bluuebunny/crossref_metadata_2025 huggingface dataset:
Extreme heat changes post‐heat wave community reassembly
Authors: Seifert Linda I. , Weithoff Guntram , Vos Matthijs
Published: May 2015

Climate forecasts project further increases in extremely high‐temperature events. These present threats to biodiversity, as they promote population declines and local species extinctions. This implies that ecological communities will need to rely more strongly on recovery processes, such as recolonization from a meta‐community context. It is poorly understood how differences in extreme event intensity change the outcome of subsequent community reassembly and if such extremes modify the biotic environment in ways that would prevent the successful re‐establishment of lost species. We studied replicated aquatic communities consisting of algae and herbivorous rotifers in a design that involved a control and two different heat wave intensity treatments (29°C and 39°C). Animal species that suffered heat‐induced extinction were subsequently re‐introduced at the same time and density, in each of the two treatments. The 39°C treatment led to community closure in all replicates, meaning that a previously successful herbivore species could not re‐establish itself in the postheat wave community. In contrast, such closure never occurred after a 29°C event. Heat wave intensity determined the number of herbivore extinctions and strongly affected algal relative abundances. Re‐introduced herbivore species were thus confronted with significantly different food environments. This ecological legacy generated by heat wave intensity led to differences in the failure or success of herbivore species re‐introductions. Reassembly was significantly more variable, and hence less predictable, after an extreme heat wave, and was more canalized after a moderate one. Our results pertain to relatively simple communities, but they suggest that ecological legacies introduced by extremely high‐temperature events may change subsequent ecological recovery and even prevent the successful re‐establishment of lost species. Knowing the processes promoting and preventing ecological recovery is crucial to the success of species re‐introduction programs and to our ability to restore ecosystems damaged by environmental extremes.
Dihydroazulene/Vinylheptafulvene Photoswitch: Ultrafast Back Reaction Induced by Dihydronaphthalene Annulation
Authors: Broman Søren Lindbæk , Kushnir Oleg , Rosenberg Martin , Kadziola Anders , Daub Joerg , Nielsen Mogens Brøndsted
Published: May 2015

The vinylheptafulvene (VHF) to dihydroazulene (DHA) electrocyclization is known to proceed from an s‐cis conformation of VHF and cannot occur from the more stable s‐trans conformation. Locking the VHF in the s‐cis conformation by the introduction of a dihydronaphthalene (DHN) unit has been found to greatly enhance the speed of this reaction. Thus, the half‐life was reduced by more than a factor of 150000 in cyclohexane and by a factor of approximately 950000 in ethanol. In addition, the characteristic absorption of the photoactive DHA isomer, now annulated to DHN, exhibited a desired redshift relative to the parent compound. Here, we present the synthesis and study of these DHN‐DHA/VHFs, including a protocol for the incorporation of a pseudo‐halide to enable the further functionalization of the molecule by metal‐catalyzed cross‐coupling reactions. For proof‐of‐concept, two different sulfur end‐groups were incorporated as anchoring groups for potential molecular electronics applications.
SWOT analysis of program design and implementation: a case study on the reduction of maternal mortality in Afghanistan
Authors: Ahmadi Qudratullah , Danesh Homayoon , Makharashvili Vasil , Mishkin Kathryn , Mupfukura Lovemore , Teed Hillary , Huff‐Rousselle Maggie
Published: May 2015

This case study analyzes the design and implementation of the Basic Package of Health Services (BPHS) in Afghanistan by synthesizing the literature with a focus on maternal health services. The authors are a group of graduate students in the Brandeis University International Health Policy and Management Program and Sustainable International Development Program who used the experience in Afghanistan to analyze an example of successfully implementing policy; two of the authors are Afghan physicians with direct experience in implementing the BPHS. Data is drawn from a literature review, and a unique aspect of the case study is the application of the business‐oriented SWOT analysis to the design and implementation of the program that successfully targeted lowering maternal mortality in Afghanistan. It provides a useful example of how SWOT analysis can be used to consider the reasons for, or likelihood of, successful or unsuccessful design and implementation of a policy or program. Copyright © 2015 John Wiley & Sons, Ltd.
Integrated frameworks for assessing and managing health risks in the context of managed aquifer recharge with river water
Authors: Assmuth Timo , Simola Antti , Pitkänen Tarja , Lyytimäki Jari , Huttula Timo
Published: May 2015

Integrated assessment and management of water resources for the supply of potable water is increasingly important in light of projected water scarcity in many parts of the world. This article develops frameworks for regional-level waterborne human health risk assessment of chemical and microbiological contamination to aid water management, incorporating economic aspects of health risks. Managed aquifer recharge with surface water from a river in Southern Finland is used as an illustrative case. With a starting point in watershed governance, stakeholder concerns, and value-at-risk concepts, we merge common methods for integrative health risk analysis of contaminants to describe risks and impacts dynamically and broadly. This involves structuring analyses along the risk chain: sources—releases—environmental transport and fate—exposures—health effects—socio-economic impacts—management responses. Risks attributed to contaminants are embedded in other risks, such as contaminants from other sources, and related to benefits from improved water quality. A set of models along this risk chain in the case is presented. Fundamental issues in the assessment are identified, including 1) framing of risks, scenarios, and choices; 2) interaction of models and empirical information; 3) time dimension; 4) distributions of risks and benefits; and 5) uncertainties about risks and controls. We find that all these combine objective and subjective aspects, and involve value judgments and policy choices. We conclude with proposals for overcoming conceptual and functional divides and lock-ins to improve modeling, assessment, and management of complex water supply schemes, especially by reflective solution-oriented interdisciplinary and multi-actor deliberation. Integr Environ Assess Manag 2016;12:160–173. © 2015 SETAC

Key Points

Integrated frameworks need to be developed for the assessment and management of risks to human health from contamination of water resources by both chemicals and pathogens, to reduce knowledge-and action-related gaps in the governance of such risks. Relationships between various assessment areas and approaches, including risk-cost-benefit analyses of options, are identified and incorporated in a framework structured around chains and cycles of risk formation and management, specifically in artificial groundwater recharge with river water. The case of managed Aquifer Recharge with water from a major river basin exemplifies the need to consider improvements for health and subsequently for economy from such solutions, but also potential new risks such as those from emerging contaminants and unforeseen sudden events. Assessment approaches and models need to flexibly combine breadth with focus and detail with simplification, and facilitate reframing of the risks and impacts considered and the associated uncertainties and ambiguities, especially as assessment is closely linked with decisions and actions.
Fourth‐order hybrid implicit and explicit‐FDTD method
Authors: Dong Mian , Chen Juan , Zhang Anxue
Published: May 2015

A fourth‐order hybrid implicit and explicit finite‐difference time‐domain Method has been presented in this paper. This new method investigates the use of a second‐order accurate in time and a fourth‐order accurate in space. The 2D formulation of the method is presented and the time stability condition of the method is certified. The maximum time step size in this method is only determined by one spatial discretization. The numerical dispersion is discussed. Numerical examples demonstrate that when this method is used to solve electromagnetic problems, higher computational efficiency and less dispersion error can be obtained by comparing with the traditional finite‐difference time‐domain algorithm. Copyright © 2015 John Wiley & Sons, Ltd.
The effect of adenosine 5′‐monophosphate (AMP) on tenderness, microstructure and chemical–physical index of duck breast meat
Authors: Wang Daoying , Deng Shaoying , Zhang Muhan , Geng Zhiming , Sun Chong , Bian Huan , Xu Weimin , Zhu Yongzhi , Liu Fang , Wu Haihong
Published: May 2015

BACKGROUND

Adenosine 5′‐monophosphate (AMP) is often used in meat and poultry soups as a flavor enhancer (flavor modifier), or as food additives for specific nutritional purposes. Our previous research as well as evidence from others showed that actomyosin could be dissociated into myosin and actin by AMP in extracted muscle solution. However, there is no report available on the application of AMP to dissociate actomyosin and to improve meat tenderness. The objectives of this study were to evaluate the effect of AMP on duck meat tenderness and other quality traits and to explore the mechanism of the action of AMP on meat tenderness.

RESULTS

Duck breast muscle was treated with 0, 10, 20, 30, 40 mmol L−1 AMP at 5 °C for 10 h and examined for shear force, microstructure, actomyosin dissociation, myofibril fragmentation index (MFI), pH, water content, cooking loss, CIE* color (L*, a*, b*), inosine monophosphate (IMP) and free amino acid (FAA) contents. Results showed that shear force, cooking loss, L* and b* of the muscles significantly decreased after AMP treatment (P < 0.05); actomyosin dissociation, MFI, pH, water content, fiber diameter, sarcomere length, IMP and ammonia significantly increased (P < 0.05); no significant change in a* or other FAA content was observed (P > 0.05), and muscle shrinkage in transverse and longitudinal directions were restrained after AMP treatment.

CONCLUSION

The results suggest that AMP could notably improve meat tenderness, and this effect was probably mainly through increasing muscle pH, promoting actomyosin dissociation and disrupting the Z‐line; meanwhile, the conversion of AMP to IMP may contribute to the flavor of meat. © 2015 Society of Chemical Industry
Application of ZnSO4 or Zn‐EDTA fertilizer to a calcareous soil: Zn diffusion in soil and its uptake by wheat plants
Authors: Zhao Ai‐qing , Tian Xiao‐hong , Chen Yan‐long , Li Shuo
Published: May 2015

BACKGROUND

The objective of this study was to compare the efficiency of two Zn sources and two application methods on (i) Zn diffusion from fertilized soil to unfertilized soil, (ii) grain Zn concentration and (iii) grain Zn bio‐accessibility to humans. In the laboratory experiment, 20 mg ZnSO4 or 4 mg Zn‐EDTA were applied to a 5 mm and 1 mm‐wide space in the soil in the half‐cell technique. In the greenhouse experiment, Zn‐ZnSO4 or Zn‐ethylenediaminetetraacetic acid (Zn‐EDTA) was mixed or banded with the soil at a rate of 20 or 4 mg Zn kg−1, respectively.

RESULTS

The results from the diffusion experiment showed that both the extractability and the diffusion coefficient of Zn were higher when Zn fertilizer was applied to a 1 mm‐wide space than when it was applied to a 5 mm‐wide space. Zn‐EDTA had a greater diffusion distance than ZnSO4. The greenhouse experiment showed that the mixed ZnSO4 application and the Zn‐EDTA application (both mixed and banded) treatments significantly increased grain Zn concentration and bio‐accessibility. The positive effect of Zn‐EDTA on grain Zn concentrations and bio‐accessibility was greater than that of ZnSO4. The banded application reduced the effectiveness of ZnSO4 but not of Zn‐EDTA.

CONCLUSION

It was concluded that Zn‐EDTA was a better Zn source than ZnSO4 for increasing grain Zn content in a potentially Zn‐deficient calcareous soil. © 2015 Society of Chemical Industry
When Stakes are High and Guards are Low: High‐quality Connections in Knowledge Creation
Authors: Aarrestad Martine , Brøndbo Marthe Turnes , Carlsen Arne
Published: May 2015

We provide a first qualitative empirical investigation of the dynamics of high‐quality connections in organizational knowledge creation through a comparative analysis of two organizations involved in management consulting and oil exploration. The study combines approaches from positive organizational scholarship with practice‐based studies. We found three types of positively deviant practices for knowledge creation where high‐quality connections play a major role: (i) Intensifying collaboration is a response to felt urgency and mutual dependency in high‐stakes projects and involves expanding the types of interactions and the emotional intensity in knowledge creation. (ii) Caring questioning unfolds when inviting, open‐ended and appreciative questions enable joint dwelling on problems and stimulate help‐seeking and help‐giving. (iii) Getting physical takes place when the making of collaborative space and use of shared visuals and artifacts enlarge the sensory‐motor connectivity in knowledge creation. The paper contributes to both the literature on high‐quality connections and knowledge creation, showing how the two phenomena are mutually shaping in positively deviant practice. We shed new light on knowledge creation as informal social processes emerging in daily work. Unlike previous research on high‐quality connections, we show how they are first of all ignited by the pull dynamic of high‐stakes projects, with caring questioning and getting physical as the fuel that keeps the fire burning. Copyright © 2015 John Wiley & Sons, Ltd.
Axisymmetric squeezing of a Phan‐Thien and Tanner lubricant film under imposed constant load in the presence of a poroelastic medium
Authors: Yousfi Mahdia , Bou‐Saïd Benyebka , Tichy John
Published: May 2015

In this paper, a modified Reynolds equation in polar coordinates using the Phan‐Thien and Tanner rheological model is combined with a modified Darcy law describing a poroelastic confining surface. The Phan‐Thien and Tanner model is commonly used to describe the viscoelastic behaviour of synovial fluid, while the poroelastic model can portray articular cartilage. Together, they may provide a simulation basis for lubrication of the tribology of the knee contact under squeezing. The results obtained for the axisymmetric case are analysed and compared for certain non‐Newtonian shear phenomena on the basis of works from the literature. Copyright © 2015 John Wiley & Sons, Ltd.
Treatment of acral persistent papular mucinosis using an Erbium‐YAG laser
Authors: Graves Michael S. , Lloyd Amanda A. , Ross Edward V.
Published: May 2015

Background and Objectives

Acral persistent papular mucinosis (APPM) is a rare condition with persistent flesh colored papules on the hands and extensor wrists. The authors aim to present a novel treatment option for this condition.

Patients and Methods

A female with APPM was treated using a 2940 nm Erbium‐YAG laser with a 1 mm spotsize defocused to 2‐3 mm with settings of 200‐300 mJ until the lesion was flush with the surrounding skin.

Results

Healing of the wounds with resolution of the individually treated papules.

Conclusions

Erbium‐YAG lasers should be considered a treatment option for APPM. Lasers Surg. Med. 47:467–468, 2015. © 2015 Wiley Periodicals, Inc.
Interfacial RAFT Miniemulsion Polymerization: Architectures from an Interface
Authors: Fuchs Adrian V. , Thurecht Kristofer J.
Published: May 2015

Directing polymerization from a liquid–liquid interface is an emergent field delivering new insights into polymerization mechanisms, while creating interesting and novel poly­mer architectures. This review aims to explore how reversible addition–fragmentation chain‐transfer (RAFT) polymerization has been utilized in miniemulsion to perform controlled polymerizations at the biphasic liquid–liquid interface. Highlighted herein are the initial investigations that led to a new class of interfacially active macro‐RAFT agents. These are capable of stabilizing emulsions, directing polymer growth from that interface, and subsequently producing capsule‐like architectures. A comprehensive description is provided concerning the various macro‐RAFT agents employed and the importance of performing this under miniemulsion conditions to obtain either nanoparticles, nanocapsules, and/or core–shell morphologies. Finally, a focus on exciting applications of such systems for the production of nanomaterials including delivery vehicles with stimuli‐responsive properties is presented.

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Synthesis of Cyclic Poly(methyl methacrylate) Directly from Dihalogenated Linear Precursors
Authors: Blackburn Scott C. , Tillman Eric S.
Published: May 2015

Cyclic poly(methyl methacrylate) (PMMA) is prepared by intramolecular radical trap‐assisted atom transfer radical coupling (RTA‐ATRC) of dihalogenated PMMA precursors. The inclusion of the radical trap nitrosobenzene (NBz) in the coupling sequence affords high yields of cyclic polymers, as observed by gel permeation chromatography and confirmed by 1H NMR and electrospray ionization mass spectra, which show the presence of the aromatic group from the NBz incorporated into the cycle. Analogous coupling reactions in the absence of the radical trap do not lead to appreciable cyclization or even intermolecular elongation, consistent with chain‐end sterics preventing radical–radical coupling as the predominant termination pathway. Thermolysis of the cyclic PMMA, possible because of the labile CO bond in the alkoxyamine linkage contained in the macrocycle, causes a reversion back to the linear form and is consistent with the role of the radical trap in the coupling sequence. Differential scanning calorimetry is also used to compare cyclic PMMA with its linear analog, with a marked increase in glass transition temperatures found after cyclization.

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Identification and Aftermarket Personalization with Durable Goods
Authors: Donavan D. Todd , Janda Swinder , Maxham James G.
Published: May 2015

Blending elements of the heuristic–systematic model and social identity theory, the authors extend theory by exploring the role of intimacy as a key boundary condition for identification (ID). Specifically, this research illustrates how intimacy affects the relationship between brand characteristics (prestige and distinctiveness) and ID. Further, the authors explore the relationship between ID and aftermarket spending on accessories. In a consumer durables setting, the authors conducted a field study with 1,193 consumers and matched customer perceptions with their actual retail spending on aftermarket goods. The results suggest that an individual's intimacy with a brand may affect how prestige and distinctiveness shape their ID. In addition, results show that the relationship between ID and customer aftermarket spending is moderated by a customer's level of satisfaction. Managerial implications of the findings are also outlined.
Affective and Cognitive Components of Attitudes in High‐Stakes Decisions: An Application of the Theory of Planned Behavior to Hormone Replacement Therapy Use
Authors: Schaller Tracey King , Malhotra Naresh K.
Published: May 2015

Consumers are increasingly encouraged to take charge of high‐stakes decisions such as those regarding medical treatments. However, the important inputs into overall evaluations of risky and important behaviors, such as undergoing medical therapy, are not well understood. The purpose of this research is to study the interplay of cognitive and affective factors in determining consumer attitudes and intentions toward high‐stakes decision behaviors. This is done in the context of consumer choices regarding medical treatments, and specifically, the decision to use (or not to use) hormone replacement therapy (HRT). Overall, both affective and cognitive responses are found to be independent significant predictors of attitude toward HRT use. Moreover, the results support an extended version of the theory of planned behavior model that is useful in predicting consumer's intentions to engage in high‐stakes decision behaviors, such as using HRT. These findings have implications for the design of decision support systems and behavioral change interventions.
Expanded newborn screening by mass spectrometry: New tests, future perspectives
Authors: Ombrone Daniela , Giocaliere Elisa , Forni Giulia , Malvagia Sabrina , la Marca Giancarlo
Published: May 2015

Tandem mass spectrometry (MS/MS) has become a leading technology used in clinical chemistry and has shown to be particularly sensitive and specific when used in newborn screening (NBS) tests. The success of tandem mass spectrometry is due to important advances in hardware, software and clinical applications during the last 25 years. MS/MS permits a very rapid measurement of many metabolites in different biological specimens by using filter paper spots or directly on biological fluids. Its use in NBS give us the chance to identify possible treatable metabolic disorders even when asymptomatic and the benefits gained by this type of screening is now recognized worldwide. Today the use of MS/MS for second‐tier tests and confirmatory testing is promising especially in the early detection of new disorders such as some lysosomal storage disorders, ADA and PNP SCIDs, X‐adrenoleucodistrophy (X‐ALD), Wilson disease, guanidinoacetate methyltransferase deficiency (GAMT), and Duchenne muscular dystrophy. The new challenge for the future will be reducing the false positive rate by using second‐tier tests, avoiding false negative results by using new specific biomarkers and introducing new treatable disorders in NBS programs. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 35: 71–84, 2016.
Towards Better BBB Passage Prediction Using an Extensive and Curated Data Set
Authors: Brito‐Sánchez Yoan , Marrero‐Ponce Yovani , Barigye Stephen J. , Yaber‐Goenaga Iván , Morell Pérez Carlos , Le‐Thi‐Thu Huong , Cherkasov Artem
Published: May 2015

In the present report, the challenging task of drug delivery across the blood‐brain barrier (BBB) is addressed via a computational approach. The BBB passage was modeled using classification and regression schemes on a novel extensive and curated data set (the largest to the best of our knowledge) in terms of log BB. Prior to the model development, steps of data analysis that comprise chemical data curation, structural, cutoff and cluster analysis (CA) were conducted. Linear Discriminant Analysis (LDA) and Multiple Linear Regression (MLR) were used to fit classification and correlation functions. The best LDA‐based model showed overall accuracies over 85 % and 83 % for the training and test sets, respectively. Also a MLR‐based model with acceptable explanation of more than 69 % of the variance in the experimental log BB was developed. A brief and general interpretation of proposed models allowed the estimation on how ‘near’ our computational approach is to the factors that determine the passage of molecules through the BBB. In a final effort some popular and powerful Machine Learning methods were considered. Comparable or similar performance was observed respect to the simpler linear techniques. Most of the compounds with anomalous behavior were put aside into a set denoted as controversial set and discussion regarding to these compounds is provided. Finally, our results were compared with methodologies previously reported in the literature showing comparable to better results. The results could represent useful tools available and reproducible by all scientific community in the early stages of neuropharmaceutical drug discovery/development projects.
A Branch‐and‐Bound Approach for Tautomer Enumeration
Authors: Thalheim Torsten , Wagner Barbara , Kühne Ralph , Middendorf Martin , Schüürmann Gerrit
Published: May 2015

Knowledge about tautomer forms of a structure is important since, e.g., a property prediction for a molecule can yield to different results which depend on the individual tautomer. Tautomers are isomers that can be transformed to each other through chemical equilibrium reactions. In this paper the first exact Branch‐and‐Bound (B&B) algorithm to calculate tautomer structures is proposed. The algorithm is complete in the sense of tautomerism and generates all possible tautomers of a structure according to the tautomer definition, it is initialized with. To be efficient, the algorithm takes advantage of symmetric and formation properties. Some restrictions are used to enable an early pruning of some branches of the B&B tree. This is important, since a simple enumeration strategy would lead to number of candidate tautomers that is exponentially increasing with the number of hydrogen atoms and their attachment sites. The proposed implementation of the B&B algorithm covers the majority of the prototropic tautomer cases, but can be adapted to other kinds of tautomerism too. Furthermore, a computer processable definition of tautomerism is given in the form of the moving hydrogen atom problem.
Improved longitudinal compression performance of a unidirectional fiber‐reinforced composite with a filament covering
Authors: Ruan Fangtao , Bao Limin
Published: May 2015

A filament covering is proposed to improve the longitudinal compressive properties of unidirectional fiber reinforced plastic. Based on compressive buckling theory, fiber buckling can be prevented by shortening the buckling critical wavelength by covering the filament. In this paper, a UHMWPE fiber bundle and a PBO filament were selected as the reinforcing fiber and the covering filament, respectively, to verify this statement. The effect of a covering PBO filament on a UHMWPE fiber reinforced epoxy resin on compressive performance was investigated by a compressive test and morphology observations. Results show that the filament covering has positive effect on the compressive strength of the FRP, and the tension‐exerted filament covering increased the compressive strength and increased the longitudinal compressive modulus of the UFRP. POLYM. COMPOS., 37:3127–3133, 2016. © 2015 Society of Plastics Engineers
Differential quadrature based nonlocal flapwise bending vibration analysis of rotating nanobeam using the eringen nonlocal elasticity theory under axial load
Authors: Pourasghar Amin , Homauni Mostafa , Kamarian Saeed
Published: May 2015

The present paper deals with the dynamic behavior of rotating nanobeam subjected to follower force using the nonlocal elasticity theory. The nonlocal elasticity theory is used to analyze the mechanical behavior of nanoscale materials. The used method of solution is the Differential Quadrature Method (DQM). It is shown that the frequencies are affected when the size effect is taken into consideration. The effects of the nonlocal small scale parameter and the hub radii on the natural frequencies of the rotating nanobeam with respect to the rotating angular velocity are investigated in the present work. This study could be useful in design of the next generation of nanodevices such as blades of a nanoturbine, nanogears, nanoscale molecular bearings, that make use of the vibration analysis of rotating nanobeam. POLYM. COMPOS., 37:3175–3180, 2016. © 2015 Society of Plastics Engineers
Dopamine modification of multiwalled carbon nanotubes and its influences on the thermal, mechanical, and tribological properties of epoxy resin composites
Authors: Wang Huaiyuan , Sun Liyuan , Wang Rui , Yan Lei , Zhu Yanji , Wang Chao , Wang Enqun
Published: May 2015

A functionalization process with dopamine on multiwalled carbon nanotubes (MWNTs) has been carried out in order to enhance the tribological properties of MWNTs/epoxy resin (EP) composites. Dopamine modification is of signality for the performance of MWNTs/EP composites. The hardness and flexural strength of the composites were significantly improved with the incorporation of dopamine modified MWNTs, owning to the enhanced interfacial bonding between MWNTs and EP. Meanwhile, the thermal characterizations indicated that dopamine played an important role in improving the thermal stability of MWNTs/EP composites. More importantly, the friction and wear properties of dopamine modified MWNTs/EP composites were enhanced considerably and its wear rate was 85.8% lower than that of pure EP. Dopamine modified MWNTs were linked with the matrix by strong covalent bond to form a great network structure and impeded the movement of polymer molecule chains in the composites. Then the friction load transmitted efficiently through the network structure and the plastic deformation was restrained as well as the initiation and growth of cracks on the worn surfaces. POLYM. COMPOS., 38:116–125, 2017. © 2015 Society of Plastics Engineers
Effect of selective localization of carbon nanotubes in PA6 dispersed phase of PP/PA6 blends on the morphology evolution with time, part 1: Droplet deformation under simple shear flows
Authors: Gooneie A. , Nazockdast H. , Shahsavan F.
Published: May 2015

The deformation of carbon nanotube (CNT)‐filled PA6 droplets in PP matrix was examined under simple shear flows. The morphology of blends with various CNT contents in PA6 were probed by FE‐SEM. Based on the wetting coefficient calculations and rheological measurements, it was noted that the majority of CNTs were selectively located in the PA6 phase for concentrations up to 2 wt%. TEM micrographs evidenced the results for a sample with 0.5 wt% CNT in PA6. Optical microscopy of the blends during simple shear flows revealed the reduced deformability and breakups for filled‐droplets. Such observations were ascribed to the increased viscosity ratio and gradual formation of an elastic structure within the droplets. Maffetone‐Minale transient droplet deformation model was coupled with a modified capillary number to account for the developed elastic forces. It was shown that the contribution of such forces to the total shape‐conserving forces could arise up to 99% in comparison with the well‐known interfacial forces. These resisting forces can be so strong that for blends with CNT concentrations above 0.5 wt% in PA6 almost no deformation was observed under the applied shear stresses in this work. POLYM. ENG. SCI., 55:1504–1519, 2015. © 2014 Society of Plastics Engineers
Preparation of magnetic poly(lactic‐co‐glycolic acid) microspheres featuring monodispersity and controllable particle size using a microchannel device
Authors: Zhang Hengdi , Hu Lili , Zhong Yi , Luo Yan
Published: May 2015

Poly(lactic‐co‐glycolic acid) (PLGA) microspheres prepared using a traditional solvent evaporation or double emulsification method are usually polydisperse with an uncontrollable particle size distribution, which brings about poor application performance. In our research, monodisperse magnetic PLGA microspheres were prepared using a microchannel device based on a water‐in‐oil‐in‐water composite emulsion. The composite emulsion was formed by injecting a dichloromethane–gelatin water‐in‐oil emulsion into a microchannel together with an external water phase, i.e. poly(vinyl alcohol) (PVA) aqueous solution. Mean particle size control of the microspheres was executed using the osmotic pressure difference between internal and external aqueous phases caused by regulating NaCl concentration in PVA aqueous phase. It is found that monodisperse magnetic PLGA microspheres with high magnetic responsiveness can be successfully prepared combining the microchannel device with composite emulsion method. Mean particle size of the microspheres with coefficient of variation value below 4.72% is controllable from 123 to 203 µm depending on the osmotic pressure. The resulting samples have pyknotic and smooth surfaces, as well as spherical appearance. These monodisperse magnetic PLGA microspheres with good superparamagnetism and magnetic mobility have potential use as drug carriers for uniform release and magnetic targeting hyperthermia in biological fields. © 2015 Society of Chemical Industry
Toward High Reliability Project Organizing in Safety-Critical Projects
Authors: Saunders Fiona C.
Published: May 2015

High reliability organizations claim to be special organizations that have consistently demonstrated safe performance in operating environments, which are simultaneously of high technical complexity, high consequence, and high tempo. This article argues that the literature on high reliability organizing, which emerged through studying day-to-day operations in the nuclear industry, air traffic control industry, and U.S. navy aircraft carriers, might hold important lessons for how the project management community can approach the management of safety-critical projects–projects in which safety is of paramount importance. Its aim is to consider how high reliability organizing might be realized in these safety-critical projects.
Field‐evolved resistance to four modes of action of herbicides in a single kochia (Kochia scoparia L. Schrad.) population
Authors: Varanasi Vijay K , Godar Amar S , Currie Randall S , Dille Anita J , Thompson Curtis R , Stahlman Phillip W , Jugulam Mithila
Published: May 2015

BACKGROUND

Evolution of multiple herbicide resistance in weeds is a serious threat to weed management in crop production. Kochia is an economically important broadleaf weed in the US Great Plains. This study aimed to confirm resistance to four sites of action of herbicides in a single kochia (Kochia scoparia L. Schrad.) population from a crop field near Garden City (GC), Kansas, and further determine the underlying mechanisms of resistance.

RESULTS

One‐fourth of the GC plants survived the labeled rate or higher of atrazine [photosystem II (PSII) inhibitor], and the surviving plants had the Ser‐264 to Gly mutation in the psbA gene, the target site of atrazine. Results showed that 90% of GC plants survived the labeled rate of dicamba, a synthetic auxin. At least 87% of the plants survived up to 72 g a.i. ha−1 of chlorsulfuron [acetolactate synthase (ALS) inhibitor], and analysis of the ALS gene revealed the presence of Pro‐197 to Thr and/or Trp‐574 to Lue mutation(s). Most GC plants also survived the labeled rate of glyphosate [5‐enolpyruvylshikimate‐3‐phosphate synthase (EPSPS) inhibitor), and the resistant plants had 5–9 EPSPS gene copies (relative to the ALS gene).

CONCLUSION

We confirm the first case of evolution of resistance to four herbicide sites of action (PSII, ALS and EPSPS inhibitors and synthetic auxins) in a single kochia population, and target‐site‐based mechanisms confer resistance to atrazine, glyphosate and chlorsulfuron. © 2015 Society of Chemical Industry
Inducing out‐of‐plane auxetic behavior in needle‐punched nonwovens
Authors: Verma Prateek , Shofner Meisha L. , Lin Angela , Wagner Karla B. , Griffin Anselm C.
Published: May 2015

We describe here a heat‐compression protocol used on needle‐punched commercial nonwoven fabrics which induces an out‐of‐plane auxetic response in these treated fabrics. The as‐received samples, however, are not auxetic and show a decrease in thickness when stretched uniaxially. Using micro‐CT imaging it was found that the vertical fiber bundles/columns, produced in the needle punching step of fabric manufacture, are tilted and buckled as a result of the heat‐compression treatment. It is suggested that it is likely the reorientation of these columns during subsequent uniaxial strain that drives thickness increase (auxetic response).

Variation of instantaneous Poisson's ratio with axial strain for as‐received and treated nonwovens.
Ab‐initio study of ferromagnetism in Mn‐doped ZnSnAs2
Authors: Jafarova Vusala , Huseynova Suma , Orudzhev Guseyn , Uchitomi Naotaka , Wakita Kazuki , Mamedov Nazim
Published: May 2015

The electronic and magnetic properties of pure as well as Mn‐doped chalcopyrite semiconductor ZnSnAs2 were studied by the DFT+U ab initio method within the spin generalized gradient approximation. The band structure and DOS calculations resulted in a direct gap scenario for semiconducting ZnSnAs2. The energy gap of 0.34 eV occurs at the center of the Brillouin zone and linearly increases with increasing Mn concentration x at a rate of 2.05 eV for x < 0.03. The total energy calculations for a number of supercells showed that a ferromagnetic rather than antiferromagnetic ordering is favorable in Mn‐doped ZnSnAs2 when Mn replaced Sn. The energy deficient substitution of Zn by Mn led to the antiferromagnetic ordering. The magnetic moment per Mn atom, together with contribution of each atom into the total moment of ZnSnAs2: Mn was determined. The contributions from Mn and As are dominant but have opposite signs. Besides, the As atoms chemically bounded to Mn dopant were found to be most contributive. At last it was shown that the vacancies such as V(Zn), V(Sn), and V(As) affect the magnetic properties and may even strengthen the magnetization of Mn‐doped ZnSnAs2. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of β‐gallium oxide films and nanostructures by atmospheric‐ pressure CVD using gallium and water as source materials
Authors: Terasako Tomoaki , Ichinotani Hikaru , Yagi Masakazu
Published: May 2015

Films and nanostructures of β‐Ga2O3 were successfully grown by atmospheric‐pressure CVD (AP‐CVD) using metal Ga and H2O as source materials. It was confirmed that highly (‐201) oriented polycrystalline β‐Ga2O3 films can be obtained on c ‐plane sapphire (c ‐Al2O3) substrates by optimizing growth temperature (Tg) and source supply ratio of H2O to Ga. The optical gap energy of the β‐Ga2O3 film with a relatively flat surface was estimated to be ∼4.9 eV. Photoluminescence (PL) measurements for the β‐Ga2O3 films revealed the existence of at least three emission bands with their peaks at ∼370 nm, ∼440 nm and ∼520 nm. Various shapes of quasi 1D nanostructures, such as nanowires (NWs), nanorods (NRs), tapered NRs and nanobelts (NBs), were obtained on the c ‐Al2O3 substrates coated with the Au films by utilizing vapour‐liquid‐solid (VLS) growth mechanism. The diversity of the quasi 1D nanostructures is probably due to the contribution of vapour‐solid (VS) growth mechanism and/or the coalescence between the neighbouring Au metal particles before initiating the NW (or NR) growth. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
CVD nanographite films covered by ALD metal oxides: structural and field emission properties
Authors: Ismagilov Rinat R. , Tuyakova Feruza T. , Kleshch Victor I. , Obraztsova Ekaterina A. , Obraztsov Alexander N.
Published: May 2015

Nanographite films produced by direct current plasma enhanced chemical vapour deposition technique were covered by metal oxides TiO2 and Al2O3 using atomic layer deposition. Nanographite films are composed of few‐layer graphene nanowalls and nanoscrolls, which are mostly oriented perpendicular to the silicon substrate surface. The nanographite and nanographite‐metal oxide composite film materials, with oxide layer thickness between 50 nm and 250 nm, were characterized by scanning electron microscopy, energy dispersive X‐ray analysis, thermal gravimetric analysis, and Raman spectroscopy. We demonstrate that the metal oxide deposit homogenously covers graphene nanowalls and forms individual spherical particles on the surface of needle‐like nanoscrolls. Field emission properties of the samples were measured in a flat vacuum diode configuration. It was found that the metal oxide layers thinner than 200 nm do not significantly affect the field emission characteristics of the nanographite. At the same time, metal oxides form a passivation shell which may improve the nanographite film performance as cold cathode in vacuum electronic devices. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of substrate temperature on initiated plasma enhanced chemical vapor deposition of PHEMA thin films
Authors: Gürsoy Mehmet , Karaman Mustafa
Published: May 2015

Poly(2‐hydroxyethyl methacrylate) (PHEMA) thin films were deposited on silicon wafers by initiated plasma enhanced chemical vapour deposition (i‐PECVD) method at different substrate temperatures. Di tert‐butyl peroxide (TBPO) was used as an initiator, and all deposition experiments were performed at 3:1 monomer to initiator flow ratio. Deposition rates up to 44 nm/min were observed at relatively low plasma power depending on the deposition conditions. The high deposition rates at low plasma powers were attributed to the usage of the initiator. Fourier transform infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS) analyses of the deposits indicated very high retention of hydroxyl and carbonyl functionalities especially for the polymers deposited at low plasma powers. Water contact angle measurements were carried out to determine the wettability of as‐deposited PHEMA surfaces. This study indicated that the substrate temperature is an important parameter determining the polymerization rate. Being a dry, low‐cost, reliable and environmentally friendly process, the i‐PECVD technique developed in this study can be used to deposit other functional polymers. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
From cytology to histology: diagnosis of a relapsed mediastinal lymphoma by endobronchial ultrasound transbronchial histological needle
Authors: Ariza‐Prota Miguel Angel , Bango Álvarez Antonio , Pérez Liliana , Pando‐Sandoval Ana , Fuentes Nelson , Casan Pere
Published: May 2015

Endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) is highly accurate in diagnosing mediastinal lymphadenopathies of lung cancer and benign disorders, with the advantage that it is a minimally invasive technique, unlike open surgery and mediastinoscopy. However, the diagnostic accuracy of EBUS‐TBNA for the diagnosis of lymphoma in patients with mediastinal lymphadenopathy is not well defined. The lack of tissue architecture obtained by cytological needles decreases the diagnostic accuracy for diagnosis and subtyping of de novo and relapsed mediastinal lymphomas. We present the first described case in the literature of an anaplastic large cell lymphoma relapsed, diagnosed on tissue fragments obtained by EBUS‐TBNA with the particularity of using a histological needle.
Motivation matters: Corporate scope and competition in complementary product markets
Authors: Bennett Victor M. , Pierce Lamar
Published: May 2015

Research summary: We argue that a pure capabilities‐based view does not accurately explain the competitive dynamics of increasingly common settings in which firms act as both complementors and competitors. We propose that the Awareness‐Motivation‐Capability framework is more appropriate for these settings. We derive predictions from both a pure capabilities view and the AMC framework, and test those predictions in the U.S. auto leasing market, in which the leasing subsidiaries of car manufacturers directly compete with the same independent lessors who provide complements to the manufacturers. Although our results are consistent with capabilities playing an important role, motivation appears to be a critical factor explaining the competitive dynamics of the market.

Managerial summary: Firms that compete with business units owned by larger corporate parents face additional considerations. Such subsidiary competitors can be motivated by broader corporate considerations, shifting their objectives, and consequently, their strategic actions. Expecting subsidiary competitors to pursue business unit profitability can mislead managers toward pricing, product mix, or market entry errors. We present an important example from consumer finance, where independent auto lessors, such as Bank of America (BoA), compete with captive leasing subsidiaries like Ford Motor Credit (FMC). Since FMC is motivated to subsidize and support vehicle sales for its manufacturer parent, a cost advantage is not enough for BoA to dominate the market. Understanding broader corporate motivations of competitors helps managers anticipate competition levels in potential markets, thereby improving decision‐making and performance. Copyright © 2015 John Wiley & Sons, Ltd.
Progressive collapse mitigation of 2D steel moment frames
Authors: Gerasimidis Simos , Baniotopoulos Charalampos
Published: May 2015

The problem of the progressive collapse of structures is today at the forefront of structural engineering because of multiple natural and man‐made hazards, the aging of the infrastructure and the catastrophic consequences associated with that. This paper investigates the effects of different strengthening techniques for mitigating the phenomenon of progressive collapse for 2D steel moment frames. These techniques are applied to a series of moment frames of varying heights and designs using a finite element analysis involving both material and geometric non‐linearities. The results of this work demonstrate that, when analysed as 2D assemblies, realistic, similar steel frame structures undergo different collapse mechanisms and that a general strengthening scheme cannot be applied to all collapse mechanisms.

Verhinderung des fortschreitenden Versagens von zweidimensionalen biegesteifen Stahlrahmen – Bewertung der Wirksamkeit unterschiedlicher Verstärkungsmaßnahmen. Das Problem fortschreitenden Versagens von Konstruktionen steht heute im Mittelpunkt des Ingenieurhochbaus. Gründe dafür sind verschiedene durch Mensch und Natur verursachte Unfälle, die alternde Infrastruktur und die damit verbundenen katastrophalen Folgen. Im vorliegenden Beitrag wird die Wirksamkeit unterschiedlicher Verstärkungsmaßnahmen zur Verhinderung des fortschreitenden Versagens bei zweidimensionalen biegesteifen Stahlrahmen untersucht. Die Verstärkungsmaßnahmen werden für eine Reihe von biegesteifen Stahlrahmen unterschiedlicher Höhe und Ausführung betrachtet. Dazu wird die Finite‐Elemente‐Methode unter Berücksichtigung von materiellen und geometrischen Nichtlinearitäten verwendet. Die Untersuchungsergebnisse zeigen, dass reale, vergleichbare Stahlrahmen‐Konstruktionen, die als zweidimensionale Baugruppen analysiert wurden, unterschiedlichen Versagensmechanismen unterworfen sind und dass eine allgemeine Verstärkungsmaßnahme nicht für alle Versagensmechanismen angewendet werden kann.
Kraftgrößenverfahren und Deformationsmethode im Licht der Habilitationsschrift von Georg Prange (1885–1941)
Authors: Knothe Klaus
Published: May 2015

Ende des 19. und Anfang des 20. Jahrhunderts wurden für die Strukturberechnung von Rahmentragwerken Verfahren entwickelt, die heute als “Kraftgrößenverfahren“ und “Deformationsmethode“ bezeichnet werden. In Deutschland war die Entwicklung mit den Namen Heinrich Müller‐Breslau und Otto Mohr verbunden. Zwischen beiden entwickelte sich eine heftige Kontroverse zu der Frage, ob die Grundlagen der beiden Verfahren gleichberechtigt waren. Erst durch Georg Prange wurde gezeigt, dass die Variationsprinzipien, die den beiden Verfahren zu Grunde lagen, durch eine Legendre‐Transformation ineinander überführt werden konnten.

Heute lässt sich auf der Grundlage der Habilitationsschrift von Prange zeigen, wieso Finite‐Elemente‐Verfahren nahezu ausschließlich auf der Grundlage der “Deformationsmethode“ (d. h. mit Verschiebungsgrößen als Unbekannten) arbeiten.

Force Method and Deformation Method in the light of Georg Prange‘s (1885–1941) Habilitation Thesis. At the end of the 19th and at the beginning of the 20th century different computing methods have been developed for the structural analysis of frames, which today are called ”force method” and “deformation method”. Heinrich Müller‐Breslau was the pioneer of the force method whereas the deformation method was combined with the name of Otto Mohr. It was not clear for them, whether the bases for both methods were equivalent. Only Georg Prange was able to show, that the variational principles behind both methods could be transformed into each other by a Legendre transformation.

Today it can be shown by Prange‘s habilitation thesis why finite‐element‐methods almost exclusively are based on the deformation method, working with deformations as unknown variables.