bluuebunny/crossref_metadata_2025 huggingface dataset:
Qualitative Communication Research Methods and Techniques
Authors: Kavoura Androniki , Tomaras Peter
Published: October 2014

This chapter examines the multi-method research design of qualitative communication research methodology associated with a case study from Greece for the European Youth Card (EYCA) for people under 30 years old. The data gathering technique included group interviews with focus groups and consumers' online communication, namely Facebook, the most important social medium that the EYCA uses. The interpretative phenomenological methodological approach and content analysis for Greek speaking people took place for a well-defined period of 4 years after the initiation of the EYCA in Greece and the creation of its Facebook profile. The research methods and tools were also used for the analysis of the EYCA's official website and its printed promotional material. Triangulation of research results and issues of validity and reliability are discussed. These data may lead to communication that can provide valuable information to the enterprises that will then have an in-depth knowledge of customers for advertising and marketing.
The Role of Honors Education Programs
Authors: Khan Mohammad Ayub
Published: October 2014

This chapter discusses the role of honors education programs in advancing the university education standards in general and the quality of business education in particular. Given the current reality of evolutionary and revolutionary forces (i.e., educational technologies, knowledge economies, globalization, diversity, and stakeholder orientations), educational institutions of all categories and especially institutions providing higher education are in the search of innovative, demanding, and premium educational models for their talented and academically superior students. Developing an honors education program as an educational model or strategy at any level of the university in general, and at a bachelor level in particular, definitely provides opportunities to a relatively large number (approximately 10% of the campus population) of students who are naturally motivated and high performing to further enhance their potentials and competencies. More than that, it helps establish a challenging and exemplary educational environment for students, faculty, academic managers, and policymakers.
Evaluating Social Interaction and Support Methods Over Time
Authors: Kopp Birgitta Maria
Published: October 2014

This research focuses on the evaluation of social interaction and support methods for computer-supported collaborative learning over the period of one semester. Specifically, there are three main topics for investigation: first, the subjective evaluation of social interaction and support methods, second, the students' perceptions of these over time, and third, the correlations between social interaction and support methods. Results indicate a specific pattern regarding important aspects of social interaction indicating possible problems in group dynamics (especially relating to taking responsibility). This evaluation pattern remains nearly constant over time. Furthermore, correlation analyses show strong connections between the design of group work and group dynamics, indicating a positive influence of support methods on problematic dimensions of social interaction. As this relation is strongest during the middle phase of collaboration, this study gives a first indication that also CSCL groups may go through the storming and norming stage of collaboration. These findings substantiate the necessity of providing support for computer-based learning.
A Scale of University Students' Attitudes toward e-Learning on the Moodle System
Authors: Chou Tzu-Chin Rejoice
Published: October 2014

There are more universities in Taiwan have incorporated e-learning as the main teaching system. However, it is a critical issue to understand learners' attitudes toward the system. Therefore, the purpose of this research was to test an e-learning attitudes scale on Taiwan Ming Chuan University (TMCU) students using the Moodle system in Taiwan. The study group comprised of 324 students and the overall scale and subscale proved to be highly reliable. The questionnaire was taken from Liaw (2008), and approved by them in 2009. After factor analysis, five factors were extracted from 26 items: Perceived usefulness & behavioral intention (8 items), e-learning effectiveness (5 items), e-learning system satisfaction (5 items), perceived self-efficacy & satisfaction (5 items), and multimedia instruction (3 items). Through application of a secondary confirmatory factor analysis (CFA) test, the construct validity of the scale was empirically constructed.
Intravenous Immunoglobulin Promotes Antitumor Responses by Modulating Macrophage Polarization
Authors: Domínguez-Soto Angeles , de las Casas-Engel Mateo , Bragado Rafael , Medina-Echeverz José , Aragoneses-Fenoll Laura , Martín-Gayo Enrique , van Rooijen Nico , Berraondo Pedro , Toribio María L. , Moro María A. , Cuartero Isabel , Castrillo Antonio , Sancho David , Sánchez-Torres Carmen , Bruhns Pierre , Sánchez-Ramón Silvia , Corbí Angel L.
Published: October 2014

Intravenous Igs (IVIg) therapy is widely used as an immunomodulatory strategy in inflammatory pathologies and is suggested to promote cancer regression. Because progression of tumors depends on their ability to redirect the polarization state of tumor-associated macrophages (from M1/immunogenic/proinflammatory to M2/anti-inflammatory), we have evaluated whether IVIg limits tumor progression and dissemination through modulation of macrophage polarization. In vitro, IVIg inhibited proinflammatory cytokine production from M1 macrophages and induced a M2-to-M1 polarization switch on human and murine M2 macrophages. In vivo, IVIg modified the polarization of tumor-associated myeloid cells in a Fcεr1γ chain–dependent manner, modulated cytokine blood levels in tumor-bearing animals, and impaired tumor progression via FcγRIII (CD16), FcγRIV, and FcRγ engagement, the latter two effects being macrophage mediated. Therefore, IVIg immunomodulatory activity is dependent on the polarization state of the responding macrophages, and its ability to trigger a M2-to-M1 macrophage polarization switch might be therapeutically useful in cancer, in which proinflammatory or immunogenic functions should be promoted.
Inhibition of fibrous adhesion formation in the temporomandibular joint of tenascin-C knockout mice
Authors: Shinohara Y. , Okamoto K. , Goh Y. , Kiga N. , Tojyo I. , Fujita S.
Published: October 2014

Tenascin-C (TNC) is a large hexameric extracellular matrix glycoprotein that is expressed in developing organs and tumors. It has been reported that TNC is expressed in inflamed synovial membranes and deformed discs of temporomandibular joint (TMJ) disorder. However, the role of TNC in TMJ is not fully known. In this study, the role of TNC in fibrous adhesion formation of TMJ was examined using TNC knockout (TNCKO) mice. Hypermobility was produced by excessive mouth opening method on the TMJ of both wild-type (WT) and TNCKO mice. TMJ wound healing was compared histologically, and the expression of TNC, fibronectin (FN) and Î±-smooth muscle actin (Î±-SMA) in the wounded TMJ was examined by immunohistochemical and immunoblot analyses. Based on histologic analysis, fibrous adhesions were observed in the TMJ of both TNCKO and wild-type (WT) mice after excessive mouth opening. However, fibrous adhesion formation in TNCKO mice occurred later than in WT mice. TNC was expressed in the wounded TMJ disc and mandibular fossa. Although FN and Î±-SMA expression in the TMJ of TNCKO and WT mice was up-regulated after excessive mouth opening, FN and Î±-SMA protein levels were higher in WT mice at the same time points. In the wounded TMJ, TNC appears to enhance the expression of FN and Î±-SMA, and a lack of TNC may reduce fibrous adhesion formation in the TMJ. TNC plays an important role in TMJ wound healing, especially for wounds generated by mechanical stress.
Shallow drilling and piezometer installations near Killarney, Manitoba for hydrogeological investigations of the Spiritwood Buried Valley Aquifer
Authors: Hinton M J , Sharpe D R
Published: October 2014

The Geological Survey of Canada (GSC) is investigating the hydrogeology of the Spiritwood buried valley aquifer in southwestern Manitoba as part of its Groundwater Geosciences Program. This Open File reports on a drilling program conducted in November 2010 in
which one shallow and one intermediate depth piezometer were installed within separate boreholes at each of three sites near Killarney, Manitoba to complement existing deep wells monitored by Manitoba Conservation and Water Stewardship (Government of Manitoba, Ministry of CWS). Boreholes were
advanced without drilling fluids by the cable tool method and by driving core tubes which allowed for accurate borehole logging and the collection of sample cores at selected depths. This Open File includes the geological logs of the boreholes, the piezometer construction details and the
geotechnical data measured on sampled core. Geotechnical analyses included measurement of approximate shear strength using a pocket penetrometer (n=21), grain size distribution (n=8), gravimetric water content (n=91), and wet bulk density (n=22) from which dry bulk density (n=22) and volumetric
water content (n=22) were calculated and porosity (n=22) estimated.

The drilling program was a collaborative effort between the Agri-Environmental Services Branch (AESB) of Agriculture and Agri-Food Canada (AAFC) and the Geological Survey of Canada of Natural Resources Canada (NRCan).
Till geochemical signatures of the Broken Hammer Cu-(Ni)-PGE occurrence, North range, Sudbury Structure, Ontario
Authors: McClenaghan M B , Ames D E , Buckle J
L , Bajc A F
Published: October 2014

The Geological Survey of Canada conducted detailed till sampling around the Broken Hammer Cu-(Ni)- PGE occurrence in the North Range of the Sudbury Structure, northeastern Ontario, to document the indicator mineral and multi-element geochemical signature in the
till. The Broken Hammer occurrence consists of a shallow surface zone of vein and vein stockwork-hosted Cu-PGE mineralization within Sudbury breccia developed in the NeoArchean quartz-monzonite Levack Gneiss Complex. It consists of a main 2 to 120 cm wide chalcopyrite vein dominated by
chalcopyrite-magnetite-millerite with numerous trace and rare precious metal minerals, including tellurides, bismuthides, selenides, and stannides. The Laurentide Ice Sheet flowed southward across the Broken Hammer region depositing a sandy till. The main indicator minerals in till overlying and
just down-ice of the occurrence include sperrylite, chalcopyrite, and gold. The <0.063 mm size fraction of till overlying and just down-ice of the occurrence displays a strong geochemical signature of the mineralization, most notably for Pd, Pt, Au, and Cu, as well as Ni, Ag, Cd, Sb, Bi,
Se, Te, Tl, and Sn.
Community Based Research Network: Opportunities for Coordination of Care, Public Health Surveillance, and Farmworker Research
Authors: Cooper Sharon P , Heyer Nicholas , Shipp Eva M , Ryder E. Roberta , Hendrikson Edward , Socias Christina M , Del Junco Deborah J , Valerio Melissa , Partida Sylvia
Published: October 2014

Introduction:  The lack of aggregated longitudinal health data on farmworkers has severely limited opportunities to conduct research to improve their health status. To correct this problem, we have created the infrastructure necessary to develop and maintain a national Research Data Repository of migrant and seasonal farmworker patients and other community members receiving medical care from Community and Migrant Health Centers (C/MHCs). Project specific research databases can be easily extracted from this repository.Methods:  The Community Based Research Network (CBRN) has securely imported and merged electronic health records (EHRs) data from five geographically dispersed C/MHCs.  To demonstrate the effectiveness of our data aggregation methodologies, we also conducted a small pilot study using clinical, laboratory and demographic data from the CBRN Data Repository from two initial C/MHCs to evaluate HbA1c management.Results:  Overall, there were 67,878 total patients (2,858 farmworkers) that were seen by two C/MHCs from January to August 2013.  A total of 94,189 encounters were captured and all could be linked to a unique patient. HbA1c values decreased as the number of tests or intensity of testing increased.Conclusion:   This project will inform the foundation for an expanding collection of C/MHC data for use by clinicians for medical care coordination, by clinics to assess quality of care, by public health agencies for surveillance, and by researchers under Institutional Review Board (IRB) oversight to advance understanding of the needs and capacity of the migrant and seasonal farmworker population and the health centers that serve them. Approved researchers can request data that constitute a Limited Data Set from the CBRN Data Repository to establish a specific research database for their project.
Goal Orientation of Adult Students Towards Learning Strategies: The Malaysian Context
Authors: Ong Choon Hee
Published: October 2014

The purpose of this study is to identify the goal orientation of adult students in the Malaysian context. The finding of this study shows that mastery goal orientation registered the highest mean among the adult students. Therefore, the adult students were found to have adopted mastery goal orientation in their learning process. The analysis oft-Test and One-Way ANOVA indicates that there were no significant group differences in the mean scores of mastery goal orientation among gender, age group and years of experience of the respondents. In addition, this study also attempts to offer the higher education institutions to understand the students’ learning strategies by knowing their goal orientation. It provides information on how deep learning strategies can be integrated with mastery goal orientation so that they are in line to produce better learning outcomes. It is recommended in this study that deep learning methods such as flexible learning and problem-based learning can be used to encourage students to take greater responsibilities for their learning outcomes. In this respect, they will be able to interact with the facilitator on the course material in a more practical and analytical manner. In terms of future research, this study provides validated measures of goal orientation which can be used by future researchers in the similar research setting.
Electron losses from the radiation belts caused by EMIC waves
Authors: Kersten Tobias , Horne Richard B. , Glauert Sarah A. , Meredith Nigel P. , Fraser Brian J. , Grew Russell S.
Published: October 2014

Electromagnetic Ion Cyclotron (EMIC) waves cause electron loss in the radiation belts by resonating with high‐energy electrons at energies greater than about 500 keV. However, their effectiveness has not been fully quantified. Here we determine the effectiveness of EMIC waves by using wave data from the fluxgate magnetometer on CRRES to calculate bounce‐averaged pitch angle and energy diffusion rates for L*=3.5–7 for five levels of Kp between 12 and 18 MLT. To determine the electron loss, EMIC diffusion rates were included in the British Antarctic Survey Radiation Belt Model together with whistler mode chorus, plasmaspheric hiss, and radial diffusion. By simulating a 100 day period in 1990, we show that EMIC waves caused a significant reduction in the electron flux for energies greater than 2 MeV but only for pitch angles lower than about 60°. The simulations show that the distribution of electrons left behind in space looks like a pancake distribution. Since EMIC waves cannot remove electrons at all pitch angles even at 30 MeV, our results suggest that EMIC waves are unlikely to set an upper limit on the energy of the flux of radiation belt electrons.
Morphology of magnetic field in near‐Venus magnetotail: Venus express observations
Authors: Rong Z. J. , Barabash S. , Futaana Y. , Stenberg G. , Zhang T. L. , Wan W. X. , Wei Y. , Wang X.‐D. , Chai L. H. , Zhong J.
Published: October 2014

Knowledge of the magnetic field morphology in the near‐Venus wake is essential to the studies of magnetotail dynamics and the planetary plasma escape. In this study we use the magnetic field measurements made by Venus Express during the period of April 2006 to December 2012 to investigate the global magnetic field morphology in the near‐Venus magnetotail (0–3 Venusian radii, RV, down tail) in the frame of solar wind electric field coordinates. The hemisphere with electric field pointing toward/away is indicated as ±E hemisphere. It has been reported that the cross‐tail field component has a hemispheric asymmetry in the Venusian magnetotail. We report here that this asymmetry should have been formed at the terminator and would transport tailward. In addition, we find that the draped magnetic field lines near both hemispheric flanks are directed equatorward in the region 0–1.5 RV down tail as it looks like “sinking” into Venus umbra. We estimate the thickness of the magnetotail current sheet and the current density at the sheet center. We find that the average half thickness of central current sheet near +E hemispheric flank (~460 km) is almost twice as thick as that near magnetic equatorial plane (~200 km), but the corresponding current densities at the sheet center are comparable (~6.0 nA/m2). As a result, the larger cross‐tail field component found near the +E hemispheric flank suggests a stronger tailward j × B force, i.e., the more efficient tailward acceleration of plasma in this region, showing the agreement with previous observations of heavy ion outflow from Venus. In contrast, the average magnetic field structure near −E hemispheric flank is irregular, which suggests that dynamic activities, such as magnetic reconnection and magnetic field turbulence, preferentially appear there.
Seismic velocity structure and anisotropy of the Alaska subduction zone based on surface wave tomography
Authors: Wang Yun , Tape Carl
Published: October 2014

Southcentral Alaska is a complex tectonic region that transitions from subduction of Pacific crust to flat slab subduction—and collision—of overthickened Yakutat crust. Because much of the Yakutat crust has been subducted, seismic imaging is needed in order to understand the crustal and upper mantle structural framework for this active tectonic setting. Here we use teleseismic Rayleigh waves to image large‐scale variations in shear wave structure. Our imaging technique employs a two‐plane wave representation with finite frequency sensitivity kernels. Our 3‐D isotropic model reveals several features: the subducting Pacific/Yakutat slab, slow wave speeds characterizing the onshore Yakutat collision zone, slow wave speeds of the Wrangell subduction zone, and a deep tomographic contrast at the eastern edge of the Pacific/Yakutat slab. We produce anisotropic phase velocity maps that exhibit variations in the fast direction of azimuthal anisotropy. These maps show the dominance of the Yakutat slab on the observed pattern of anisotropy. West of the Yakutat slab the fast directions are approximately aligned with the plate convergence direction. In the region of the Yakutat slab the pattern is more complicated. Along the margins of the slab the fast directions are roughly parallel to the margins. We identify notable differences and similarities with published SKS splitting measurements. Integrative modeling using 3‐D anisotropy models and different seismic measurements will be needed in order to establish a detailed 3‐D anisotropic velocity model for Alaska. This study provides a large‐scale starting point for such an effort.
The Effect of Fluorination in Manipulating the Nanomorphology in PTB7:PC71BM Bulk Heterojunction Systems
Authors: Guo Shuai , Ning Jing , Körstgens Volker , Yao Yuan , Herzig Eva M. , Roth Stephan V. , Müller‐Buschbaum Peter
Published: October 2014

The best performing low bandgap copolymers PTB series to date which is based on thieno[3,4‐b]thiophene‐alt‐benzodithiophene units blended with [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM), have been the focus of polymer‐based solar cells. Here, novel fluorinated polymers PTB7‐Fx (fluorine units coupled with submonomer thieno[3,4‐b]thiophene) with varied degree of fluorination are used as electron donor materials. The PTB7‐Fx:PC71BM bulk heterojunction (BHJ) films spin‐coated from the host solvent chlorobenzene without and with solvent additive 1,8‐diiodooctane (DIO) and the corresponding solar cell devices are systematically investigated to address the morphology‐efficiency relationship. Self‐assembled BHJ morphology is already observed for as‐spun blend films. After adding the solvent additive DIO, the pronounced ordered structures are suppressed and better intermixed films with much smaller domain sizes result. Full fluorination of the third C‐atom of thienothiophene gives rise to the highest power conversion efficiency. As the absorption properties, film morphology and crystallinity remain similar for different degrees of fluorination, the main influence of the photovoltaic performance is ascribed to the different lowest unoccupied molecular orbital (LUMO) of each polymer instead of the film morphology. Thus the device performance can be efficiently improved by tuning the energy level of the polymer without necessarily changing either the film nanomorphology or crystallinity dramatically.
A Comparison of Five Experimental Techniques to Measure Charge Carrier Lifetime in Polymer/Fullerene Solar Cells
Authors: Clarke Tracey M. , Lungenschmied Christoph , Peet Jeff , Drolet Nicolas , Mozer Attila J.
Published: October 2014

It is important to accurately measure the charge carrier lifetime, a crucial parameter that influences the collection efficiency in organic solar cells. Five transient and small perturbation experimental techniques that measure charge carrier lifetime are applied to a device composed of the polymer PDTSiTTz blended with the fullerene PCBM: time‐resolved charge extraction (TRCE), transient absorption spectroscopy (TAS), photoinduced charge extraction by linearly increasing voltage (photo‐CELIV), transient photovoltage, and electrochemical impedance spectroscopy. The motivation is to perform a comprehensive comparison of several different lifetime measurement techniques on the same device in order to assess their relative accuracy, applicability to operational devices, and utility in data analysis. The techniques all produce similar charge carrier lifetimes at high charge densities, despite previous suggestions that transient methods are less accurate than small perturbation ones. At lower charge densities an increase in the apparent reaction order is observed. This may be related to surface recombination at the contacts beginning to dominate, or an inhomogeneous charge distribution. A combination of TAS and TRCE appears suitable. TAS enables the investigation of recombination mechanisms at early times since it is not limited by RC (resistance‐capacitance product) or charge extraction losses. Conversely, TRCE is useful particularly at low densities when other mechanisms, such as surface recombination, may occur.
Enantioseparation of chiral aromatic acids in process intensified liquid–liquid extraction columns
Authors: Holbach Alexander , Godde Julia , Mahendrarajah Ramanan , Kockmann Norbert
Published: October 2014

Enantioselective liquid–liquid extraction (ELLE) is a powerful alternative to common technologies for separation of racemic mixtures. The first application of ELLE for aromatic acids in liquid–liquid extraction columns is described. The ELLE is investigated experimentally and theoretically for phenylsuccinic acid (PSA) as a representative for aromatic acids. A racemic mixture of (R/S)‐PSA is separated with hydroxypropyl‐β‐cyclodextrin as selector molecule. The ELLE obtained the highest operative selectivity (αop = 1.8–2) for low pH‐values and temperatures. Because of the low operative selectivity, a countercurrent process is necessary to separate both enantiomers completely. The countercurrent process is investigated in process intensified extraction columns (Øin = 15 mm) with a high number of equilibrium stages. The experiments demonstrate a good symmetric separation with an enantiomeric excess of 60% and yields of 80% for both enantiomers. Finally, the back extraction is investigated to recycle the selector molecule and increase the efficiency. © 2014 American Institute of Chemical EngineersAIChE J, 61: 266–276, 2015
Investigation on liquid flow characteristics in microtubes
Authors: Chen Qiao‐Li , Wu Ke‐Jun , He Chao‐Hong
Published: October 2014

The fundamental understanding and prediction of liquid flow characteristics in microscale are important to control the performance of microfluidic devices. However, fundamental questions about liquid flow characteristics in microscale have not been settled yet and systematical investigation is needed. A systematical investigation on liquid flow characteristics through microtubes with diameters varying from 44.5–1011 μm and relative roughness in the range 0.02–4.32% in the Reynolds number range 29–11,644 was performed in this work, using water as working fluid. Experimental results indicated that early transition occurred when the diameter was smaller than 1000 μm, the transitional flow characteristics for smooth microtubes differed from rough microtubes and the friction factor in turbulent region for rough microtubes was larger than conventional theory. Moreover, a parameter α was proposed to describe the characteristic of microtube. The characteristic parameter was used to calculate the critical Reynolds number and the friction factor in turbulent region for microscale. © 2014 American Institute of Chemical Engineers AIChE J, 61: 718–735, 2015
Social, contextual, and individual factors affecting the occurrence and acoustic structure of drumming bouts in wild chimpanzees (Pan troglodytes)
Authors: Babiszewska Magdalena , Schel Anne Marijke , Wilke Claudia , Slocombe Katie E.
Published: October 2014

The production of structured and repetitive sounds by striking objects is a behavior found not only in humans, but also in a variety of animal species, including chimpanzees (Pan troglodytes). In this study we examined individual and social factors that may influence the frequency with which individuals engage in drumming behavior when producing long distance pant hoot vocalizations, and analyzed the temporal structure of those drumming bouts. Male chimpanzees from Budongo Forest, Uganda, drummed significantly more frequently during travel than feeding or resting and older individuals were significantly more likely to produce drumming bouts than younger ones. In contrast, we found no evidence that the presence of estrus females, high ranking males and preferred social partners in the caller's vicinty had an effect on the frequency with which an individual accompanied their pant hoot vocalization with drumming. Through acoustic analyses, we demonstrated that drumming sequences produced with pant hoots may have contained information on individual identity and that qualitatively, there was individual variation in the complexity of the temporal patterns produced. We conclude that drumming patterns may act as individually distinctive long‐distance signals that, together with pant hoot vocalizations, function to coordinate the movement and spacing of dispersed individuals within a community, rather than as signals to group members in the immediate audience. Am J Phys Anthropol 156:125–134, 2015 © 2014 Wiley Periodicals, Inc.
Elucidating inequality inNubia: An examination of entheseal changes atKerma (Sudan)
Authors: Schrader Sarah A.
Published: October 2014

Located 10 km south of the Third Cataract of the Nile River, the ancient city of Kerma was once capital to the second largest state in Africa. The Eastern Cemetery at Kerma (∼4 km east of city center) encompasses 80+ hectares and was used over a period of 1,500 years (3,200–1,500 BC). Excavated in the early 20th century by George Reisner, the cemetery contained an estimated 20,000–40,000 individuals. Reisner classified these burials into multiple categories, including chiefs and human sacrifices, based on burial position and grave goods. This study investigates the skeletal embodiment of social inequality by examining variation in entheseal severity between the Kerma burial classifications. Seventeen entheses were examined using the Hawkey and Merbs (1995) scoring method (n = 205 individuals); age, sex, and body size variables were considered by employing Mann–WhitneyUtests and partial Spearman's correlations. This analysis suggests that significant differences in entheseal changes existed between select burial types. Specifically, “corridor sacrifices” had significantly higher rates of entheseal changes while “chiefs” and “subsidiary burials” had similar entheseal changes; furthermore, within these burial categories, males had higher entheseal scores despite body size controls. The elevated entheseal changes in the sacrificial burials may be due to an intensive agro‐pastoral lifestyle or other demanding forms of manual labor. In conclusion, the disparity of entheseal markers between burial subgroups at Kerma might reflect a degree of social inequality within this state level society. This bioarchaeological research informs our understanding of socially‐defined categories of persons as well as everyday life in Ancient Kerma. Am J Phys Anthropol 156:192–202, 2015. © 2014 Wiley Periodicals, Inc.
Estimating age of mature adults from the degeneration of the sternal end of the clavicle
Authors: Falys Ceri G. , Prangle Dennis
Published: October 2014

The sternal end of the clavicle has been illustrated to be useful in aging young adults, however, no studies have investigated what age‐related changes occur to the sternal end post epiphyseal fusion. In this study, three morphological features (i.e., surface topography, porosity, and osteophyte formation) were examined and scored using 564 clavicles of individuals of European ancestry (n = 318 males;n = 246 females), with known ages of 40+ years, from four documented skeletal collections: Hamann‐Todd, Pretoria, St. Bride's, and Coimbra. An ordinal scoring method was developed for each of the three traits. Surface topography showed the strongest correlation with age, and composite scores (formed by summing the three separate trait scores) indicated progressive degeneration of the surface with increasing chronological age. Linear regression analyses were performed on the trait scores to produce pooled‐sample age estimation equations. Blind tests of the composite score method and regression formulae on 56 individuals, aged 40+ years, from Christ Church Spitalfields, suggest accuracies of 96.4% for both methods.

These preliminary results display the first evidence of the utility of the sternal end of the clavicle in aging older adult individuals. However, in the current format, these criteria should only be applied to individuals already identified as over 40 years in order to refine the age ranges used for advanced age. These findings do suggest the sternal end of the clavicle has potential to aid age estimates beyond the traditional “mature adult” age category (i.e., 46+ years), and provides several suggestions for future research. Am J Phys Anthropol 156:203–214, 2015. © 2014 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.
Breathable properties of m‐Aramid nanofibrous membrane with high thermal resistance
Authors: Park Young Shin , Lee Jong Wha , Nam Young Sik , Park Won Ho
Published: October 2014

Electrospinning of m‐aramid in dimethyl acetamide/LiCl solution was investigated to develop thermo‐resistant nanofibrous membranes for breathable waterproof materials. The m‐aramid nanofibers were continuously generated and densely mounted to the membrane without the blockage of the spinning tip during electrospinning. In order to obtain the electrospun m‐aramid nanofibers with different fiber diameters, the polymer concentration in the solution and the spinning distance were varied. Electrospun m‐aramid nanofibrous membranes of various fiber diameters and thicknesses were prepared, and then compared with two commercial expanded polytetrafluoroethylene (ePTFE) membranes with respect to water vapor permeability and pore size. The m‐aramid nanofibrous membrane showed a good water vapor permeability that satisfied the criterion of a breathable membrane, higher than those of the ePTFE porous membranes. Therefore, m‐aramid nanofibrous membrane with thermal and mechanical resistance has great potential for breathable waterproof materials and filters. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41515.
Processing optimization of latex‐compounded montmorillonite/styrene‐butadiene rubber–polybutadiene rubber
Authors: Bao Zuguo , Flanigan Cynthia , Beyer Laura , Tao Jie
Published: October 2014

Organo‐montmorillonite was incorporated into model tire tread formulations through latex compounding methods, to evaluate its effects on elastomer reinforcement and dynamic properties. An intercalation structure was obtained by applying latex compounding method to prepare organoclay‐emulsion stryene butadiene (E‐SBR) masterbatches, for compounding with organoclay loading levels of 0–20 parts per hundred rubber (phr). Microstructure, curing properties and tire performance of the compounded rubber were investigated with the aid of X‐ray diffraction, rheometor and dynamic‐mechanical analysis, respectively. The results showed that organo‐montmorillonite filler provided effective reinforcement in the elastomer matrix, as indicated through mechanical and dynamic mechanical properties. Tread compounds using higher organoclay loadings displayed preferred ice traction, wet traction, and dry handling, but decreased winter traction and rolling resistance. Model compounds using 15 phr of organoclay loading levels were preferred for balanced physical and dynamic properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41521.
Electrochemical synthesis and In situ spectroelectrochemistry of conducting NMPy‐TiO2 and ZnO polymer nanocomposites for Li secondary battery applications
Authors: Arjomandi Jalal , Keramat Irad Mossa Niloofar , Jaleh Babak
Published: October 2014

Poly(N‐methylpyrrole) (PNMPy), poly(N‐methylpyrrole‐TiO2) (PNMPy‐TiO2), and poly (N‐methylpyrrole‐ZnO) (PNMPy‐ZnO) nanocomposites were synthesized by in situ electropolymerization for cathode active material of lithium secondary batteries. The charge–discharging behavior of a Li/LiClO4/PNMPy battery was studied and compared with Li/LiClO4/PNMPy‐nanocomposite batteries. The nanocomposites and PNMPy films were characterized by cyclic voltammetry, in situ resistivity measurements, in situ UV–visible, and Fourier transform infra‐red (FTIR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The differences between redox couples (ΔE) were obtained for polymer nanocomposites and PNMPy films. During redox scan, a negative shift of potential was observed for polymer nanocomposite films. Significant differences from in situ resistivity of nanocomposites and PNMPy films were obtained. The in situ UV–visible spectra for PNMPy and polymer nanocomposite films show the intermediate spectroscopic behavior between polymer nanocomposites and PNMPy films. The FTIR peaks of polymer nanocomposite films were found to shift to higher wavelengths in PNMPy films. The SEM and TEM micrographs of nanocomposite films show the presence of nanoparticle in PNMPy backbone clearly. The result suggests that the inorganic semiconductor particles were incorporated in organic conducting PNMPy, which consequently modifies the properties and morphology of the film significantly. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41526.
Effect of interfacial area on heterogeneous free radical grafting of vinyl monomers in supercritical carbon dioxide: Grafting of acrylic acid on poly(vinylidenefluoride) nanoparticles
Authors: Lanzalaco Sonia , Scialdone Onofrio , Galia Alessandro
Published: October 2014

The role of the polymer interfacial area on free radical grafting of acrylic acid (AA) onto poly(vinylidenefluoride) (PVDF) was studied at 65°C using supercritical carbon dioxide (scCO2) as a solvent and swelling agent, benzoylperoxide (BPO) as chemical initiator and PVDF nanoparticles as polymer matrix. Under adopted conditions PVDF particles do not melt neither dissolve in the reaction medium and FTIR analyses performed on carefully washed nanoparticles confirmed the achievement of high grafting levels. The mass fraction of grafted AA increased with the grafting time and the BPO concentration while it decreased when the density of the fluid phase was enhanced. Collected results suggest that the grafting level obtained by free radical grafting of vinyl monomers onto solid polymer in scCO2 can be significantly enhanced by increasing the interfacial area of the matrix. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41541.
Fabrication and characterization of novel hyperbranched polyimides with excellent organosolubility, thermal and mechanical properties
Authors: Chen Wenqiu , Li Quantao , Zhang Quanyuan , Xu Zushun , Wang Xianbao , Yi Changfeng
Published: October 2014

A series of amine‐terminated and anhydride‐terminated hyperbranched polyimides (HBPIs) were successfully prepared with various commercial dianhydrides and a novel BB′2‐type aromatic triamine, 2,4,6‐tris[4‐(4‐aminophenoxy)phenyl]pyridine, with a symmetrical triaryl‐substituted pyridine segment and prolonged flexible linkages. The chemical structure of the triamine monomer and the hyperbranched structure of the resulting polymers were verified by Fourier transform infrared spectroscopy and 1H‐NMR spectroscopy. The resulting HBPIs, which mainly held an amorphous morphology, exhibited improved organosolubilities in several strong polar aprotic solvents, good heat resistance with glass‐transition temperature values in the range 218.6–311.0°C, and excellent thermal stabilities in both N2 and air [the temperature at 5% weight loss (T5%) in N2 was higher than 529.8°C and the T5% in air was higher than 465.1°C]. The obtained HBPI films also showed outstanding mechanical properties with tensile strength, tensile modulus, and elongation at break values of 86.4–101.3 MPa, 1.73–2.04 GPa, and 5.07–10.67%, respectively; considerable optical transparency; low water absorption; and neutral interface wettability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41544.
Flame‐retardant materials based on phosphorus‐containing polyhedral oligomeric silsesquioxane and bismaleimide/diallylbisphenol a with improved thermal resistance and dielectric properties
Authors: Wang Zheng , Wu Wei , Zhong Yuhua , Ruan Mingzhu , Hui Lin Lin
Published: October 2014

Polyhedral oligomeric silsesquioxane containing 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DP) was used to flame‐retard 4,4′‐bismaleimidophenyl methane (BDM)/2,2′‐dially bisphenol A (DBA) resins, and the integrated properties of the resins were investigated. The fire resistance of BDM/DBA resins containing DP was analyzed by limiting oxygen index (LOI) and vertical burning (UL94) tests. The results show that DP increased the LOI of the resins from 25.3 to 38.5%. The BDM/DBA resins were evaluated to have a UL‐94 V‐1 rating, which did not satisfy the high standards of industry. On the other hand, BDM/DBA containing DP achieved a UL‐94 V‐0 rating. The thermal stability and char formation were studied by thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy. TGA and scanning electron microscopy–energy‐dispersive X‐ray spectrometry measurements demonstrated that the DP resulted in an increase in the char yield and the formation of the thermally stable carbonaceous char. The results of Raman spectroscopy showed that the DP enhanced the graphitization degree of the resin during combustion. Moreover, the modified BDM/DBA resins exhibited improved dielectric properties. Specifically, the dielectric constant and loss at 1 MHz of the BDM/DBA/15% DP resin were 3.11 and 0.008, respectively, only about 93 and 73% of those of the BDM/DBA resin. All of the investigations showed that DP was an effective additive for developing high‐performance resins with attractive flame‐retardant and dielectric properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41545.
Electrical conductivity and tensile properties of block‐copolymer‐wrapped single‐walled carbon nanotube/poly(methyl methacrylate) composites
Authors: Ansón‐Casaos Alejandro , Pascual F. Javier , Ruano Cristina , Fernández‐Huerta Natalia , Fernández‐Pato Isaías , Otero Juan C. , Puértolas J. Antonio , Martínez M. Teresa
Published: October 2014

Poly(methyl methacrylate) (PMMA) composites containing raw or purified single‐walled carbon nanotubes (SWCNTs) are prepared by in situ polymerization and solution processing. The SWCNTs are purified by centrifugation in a Pluronic surfactant, which consists of polyethyleneoxide and polypropyleneoxide blocks. Both the effects of SWCNT purity and non‐covalent functionalization with Pluronic are evaluated. Electrical conductivity of PMMA increases by 7 orders of magnitude upon the integration of raw or purified SWCNTs. The best electrical properties are measured for composites made of purified SWCNTs and prepared by in situ polymerization. Strains at fracture of the SWCNT/PMMA composites are nearly identical to those of the neat matrix. A certain decrease in the work to fracture is measured, particularly for composites containing purified SWCNTs (−31.6%). Fractography and Raman maps indicate that SWCNT dispersion in the PMMA matrix improves upon the direct addition of Pluronic, while dispersion becomes more difficult in the case of purified SWCNTs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41547.
Evolution of mechanical properties during cure for out‐of‐autoclave carbon‐epoxy prepregs
Authors: Vora Khalil , Vo Tien , Islam Mohammad , Habibi Mohammad , Minaie Bob
Published: October 2014

Extent of cure and rheological properties were obtained for out‐of‐autoclave materials, Cycom 5320‐8HS and Cycom 5320‐PW, for the manufacturer recommended cure cycle using differential scanning calorimeter and encapsulated sample rheometer (ESR), respectively. Rheological properties from ESR were further used in designing the cure cycles to study the evolution of mechanical properties. Five panels were cured at different cure stages using the designed cure cycles and coupons were tested for short beam shear and combined loading compression properties at different cure stages. To correlate the mechanical properties with its respective glass transition temperature, dynamic mechanical analyzer was used to obtain the glass transition temperature for the coupons obtained from the respective panels. Statistical results showed significant difference in short beam shear and combined loading compression properties up to vitrification, however, no significant difference was observed on these mechanical properties after vitrification. The observed linear trend between degree of cure (DOC) and glass transition temperature (Tg) was validated using DiBenedetto relation. Linearly increasing trend between DOC and glass transition temperature (Tg) for different cure states suggests that both DOC and Tg can be used interchangeably to define the state of material. A good correlation was observed between material cure state and the mechanical properties. A mathematical model was also proposed to determine the short beam shear and combined loading compression properties based on material cure state. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41548.
Effect of a chain extender on the properties of poly(lactic acid)/zinc oxide/copper chlorophyll acid antibacterial nanocomposites
Authors: Fan Weihua , Zhao Yue , Zhang Aijing , Liu Yukun , Cao Yanxia , Chen Jinzhou
Published: October 2014

Poly(lactic acid) (PLA)/nano zinc oxide/copper chlorophyll acid (CCA) antibacterial nanocomposites with excellent mechanical properties were prepared in the presence of a chain extender named tolylene diisocyanate (TDI). The effect of the chain extender on the PLA long chain was confirmed by the increased molecular weight shown in the mass flow rate and gel permeation chromatography. Escherichia coli were adopted to examine the antibacterial ability of the blends. The effect of CCA is also discussed with regard to the enhancement of the antibacterial effect of zinc oxide (ZnO) over E. coli. Scanning electron microscopy and transmission electron microscopy were used to view the agglomeration and dispersion of ZnO in the PLA matrix. Differential scanning calorimetry and thermogravimetric analysis revealed a relatively stable thermal performance of the nanocomposites with and without TDI. A sharp increase in the mechanical properties was also observed after the addition of the chain extender under different processing conditions. Additionally, we found that the nanocomposites with the incorporation of TDI and the masterbatches in batches effectively improved the mechanical properties of PLA/ZnO/CCA without a sacrifice of the antibacterial effect. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41561.
Thiol–norbornene photoclick hydrogels for tissue engineering applications
Authors: Lin Chien‐Chi , Ki Chang Seok , Shih Han
Published: October 2014

Thiol–norbornene (thiol–ene) photoclick hydrogels have emerged as a diverse material system for tissue engineering applications. These hydrogels are crosslinked through light‐mediated orthogonal reactions between multifunctional norbornene‐modified macromers [e.g., poly(ethylene glycol) (PEG), hyaluronic acid, gelatin] and sulfhydryl‐containing linkers (e.g., dithiothreitol, PEG–dithiol, biscysteine peptides) with a low concentration of photoinitiator. The gelation of thiol–norbornene hydrogels can be initiated by long‐wave UV light or visible light without an additional coinitiator or comonomer. The crosslinking and degradation behaviors of thiol–norbornene hydrogels are controlled through material selections, whereas the biophysical and biochemical properties of the gels are easily and independently tuned because of the orthogonal reactivity between norbornene and the thiol moieties. Uniquely, the crosslinking of step‐growth thiol–norbornene hydrogels is not oxygen‐inhibited; therefore, gelation is much faster and highly cytocompatible compared with chain‐growth polymerized hydrogels with similar gelation conditions. These hydrogels have been prepared as tunable substrates for two‐dimensional cell cultures as microgels and bulk gels for affinity‐based or protease‐sensitive drug delivery, and as scaffolds for three‐dimensional cell encapsulation. Reports from different laboratories have demonstrated the broad utility of thiol–norbornene hydrogels in tissue engineering and regenerative medicine applications, including valvular and vascular tissue engineering, liver and pancreas‐related tissue engineering, neural regeneration, musculoskeletal (bone and cartilage) tissue regeneration, stem cell culture and differentiation, and cancer cell biology. This article provides an up‐to‐date overview on thiol–norbornene hydrogel crosslinking and degradation mechanisms, tunable material properties, and the use of thiol–norbornene hydrogels in drug‐delivery and tissue engineering applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41563.