bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced Dyes Enhance Single‐Molecule Localization Density for Live Superresolution Imaging
Authors: Carlini Lina , Benke Alexander , Reymond Luc , Lukinavičius Gražvydas , Manley Suliana 
Published: February 2014

AbstractCell‐permeable rhodamine dyes are reductively quenched by NaBH4 into a non‐fluorescent leuco‐rhodamine form. Quenching is reversible, and their fluorescence is recovered when the dyes are oxidized. In living cells, oxidation occurs spontaneously, and can result in up to ten‐fold higher densities of single molecule localizations, and more photons per localization as compared with unmodified dyes. These two parameters directly impact the achievable resolution, and we see a significant improvement in the quality of live‐cell point‐localization super‐resolution images taken with reduced dyes. These improvements carry over to increase the density of trajectories for single‐molecule tracking experiments.
Synthesis and Growth Mechanism of White‐Fungus‐Like Nickel Sulfide Microspheres, and Their Application in Polymer Composites with Enhanced Microwave‐Absorption Properties
Authors: He Shuai , Lu Chang , Wang Guang‐Sheng , Wang Jia‐Wei , Guo Hao‐Yue , Guo Lin 
Published: February 2014

AbstractWhite‐fungus‐like NiSx microspheres have been synthesized on a large scale by using a simple hydrothermal method. The influence of the reaction time and the surfactant on the final products was investigated, and the formation mechanism was discussed. The synthesized white‐fungus‐like NiSx microspheres were used firstly as fillers in the fabrication of NiSx/polyvinylidene fluoride (PVDF) composites. Relationships between the loadings of the NiSx and wave‐absorption properties of the composites were analyzed. The loss mechanisms of NiSx/PVDF with different loadings were also discussed according to their dielectric and magnetic behaviors.
Anodic Nanotubular/porous Hematite Photoanode for Solar Water Splitting: Substantial Effect of Iron Substrate Purity
Authors: Lee Chong‐Yong , Wang Lei , Kado Yuya , Killian Manuela S. , Schmuki Patrik 
Published: February 2014

AbstractAnodization of iron substrates is one of the most simple and effective ways to fabricate nanotubular (and porous) structures that could be directly used as a photoanode for solar water splitting. Up to now, all studies in this field focused on achieving a better geometry of the hematite nanostructures for a higher efficiency. The present study, however, highlights that the purity of the iron substrate used for any anodic‐hematite‐formation approach is extremely important in view of the water‐splitting performance. Herein, anodic self‐organized oxide morphologies (nanotubular and nanoporous) are grown on different iron substrates under a range of anodization conditions, including elevated temperatures and anodization supported by ultrasonication. Substrate purity has not only a significant effect on oxide‐layer growth rate and tube morphology, but also gives rise to a ninefold increase in the photoelectrochemical water‐splitting performance (0.250 vs. 0.028 mA cm−2 at 1.40 V vs. reversible hydrogen electrode under AM 1.5 100 mW cm−2 illumination) for 99.99 % versus 99.5 % purity iron substrates of similar oxide geometry. Elemental analysis and model alloys show that particularly manganese impurities have a strong detrimental effect on the water‐splitting performance.
Facet‐Dependent Photocatalytic Properties of TiO2‐Based Composites for Energy Conversion and Environmental Remediation
Authors: Ong Wee‐Jun , Tan Lling‐Lling , Chai Siang‐Piao , Yong Siek‐Ting , Mohamed Abdul Rahman 
Published: February 2014

AbstractTitanium dioxide (TiO2) is one of the most widely investigated metal oxides because of its extraordinary surface, electronic, and photocatalytic properties. However, the large band gap of TiO2 and the considerable recombination of photogenerated electron–hole pairs limit its photocatalytic efficiency. Therefore, research attention is being increasingly directed towards engineering the surface structure of TiO2 on the atomic level (namely morphological control of {001} facets on the micro‐ and nanoscale) to fine‐tune its physicochemical properties; this could ultimately lead to the optimization of selectivity and reactivity. This Review encompasses the fundamental principles to enhance the photocatalytic activity by using highly reactive {001}‐faceted TiO2‐based composites. The current progress of such composites, with particular emphasis on the photodegradation of pollutants and photocatalytic water splitting for hydrogen generation, is also discussed. The progresses made are thoroughly examined for achieving remarkable photocatalytic performances, with additional insights with regard to charge transfer. Finally, a summary and some perspectives on the challenges and new research directions for future exploitation in this emerging frontier are provided, which hopefully would allow for harnessing the outstanding structural and electronic properties of {001} facets for various energy‐ and environmental‐related applications.
In situ synthesis of Nanocomposite Membranes: Comprehensive Improvement Strategy for Direct Methanol Fuel Cells
Authors: Rao Siyuan , Xiu Ruijie , Si Jiangju , Lu Shanfu , Yang Meng , Xiang Yan 
Published: February 2014

AbstractIn situ synthesis is a powerful approach to control nanoparticle formation and consequently confers extraordinary properties upon composite membranes relative to conventional doping methods. Herein, uniform nanoparticles of cesium hydrogen salts of phosphotungstic acid (CsPW) are controllably synthesized in situ in Nafion to form CsPW–Nafion nanocomposite membranes with both improved proton conductivity and methanol‐crossover suppression. A 101.3 % increase of maximum power density has been achieved relative to pristine Nafion in a direct methanol fuel cell (DMFC), indicating a potential pathway for large‐scale fabrication of DMFC alternative membranes.
Formfaktoren für Mauersteine
Authors: Brameshuber Wolfgang , Graubohm Markus 
Published: February 2014

AbstractBei der Druckfestigkeitsprüfung von Mauersteinen ist die Höhe des Prüfwertes von verschiedenen Faktoren abhängig. So kann u. a. die während der Druckbelastung hervorgerufene Querdehnungsbehinderung den Prüfwert der Druckfestigkeit deutlich beeinflussen. Wie groß dieser Einfluss ist, hängt im Wesentlichen von der Schlankheit der Mauersteine ab. Mit abnehmender Schlankheit vergrößert sich der Prüfwert der Druckfestigkeit durch den Einfluss der Querdehnungsbehinderung. Bei gleichem Mauersteinmaterial ergeben sich somit für Mauersteine mit geringer Schlankheit deutlich höhere Druckfestigkeitswerte als für Mauersteine mit größerer Schlankheit. Als weitere Einflussfaktoren können der Feuchtegehalt und das Größenformat der Prüfkörper genannt werden. Ziel einer am Institut für Bauforschung (ibac) der RWTH Aachen University durchgeführten Forschungsarbeit war die voneinander losgelöste Herleitung von differenzierten Formfaktoren für die zuvor genannten Einflussfaktoren. Untersucht wurden Prüfkörper mit unterschiedlichen Schlankheiten, Feuchtegehalten und Formaten, die aus Porenbeton‐Planelementen der Festigkeitsklassen 2 und 6 sowie Kalksandstein‐Planelementen der Festigkeitsklasse 20 entnommen wurden. Die Ergebnisse dieser Untersuchungen werden im vorliegenden Artikel vorgestellt.Shape factors for masonry units. In compressive tests on masonry units, the height of the test value depends on different factors. Among others, the effect of platen restraint occurring during compression may exert a significant influence on the test value of the compressive strength. The extent of this influence mainly depends on the slenderness of the masonry units. The test value of the compressive strength increases with decreasing slenderness due to the influence exerted by the effect of platen restraint. Thus, when the masonry units are made of the same material, masonry units with a low slenderness yield significantly higher compressive strength values than masonry units with a high slenderness. Further influencing factors are the moisture content and the dimensions of the test specimens. It was the aim of a research project conducted at the Institute of Building Materials research (ibac) of RWTH Aachen University to separately derive defined shape factors for the previously mentioned influencing factors. Test specimens with different ratios of slenderness, moisture contents and dimensions which were taken from autoclaved aerated concrete high precision elements of strength classes 2 and 6 as well as from calcium silicate high precision elements of strength class 20 were examined. The results of these investigations are presented in the present paper.
Risk of disordered eating attitudes among male adolescents in five Emirates of the United Arab Emirates
Authors: Musaiger Abdulrahman O. , Al‐Mannai Mariam , Al‐Lalla Osama 
Published: February 2014

ABSTRACTObjectiveThe aim of this study was to highlight the prevalence of disordered eating attitudes among male adolescents in the United Arab Emirates (UAE).MethodA multistage stratified sampling method was used to select 731 male students aged 15–18 years from five Emirates of the UAE. The Eating Attitudes Test (EAT‐26) was used to determine the prevalence of disordered eating attitudes in students.ResultsThe findings revealed that the proportion of disordered eating attitudes in the UAE was relatively high compared with many developing and developed countries and ranged from 33.1% to 49.1%. Moreover, students living in the Emirates of Dubai and Al‐Fujairah have double the risk of having disordered eating attitudes compared with students living in the other Emirates.DiscussionThe results suggest the need for screening adolescents for eating disorders, as well as for increased awareness and understanding of eating disorders and their associated risk factors in all male adolescents in the UAE. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:898–900)
Electrochemical and Photoelectrochemical Sensing of NADH and Ethanol Based on Immobilization of Electrogenerated Chlorpromazine Sulfoxide onto Graphene‐CdS Quantum Dot/Ionic Liquid Nanocomposite
Authors: Jafari Fereydoon , Salimi Abdollah , Navaee Aso 
Published: February 2014

AbstractHere, a simple one‐step solvothermal procedure was employed to synthesize a nanocomposite containing graphene‐nanosheets and CdS quantum dots (GNs‐CdS QDs). The electrochemical oxidation of chlorpromazine (CPZ) to chlorpromazine‐sulfoxide (CPZ‐SO) onto a GNs‐CdS QDs/ionic liquid (IL) nanocomposite modified glassy carbon (GC) electrode give rise to redox‐active products which showed excellent electrocatalytic and photoelectrocatalytic activity toward NADH oxidation at reduced overpotential. A linear response up to 200 µM was obtained for photoamperometric determination of NADH with detection limit 1 µM. Immobilizing alcohol dehydrogenase(ADH) onto the modified electrode via a simple cross linking procedure, the photoelectrochemical capability of the proposed system toward ethanol biosensing was clearly shown.
Point‐of‐Care Amperometric Testing of Diabetic Marker (HbA1c) Using Specific Electroactive Antibodies
Authors: Chopra Adity , Rawat Sanjay , Bhalla Vijayender , Suri C. Raman 
Published: February 2014

AbstractSpecific immune detection of glycated hemoglobin is still a great challenge owing to the small epitopic difference between Hemoglobin (Hb) and HbA1c. We report a new electrochemical immunoassay format for point of care testing of HbA1c. A conducting self‐assembled monolayer of mercaptophenyl boronic acid (MPBA) was used as a capture layer for binding of glycated proteins and ferrocene tagged anti‐HbA1c antibody (FcAb) as a tracer molecule on a gold screen printed electrode. Validation of the new HbA1c assay was carried out using 6 clinical samples with known HPLC values and a correlation coefficient of 98 % was observed.
Assessing the Tearing Energy of a Hydrocarbon Elastomeric Seal Material for Fuel Cell Applications
Authors: Klein Justin E. , Singh Hitendra K. , Divoux Gilles M. , Case Scott W. , Dillard David A. , Dillard John G. , Moore Robert B. , Parsons Jason B. 
Published: February 2014

AbstractElastomeric gaskets are commonly used between cells within a fuel cell stack to ensure that the reactant gases are isolated. Failure of a fuel cell gasket can cause the reactant gases to mix and can lead to failure of the fuel cell. An investigation of the durability of a hydrocarbon elastomeric seal material developed for proton exchange membrane fuel cells was performed by comparing the tearing energy required for crack propagation of as‐received and environmentally aged samples. Tear force was recorded as a function of crosshead displacement rate and the critical strain energy release rate was calculated and plotted against crack growth rate. Data obtained at different temperatures were then used to generate a fracture energy master curve. Additional samples were aged in selected relevant environments and compared to the as‐received material to study the effect of environmental aging on tear energy master curves. Comparison of tearing energy master curves for different test conditions showed an increase in the tearing energy for all aging environments. The tear energy master curve for testing carried out in water suggested that the crack propagation rates as low as of 10–8 ms–1 can be seen as the fracture energy approaches 80 Jm–2.
Distance Measurements to Metal Ions and Other Quadrupolar Spins by Magic Angle Spinning Solid State NMR
Authors: Goldbourt Amir 
Published: February 2014

AbstractThe characterization of metal sites in many types of materials is essential for understanding many aspects of chemistry and biochemistry, such as catalysis, enzymatic activity, and coordination. Of the many approaches to study such sites, this review deals with the utilization of dipolar recoupling in the context of magic angle spinning solid state NMR for qualitative and, in particular, quantitative distance measurements between metals and other quadrupolar nuclei to their surrounding environment. It will focus on the development of techniques, on their applicability towards experimental realizations, on key applications to materials and biological systems, and on current challenges and limitations.
Topical Developments in High‐Field Dynamic Nuclear Polarization
Authors: Michaelis Vladimir K. , Ong Ta‐Chung , Kiesewetter Matthew K. , Frantz Derik K. , Walish Joseph J. , Ravera Enrico , Luchinat Claudio , Swager Timothy M. , Griffin Robert G. 
Published: February 2014

AbstractWe report our recent efforts directed at improving high‐field dynamic nuclear polarization (DNP) experiments. We investigated a series of thiourea nitroxide radicals and the associated DNP enhancements ranging from ε=25 to 82, which demonstrate the impact of molecular structure on performance. We directly polarized low‐gamma nuclei, including 13C, 2H, and 17O, by the cross effect mechanism using trityl radicals as a polarization agent. We discuss a variety of sample preparation techniques for DNP with emphasis on the benefits of methods that do not use a glass‐forming cryoprotecting matrix. Lastly, we describe a corrugated waveguide for use in a 700 MHz/460 GHz DNP system that improves microwave delivery and increases enhancements up to 50 %.
First‐Year Students' Environmental Awareness and Understanding of Environmental Sustainability Through a Life Cycle Assessment Module
Authors: Weber Nicole R. , Strobel Johannes , Dyehouse Melissa A. , Harris Constance , David Ray , Fang Jun , Hua Inez 
Published: February 2014

AbstractBackgroundIncorporating environmental sustainability (ES) into engineering education is vital to both individual engineering students' success and to the profession as a whole. This study explores attitudes, conceptions, and misconceptions about ES that students bring to the classroom. A promising framework of design‐based research is applied to gauge how instructional innovation can impact student attitudes, conceptions, and misconceptions.PurposeTwo questions guided this research: What knowledge and attitudes about ES, particularly those pertaining to engineering, do first‐year engineering students have? How can an engineering module focused on life cycle assessment in a first‐year engineering course affect students' conceptual understanding to prepare them to develop a robust appreciation of environmental issues and ES in engineering?Design/MethodA quantitative research design in the context of a comparative design‐based research study was utilized to examine first‐year engineering students' environmental awareness coming into the program and changes in their conceptions of ES following their participation in a module that focused on life cycle assessment (LCA).Results/ConclusionFollowing the participation in the LCA module, the intervention was able to address certain misconceptions and support students' shift to deeper understanding about ES. Students' perceptions regarding the complexity of LCA did not change. Including multifaceted issues such as LCA in the teaching of engineering students seems beneficial.
Exploring Student Conceptions of Modeling and Modeling Uses in Engineering Design
Authors: Carberry Adam R. , McKenna Ann F. 
Published: February 2014

AbstractBackgroundModeling is a pervasive feature of engineering that is rarely taught explicitly to engineering students. The implicit inclusion of modeling often results in conceptions held by students of models based on the everyday use of the term that neglects important predictive types of models.PurposeWe studied the effectiveness of an explicit modeling module designed to broaden student understandings of various approaches to and applications of modeling.Design/MethodA two‐phase analysis of student conceptions was undertaken. Phase I analyzed the conceptions of an experimental group before and after they were taught an explicit modeling module. Phase II added a comparison group at a second institution.ResultsA significant shift was observed for engineering students who were explicitly taught a modeling module. Student‐held conceptions were predominantly descriptive‐centric (e.g., physical models) throughout the investigation with an added focus on predictive (e.g., mathematical) modeling after completing the modeling module. These results were consistent for a comparison group.ConclusionsExplicit learning experiences about models and the modeling process need to be embedded into the engineering curriculum, specifically in the teaching of engineering design. Teaching modeling will improve student use and understanding of modeling as an important and pervasive engineering tool.
Sustainability as a Route to Broadening Participation in Engineering
Authors: Klotz Leidy , Potvin Geoff , Godwin Allison , Cribbs Jennifer , Hazari Zahra , Barclay Nicole 
Published: February 2014

AbstractBackgroundSustainability is increasingly a vital consideration for engineers. Improved understanding of how attention to sustainability influences student major and career choice could inform efforts to broaden participation in engineering.PurposeTwo related questions guided our research. How do career outcome expectations related to sustainability predict the choice of an engineering career? Which broader sustainability‐related outcomes do students perceive as related to engineering? To address both questions, we compared effects for engineering and nonengineering students while controlling for various confounding variables.Design/MethodWe conducted a survey to collect responses about sustainability and other variables of interest from a national sample of college students in introductory English classes. Data were analyzed using descriptive statistics and correlational analysis.ResultsStudents who hope to address certain sustainability issues such as energy, climate change, environmental degradation, and water supply are more likely to pursue engineering. Those who hope to address other sustainability issues such as opportunities for women and minorities, poverty, and disease are less likely to do so. Students hoping to address sustainability‐related outcome expectations with obvious human relevance are less likely to pursue engineering. Yet those students who perceive “improving quality of life” and “saving lives” as associated with engineering are more likely to pursue the profession.ConclusionsOur results suggest that showing students the connection between certain sustainability issues and engineering careers could help those striving to increase and diversify participation in engineering. A broader range of engineers would likely bring new ideas and ways of thinking to engineering for sustainability.
Marginalized Identities of Sense‐Makers: Reframing Engineering Student Retention
Authors: Danielak Brian A. , Gupta Ayush , Elby Andrew 
Published: February 2014

AbstractBackgroundStudents' identities and sense of belonging in a program affect whether they stay in engineering. Research suggests that students' ways of knowing and beliefs about what counts as knowing and learning – their personal epistemologies – can be aspects of their identities, or sense of self as knowers and learners.Purpose/HypothesisCombining personal epistemology and identity theories suggests epistemological aspects of students' identities can influence whether they feel they belong in their engineering program. We have two research questions: Can a high‐achieving engineering student be in danger of leaving a program because of a mismatch between epistemological aspects of his identity and his perceptions of the intellectual climate of their program? How does such a mismatch affect the student's day‐to‐day academic experiences?Design/MethodFor three years, we followed Michael, an electrical engineering student, through interviews and in‐class observations. From more than 12 hours of semistructured clinical interviews, more than 10 hours of videotaped discussion sections, and two in‐class observations in lectures, we produced a case study to characterize epistemological aspects of Michael's identity and how they influenced his perception of his program.ResultsMichael expressed and enacted a sense‐making epistemology that is a fundamental aspect of his identity as a learner. Due to this sense‐making aspect of Michael's identity, he often felt alienated from the intellectual climate of his program, and he considered leaving engineering.ConclusionResearchers focused on student retention should attend to epistemological aspects of student identities. Instructors and administrators focused on retention should attend to the epistemological messages students hear from their programs.