bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Magnetic Heterogeneous Biocatalyst Composed of Immobilized Laccase and 2,2,6,6‐Tetramethylpiperidine‐1‐oxyl (TEMPO) for Green One‐Pot Cascade Synthesis of 2‐Substituted Benzimidazole and Benzoxazole Derivatives under Mild Reaction Conditions
Authors: Mogharabi‐Manzari Mehdi , Kiani Mahshid , Aryanejad Sima , Imanparast Somaye , Amini Mohsen , Faramarzi Mohammad Ali 
Published: June 2018

AbstractThe design of reusable high‐performance heterogeneous catalysts via the immobilization of chemical and biochemical species on magnetic nanoparticles increases the efficiency of catalytic systems by facilitating easy, fast, and clean separation processes. Laccase and 4‐amino‐2,2,6,6‐tetramethylpiperidine‐1‐oxyl were separately immobilized on amine functionalized iron (II, III) oxide nanoparticles with covalent bonding using glutaraldehyde as a coupling reagent. The prepared catalyst was used to synthesize 12 benzoxazole and benzimidazole derivatives. The one‐pot, two‐step enzymatic aerobic oxidation reaction included the condensation of in situ‐produced salicylaldehyde derivatives with aromatic amines, followed by an enzymatic dehydrogenation process. Optimal reaction conditions consisted of a citrate buffer (10 mM, pH 4.5) at 40 °C for an incubation time of 10 h and a heterogeneous catalyst containing immobilized laccase (80 mg, 100 U) and immobilized 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) (40 mg, 2 mol%). The catalyst retained more than 85% of its initial activity after 10 runs. In addition to the potential for reuse without significant losses in performance, eco‐friendly attributes of this catalytic system include its high catalytic activity and the ease with which it can be recovered from the reaction mixture using an external magnet.magnified image
Giant Inverse Spin Hall Effect in Bi Doped PtBi Alloy
Authors: Hong Caiyun , Jin Lichuan , Zhang Huaiwu , Li Mingming , Rao Yiheng , Ma Bo , Li Jialu , Zhong Zhiyong , Yang Qinghui 
Published: June 2018

AbstractFor generating or detecting spin currents without ferromagnetic materials in spintronic devices, nonmagnetic materials with large spin Hall angles would elicit extreme interest. A giant inverse spin Hall effect (ISHE) generating in Pt doped with 8% Bi by composition is demonstrated. From a combination of ferromagnetic resonance, spin pumping, and ISHE experiments, a large spin current is found induced in an yttrium iron garnet/Pt0.92Bi0.08 bilayer. The spin diffusion length and spin Hall angle of the Pt0.92Bi0.08 alloy are λSD = 3.3 ± 0.1 nm and θSH = 0.106 ± 0.005, respectively. In the experiments, the spin–charge conversion of this alloy is twice that of Pt and is larger than most reported heavy metals. Such enhancement can be attributed to the skew scattering from the high atomic number of Bi impurities via the spin–orbit interaction.
Übergangsmetallvermittelte und ‐katalysierte C‐F‐Bindungsaktivierung durch Fluoreliminierung
Authors: Fujita Takeshi , Fuchibe Kohei , Ichikawa Junji 
Published: June 2018

AbstractDie Aktivierung von Kohlenstoff‐Fluor‐Bindungen (C‐F‐Bindungen) ist ein bedeutendes Thema in der organischen Synthesechemie. Metallvermittelte und ‐katalysierte Eliminierungen von β‐ oder α‐Fluor finden unter milderen Bedingungen statt als oxidative Additionen an C‐F‐Bindungen. Die β‐ oder α‐Fluor‐Eliminierung wird ausgehend von organometallischen Intermediaten mit Fluorsubstituenten in β‐ oder α‐Position zu Metallzentren eingeleitet. Umsetzungen durch solche Eliminierungsprozesse (C‐F‐Bindungsspaltungen), welche typischerweise auf eine Kohlenstoff‐Kohlenstoff‐Bindungsknüpfung (oder Kohlenstoff‐Heteroatom‐Bindungsknüpfung) folgen, wurden in den vergangenen fünf Jahren zunehmend zur C‐F‐Bindungsaktivierung entwickelt. In diesem Kurzaufsatz fassen wir die Anwendungen Übergangsmetallvermittelter und ‐katalysierter Fluoreliminierung in der organischen Synthesechemie aus einer historischen Perspektive anhand früher Arbeiten und aus einer systematischen Perspektive am Beispiel aktueller Untersuchungen zusammen.
A Stable Crown Ether Complex with a Noble‐Gas Compound
Authors: Marczenko Katherine M. , Mercier Hélène P. A. , Schrobilgen Gary J. 
Published: June 2018

AbstractCrown ethers have been known for over 50 years, but no example of a complex between a noble‐gas compound and a crown ether or another polydentate ligand had previously been reported. Xenon trioxide is shown to react with 15‐crown‐5 to form the kinetically stable (CH2CH2O)5XeO3 adduct, which, in marked contrast with solid XeO3, does not detonate when mechanically shocked. The crystal structure shows that the five oxygen atoms of the crown ether are coordinated to the xenon atom of XeO3. The gas‐phase Wiberg bond valences and indices and the empirical bond valences indicate that the Xe‐ ‐ ‐Ocrown bonds are predominantly electrostatic and are consistent with σ‐hole bonding. Mappings of the electrostatic potential (EP) onto the Hirshfeld surfaces of XeO3 and 15‐crown‐5 in (CH2CH2O)5XeO3 and a detailed examination of the molecular electrostatic potential surface (MEPS) of XeO3 and (CH2CH2O)5 reveal regions of negative EP on the oxygen atoms of (CH2CH2O)5 and regions of high positive EP on the xenon atom, which are also in accordance with σ‐hole interactions.
Transition‐Metal‐Mediated and ‐Catalyzed C−F Bond Activation by Fluorine Elimination
Authors: Fujita Takeshi , Fuchibe Kohei , Ichikawa Junji 
Published: June 2018

AbstractThe activation of carbon–fluorine (C−F) bonds is an important topic in synthetic organic chemistry. Metal‐mediated and ‐catalyzed elimination of β‐ or α‐fluorine proceeds under milder conditions than oxidative addition to C−F bonds. The β‐ or α‐fluorine elimination is initiated from organometallic intermediates having fluorine substituents on carbon atoms β or α to metal centers, respectively. Transformations through these elimination processes (C−F bond cleavage), which are typically preceded by carbon–carbon (or carbon–heteroatom) bond formation, have been increasingly developed in the past five years as C−F bond activation methods. In this Minireview, we summarize the applications of transition‐metal‐mediated and ‐catalyzed fluorine elimination to synthetic organic chemistry from a historical perspective with early studies and from a systematic perspective with recent studies.
Exploiting the Synthetic Potential of Sesquiterpene Cyclases for Generating Unnatural Terpenoids
Authors: Oberhauser Clara , Harms Vanessa , Seidel Katja , Schröder Benjamin , Ekramzadeh Kimia , Beutel Sascha , Winkler Sven , Lauterbach Lukas , Dickschat Jeroen S. , Kirschning Andreas 
Published: June 2018

AbstractThe substrate flexibility of eight purified sesquiterpene cyclases was evaluated using six new heteroatom‐modified farnesyl pyrophosphates, and the formation of six new heteroatom‐modified macrocyclic and tricyclic sesquiterpenoids is described. GC‐O analysis revealed that tricyclic tetrahydrofuran exhibits an ethereal, peppery, and camphor‐like olfactoric scent.
Performance Enhancement for Rigid Tapping by Iterative Learning Control
Authors: Chen Shyh‐Leh , Wen Chih‐Chao , Zhao Ruo‐Lan 
Published: June 2018

AbstractIn this study, an iterative learning control (ILC) algorithm is proposed to improve synchronous errors in rigid tapping. In rigid tapping, the displacements of the z‐axis and spindle must be kept synchronous to prevent damage. Using learning control provides better commands for both the z‐axis and spindle dynamics, improving the synchronicity of the output responses of the z‐axis and spindle. The proposed ILC makes use of synchronous errors in the previous cycle of tapping to modify the current position commands of both the z‐axis and spindle. A systematic algorithm is proposed for the computation of learning gains that guarantee the monotonic convergence of synchronous errors. A systematic procedure of applying ILC to rigid tapping is also proposed, where the ideas of effective learning gains and stop learning criteria are discussed. Experimental results on a tapping machine verify the effectiveness of the proposed ILC algorithm.
A high‐performance liquid chromatography–tandem mass spectrometry method for simultaneous determination of imigliptin, its five metabolites and alogliptin in human plasma and urine and its application to a multiple‐dose pharmacokinetic study
Authors: Liu Yang , Song Ling , Yao Xueting , Wu Yiwen , Liu Hongzhong , Zhao Qian , Jiang Ji , Shi Chongtie , Ma Xifeng , Zhou Huimin , Liu Dongyang , Hu Pei 
Published: June 2018

AbstractImigliptin is a novel DPP‐4 inhibitor, designed to treat type 2 diabetes mellitus (T2DM). A selective and sensitive method was developed using high performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS) to simultaneously quantify imigliptin, its five metabolites, and alogliptin in human plasma and urine. Solid‐phase extraction (SPE) and direct dilution were used to extract imigliptin, its five metabolites, alogliptin from plasma and urine, respectively. The extracts were injected onto a SymmetryShield RP8 column with a gradient elution of methanol and water containing 10 mM ammonium formate (pH = 7). Ionization of all analytes was performed using an electrospray ionization (ESI) source in positive mode and detection was carried out with multiple reaction monitoring (MRM) mode. The results revealed that the method had excellent selectivity and linearity. Inter‐ and intra‐batch precisions of all analytes were less than 15% and the accuracies were within 85%–115% for both plasma and urine. The sensitivity, matrix effect, extraction recovery, linearity, and stabilities were validated for all analytes in human plasma and urine. In conclusion, the validation results showed that this method was robust, specific, and sensitive and it can successfully applied to a pharmacokinetic study of Chinese T2DM subjects after oral dose of imigliptin and alogliptin.
A survey on modeling and simulation practices for teaching power harmonics
Authors: Igual Raúl , Plaza Inmaculada , Marcuello Juan José , Arcega Francisco 
Published: June 2018

AbstractIn recent years the undergraduate engineering curriculum of several areas has started to incorporate the study of harmonic distortion on electrical systems. Several education simulation tools have been developed and investigated, most of them a short time ago. However, to the best of our knowledge, there is not any literature review on this topic. In this work, we present for the first time a systematic survey on educational tools to model and simulate the effect of power harmonics on industrial electrical networks. As a result, several improvement aspects have been identified and recommendations and implications for future research have been provided. For that, a retrospective study has been accomplished, showing a growing trend toward simulation and modeling. The key teachers’ perceptions to incorporate these practices are the ease of the teaching‐learning process and the importance of modeling and simulation in the industry. The main research challenge is the conduction of integral assessments that comprise both tools’ quality and use experience, and their contribution to achieve learning outcomes. Statistical tests should be used to validate the academic results obtained. This is a major challenge, since only a few of the existing studies incorporate such tests. Other implications for future research refer to the involvement of a higher number of students in the evaluations and the use of free software in the development of the applications.
A classroom‐based simulation‐centric approach to microelectronics education
Authors: Dickerson Samuel J. , Clark Renee M. 
Published: June 2018

AbstractIntroductory courses in microelectronic circuits are integral components to electrical and computer engineering undergraduate curriculums. The nature of the material is well‐suited for the incorporation of simulation tools to enhance student understanding of core concepts. SPICE is an electrical circuit simulation tool that has been widely adopted for industrial applications and education. In many instances, engineering instructors have used SPICE‐based simulation tools for homework problems, laboratory exercises, and course projects. Although generally accepted as beneficial to electronics education, the use of SPICE simulation tools is typically restricted to these types of assignments and not heavily used for classroom activity. In this paper, we present a novel method for incorporating SPICE simulation tools into the classroom. Specifically, in a summer 2017 microelectronics course, we used simulation tools for all aspects of the course, incorporating simulation into lecture, in‐class active learning, as well as assignments, and projects. To evaluate this approach, we carried out a rigorous, comprehensive study of this pedagogical approach on student learning, and perspectives using a variety of direct and indirect assessment methods. The results across all measures showed substantial benefits for students to using this methodology and positive responses to the active learning. Beyond microelectronics and other electrical and computer engineering courses, this approach can be applied to other STEM courses where complex systems are studied and simulation tools for these systems are readily accessible to students.
Effects of interactive computer simulation and animation (CSA) on student learning: A case study involving energy, impulse, and momentum in rigid‐body engineering dynamics
Authors: Ha Oai , Fang Ning 
Published: June 2018

AbstractThis paper describes the development and assessment of computer simulation and animation learning modules that involve energy, impulse, and momentum in rigid‐body engineering dynamics. The assessment results show that the group‐average learning gain increases from less than 23% in the comparison group to more than 60% in the intervention group.
Assessing Shiny apps through student feedback: Recommendations from a qualitative study
Authors: González José A. , López Mireia , Cobo Erik , Cortés Jordi 
Published: June 2018

AbstractTeaching statistics has benefited from Java applets, the successful technology that appeared in the late 90s and which allowed real interactivity on an Internet browser. Combining dynamic functionality with the web provides an inspirational complement to the contents of many subjects in undergraduate statistics courses, especially for active learning activities. Since Java applets are becoming obsolete, we explore a different technology based on R (currently a popular statistical language) and Shiny, which is a web framework for developing interactive applications inside the R environment. Although the pedagogical value of these tools has been implicitly accepted so far, our aim is to consider the students' perspective while investigating more suitable means to accompany the use of apps in statistics. We conducted a qualitative study in which we tested 10 of our applications and collected student opinions through questionnaires and regular meetings. Our conclusions indicate that the students view these resources positively, although they demand more support, just enough to facilitate both getting started and using the tools effectively. In addition, programming in R is surely more accessible and satisfying for statistics lecturers than other languages and, consequently, implementing instructional activities can be specially tailored by the teacher.
Numerical methods to biosystems and food engineering students: Hands‐on practices and cross‐disciplinary integration
Authors: Rabi Jose A. , Caneppele Fernando L. 
Published: June 2018

AbstractWhile virtualization has supported many engineering sectors, it remains underexplored in agroindustrial engineering. Accordingly, hands‐on activities in numerical methods have been proposed to food and biosystems engineering students at a didactic computational laboratory. As those learning‐by‐doing tasks refer to agroindustrial problems, integration with forthcoming disciplines has been achieved and pedagogical ethos has indeed been promoted.
A model parameter estimation method using Mathematica© applied to transient chemical engineering processes
Authors: Mejri Sabrine , Binous Housam , Mahgoub Kamal , Bellagi Ahmed 
Published: June 2018

AbstractIn the present paper, we apply a new approach, based on mainly two built‐in functions of the computer algebra Mathematica©, in order to estimate the parameters of several models that describe various transient (i.e., time‐dependent) chemical engineering processes. These models usually consist of either a set of ordinary differential equations (ODEs) or partial differential equations (PDEs). Basing on experimental data, it is possible to obtain, both readily and accurately, estimates of the values of the parameters involved in such models by adopting the proposed methodology. We illustrate the approach with three case studies, all related to chemical reactors. Actual experimental data, collected by senior students at King Fahd University of Petroleum & Minerals during their core laboratory course (i.e., Chemical Engineering Lab II or CHE 409) are used in the first two case studies: (1) response to a tracer input of three continuous stirred‐tank reactors in series and (2) saponification reaction of ethyl acetate in a batch reactor. In the first case study, the residence time distribution and the mean residence time in each reactor are deduced from the set of gathered data. Reaction order and rate constant are estimated from the experimental findings in the second case study. A more advanced situation, involving the solution of the advection–diffusion equation applied to a tubular micro‐reactor, is considered in the third case study. Data were collected, as part of a Ph.D. research of S. Mejri, using an experimental set‐up at Energy Intensified Reactor Engineering Lab at the University of Warwick, U.K. Here, we obtained an estimate of the relevant dimensionless number namely, the Péclet number.
Teaching optimization of manufacturing problems via code components of a Jupyter Notebook
Authors: Suárez Andres , Alvarez‐Feijoo Miguel A. , Fernández González Raquel , Arce Elena 
Published: June 2018

AbstractThe Degree in Mechanical Engineering combines knowledge and skills of the academic STEM disciplines (Science, Technology, Engineering, and Mathematics). The teaching of the STEM subjects must give prominence to the association of the physical, chemical, and mathematical concepts with the real world. The Jupyter Notebook can be defined as a scientific interactive framework. They can contain text, mathematical equations, interactive graphs, and videos. It allows creating a workspace for watching and playing with the concepts to be learned. Because of their didactic usefulness and easy divulgation, they are highly recommended as a learning environment. In the present work, there are reflected the experiences of using interactive Jupyter Notebook in virtual laboratory sessions within a 4th year subject of Mechanical Engineering related with manufacturing processes. Students' judgments on the efficacy of this resource were evaluated. The results showed that students are in agreement on the effectiveness of using Jupyter notebooks as a teaching‐learning tool.
Personalization of engineering education with the mixed reality mobile applications
Authors: Tumkor Serdar 
Published: June 2018

AbstractGeometric visualization, the spatial perception of problems, and geometric reasoning are always considered essential skills for an engineering student. Although the student can learn geometric visualization eventually, some students with the missing visualization skills cannot follow the instructions to solve the engineering problems. Immersive mixed reality (MR) technologies have been used by the author to help students with object visualization problems. MR technologies virtually project the objects and allow students observing three dimensional (3D) representation of two dimensional (2D) sketches in front of them, while also rotating the virtual model as they wish. These educational mobile applications have been tested in engineering drawing classes and overall improvement of student visualization skills has been reported. In this study, the research question is if some students benefit more from the immersive technologies. Some students have previous CAD experiences from their high school education or interest in technology as a hobby. Playing video games gives students some visualization skills too. Pre‐ and post‐ mental rotation tests (MRTs) are analyzed along with their pre‐existing educational and video game experiences to evaluate the level of benefits of MR technology in class.
Star Life Cycle and games development projects for conducting the human–computer interaction course: A practical experience
Authors: Farinazzo Martins Valéria , de Paiva Guimarães Marcelo 
Published: June 2018

AbstractThis paper describes an approach to teaching a course in human–computer interaction that is supported by the use of Star Life Cycle methodology and game development projects. This approach aims to increase students’ motivation, commitment, and proactivity during the learning process. The Star Life Cycle methodology was extended to facilitate follow‐up of the projects developed by students and to enable coverage of the whole course. The teacher evaluated the deliverable artifacts that were associated with each activity, thus becoming a central part of the evaluation phase of the methodology as well as the leader of the development. In this paper, a case study is presented in which a mathematical game was defined as a final project for 145 students, who were divided into groups. The viewpoints of both the students involved and their teacher are taken into account in the discussion of the results.
Design and usability of learning objects applied in graphic expression
Authors: Melian‐Melian Juan A. , Martin‐Gutierrez Jorge 
Published: June 2018

AbstractThe application of ICT in the field of teaching has meant that learning objects can be used to fulfill an important role in the student‐centered learning process that is being widely promoted across the European Higher Education Area (EHEA). For this study, learning objects were designed as a resource to support teaching and encourage autonomous learning practices in the subject of Graphic Expression belonging to the Architecture Degree. An analysis of their application was performed that involved evaluating the “usability” ratings of students who tested the learning objects. Survey results reveal positive scores were consistently awarded to all three usability components (effectiveness, efficiency, and satisfaction), indicating receptiveness to said learning objects on the part of students. This positive feedback has proven encouraging with regards to continuing with the design and development of new learning objects, and the study of their application in other areas.