bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of the Boston Active School Day Policy to Promote Physical Activity among Children
Authors: Cradock Angie L. , Barrett Jessica L. , Carter Jill , McHugh Anne , Sproul Jonathan , Russo Elizabeth T. , Dao-Tran Patricia , Gortmaker Steven L.
Published: December 2013

Purpose.

To test effectiveness of Active School Day policy implementation on physical activity outcomes and estimate school-level implementation costs.

Design.

The design of the study was quasi-experimental (pretest–posttest matched controls).

Setting.

The study took place in six elementary schools with three matched pairs in Boston, Massachusetts, February to June 2011.

Subjects.

Subjects were 455 consenting fourth- and fifth-grade students among 467 eligible.

Intervention.

Active School Day policy implementation provided equipment, curricular materials, and training to physical educators and school wellness champions to promote 150 weekly minutes of quality physical education, recess, and physical activity integrated into classrooms.

Measures.

Accelerometer assessments of accumulated minutes and bouts of moderate, vigorous, and sedentary physical activity on 5 school days before and after implementation were used. Implementation costs were collected by record review and reported resource utilization.

Analysis.

Analysis was conducted using multivariate mixed models estimated with repeated measures of daily physical activity, adjusted for student demographics and other confounding and design/clustering variables.

Results.

Accelerometer data were provided by 201 intervention and 192 comparison students for an average of 4 days per period (84% response). During school time, students in intervention schools demonstrated greater increases in minutes per day of moderate-to-vigorous physical activity (3.9, 95% confidence interval [CI] 1.8–6.0; p < .001) and vigorous physical activity (1.8, 95% CI.7–3.0; p < .001), and greater decreases in minutes per day of sedentary time (–10.6, 95% CI—15.3– −5.8; p < .001) than controls. Ongoing annual implementation costs totaled $4,523/school ($14/student).

Conclusion.

Active School Day implementation increased student moderate-to-vigorous physical activity levels by 24% and decreased sedentary time during school at modest cost.
Demographic, Physical Activity, and Route Characteristics Related to School Transportation: An Exploratory Study
Authors: Lee Chanam , Li Li
Published: December 2013

Purpose.

To investigate the demographic, physical activity, and route characteristics related to children's school trips.

Design.

Cross-sectional exploratory study.

Setting.

Eighteen elementary schools in the Austin Independent School District, Austin, Texas.

Subjects.

One hundred twelve children aged 7 to 12 years.

Measures.

Accelerometer and Global Positioning System (GPS) devices provided objective measures of school travel and physical activity. Parental survey (response rate = 34.2%) provided children's demographic and household information.

Analysis.

Generalized linear regression analyses were used for unadjusted and adjusted models estimating correlates of total moderate to vigorous physical activity (MVPA) and school trip–related MVPA's contribution rate.

Results.

Walking trips were .44 miles (.71 km) on average. Those who walked to school had about 11 more minutes of daily MVPA than nonwalkers (35.03 vs. 24.06) and higher proportions of their daily MVPA obtained from school commute trips (21.78% vs. 2.41%). School trips accounted for 11.2% of total daily MVPA on average, 12.9% for those who met the physical activity recommendation, and 35.2% for the sedentary children who belonged to the lowest MVPA quartile.

Conclusion.

Active school commuting appears to be a valuable means to promote physical activity, and its contributions toward total physical activity vary across different demographic groups and community settings. Objective and detailed data from GPS and accelerometer units can facilitate the assessment of route/trip characteristics and physical activity implications of school transportation.
How gaming venue staff use behavioural indicators to assess problem gambling in patrons
Authors: Hing Nerilee , Nuske Elaine , Holdsworth Louise
Published: December 2013

Staff in gaming venues are increasingly expected to identify people with possible gambling problems based on observable behaviour. We report on interviews with 48 venue staff in Queensland, Australia with the goal of assessing whether they feel they can detect patrons with possible gambling problems, and what indicators they use to assess this and to decide whether to intervene. Results showed wide variation in the indicators used by these staff members with only one indicator, aggressive behaviour, reported by the majority. Most contemplated intervening only if patron behaviour is seen as a threat to themselves or others. Venue staff would benefit from clearer direction on indicators of problem gambling behaviour and when to intervene.
Trust in Internet gambling and its association with problem gambling in university students
Authors: Harris Nicholas M. , Mazmanian Dwight , Jamieson John
Published: December 2013

The Internet has become a major means of accessing a variety of gambling activities. As a result, there is concern that the Internet may provide more opportunities for consumers to engage in problematic gambling behaviours. The current study examined factors related to Internet gambling and problem gambling in a university student sample (N = 325). Measures included the South Oaks Gambling Screen, the DSM-IV-TR-Based Questionnaire, the Canadian Problem Gambling Index, and a questionnaire examining Internet gambling behaviours and trust. Internet gamblers (n = 53) reported significantly higher levels of trust in Internet gambling sites than non-Internet gamblers (n = 182) and non-gamblers (n = 90). Among Internet gamblers, significant predictors of problem gambling included level of trust in Internet gambling sites, negative effects of this activity on academic achievement and class attendance, and alcohol consumption while gambling on the Internet. Implications of these findings are discussed.
Imagining Arab Communities: Colonialism, Islamic Reform, and Arab Identity in Mombasa, Kenya, 1897–1933
Authors: Mathews Nathaniel
Published: December 2013

After the advent of British colonial rule, the epistemological prestige of Muslim culture, Arabic literacy, and qadi courts declined in Kenya. Coastal residents sought favorable court rulings outside qadi courts, which no longer had independent jurisdiction, and many sought education and jobs in a British colonial system less favorable to Islamic learning. Recognizing these challenges, Sheikh al-Amin Mazrui—Kenya’s most prominent Islamic scholar—founded a newspaper called al-Islah in 1932. He was inspired by the prominent Cairo journal al-Manar, by the Salafi reformers Rashid Rida and Muhammad Abduh. Although al-Islah’s themes were similar to al-Manar’s in advocating for Islamic reform, al-Islah addressed itself to Swahili-speaking Arabs in a milieu where Muslims were increasingly a demographic minority and culturally marginalized. Print technology (al-Islah was printed in both Kiswahili and Arabic) and Salafi ideas in al-Islah worked together to spread reform and encourage East African Muslims to value Arabic and the pursuit of sharîʾa. Although these ideas were products of a long Islamic tradition that privileged access to knowledge as the passport of the believer, they were also newly self-conscious reflections of Arab cultural and religious identity; al-Islah’s articles stressed the Arab role in creating Muslim civilization in Africa. Al-Islah critiqued the parochial nature of the British colonial project, urging a return to pre-colonial modes of Islamic hegemony and stressing the essential role of sharîʾa in constituting Islamic identity. Islamic reform in East Africa and the “reimagination” of transnational Arab identity within it depended on Arab Muslims understanding the importance of Islamic knowledge—particularly Arabic and sharîʾa—in constituting coastal communities.
“Serfs,” Civics, and Social Action: Islamic Identity and Grassroots Activism during Eritrea’s Tigre Emancipation Movement, 1941–1946
Authors: Venosa Joseph L.
Published: December 2013

This article examines the growth of political activism within various Tigre-speaking communities across Eritrea during the early and mid-1940s. Using previously overlooked archival as well as oral sources, it explores how some tigre “serfs” became increasingly proactive in challenging their subordinate position against local landlords, even as communities experienced a haphazard transition from Italian to temporary British colonial rule. Refusing to comply with the traditional payment of customary dues and taxes to local landlords, disenfranchised tigre across Eritrea’s Western Province pressed their claims for economic and even political independence. In the process, some tigre leaders also demonstrated the complex and often problematic nature of Islamic “identity” as the emancipation movement expanded. Activists’ overall success also depended upon their ability to articulate a broad, Islamicinspired understanding of the need to rectify social and economic injustice, even though such actions challenged the existing religious institutions and authorities in the region, particularly the leadership within the dominant Khatmiyya Sufi order. Ultimately, the surge in antifeudal activism helped enrich the emerging public discourse across the colony, which fused ideas of political independence with the need to ensure the collective security of the region’s various Muslim communities, including those residing beyond the country’s Tigre-speaking areas.
Central Sudanic Arabic Scripts (Part 2): Barnāwī
Authors: Brigaglia Andrea , Nobili Mauro
Published: December 2013

This article describes and analyzes barnāwī, the Arabic script of Borno (northeastern Nigeria) and most ancient prototype of what we define as the Central Sudanic family of scripts. Barnāwī shows paleographic features that clearly set it apart from some other West African Arabic scripts, thereby confirming the inadequacy of the label sūdānī, which often surfaces in literature to collectively brand a variety of scripts used in different regions of West Africa. A paleographic analysis of barnāwī also suggests that its origins predate the development of the maghribī script in North Africa in the twelfth century.
Asymmetry and uncertainties in biogeophysical climate–vegetation feedback over a range of CO2 forcings
Authors: Willeit M. , Ganopolski A. , Feulner G.
Published: January 2014

Abstract. Climate–vegetation feedback has the potential to significantly contribute to climate change, but little is known about its range of uncertainties. Here, using an Earth system model of intermediate complexity we address possible uncertainties in the strength of the biogeophysical climate–vegetation feedback using a single-model multi-physics ensemble. Equilibrium experiments with halving (140 ppm) and doubling (560 ppm) of CO2 give a contribution of the vegetation–climate feedback to global temperature change in the range −0.3 to −0.1 °C and −0.1 to 0.2 °C, respectively. There is an asymmetry between warming and cooling, with a larger, positive vegetation–climate feedback in the lower CO2 climate. Hotspots of climate–vegetation feedback are the boreal zone, the Amazon rainforest and the Sahara. Albedo parameterization is the dominant source of uncertainty in the subtropics and at high northern latitudes, while uncertainties in evapotranspiration are more relevant in the tropics. We analyse the separate impact of changes in stomatal conductance, leaf area index and vegetation dynamics on climate and we find that different processes are dominant in lower and higher CO2 worlds. The reduction in stomatal conductance gives the main contribution to temperature increase for a doubling of CO2, while dynamic vegetation is the dominant process in the CO2 halving experiments. Globally the climate–vegetation feedback is rather small compared to the sum of the fast climate feedbacks. However, it is comparable to the amplitude of the fast feedbacks at high northern latitudes where it can contribute considerably to polar amplification. The uncertainties in the climate–vegetation feedback are comparable to the multi-model spread of the fast climate feedbacks.
Numerical modeling of the lateral widening of levee breach by overtopping in a flume with 180° bend
Authors: Dou S.-T. , Wang D.-W. , Yu M.-H. , Liang Y.-J.
Published: January 2014

Abstract. Floods caused by levee breaching pose disastrous risks to the lower reaches and the flood flow zones of rivers. Thus, a comprehensive assessment of flow and sediment transport during floods must be performed to mitigate flood disasters. Given that the flow state becomes relatively more complex and the range of the submerged area becomes more extensive after a levee breach, this paper established a flow and sediment model by using two-dimensional shallow water equations (SWEs) to explore the breach development process and the flow and sediment transport in a curved bed after a levee breach due to overtopping. A three-element weighted essentially non-oscillatory Roe scheme was adopted for the discretization of SWEs. In addition, a non-equilibrium total-load sediment transport model was established to simulate the scour depth development process of the breach. A stable equilibrium of the breach was established based on flow shear force and soil shear strength. The lateral widening of the breach was simulated by the scouring-collapse lateral widening mode. These simulations, together with the levee breach experiment conducted in the laboratory, demonstrate the validity of the flow and sediment transport process established in this paper. The effects of water head in and out of the watercourse, the flow rate, the levee sediment grading, and other variables during levee breaching were also analyzed. The mathematical model calculation provided a number of physical quantities, such as flow rate and flow state at the breach, that are difficult to measure by using the current laboratory facilities. The results of this research provide fundamental data for developing measures that can reduce casualties and asset loss due to floods caused by levee breaching.
Boundary conditions of an active West Antarctic subglacial lake: implications for storage of water beneath the ice sheet
Authors: Siegert M. J. , Ross N. , Corr H. , Smith B. , Jordan T. , Bingham R. G. , Ferraccioli F. , Rippin D. M. , Le Brocq A.
Published: January 2014

Abstract. Repeat-pass ICESat altimetry has revealed 124 discrete surface height changes across the Antarctic Ice Sheet, interpreted to be caused by subglacial lake discharges (surface lowering) and inputs (surface uplift). Few of these active lakes have been confirmed by radio-echo sounding (RES) despite several attempts (notable exceptions are Lake Whillans and three in the Adventure Subglacial Trench). Here we present targeted RES and radar altimeter data from an "active lake" location within the upstream Institute Ice Stream, into which at least 0.12 km3 of water was previously calculated to have flowed between October 2003 and February 2008. We use a series of transects to establish an accurate depiction of the influences of bed topography and ice surface elevation on water storage potential. The location of surface height change is downstream of a subglacial hill on the flank of a distinct topographic hollow, where RES reveals no obvious evidence for deep (> 10 m) water. The regional hydropotential reveals a sink coincident with the surface change, however. Governed by the location of the hydrological sink, basal water will likely "drape" over topography in a manner dissimilar to subglacial lakes where flat strong specular RES reflections are measured. The inability of RES to detect the active lake means that more of the Antarctic ice sheet bed may contain stored water than is currently appreciated. Variation in ice surface elevation data sets leads to significant alteration in calculations of the local flow of basal water indicating the value of, and need for, high-resolution altimetry data in both space and time to establish and characterise subglacial hydrological processes.
Les limites du récit
Authors: Porée Jérôme
Published: January 2014

Les notions de ˝temps raconté˝ et d’˝identité narrative˝ sont devenues, en moins de trois décennies, des lieux communs non seulement pour le philosophe mais encore pour le psychologue et l’éthicien. On devrait s’en réjouir si elles n’alimentaient souvent, aujourd’hui, ce qu’il faut bien appeler un nouveau dogmatisme. Or si Paul Ricœur a bien affirmé, de plusieurs façons, les ressources du récit, il a été aussi le premier à reconnaître ses limites – des limites dont on peut se demander si elles ne sont pas, plus généralement, celles de l’herméneutique elle-même.
Mémoires et conflits: Conflits des mémoires, collision des durées
Authors: Vieillard-Baron Jean-Louis
Published: January 2014

Il y a collision entre les durées et entre les mémoires quand les rythmes de fluence sont différents. Chez Bergson il y a différence des degrés de tension entre durées, mais le flux est unique. Ricœur distingue des degrés de passéité selon la proximité ou l’éloignement. Le Zauberberg de Thomas Mann en est un exemple. Oubli et pardon sont des formes de collision des durées. La distensio animi de saint Augustin signifie éparpillement; Ricœur l’a comprise à tort comme l’intratemporalité phénoménologique, et il en reste au déchirement de l’âme éloignée de l’éternité.
The Mitsui Collection
Authors: Bytheway Simon James
Published: January 2014

There are many reasons why historians, social scientists, and Japanologists would benefit from acquainting themselves with the Mitsui Collection. As an aspiring financial historian, I, for one, wanted to see what I could learn about Mitsui’s role in the establishment of the early Meiji state.
There Is Hope: Autogenic Biofeedback Training for the Treatment of Psoriasis
Authors: Klein Aaron , Peper Erik
Published: January 2014

Many college students experience stress-related illness, and in one study, 82% of students reported significant improvement in health when they participated in a semester-long stress management program. The factors that contribute to symptom reduction are illustrated by the case report of a 23-year-old male student who had been suffering from psoriasis for the past 5 years, which was not alleviated with medication and traditional medical treatment. He participated in an integrated self-regulation program consisting of daily self-healing home practice for 3 weeks, a desensitization strategy, autogenic training, and biofeedback training, coupled with pre- and posttreatment biofeedback assessments. Results showed a significant improvement in the clearing of the skin, more positive self-talk, and improved posture. The benefits have been maintained at the 4-month follow-up. Discussed are the training components and procedures along with factors that contributed to the clinical success and that can be applied to numerous other stress-related disorders.
Treating Postconcussion Syndrome Using Neurofeedback: A Case Study
Authors: Bhandari Tanushree , Thompson Lynda , Reid-Chung Andrea
Published: January 2014

The present article provides a case study showing the application of neurofeedback and biofeedback training with heart rate variability (HRV) training to a 27-year-old man, Mike, who suffered a severe traumatic brain injury (TBI) in a motor vehicle accident. The study demonstrates the use of single-site neurofeedback training, metacognitive strategies, and low-resolution brain electromagnetic tomography (LORETA) z-score training along with HRV. A review of the initial assessment and subsequent progress updates included an examination of continuous performance tests such as test of variables of attention, integrated visual and auditory continuous performance test, and single-channel electroencephalography results, HRV statistics, and 19-channel quantitative electroencephalogram results. The client demonstrated significant improvements on all measures posttraining with marked improvement in five areas: memory, sleep and energy level, academics, mood and irritability, and mental sharpness. Working with clients such as Mike supports the view that one- and two-channel neurofeedback and LORETA z-score neurofeedback, combined with HRV training, are promising interventions for clients with TBIs.
BCIA in 2014: What's New?
Authors: Crawford Judy , Shaffer Fred
Published: January 2014

The Biofeedback Certification International Alliance (BCIA) has revised its recertification requirements and fees to reduce certificant costs. BCIA has expanded options for earning inexpensive and accessible continuing education, including Massive Open Online Courses (MOOCs). BCIA continues to promote ethics education to protect clients, professionals, and the credibility of our field. More educators teach BCIA's HRV Biofeedback Certificate of Completion didactic course to students and professionals. BCIA's Job Board has helped employers recruit our skilled certificants. Finally, there is a need for infection prevention standards in private practice.
Managing Traumatic Brain Injury: Appropriate Assessment and a Rationale for Using Neurofeedback and Biofeedback to Enhance Recovery in Postconcussion Syndrome
Authors: Thompson Michael , Thompson Lynda , Reid-Chung Andrea , Thompson James
Published: January 2014

Impairments that may result from a mild traumatic brain injury (TBI) or concussion can be both severe and long-lasting. This article will list some of the common persisting symptoms that may occur and give a brief description of the neuropathological processes that can be triggered by TBI, including diffuse axonal injury and its effects on the mitochondrial Kreb's cycle and the production of adenosine triphosphate, the brain's source of energy. This is followed by a summary of a comprehensive assessment process that includes quantitative electroencephalography, evoked potentials, heart rate variability (HRV) measures, neuropsychological testing, and blood and urine analysis. Details concerning a neurophysiological approach to effective treatment are given. These include conventional single-channel neurofeedback (NFB), also called brain-computer interface training, low-resolution electromagnetic tomography z-score neurofeedback, HRV training, and counseling on diet, sleep, and exercise. The authors expand the discussion on their treatment approach to include a neuroanatomical explanation of why the practitioner should consider combining the NFB training with HRV training.
From the Zoo to the Jungle – Narrative Pedagogies and Enterprise Education
Authors: Costin Yvonne , Dodd Sarah Drakopoulou , Hynes Briga , Lichrou Maria
Published: December 2013

There is scope for a better understanding of the development of entrepreneurial competences in students through experiential learning pedagogies by engaging them with the entrepreneurs in the entrepreneurs' habitats. This study analyses a novel pedagogical interaction which embraces the narrative aspects of entrepreneurial learning by encouraging students to review and relate their experiences of enterprise education critically and to reflect on how those experiences prepare them for an entrepreneurial career. The study highlights the value of experimenting with more embedded ways of teaching entrepreneurship that resonate with the lived experience of entrepreneurs. In light of their analysis, the authors offer recommendations on how to incorporate entrepreneurial learning mechanisms as part of the education of future entrepreneurs.
Self-organized atomic switch networks
Authors: Stieg Adam Z. , Avizienis Audrius V. , Sillin Henry O. , Martin-Olmos Cristina , Lam Miu-Ling , Aono Masakazu , Gimzewski James K.
Published: December 2013

The spontaneous emergence of complex behavior in dynamical systems occurs through the collective interaction of nonlinear elements toward a highly correlated, non-equilibrium critical state. Criticality has been proposed as a model for understanding complexity in systems whose behavior can be approximated as a state lying somewhere between order and chaos. Here we present unique, purpose-built devices, known as atomic switch networks (ASN), specifically designed to generate the class of emergent properties which underlie critical dynamics in complex systems. The network is an open, dissipative system comprised of highly interconnected (∼109/cm2) atomic switch interfaces wired through the spontaneous electroless deposition of metallic silver fractal architectures. The functional topology of ASN architectures self-organizes to produce persistent critical dynamics without fine-tuning, indicating a capacity for memory and learning via persistent critical states toward potential utility in real-time, neuromorphic computation.
Partially fluorinated copper phthalocyanine toward band engineering for high-efficiency organic photovoltaics
Authors: Kuzumoto Yasutaka , Matsuyama Hirotaka , Kitamura Masatoshi
Published: December 2013

The electronic structures of copper phthalocyanine (CuPc) and fluorinated CuPc, F
x
CuPc (x = 4, 8, 12, and 16), have been investigated by density functional theory. The HOMO and LUMO energies systematically decrease with an increase in the number of fluorine atoms. The degree of the decrease depends on the position of the substitution of hydrogen with fluorine. The HOMO (LUMO) energies vary in the range of −5.33 to −6.82 eV (−3.12 to −4.65 eV). The UV–visible absorption spectra and photoelectron ionization energies of the deposited F
x
CuPc (x = 0, 8, and 16) thin films are compared with the calculation results. The calculated bandgap energies and HOMO levels are consistent with those obtained from the experimental results.
Comparison of properties of polymer organic solar cells prepared using highly conductive modified PEDOT:PSS films by spin- and spray-coating methods
Authors: Kumar Palanisamy , Santhakumar Kannappan , Tatsugi Jiro , Shin Paik-Kyun , Ochiai Shizuyasu
Published: December 2013

Bulk heterojunction (BHJ) solar cells have made great progress over the past decade and consequently are now attracting extensive academic and commercial interest because of their potential advantages: lightweight, flexible, low cost, and high-throughput production. Polymer conductivity is a key factor for improving the performance of electronic and photonic devices. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is promising for use as a next-generation transparent electrode of optoelectronic devices. In this research, we compare the effect of nanomorphology on conductivity, and power conversion efficiency of polymer organic solar cells prepared by the spin- and spray-coating methods. To improve the conductivity of spray-deposited PEDOT:PSS, we modified the PEDOT:PSS films by simple UV irradiation and by UV irradiation with treatment using various solvents such as methanol, ethanol, acetone, acetonitrile, hydrochloric acid, and sulfuric acid to form a hole transport layer (HTL). The active layer of PTB7:PC70BM is spray-coated on top of the PEDOT:PSS layer. The films were examined by optical spectroscopy, micro-Raman spectroscopy, and conductivity measurements. The surface morphology of the deposited films was examined by atomic force microscopy (AFM). The current density–voltage (J–V) characteristics were measured under illumination with simulated solar light at 100 mW/cm2 (AM 1.5G) using an oriel 1000 W solar simulator. The obtained results are expected to have a considerable impact and suggest a bright future for organic polymer solar cells.
Effect of energetic disorder on the open-circuit voltage in organic bulk heterojunction composites
Authors: Seki Kazuhiko , Marumoto Kazuhiro , Tachiya Masanori
Published: December 2013

Under open-circuit condition, the current is not extracted and the photogenerated carriers in principle disappear only by recombination. We study the open-circuit voltage

and transient photovoltage under the effect of bulk recombination in a medium with energetic disorder by using the multiple trapping (MT) model. The key parameter in the MT model is the dispersion parameter

given by the ratio of thermal energy to the characteristic energy of trap states. We show that

depends linearly on the logarithm of the light intensity and the slope depends on the

of the MT model. Under the continuous irradiation of light, the photovoltage response to the weak perturbation by a pulsed light obeys pseudo-first-order decay. The rate as a function of

is independent of the dispersion parameter. However, it obeys the power law as a function of light intensity, and the exponent is given by

, which reduces to 1/2 in the absence of energetic disorder.
Finite-difference time-domain analysis of photonic nanojets from liquid-crystal-containing microcylinder
Authors: Matsui Tatsunosuke , Okajima Akiko
Published: December 2013

The photonic nanojet (PNJ) from a microcylinder with liquid crystals (LCs) showing tangential molecular alignment inside the microcylinder has been numerically analyzed on the basis of the finite-difference time-domain method. By introducing a small degree of birefringence, the characteristics of the PNJ, such as propagation length and polarization state, can be drastically changed. The azimuth angle and the ellipticity of the elliptically polarized PNJ obtained from the LC microcylinder changes within the propagation lengths in the micrometer range even in the isotropic matrix, which might be attributed to the jet like spatial profile of the PNJ. By using LC microcylinders or microspheres, we may obtain a rich variety of PNJs with unique polarization characteristics, which might open a new avenue for the development of novel optical devices with electrical tunability.
Carrier transport and viscosity of discotic liquid-crystalline photoconductor hexaoctylthio-triphenylene
Authors: Monobe Hirosato , Shimizu Yo
Published: December 2013

In this study, the electronic and ionic carrier transports and viscosity of 2,3,6,7,10,11-hexaoctylthio-triphenylene (C8STP) were studied by a time-of-flight method and using a rotational viscometer. Ambipolar charge carrier transport was investigated in the isotropic liquid (Iso) phase of C8STP, similarly to the columnar hexagonal mesophase, and the activation energies were estimated to be 0.1 eV for one positive and one negative, and 0.4 eV for the other negative charge carrier mobility in Iso. The viscosity of C8STP was investigated using a rotation viscometer, and relative viscosity was measured by a capillary method in the isotropic phase, and the activation energy of viscosity was 0.4 eV. The Stokes radii of ionic carriers were experimentally estimated using Walden’s rule. The existence of ionic and electronic (hopping) carrier transports in Iso was implied for the discotic liquid crystalline photoconductor.
Improvement of decay time in nematic-liquid-crystal-loaded coplanar-waveguide-type microwave phase shifter by polymer stabilizing method
Authors: Nguyen Thanh , Umeno Shuhei , Higuchi Hiroki , Kikuchi Hirotsugu , Moritake Hiroshi
Published: December 2013

Polymer stabilization by UV light irradiation in nematic liquid crystals is proposed to improve the decay time of coplanar-waveguide-type microwave phase shifters. The effect of polymer concentration on the decay time of polymer-stabilized nematic liquid crystals is confirmed by a dielectric experiment on a liquid-crystal-sandwiched indium–tin-oxide (ITO) glass cell before loading into a coplanar-waveguide-type microwave phase shifter. The decay time, phase shift value, and insertion loss of microwave phase shifters with different polymer concentrations are measured. The decay time of polymer-stabilized nematic liquid crystals in the microwave phase shifter markedly decreases compared with that of pure nematic liquid crystals. It is confirmed that the use of polymer-stabilized nematic liquid crystals is effective to improve the response time of microwave phase shifters.
Two dimensional array of ZnSe–ferritin for dopamine detection
Authors: Choi Eun Ah , Park Sang Joon
Published: December 2013

Less toxic zinc selenide (ZnSe) quantum dots were synthesized in the cavity of the apoferritin from horse spleen (HsAFr), and the two-dimensional ZnSe–ferritin nanodots were prepared on modified silicon surface. For utilizing the array as a biosensor, the photoluminescence (PL) spectrum change was investigated by accompanying its conjugation reaction with a neurotransmitter dopamine. When the array was conjugated with dopamine, a significant quenching of the fluorescence occurred and the PL intensity was a linear function of the dopamine concentration in the range of 0–0.6 µM. Accordingly, the ZnSe–ferritin nanodot arrays can be employed as a useful sensing media for tiny concentration of dopamine.
Electro-optic properties of a bi-chromophore norbornene polymer brush system
Authors: Jia Yue , Spring Andrew M. , Qiu Feng , Yu Feng , Yamamoto Kazuhiro , Aoki Isao , Otomo Akira , Yokoyama Shiyoshi
Published: December 2013

A selection of poly(norbornene-exo-dicarboximide) brush-type polymers decorated with a pendent azobenzene dye have been prepared for use as electro-optic (EO) hosts. These polymer brushes were employed as EO polymer hosts for a high molecular hyperpolarizability phenyl vinylene thiophene vinylene (FTC) chromophore guest. These polymer brushes contained methoxy or cyano azobenzene substituents, which were able to manipulate the π-electronic polarization, refractive index, and EO activity. The concentration of the azobenzene dye was increased from 6 to 38%, in order to find the optimum and to maximise the EO coefficient. The refractive index of the mixtures could also be tuned by changing the azobenzene content. Ultimately an EO coefficient of nearly 95 pm/V could be realized using a methoxy substituted azobenzene brush at a concentration of 25% with an added FTC chromophore.
Is there a north‐south phase shift in the surface Labrador Current transport on the interannual‐to‐decadal scale?
Authors: Han Guoqi , Chen Nancy , Ma Zhimin
Published: December 2013

The transport of the Labrador Current has substantial interannual‐to‐decadal variability that may significantly impact the ocean climate and marine ecosystem off Atlantic Canada and Northeast United States. Nevertheless the alongshore coherence of the Labrador Current on the interannual‐to‐decadal scales has been a long standing question. Here we have used satellite altimetry data to study interannual‐to‐decadal variability of the unit‐depth surface Labrador Current in the past two decades, in the context of the subpolar gyre of the North Atlantic. The study for the first time reveals that the transport over the Labrador and northeastern Newfoundland Slope is out of phase with that over the Scotian Slope. The surface Labrador Current transport is positively and negatively correlated with the winter North Atlantic Oscillation (NAO) index (with the transport lagging by about 1 year) in the north (the Labrador and northeastern Newfoundland Slope) and in the south (the Scotian Slope), respectively. In addition, the surface Labrador Current transport declines over the Labrador Slope and northeastern Newfoundland Slope and increases over the Scotian Slope. The north‐south phase shift suggests two distinct regimes, which warrants further studies of underlying dynamic mechanisms and may have important implications for regional ecosystems and climate.
Seasonality of sporadic physical processes driving temperature and nutrient high‐frequency variability in the coastal ocean off southeast Australia
Authors: Rossi Vincent , Schaeffer Amandine , Wood Julie , Galibert Guillaume , Morris Brad , Sudre Joel , Roughan Moninya , Waite Anya M.
Published: December 2013

Physical processes forced by alongshore winds and currents are known to strongly influence the biogeochemistry of coastal waters. Combining in situ observations (moored platforms, hydrographic surveys) and satellite data (sea surface wind and sea surface height), we investigate the transient occurrence of wind‐driven upwelling/downwelling and current‐driven upwelling events off southeast Australia. Remote‐sensed indices are developed and calibrated with multiannual time series of in situ temperature and current measurements at two shelf locations. Based on archives up to 10 years long, climatological analyses of these indices reveal various latitudinal regimes with respect to seasonality, magnitude, duration of events, and their driving mechanisms (wind or current). Generally, downwelling‐favorable winds prevail in this region; however, we demonstrate that up to 10 wind‐driven upwelling days per month occur during spring/summer at 28–33.5°S and up to 5 days in summer further south. Current‐driven upwelling upstream of the East Australian Current separation zone (∼32°S) occurs twice as often as downstream. Using independent in situ data sets, we show that the response of the coastal ocean is consistent with our climatology of shelf processes: upwelling leads to a large range of temperatures and elevated nutrient concentrations on the shelf, maximized in the wind‐driven case, while downwelling results in destratified nutrient‐poor waters. The combination of these sporadic wind‐ and current‐driven processes may drive an important part of the high‐frequency variability of coastal temperature and nutrient content. Our results suggest that localized nutrient enrichment events of variable magnitude are favored at specific latitudes and seasons, potentially impacting coastal ecosystems.
A bilevel NLP sensitivity‐based decomposition for dynamic optimization with moving finite elements
Authors: Chen Weifeng , Shao Zhijiang , Biegler Lorenz T.
Published: December 2013

Optimal control has guided numerous applications in chemical engineering, and exact determination of optimal profiles is essential for operation of separation and reactive processes, and operating strategies and recipe generation for batch processes. Here, a simultaneous collocation formulation based on moving finite elements is developed for the solution of a class of optimal control problems. Novel features of the algorithm include the direct location of breakpoints for control profiles and a termination criterion based on a constant Hamiltonian profile. The algorithm is stabilized and performance is significantly improved by decomposing the overall nonlinear programming (NLP) formulation into an inner problem, which solves a fixed element simultaneous collocation problem, and an outer problem, which adjusts the finite elements based on several error criteria. This bilevel formulation is aided by a NLP solver (the interior point optimizer) for both problems as well as an NLP sensitivity component, which provides derivative information from the inner problem to the outer problem. This approach is demonstrated on 11 dynamic optimization problems drawn from the optimal control and chemical engineering literature. © 2014 American Institute of Chemical Engineers AIChE J, 60: 966–979, 2014
Impacts of PEGylation on the gene and oligonucleotide delivery system
Authors: Ikeda Yutaka , Nagasaki Yukio
Published: December 2013

Poly(ethylene glycol) (PEG) is the most widely used polymer and also the gold standard in the field of drug delivery. Therapeutic oligonucleotides, for example, are modified with PEG at the terminus to increases nuclease resistance and the circulating half‐lives. The surface of nanoparticle such as micelle and liposome has been also modified with PEG. At present, one PEGylated therapeutic oligonucleotide has been approved for the market and several more PEGylated products including oligonucleotide and liposome are being tested in clinical settings. This review summarizes the methods and effects of PEGylation on gene delivery. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40293.
Evaluation of wool nanoparticles incorporation in chitosan/gelatin composite films
Authors: Eslahi Niloofar , Dadashian Fatemeh , Hemmati Nejad Nahid , Rabiee Mohammad
Published: December 2013

The aim of this work was to develop chitosan/gelatin composite films embedded with various amounts of wool nanoparticles, which were produced by an environmental friendly process. Films loaded with wool nanoparticles were subjected to physiochemical, biological, and mechanical characterization. The obtained results showed that incorporation of wool nanoparticles into chitosan/gelatin composite led to a reduction in swelling, moisture content and dissolution degree of the films. In vitro degradation test revealed that the nanoparticles‐embedded composites had a lower degradation rate than that of chitosan/gelatin composite. Besides, composite films containing wool nanoparticles showed an improvement in the stability in phosphate buffered saline. On the other hand, tensile strength and elongation at break decreased upon loading the films with wool nanoparticles. The biocompatibility of the produced composites was also confirmed by MTT test. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40294.
Application of Plackett–Burman screening design to the modeling of grafted alginate–carrageenan beads for the immobilization of penicillin G acylase
Authors: Elnashar Magdy M. M. , Wahba Marwa I. , Amin Magdy A. , Eldiwany Ahmed I.
Published: December 2013

Grafted alginate–carrageenan beads were used to immobilize the industrial enzyme penicillin G acylase (PGA). Sixteen factors were screened with the Plackett–Burman design (PBD) to test their significance on the gel beads formation and enzyme immobilization process. The results of PBD showed a wide variation of 30‐fold in the amount of immobilized penicillin G acylase (iPGA) from 11.9 to 354.16 U/g of beads; this reflected the importance of the optimizing process. Among the 16 tested factors, only 3 were proven to be significant. These factors were the enzyme buffer pH (N), enzyme soaking time (Q) with the gel beads, and enzyme concentration (P). The Pareto chart revealed that both Q and P exerted significant positive effects on the amount of iPGA, whereas N had a negative effect. We recommend further study to optimize only these three significant, distinctive enzyme factors. The PGA covalent attachment to the gel beads were proven by Fourier transform infrared spectroscopy, elemental analysis, and NaCl and reusability tests. The best gel bead formula succeeded in the immobilization of 354.16 U/g of beads and proved to be reusable 14 times, retaining 84% of the initial enzyme activity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40295.
Influence of liquid media on lifetime predictions of nitrile rubber
Authors: Buckley Gary S. , Roland C. Michael
Published: December 2013

Evaluating a material's suitability for an application includes determination of its expected service lifetime. For alternative fuels, this entails assessing, inter alia, their effect on the durability of polymeric engine components, e.g., seals, gaskets, and O‐rings. When this is governed by thermally activated chemical deterioration, the conventional approach to characterizing aging is laboratory measurements of property changes of the polymer subjected to accelerated conditions (usually higher temperatures), with the data analyzed by an Arrhenius analysis. However, this method is inefficient and time‐consuming when the number of candidate alternative fuels is large. Herein, we test the hypothesis that the activation energy governing thermal oxidation of elastomeric engine components is independent of the fuel; thus, while the aging rate may vary, the effect of temperature is independent of the contacting liquid. Accelerated testing of the thermal oxidation of nitrile rubber O‐rings were carried out in three liquids, including a fossil fuel and a bio‐fuel. The activation energy obtained from changes in crosslink density, = 82 kJ/mol, was the same for all liquids and consistent with the broad range of literature values for similar compounds aged in air. This result suggests the possibility that estimates of the lifetime of polymeric engine components require only a single accelerated aging test, with the known activation energy used to predict the durability at the service temperature. This would represent at least an order of magnitude reduction in testing requirements. The extension of the approach to the general aging of polymers exposed to different environments is obvious. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40296.
Cationic and hydrophobically modified chitosans as additives for water‐based drilling fluids
Authors: Lopes Grazielle , de Oliveira Thacyla Campos do Carmo , Pérez‐Gramatges Aurora , da Silva Joaquim F. M. , Nascimento Regina Sandra V.
Published: December 2013

Water‐soluble chitosan derivatives are synthesized via a two‐step procedure that includes the hydrophobization of chitosan using different acyl chlorides, and then the alkylation of some of the amine groups. Rheology, conventional rolling, and filtration tests are performed to evaluate the effect of the modified polysaccharides on the rheological behavior of the fluid, as well as on the clays cuttings integrity and on the control of fluid loss for the geological formations. The results indicate that the product with C16 segments, 2% (wt/vol) concentration and high molar weight led to aqueous solutions with a pseudoplastic behavior equivalent to the one presented by the commercial rheology modifier used in water‐based drilling fluids. In addition, the hydrophobically modified cationic chitosan shows an excellent capacity for inhibiting the clays reactivity and for keeping the cuttings integrity. The results also show that this product can significantly decrease the volume of filtrate, leading to values comparable to the ones obtained with commercial additives, and therefore suggesting that it could be considered to replace some of the drilling fluid additives commonly used. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40300.
Montmorillonite reinforced type A gelatin nanocomposites
Authors: Panzavolta Silvia , Gioffrè Michela , Bracci Barbara , Rubini Katia , Bigi Adriana
Published: December 2013

This study investigates the structural, morphological, thermal, and mechanical properties of type A gelatin/montmorillonite (MMT) films as a function of MMT concentration. The variations of the X‐ray diffraction pattern suggest that the structure of the nanocomposites turns from intercalated to exfoliated on increasing clay loading up to 20 wt %. Simultaneously, gelatin interaction with clay negative sheets during gelling provokes a reduction of the triple helix content of the composite films, in agreement with the reduction of the relative intensity of the 1.1 nm diffraction reflection of gelatin and of the values of denaturation enthalpy. On the other hand, the increase of the denaturation and decomposition temperatures, the significant rise of the Young's modulus, as well as the swelling decrease observed as clay content increases, demonstrate a relevant stabilizing effect of MMT on gelatin. The reinforcement action of MMT allows to utilize a relatively low concentration of the crosslinking agent genipin to further stabilize the films. The synergic action of clay and genipin prevents dissolution of the nanocomposites in aqueous solution and enhances their mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40301.