustained after discontinuation of therapy. These findings may guide clinical use of imatinib in young NF1 patients prior to the substantial development of pNF.
Smartphone‐Based Colorimetric Method to Quantify Iron Concentration and to Determine the Nanoparticle Size from Suspensions of Magnetic Nanoparticles
Authors: Fernández‐Afonso Yilian , Salas Gorka , Fernández‐Barahona Irene , Herranz Fernando , Grüttner Cordula , Martínez de la Fuente Jesús , del Puerto Morales María , Gutiérrez Lucía
Published: May 2020

Advanced uses of smartphones are changing lifestyles, and may have a great impact in materials science in the near future. In this work, the use of these devices to develop fast, simple, and cheap methods to characterize magnetic nanoparticle suspensions is tested. A series of dilutions of a wide library of magnetic nanoparticles, composed of iron oxide materials in the range between 3 and 43 nm, with two different shapes and four different coatings is prepared. The colloid color is analyzed using the RGB (red, green, blue) color model. Ratios of these parameters are correlated with the suspension iron concentration and with the nanoparticles average size. A linear relationship between the color (in particular the G/R ratio) and both the colloid iron content and the particles size is found. The link between these parameters allows the development of two new methods to determine either the concentration or the particle size of magnetic nanoparticle suspensions just by acquiring images from suspensions of iron oxide magnetic nanoparticles with a smartphone.
Respiratory rate is an early predictor of clinical deterioration in children
Authors: Daw William , Kaur Rena , Delaney Mollie , Elphick Heather
Published: May 2020

Objective

To assess the value of respiratory rate (RR) as a predictor of clinical deterioration in children, compared with other vital sign measurements.

Design

A retrospective case‐control study, comparing children who deteriorated, requiring admission to critical care with children who did not deteriorate.

Methods

RR, heart rate (HR), and blood pressure (BP) measurements were collected from each patient for a 48‐hour duration. The 95th centile was identified for each and 5% to 30% thresholds above the 95th centile were calculated. For each threshold the sensitivity, specificity, odds ratio, positive, and negative predictive value for deterioration was calculated.

Results

Forty cases (age range 7 weeks‐15 years) and 40 control patients matched for age, gender, and hospital location were recruited. In 30/40 patients who deteriorated at least one RR ≥ 30% above the 95th centile for their age was recorded in the 48 hours before deterioration, compared with 10/40 controls, regardless of clinical diagnosis. Only 3/40 children that deteriorated had a HR > 30% greater than the 95th centile, compared with 2/40 controls. An elevated RR was the only vital sign whose odds ratios were significant at each threshold level above the 95th centile. Maximum RR occurred 16.8 hours before deterioration.

Conclusion

RR is a more accurate predictor of clinical deterioration in children than other vital signs. Greater weighting and importance should be placed on RR, which is often omitted in children due to difficulties with its measurement.
Improving the Passivation of Molybdenum Oxide Hole‐Selective Contacts with 1 nm Hydrogenated Aluminum Oxide Films for Silicon Solar Cells
Authors: Gregory Geoffrey , Feit Corbin , Gao Zhengning , Banerjee Parag , Jurca Titel , Davis Kristopher O.
Published: May 2020

The intrinsic and doped amorphous silicon layers in silicon heterojunction solar cells parasitically absorb light in the short wavelength region of the solar spectrum, lowering the generation current available to the device. Herein, a promising alternative to the hole‐selective amorphous silicon contact layers using only wide bandgap, transparent oxide materials is presented. Using thermal atomic layer deposition, a 1 nm hydrogenated aluminum oxide layer is deposited followed by a 4 nm molybdenum oxide layer on n‐type crystalline silicon. This contact stack provides an effective carrier lifetime of 1.14 ms. It is shown that the molybdenum oxide layer is successfully deposited with a high work function, which facilitates efficient hole extraction and repels majority carriers from the c‐Si surface. Then the implied open‐circuit voltage, saturation current density, and contact resistivity are recorded as a function of contact annealing temperature and show that they are relatively stable up to 200 °C.
Embedded, graph‐theoretically defined many‐body approximations for wavefunction‐in‐DFT and DFT‐in‐DFT: Applications to gas‐ and condensed‐phase ab initio molecular dynamics, and potential surfaces for quantum nuclear effects
Authors: Ricard Timothy C. , Kumar Anup , Iyengar Srinivasan S.
Published: May 2020

We present a graph‐theoretic approach to adaptively compute many‐body approximations in an efficient manner to perform (a) accurate post‐Hartree–Fock (HF) ab initio molecular dynamics (AIMD) at density functional theory (DFT) cost for medium‐ to large‐sized molecular clusters, (b) hybrid DFT electronic structure calculations for condensed‐phase simulations at the cost of pure density functionals, (c) reduced‐cost on‐the‐fly basis extrapolation for gas‐phase AIMD and condensed phase studies, and (d) accurate post‐HF‐level potential energy surfaces at DFT cost for quantum nuclear effects. The salient features of our approach are ONIOM‐like in that (a) the full system (cluster or condensed phase) calculation is performed at a lower level of theory (pure DFT for condensed phase or hybrid DFT for molecular systems), and (b) this approximation is improved through a correction term that captures all many‐body interactions up to any given order within a higher level of theory (hybrid DFT for condensed phase; CCSD or MP2 for cluster), combined through graph‐theoretic methods. Specifically, a region of chemical interest is coarse‐grained into a set of nodes and these nodes are then connected to form edges based on a given definition of local envelope (or threshold) of interactions. The nodes and edges together define a graph, which forms the basis for developing the many‐body expansion. The methods are demonstrated through (a) ab initio dynamics studies on protonated water clusters and polypeptide fragments, (b) potential energy surface calculations on one‐dimensional water chains such as those found in ion channels, and (c) conformational stabilization and lattice energy studies on homogeneous and heterogeneous surfaces of water with organic adsorbates using two‐dimensional periodic boundary conditions.
Global asymptotic tracking for nonminimum‐phase nonlinear systems in output feedback form
Authors: Su Shanwei , Lin Wei
Published: May 2020

The problem of global asymptotic tracking by output feedback is studied for a class of nonminimum‐phase nonlinear systems in output feedback form. It is proved that the problem is solvable by an n‐dimensional output feedback controller under the two conditions: (a) the nonminimum‐phase nonlinear system can be rendered minimum‐phase by a virtual output; and (b) the internal dynamics of the nonlinear system driven by a desired signal and its derivatives has a bounded solution trajectory. With the help of a new coordinate transformation, a constructive method is presented for the design of a dynamic output tracking controller. An example is given to validate the proposed output feedback tracking control scheme.
Analyzing the intellectual structure of the Knowledge base on managing for sustainability, 1982–2019: A meta‐analysis
Authors: Hallinger Philip
Published: May 2020

Although there have been numerous reviews of sustainability research in functional management disciplines, few reviews have examined this literature from a multidisciplinary perspective. This meta‐analysis integrated data and findings extracted from bibliometric reviews of research on managing for sustainability in seven different management disciplines: leadership, human resource management, entrepreneurship, innovation management, supply chain management, knowledge management, and strategic management. The meta‐analysis analyzed secondary bibliographic data associated with 9,476 Scopus‐indexed documents sourced in the seven reviews. The review found wide variability in the levels of scholarly engagement with sustainability issues across the seven disciplines. This finding was confirmed by the number of sustainability‐related documents identified in the different management disciplines, as well as by author productivity, citation and cocitation analyses. Among the seven fields of management research, scholars in supply chain management evidenced the strongest engagement with sustainability research. Using a similar combination of metrics, the review identified the most influential scholars in this the multidisciplinary management literature: Joseph Sarkis, Stefan Seuring, Stefan Schaltegger, Qingyun Zhu, Kannan Govindan, Michael Porter, and John Elkington. Author cocitation analysis of the intellectual structure of this literature found that the most influential “school of thought” was associated with “sustainable supply chain management”. Author cocitation analysis further identified core concepts that have emerged within and across these domains of sustainability management. The most influential multidisciplinary sustainability concepts, largely associated with strategic management, included resource‐based perspective, dynamic capabilities, competitive advantage, shared value, balanced scorecard, absorptive capacity, and triple bottom‐line.
K2CO3‐Promoted Ring‐Opening/Cyclization Reactions of Multi‐substituted Donor‐Acceptor Cyclopropanes with Thiourea: Access to 2‐Amino‐4,6‐diarylnicotinonitrile Derivatives
Authors: Wang Shan , Xie Zengyang , Li Mingshuang , Wang Cunde
Published: May 2020

The ring‐opening/cyclization reactions of substituted 2‐acyl‐3‐arylcyclopropane‐1,1‐dicarbonitriles with thiourea promoted by K2CO3 were investigated successfully. Using the reaction, the desired 2‐amino‐4,6‐diarylnicotinonitrile derivatives were obtained in good to excellent yields. This work provides a new strategy for the synthesis of 2‐amino‐4,6‐diarylnicotinonitrile derivatives.
Graphene Modified Montmorillonite Based Phase Change Material for Thermal Energy Storage with Enhanced Interfacial Thermal Transfer
Authors: Peng Kang , Wang Hongjie , Wan Pengfei , Wang Jianwei , Luo Hua , Zhou Senhai , Li Xiaoyu , Yang Jun
Published: May 2020

Thermal energy storage technology plays a crucial role in the thermal management system. Clay based organic phase change material has considerable advantages in the application of thermal energy storage due to low cost and high energy storage capacity. However, the low thermal conductivity of clay, especially poor interfacial thermal transfer, limits its thermal energy storage efficiency. Herein, stearic acid/reduced graphene oxide modified montmorillonite composites (SA/RGO‐MMT) were prepared by the vacuum impregnation of stearic acid into graphene modified montmorillonite matrix, which was obtained via the in situ reduction of graphene oxide on the surface of montmorillonite. Stearic acid is assembled in the porous structures of RGO‐MMT with the physical interactions. SA/RGO‐MMT possesses high melting enthalpy of 159 J/g, low extent of supercooling of 1.4 °C and excellent thermal reliability after 100 thermal cycling. Energy storage and release rates of SA/RGO‐MMT were significantly improved due to the enhanced interfacial thermal transfer by graphene. Therefore, SA/RGO‐MMT is a promising form‐stable phase change material for applications in solar heat storage fields. The strategy in this study highlights the importance of enhancing interfacial thermal transfer for the efficient thermal energy storage materials.
Visible Light Photocatalysts Based on Manganese Doped TiO2 Integrated Within Monolithic Reduced Graphene Oxide/Polymer Porous Monolith
Authors: Toshikj Nikola , Politakos Nikolaos , Veloso Antonio , de San Román Estibaliz González , Cordero‐Lanzac Tomás , Qin Zuzeng , Leal Gracia Patricia , Tomovska Radmila
Published: May 2020

3D monolithic integrated photocatlysts were prepared by self‐assembly of graphene platelets decorated with manganese doped TiO2 nanoparticles. The self‐assembly was induced by chemical reduction at mild reaction conditions. The physico‐chemical properties of the photocatalysts were improved by addition of polymer nanoparticles within the 3D structures. The rGO presence in the nanostructures affected their light absorption capability, which was red shifted. As a result, the band gap dropped from 3.12 eV in Mn doped TiO2 to 2.8 eV in the monolithic composite made of rGO and TiO2. The photocatalysts were applied for the elimination of methylene blue (MB) from aqueous solutions, the degradation of which was monitored by the Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry. It was shown that (i) MB was completely eliminated from aqueous solution; (ii) all the adsorbed MB was photocatalytically degraded under visible light, giving rise to various smaller molecules as intermediate products of degradation; and (iii) one part of the MB was completely mineralized, demonstrated by the presence of final degradation products. These results indicate that the presented materials seem to be a powerful tool in water purification process with double impact. On one hand, it will allow re‐use of water and decrease of its consumption in the textile producing plants, and on the other hand, it will assure protection of the environment by elimination of the hazards.
2D/2D Heterostructured Photocatalysts: An Emerging Platform for Artificial Photosynthesis
Authors: Ong Wee-Jun , Shak Katrina Pui Yee
Published: May 2020

2D/2D heterostructures have recently garnered substantial research attention due to their advantageous noble properties such as tunable band structures, high interfacial contact areas, and abundant active sites, which remarkably enhance photocatalytic activity. These intriguing properties render 2D/2D nanostructures highly auspicious in a multitude of photocatalytic energy applications, including water splitting for H2 oxygen (O2) evolution, reduction of CO2, and N2 fixation. As such, this leads to the development of clean energy technology by 2D/2D catalysts and solar energy as the inexhaustible energy resource. Herein, the fundamental principles of 2D/2D hybrid heterostructures and diverse types of interfaces with different material families are systematically discussed. Furthermore, photocatalytic energy applications using 2D/2D heterointerfaces over the recent years are highlighted. Insights into the interplay of 2D/2D heterojunction interfaces and the associated physicochemical properties (e.g., charge carrier dynamics) toward the photocatalytic enhancement are put forward. Last but not least, the challenges and prospects in engineering 2D/2D heterostructure photocatalysts for affordable and clean energy advancements are reviewed, which serve as a guiding star not only in photocatalysis, but also in other applications in the energy realm such as fuel cells, batteries, supercapacitors, and photovoltaics.
Structural Properties Change of Cassava Starch Granule Induced by High Shear Mixer
Authors: Airlangga Bramantyo , Puspasari Febriyati , Trisanti Prida Novarita , Juwari  , Sumarno
Published: May 2020

In this work, a high shear mixer (HSM) is designed to produce a higher theoretical shear rate than conventional HSM in order to induce structure degradation of cassava starch granules. Using scanning electron microscopy and transmission electron microscopy, the processed cassava starch granule surface changes are identified without any major change in the granule shape. The carbohydrate component analysis and intrinsic viscosity suggest that the structural change is led by the removal of a relatively low‐molecular‐weight carbohydrate component from the granule. The changes in the crystalline and thermal properties are observed by the degradation process using a HSM. The process using a rotor speed of 15 000 rpm is found to significantly induce granule surface changes and carbohydrate removal. The decrease in granule crystallinity is correlated with an increase in the granule swelling power and solubility.
Fault diagnosis of the train communication network based on weighted support vector machine
Authors: Li Zhaozhao , Wang Lide , Yang Yueyi
Published: May 2020

Multifunction vehicle bus (MVB) is the most widely used train communication network which transmits controlling and supervising data. The faults of MVB will heavily affect the train's safe and stable operation. Due to the harsh operating environment and distributed structure, the MVB fault diagnosis has always been a difficult issue in the maintenance of the train. Many MVB faults will distort the physical waveforms and cause serious packet loss. Thus, we have extracted waveform features to characterize different MVB faults and turned the fault diagnosis into a pattern recognition problem. Then a classifier based on weighted support vector machine (WSVM) has been trained to diagnose and locate network faults. Considering that samples locating in different positions of the feature space have different influences on the support vector machine (SVM) hyperplane, we have proposed a multi‐hop edge approaching method to assign sample weights in WSVM. To identify the position of the tested sample, the hops from its location to the classification margin have been counted. The less the hop‐count, the closer to the classification margin and the larger the sample weight. Compared with SVM and other WSVM methods, the proposed method has better performance on the artificial synthetic datasets, the MVB dataset, and the benchmark datasets. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Nanocontrollers for In Vitro Drug Release Based on Core‐Sheath Encapsulation of Theophylline into Hydroxypropyl Methylcellulose Acetate Succinate Nanofibers
Authors: Liu Mengzhu , Xu Zibo , Tao Junyi , Jia Zhihao , Wang Yongpeng , Jiang Zhenhua
Published: May 2020

Linear adjustable efficient nanocontrollers that could respond to pH signals to trigger selective drug release were designed and discussed. They were fabricated by encapsulating theophylline into hydroxypropyl methylcellulose acetate succinate nanofibers through coaxial electrospinning. Theophylline was fixed in the core layer in an amorphous state. in vitro drug release behaviors were examined in simulated body fluid and tested by ultraviolet‐visible spectra. Expectedly, the nanocontrollers caused the drug to be autonomously released in weak alkaline solution rather than acid solution, with a sustained release over 12 hours. Thus, prior degrading or digesting in stomach can be avoided, and targeted drug releasing in the intestine can be realized. Moreover, the release rate was varied with regard to fiber diameter and drug content, indicating their adjustable property. The released performances were attributed to the synergistic effects of the chosen polymer and the core‐sheath structural advantages, for example, enteric solubility, drug encapsulation and large surface area. These results suggested that the designed nanocontrollers can serve as ideal candidates for a sustained targeted drug delivery system.
Addressing technical challenges in 100% variable inverter‐based renewable energy power systems
Authors: Hodge Bri‐Mathias S. , Jain Himanshu , Brancucci Carlo , Seo Gab‐Su , Korpås Magnus , Kiviluoma Juha , Holttinen Hannele , Smith James Charles , Orths Antje , Estanqueiro Ana , Söder Lennart , Flynn Damian , Vrana Til Kristian , Kenyon Rick Wallace , Kroposki Benjamin
Published: May 2020

Rapidly increasing levels of variable inverter‐based renewable energy sources (are quickly changing electric power systems and prompting questions about how the systems will be operated when renewable generation becomes the dominant technologies. In this article, we review the status of this shifting paradigm in power systems throughout the world. We then review the implications of this shift, focusing on the rising challenges, and we provide an overview and technology‐readiness classifications of some proposed mitigation strategies. Finally, we highlight outstanding questions that will require solutions to reach these ultrahigh shares of variable inverter‐based renewable energy sources.

This article is categorized under:

Wind Power > Systems and Infrastructure

Energy Systems Economics > Systems and Infrastructure

Energy Infrastructure > Systems and Infrastructure
Cosmic Particle Accelerators
Authors: Hofmann W. , Hinton J. A.
Published: May 2020

In the century since the measurements of Victor Hess [1]—considered as the discovery of cosmic rays—the properties of cosmic rays, as they arrive on Earth, have been studied in remarkable detail; we know their energy spectrum, extending to 1020 eV, their elemental composition, their angular distribution, and we understand the basic energetic requirements of cosmic ray production in the Galaxy.
Non-abelian tri-vector deformations in d = 11 supergravity
Authors: Bakhmatov Ilya , Gubarev Kirill , Musaev Edvard T.
Published: May 2020

Abstract

A truncation of the SL(5) Exceptional Field Theory that allows to describe spacetimes of the form M
4 × M
7 with the 4-form flux on M
4 is constructed. The resulting theory is used to test the recently proposed tri-vector generalisation of Yang-Baxter deformations applied to the AdS4 ×

$$\mathbbm{S}$$

S

7 solution of d = 11 supergravity. We present two new supergravity solutions corresponding to non-abelian non-unimodular tri-vector deformations of AdS4 ×

$$\mathbbm{S}$$

S

7.
Soft charges from the geometry of field space
Authors: Riello Aldo
Published: May 2020

Abstract

Infinite sets of asymptotic soft-charges were recently shown to be related to new symmetries of the S-matrix, spurring a large amount of research on this and related questions. Notwithstanding, the raison-d’être of these soft-charges rests on less firm ground, insofar as their known derivations through generalized Noether procedures tend to rely on the fixing of (gauge-breaking) boundary conditions rather than on manifestly gauge- invariant computations. In this article, we show that a geometrical framework anchored in the space of field configurations singles out the known leading-order soft charges in gauge theories. Our framework unifies the treatment of finite and infinite regions, and thus it explains why the infinite enhancement of the symmetry group is a property of asymptotic null infinity and should not be expected to hold within finite regions, where at most a finite number of physical charges — corresponding to the reducibility parameters of the quasi-local field configuration — is singled out. As a bonus, our formalism also suggests a simple proposal for the origin of magnetic-type charges at asymptotic infinity based on spacetime (Lorentz) covariance rather than electromagnetic duality.
The coupled SYK model at finite temperature
Authors: Qi Xiao-Liang , Zhang Pengfei
Published: May 2020

Abstract

Sachdev-Ye-Kitaev (SYK) model, which describes N randomly interacting Majorana fermions in 0+1 dimension, is found to be an solvable UV-complete toy model for holographic duality in nearly AdS2 dilaton gravity. Ref. [1] proposed a modified model by coupling two identical SYK models, which at low-energy limit is dual to a global AdS2 geometry. This geometry is an “eternal wormhole” because the two boundaries are causally connected. Increasing the temperature drives a Hawking-Page like transition from the eternal wormhole geometry to two disconnected black holes with coupled matter field. To gain more understanding of the coupled SYK model, in this work, we study the finite temperature spectral function of this system by numerical solving the Schwinger-Dyson equation in real-time. We find in the low-temperature phase the system is well described by weakly interacting fermions with renormalized single-particle gap, while in the high temperature phase the system is strongly interacting and the single-particle peaks merge. We also study the q dependence of the spectral function.
Off-shell renormalization in the presence of dimension 6 derivative operators. Part III. Operator mixing and β functions
Authors: Binosi D. , Quadri A.
Published: May 2020

Abstract

We evaluate the one-loop β functions of all dimension 6 parity-preserving op- erators in the Abelian Higgs-Kibble model. No on-shell restrictions are imposed; and the (generalized) non-polynomial field redefinitions arising at one-loop order are fully taken into account. The operator mixing matrix is also computed, and its cancellation pat- terns explained as a consequence of the functional identities of the theory and power- counting conditions.
Bounding scattering of charged particles in 1+1 dimensions
Authors: Paulos Miguel F. , Zheng Zechuan
Published: May 2020

Abstract

We obtain general bounds on scattering processes involving charged particles in 1+1 spacetime dimensions. After a general analysis we derive mostly numerical bounds on couplings in theories with O(N ) and U(N ) global symmetries. The bounds are consistently saturated by S-matrices without particle production, and in many cases by known integrable S-matrices. Our work provides a blueprint for a similar analysis in higher dimensions.
3D-Visualization of Neurovascular Compression at the Ventrolateral Medulla in Patients with Arterial Hypertension
Authors: Manava Panagiota , Naraghi Ramin , Schmieder Roland , Fahlbusch Rudolf , Doerfler Arnd , Lell Michael M. , Buchfelder Michael , Hastreiter Peter
Published: May 2020

Purpose

Controversy exists on the association of arterial hypertension (HTN) and neurovascular compression (NVC) at the ventrolateral medulla (VLM). No standardized and reproducible technique has been introduced yet for detection of NVC in HTN. This study aimed to generate, analyze and compare different results of exact reproducible anatomical 3D-representations of the VLM in patients with HTN, based on magnetic resonance imaging (MRI).

Methods

A 3T scanner provided MRI (T2-constructive interference in steady state (CISS) high resolution imaging and three-dimensional Time-of-flight (3D-TOF) angiography) from the posterior fossa of 44 patients with clinical treatment-resistant HTN. Image processing consists of segmentation of the CISS data, registration and fusion of the CISS and TOF data and visualization. For each patient two 3D-visualizations (before and after fusion) were obtained. The reproduction quality of the vessels, flow-related signal variability and pulsation artifacts were analyzed and compared, using a ranking score.

Results

Integrating vascular information from TOF into CISS data reduced artifacts in 3D-visualizations of exclusively processed CISS data. The quality of 3D-visualization of the vessels near the brain stem was significantly improved (p = 0.004). The results were reproducible and reliable. The quality of the 3D-presentations of neurovascular relationships at the VLM improved significantly (p < 0.001).

Conclusion

The 3D-visualization of fused image data provides an excellent overview of the relationship between cranial nerves and vessels at the VLM and simplifies the detection of NVC in HTN. It provides a powerful tool for future clinical and scientific research. Although microvascular decompression (MVD) in treatment resistant HTN is not a standard procedure, it can be discussed in selected patients with intractable severe HTN.
Dringende Notwendigkeit des Off-label-Einsatzes von PAH-Medikamenten und deren Erstattung bei Kindern mit pulmonaler Hypertonie (Lungenhochdruck)
Authors: Hansmann Georg , Apitz Christian , Humpl Tilman , Koestenberger Martin , Michel-Behnke Ina , Schulze-Neick Ingram , Quandt Daniel , Lammers Astrid E.
Published: May 2020

Die pulmonale Hypertonie (PH, Lungenhochdruck), und insbesondere die pulmonalarterielle Hypertonie (PAH), ist eine chronisch-progressive, fatale Erkrankung, für die aktuell – abgesehen von einer bilateralen Lungentransplantation – kein kurativer Therapieansatz besteht. Durch die jüngste Entwicklung und Verfügbarkeit von neuen „zielgerichteten“ PAH-Medikamenten („advanced“ oder „targeted therapies“), die mittlerweile für PAH im Erwachsenenalter zugelassen sind, haben sich allerdings die Lebenserwartung und -qualität von Erwachsenen und Kindern mit PAH erheblich verbessert.

Wegen (1) des Mangels an für Kinder zugelassenen PAH-Medikamenten, (2) der gut begründeten Rationale für eine PAH-Pharmakokombinationstherapie im Kindesalter und (3) dem Fehlen schwerwiegender unerwünschter Wirkungen, sollten gerade jungen PH-Patienten die vorhandenen modernen pharmakologischen Therapiemöglichkeiten nicht vorenthalten bleiben. Ein solcher „Off-label“-Einsatz und dessen unbürokratische Erstattung (Finanzierung) durch die Kostenträger sind dringend erforderlich. Die Entscheidung zur spezifischen Therapie der pulmonalen Hypertonie mit Möglichkeit der Kombination von Medikamenten aller Substanzklassen – auch unter Einschluss von „Off-label-Präparaten“ – sollte durch einen Kinderkardiologen erfolgen, der ausreichend Erfahrung mit der Behandlung von Kindern mit pulmonaler Hypertonie – insbesondere mit vasoaktiven Medikamenten – hat, gefolgt von einer engmaschigen ambulanten Anbindung und Nachsorge dieser Patienten. Die mangelnde Zulassung moderner, gegen PAH gerichteter Arzneimittel oder die relativ dünne, evidenzbasierte Datenlage bei Kindern sollte die behandelnden Ärzte nicht davon abhalten, den jungen Patienten diese Therapien anbieten zu können.
Quality inspection planning within a multistage manufacturing process based on the added value criterion
Authors: Hamrol Adam , Kujawińska Agnieszka , Bożek Mariusz
Published: May 2020

This paper proposes an approach to the planning and optimization of quality inspections within a multistage manufacturing process based on quality costs and the value added to the production process by inspections. Inspection errors and the resulting costs of repair and scrapping are taken into account. In addition, the capability of the manufacturing process and of the inspection system is included. A mathematical model for calculating quality costs was developed with a focus on its practical application.