bluuebunny/crossref_metadata_2025 huggingface dataset:
Trends of age of consent legislation in Europe
Authors: Zhu Guangxing , van der Aa Suzan
Published: May 2017

Over the past few decades, many national jurisdictions on the European continent have revised their age of consent legislation. A comparison of the age of consent laws of 59 jurisdictions in 2004 and 2016 revealed three important developments to have taken place during the past 12 years. The first trend – to raise the general age of consent and abolish very low ages of consent (<14 years) – signals that nowadays much greater emphasis is placed on the protection of children against negative and premature sexual experiences. This protectionist approach, however, comes at a cost: A higher statutory age of consent can restrain children in their sexual autonomy. The second trend emerging from the comparison was the full and complete equalization of the age of consent for homosexual and heterosexual relations. While in 2004, one-third of the studied jurisdictions still had discriminatory provisions for homo- or heterosexual sex, all of them have now adopted laws that are neutral regarding the sexual orientation of the partners involved. The third trend is to create a higher age limit for sexual behaviours in relationships of authority or dependence. This acknowledgement of the need for increased protection of minors in relationships characterized by a power imbalance deserves following by jurisdictions that have not distinguished a different age of consent for authority relations (yet).
Therapeutic potential of dental stem cells
Authors: Chalisserry Elna Paul , Nam Seung Yun , Park Sang Hyug , Anil Sukumaran
Published: May 2017

Stem cell biology has become an important field in regenerative medicine and tissue engineering therapy since the discovery and characterization of mesenchymal stem cells. Stem cell populations have also been isolated from human dental tissues, including dental pulp stem cells, stem cells from human exfoliated deciduous teeth, stem cells from apical papilla, dental follicle progenitor cells, and periodontal ligament stem cells. Dental stem cells are relatively easily obtainable and exhibit high plasticity and multipotential capabilities. The dental stem cells represent a gold standard for neural-crest-derived bone reconstruction in humans and can be used for the repair of body defects in low-risk autologous therapeutic strategies. The bioengineering technologies developed for tooth regeneration will make substantial contributions to understand the developmental process and will encourage future organ replacement by regenerative therapies in a wide variety of organs such as the liver, kidney, and heart. The concept of developing tooth banking and preservation of dental stem cells is promising. Further research in the area has the potential to herald a new dawn in effective treatment of notoriously difficult diseases which could prove highly beneficial to mankind in the long run.
Which path the world might take
Authors: Gui Xiaowei
Published: May 2017

Owing to its features of economic nationalism, trade protectionism, anti-establishment and white nationalism, Trump’s “America First” policy brought him to the White House but also divided the USA as a nation. The policy was essentially a response to the American populist movement created by the economic and cultural anxiety of the white working class. However, rather than fix the problem, Trump’s philosophy of governance may make the situation even worse and could provide China with a significant opportunity to strengthen itself in an era of great change.
Aryl hydrocarbon receptor inhibition promotes hematolymphoid development from human pluripotent stem cells
Authors: Angelos Mathew G. , Ruh Paige N. , Webber Beau R. , Blum Robert H. , Ryan Caitlin D. , Bendzick Laura , Shim Seonhui , Yingst Ashley M. , Tufa Dejene M. , Verneris Michael R. , Kaufman Dan S.
Published: May 2017

Key Points

Small-molecule inhibition and CRISPR/Cas9 deletion of AHR promote early hematoendothelial cell differentiation from hESCs. AHR inhibition enhances the differentiation of cNK cells from hESCs whereas AHR hyperactivation supports development of ILC3s.
Mutations of MAP2K1 are frequent in pediatric-type follicular lymphoma and result in ERK pathway activation
Authors: Schmidt Janine , Ramis-Zaldivar Joan Enric , Nadeu Ferran , Gonzalez-Farre Blanca , Navarro Alba , Egan Caoimhe , Montes-Mojarro Ivonne Aidee , Marafioti Teresa , Cabeçadas Jose , van der Walt Jon , Dojcinov Stefan , Rosenwald Andreas , Ott German , Bonzheim Irina , Fend Falko , Campo Elias , Jaffe Elaine S. , Salaverria Itziar , Quintanilla-Martinez Leticia
Published: May 2017

Key Points

TNFRSF14 and MAP2K1 mutations are frequent in PTFL but do not occur together in the majority of cases. MAP2K1 mutations lead to activation of the downstream target phosphorylated extracellular signal-regulated kinase.
SOX11 promotes tumor protective microenvironment interactions through CXCR4 and FAK regulation in mantle cell lymphoma
Authors: Balsas Patricia , Palomero Jara , Eguileor Álvaro , Rodríguez Marta Leonor , Vegliante Maria Carmela , Planas-Rigol Ester , Sureda-Gómez Marta , Cid Maria C. , Campo Elias , Amador Virginia
Published: May 2017

Key Points

SOX11 regulates MCL homing and invasion via direct regulation of CXCR4 and FAK expression and PI3K/AKT and ERK1/2 signaling activation. SOX11 expression increases CAM-DR, contributing to a more aggressive MCL phenotype.
Acute exacerbations in the INPULSIS trials of nintedanib in idiopathic pulmonary fibrosis
Authors: Collard Harold R. , Richeldi Luca , Kim Dong Soon , Taniguchi Hiroyuki , Tschoepe Inga , Luisetti Maurizio , Roman Jesse , Tino Gregory , Schlenker-Herceg Rozsa , Hallmann Christoph , du Bois Roland M.
Published: May 2017

Time to first investigator-reported acute exacerbation was a key secondary end-point in the INPULSIS trials of nintedanib in patients with idiopathic pulmonary fibrosis (IPF).

We used the INPULSIS trial data to investigate risk factors for acute exacerbation of IPF and to explore the impact of nintedanib on risk and outcome of investigator-reported and adjudicated confirmed/suspected acute exacerbations. Mortality following these events and events adjudicated as not acute exacerbations was analysed using the log rank test.

Risk of acute exacerbations was most strongly associated with the following variables: baseline forced vital capacity (higher risk with lower value), baseline supplemental oxygen (higher risk with use), baseline antacid medication (higher risk with use), treatment (higher risk with placebo), and for confirmed/suspected acute exacerbations, cigarette smoking. Mortality was similar following investigator-reported and adjudicated confirmed/suspected acute exacerbations. Nintedanib had no significant effect on risk of mortality post-exacerbation.

Investigator-reported acute exacerbations of IPF are associated with similar risk factors and outcomes as adjudicated confirmed/suspected acute exacerbations.
Identifying the Endgame
Authors: DeFrantz Thomas F.
Published: May 2017

This essay begins by outlining the forces of assimilation and dissent within the history of black American performance artistry since the 1960s. DeFrantz proposes a shift in curators' priorities away from representing multiculturalism in national presenting organizations in favor of a dynamic engagement with existing communities and publics. He calls for a recentering on minoritarian forms, a shift that would embody a new ethics and reflect new American demographic and cultural realities.
Decolonizing the Curatorial
Authors: Lepecki André
Published: May 2017

In a talk originally presented at the 2015 Munich conference for the “Show Me a World” project, scholar André Lepecki, drawing from postcolonial theory and critical black studies, puts forth a critique of the colonial tendencies within curatorial practice and the art system. Lepecki proposes decolonized curation as the imaginative affirmation of a wholly new collective sociability and finds a model for these relations in the notoriously “difficult to curate” art of Lygia Clark. As “wild things,” rather than objects of art, the works of Clark escape the colonized art system, offend curatorial reason, and question the assumed hierarchies of artists, objects, and subjects inherent within traditional curatorial practice.
Multiobjective Production Planning at LG Display
Authors: Sohn Moo-Sung , Choi Jiwoong , Kang Hoseog , Choi In-Chan
Published: May 2017

In this paper, we address a glass-cutting process, which we call a post-cell process, for production planning at LG Display, one of the leading display-panel manufacturing companies in Korea. This process involves cutting glass into a variety of panels of different sizes to meet customer demands. We present mixed-integer programming models and a solution approach to generate production plans for the post-cell process. In the models, we consider multiple goals, such as minimization of shortage, inventory, and item changeover. In our solution approach, the goals are prioritized based on their importance and treated sequentially to meet the solution time requirements as set forth by work-site planners. The results of our computational experiments with real-world problem instances at LG Display show that our approach provides significant benefits in operational efficiency.
Market Mediators and the Trade-offs of Legitimacy-Seeking Behaviors in a Nascent Category
Authors: Lee Brandon H. , Hiatt Shon R. , Lounsbury Michael
Published: May 2017

Although existing research has demonstrated the importance of attaining legitimacy for new market categories, few scholars have considered the trade-offs associated with such actions. Using the U.S. organic food product category as a context, we explore how one standards-based certification organization—the California Certified Organic Farmers (CCOF)—sought to balance efforts to legitimate a nascent market category with retaining a shared, distinctive identity among its members. Our findings suggest that legitimacy-seeking behaviors undertaken by the standards organization diluted the initial collective identity and founding ethos of its membership. However, by shifting the meaning of “organic” from the producer to the product, CCOF was able to strengthen the categorical boundary, thereby enhancing its legitimacy. By showing how the organization managed the associated trade-offs, this study highlights the double-edged nature of legitimacy and offers important implications for the literatures on legitimacy and new market category formation.

The online appendix is available at https://doi.org/10.1287/orsc.2017.1126 .
Multiple Identity Configurations: The Benefits of Focused Enhancement for Prosocial Behavior
Authors: Ramarajan Lakshmi , Berger Ida E. , Greenspan Itay
Published: May 2017

This paper introduces a configurational approach to the study of multiple identities. Specifically, it examines how prosocial identity combines with collective and individualistic identities in conflicting and enhancing ways to affect prosocial behavior in organizational settings. We examine an unexplored intuition in the multiple identities literature that when all identities are enhancing (a mutual enhancement configuration), it will be best for prosocial outcomes. Our results show, however—across two field studies and two experiments—that enhancement between prosocial and collective identities (a focused enhancement configuration) results in the highest levels of prosocial behavior. Furthermore, we trace this result to the greater self-serving orientation activated in a mutual enhancement configuration, where one’s individualistic identity enhances one’s other identities. Our work demonstrates the value of a configurational approach to the study of multiple identities, and it challenges the assumption that a mutual enhancement configuration is always desirable.

The online appendix is available at https://doi.org/10.1287/orsc.2017.1129 .
Spotting the early signs of abuse: New draft guidance
Authors: O'Connell Suzanne
Published: May 2017

Most schools are clear about those signs of abuse and neglect that should lead to a referral. But what about those subtle first warning signs that something needs further investigation? NICE has released draft guidance to help professionals working with children recognise them.
How accurate is your data?
Authors: Oxford Nathan
Published: May 2017

One of the reasons behind recent improvements in outcomes at senior leader Nathan Oxford‘s school is a marked improvement in the accuracy of assessment data
SEN in Schools: Who should do what?
Authors: Freeman Garry
Published: May 2017

New legislation, including the SEND Code of Practice 2015, has led to a dramatic overhaul of SEND practice in schools. Two years on, Garry Freeman looks at who should now be doing what to meet the new requirements
Domestic abuse and women with ‘no recourse to public funds’: the state’s role in shaping and reinforcing coercive control
Authors: Dudley Rebecca Gail
Published: May 2017

If they are subject to immigration control, women who experience domestic abuse in the UK face particular barriers to finding safety and support. In particular, the ‘no recourse to public funds’ (NRPF) rule means that women subject to immigration controls on a variety of visa statuses cannot access safe refuge accommodation or other support. Based on interviews with service providers in six cities, this article explores the impact of this rule in trapping women in relationships of coercive control. These women expect, and frequently encounter, a climate of hostility to which the state contributes. The state, through this rule, plays an active role in factors that increase danger for women, even as it reduces their options.
Relationship between health-related quality of life and self-esteem of adult patients receiving chemotherapy for cancer treatment
Authors: Ahmed Sahar , Khaleel Shimaa
Published: May 2017

Purpose: To identify the relation between self-esteem and health related quality of life of adult cancer patients receiving chemotherapy and to identify the demographic variables that may have impact on health related quality of life of cancer patients receiving chemotherapy.Methods: A cross-sectional, descriptive, correlational survey was utilized in this study. The study was conducted at the in-patient and out-patient clinic of oncology at South Egypt cancer institute. The sample consisted of 100 patients with the following inclusion criteria; adult patients diagnosed of any type of cancer, fully conscious and are willing to participate in the study. Two tools were used; 36-Item Short Form Health Survey Instrument and Rosenberg self-esteem questionnaire.Results: The majority of the studied sample (67 %) was female, their age ranges from 40 years and above, they were not working and were having a breast cancer (38%), there was a highly statistical significant difference in total HRQoL score and breast and lung cancer diagnosis.Conclusion: A quarter of the studied sample was having a satisfactory quality of life while near the entire studied sample were having a good self-esteem. Age, sex and occupation were socio-demographic variables that have impact on patient's quality of life.
Los retos procesales de la criminalidad informática desde una perspectiva española.
Authors: Alonso Lorena Arocena , Esparza Leibar Iñaki
Published: May 2017

Dada su cotidianeidad, la criminalidad informática adquiere un papel muy importante y valioso en la sociedad del siglo XXI. No se pueden obviar las características intrínsecas de los delitos informáticos, pues demandan un tratamiento procesal específico en comparación con los delitos convencionales. Sin embargo, aunque la analogía ha sido la protagonista en esta materia durante un largo período en España, llegan nuevos tiempos con el Convenio sobre cibercriminalidad y la Ley Orgánica 13/2015, cuyos ejes conductores son la capacitación de todos los operadores jurídicos y la cooperación internacional.
Toward reduced transport errors in a high resolution urban CO2 inversion system
Authors: Deng Aijun , Lauvaux Thomas , Davis Kenneth J. , Gaudet Brian J. , Miles Natasha , Richardson Scott J. , Wu Kai , Sarmiento Daniel P. , Hardesty R. Michael , Bonin Timothy A. , Brewer W. Alan , Gurney Kevin R.
Published: May 2017

We present a high-resolution atmospheric inversion system combining a Lagrangian Particle Dispersion Model (LPDM) and the Weather Research and Forecasting model (WRF), and test the impact of assimilating meteorological observation on transport accuracy. A Four Dimensional Data Assimilation (FDDA) technique continuously assimilates meteorological observations from various observing systems into the transport modeling system, and is coupled to the high resolution CO2 emission product Hestia to simulate the atmospheric mole fractions of CO2. For the Indianapolis Flux Experiment (INFLUX) project, we evaluated the impact of assimilating different meteorological observation systems on the linearized adjoint solutions and the CO2 inverse fluxes estimated using observed CO2 mole fractions from 11 out of 12 communications towers over Indianapolis for the Sep.-Nov. 2013 period. While assimilating WMO surface measurements improved the simulated wind speed and direction, their impact on the planetary boundary layer (PBL) was limited. Simulated PBL wind statistics improved significantly when assimilating upper-air observations from the commercial airline program Aircraft Communications Addressing and Reporting System (ACARS) and continuous ground-based Doppler lidar wind observations. Wind direction mean absolute error (MAE) decreased from 26 to 14 degrees and the wind speed MAE decreased from 2.0 to 1.2 m s–1, while the bias remains small in all configurations (< 6 degrees and 0.2 m s–1). Wind speed MAE and ME are larger in daytime than in nighttime. PBL depth MAE is reduced by ~10%, with little bias reduction. The inverse results indicate that the spatial distribution of CO2 inverse fluxes were affected by the model performance while the overall flux estimates changed little across WRF simulations when aggregated over the entire domain. Our results show that PBL wind observations are a potent tool for increasing the precision of urban meteorological reanalyses, but that the impact on inverse flux estimates is dependent on the specific urban environment.
Académie nationale de médecine - Une tradition bicentenaire de modernité
Authors: JAFFIOL Claude
Published: May 2017

EXTRACT C'est sous le signe de la modernité, qu’est fondée l'Académie nationale de médecine, au début du XIXème siècle, alors que notre discipline émerge d'une longue période d'obscurantisme. Après Bichat, mort prématurément, les pionniers, Laënnec, dont le stéthoscope permet pour la première fois d'écouter ce qui se passe à l'intérieur du corps humain , Larrey, le premier chirurgien des temps modernes , Pinel, le premier psychiatre... sont appelés à siéger dans la jeune académie fondée par Louis XVIII en 1820. Toujours sous le signe de la modernité, c'est à l'Académie de médecine que présentent leurs travaux révolutionnaires Pasteur et Marie Curie, deux figures emblématiques de la science, des découvreurs comme Laveran, prix Nobel de médecine, des novateurs comme Robert Debré, pédiatre éminent mais aussi inventeur des CHU. Alexander Fleming y fit connaître au monde sa découverte de la pénicilline.
Childhood Social Disadvantage and Pubertal Timing: A National Birth Cohort From Australia
Authors: Sun Ying , Mensah Fiona K. , Azzopardi Peter , Patton George C. , Wake Melissa
Published: May 2017

BACKGROUND AND OBJECTIVES:

Early pubertal timing is linked with a range of adverse health outcomes later. Given recent trends of earlier pubertal maturation, there is growing interest in the factors influencing pubertal timing. Socioeconomic disadvantage has been previously linked with reproductive strategies later in life. In this study, we aim to determine the association between cumulative social disadvantages in early life and early puberty in a population-based birth cohort.

METHODS:

Data are from the B (baby) cohort of The Longitudinal Study of Australian Children. Children (n  =  5107) were aged 0 to 1 years when recruited in 2004 and 10 to 11 years (n  =  3764) at Wave 6 in 2015. Household socioeconomic position (SEP) and neighborhood socioeconomic disadvantage were collected at all 6 waves. Trajectories of disadvantage were identified through latent class models. Early puberty at Wave 6 was assessed from parental reports using an adaptation of the Pubertal Development Scale.

RESULTS:

Cumulative exposure to extremely unfavorable household SEP in boys independently predicted a fourfold increase (odds ratio = 4.22, 95% confidence interval 2.27–7.86) in the rate of early puberty. In girls, the increase was twofold (odds ratio = 1.96, 95% confidence interval 1.08–3.56). We found no effect from neighborhood disadvantage once family SEP was taken into account.

CONCLUSIONS:

Cumulative exposure to household socioeconomic disadvantage in early life predicts earlier pubertal timing in both boys and girls. This may represent 1 mechanism underpinning associations between early life disadvantage and poor health in later life.
Перспективи розвитку агропромислового комплексу України в умовах євроінтеграції
Authors: Dorosh–Kizym M. , Dadak O. , Gachek T.
Published: May 2017

Сьогодні агропромисловий комплекс є одним із найбільших і найважливіших секторів економіки України, адже саме тут формується основна частина продовольчих ресурсів та майже три чверті роздрібного товарообігу. Крім того, що агропромислові підприємства роблять значний внесок у розвиток галузі і економіки країни в цілому, агропромисловий сектор України є також одним із найважливіших елементів економічних систем більшості країн світу з ринковою економікою. Протягом останніх трьох років Україна остаточно закріпила за собою статус світового лідера з виробництва та експорту аграрної продукції. І як визнають експерти, попереду ще великий потенціал. Проте, одним із найголовніших досягнень останніх декількох років стало завоювання продовольчого ринку Європейського Союзу. Слідом за українськими зерновими на європейському ринку, на полицях європейських супермаркетів з’являються продукти харчування з позначкою «Зроблено в Україні». Європа зацікавлена у нашій продукції, але тут існують свої невід'ємні «правила гри». Проблеми міжнародної економічної інтеграції тісно пов’язані з міжнародною торгівлею, яка є невід’ємною частиною світової глобалізації, оскільки можуть суттєво впливати на географічну та товарну структури експорту й імпорту. Внаслідок зростання показників відкритості ринків з’являються нові вимоги до якості товарів і послуг національних виробників, особливо виробників сільськогосподарської продукції. Розвиток експортного потенціалу сільськогосподарської продукції стає запорукою зростання економіки в цілому, що передбачає, у тому числі, підвищення кваліфікації персоналу та якісну зміну системи маркетингу. Україні необхідно щонайменше 2–3 роки напруженої роботи, аби отримати вихід на європейський ринок по всіх видах продукції сільського господарства. І ця напружена робота включає як прийняття необхідних законодавчих актів, так і, насамперед, вдосконалення вже існуючих бізнес-практик.
Проблеми соціально-економічного розвитку сільських територій в Україні
Authors: Korobka S.V. , Pentsak T.G.
Published: May 2017

У статті обґрунтовано актуальність та узагальнено чинники, які ускладнюють соціально-економічний розвиток сільських територій. Відмічено, що у сільській місцевості спостерігається високий рівень безробіття, постійно збільшується кількість селян, які мігрують до міста, погіршується виробнича і соціальна інфраструктура. Подано визначення таким поняттям, як територія, сільська територія, розвиток сільських територій. Зокрема відмічається, що соціально-економічний розвиток сільських територій - необоротна, спрямована, закономірна зміна економічного середовища та соціальної інфраструктури території, в наслідок чого відбувається створення нового якісного стану. Наведено показники соціально-економічного розвитку сільських територій. Відмічено позитивні зміни та невирішені проблеми. Обґрунтовано необхідність розробки Концепції сталого розвитку сільських територій. Подальший розвиток сільських територій має відбуватися з врахуванням нових засадах організаційного забезпечення і фінансування, а також бути серед пріоритетів комплексного розвитку, залучення інвестиційних ресурсів, та врахування потреб сільського населення.
Актуальні проблеми становлення фермерських господарств
Authors: Salamin O.
Published: May 2017

Аналізуються причини що стримують становлення та розвиток фермерських господарств України. Основними з них є несформованість аграрного ринку, проблемність пошуку каналів збуту на альтернативних засадах, висока мінливість цін, монопольний вплив на формування яких мають посередницькі організації. Ринок не вивчається і не прогнозується. Фермерські господарства не можуть реалізувати свої переваги, які полягають у можливості швидшої, порівняно з великими підприємствами, адаптації до існуючого ринкового середовища. Намітилась тенденція передачі фермерськими підприємствами земельних угідь у суборенду агрохолдингам, що призводить до зростання безробіття у селах, посилення економічних і соціальних проблем. Показано, що лише законодавчого визначення поняття сімейного фермерського господарства для виникнення та розвитку таких господарств недостатньо. Необхідними передумовами активізації фермерського руху є створення умов для ефективного функціонування таких господарств.
Сучасний стан та перспективи розвитку світового ринку м’яса птиці
Authors: Sendetska S.
Published: May 2017

В статті показано, що виробництво м’яса птиці є тваринницькою галуззю, яка в світі демонструє найвищі темпи зростання обсягів виробництва за минулі десять років у порівнянні з іншими галузями тваринництва. Визначено найбільших світових виробників бройлерного м’яса, якими є США, Бразилія, Китай, країни Європейського Союзу, Індія, які разом виготовляють понад дві третини всього світового виробництва цього виду продукції. Україна займає 19 позицію з обсягами виробництва у 2016 р. понад 1,05 млн т. Показано, що основними експортерами бройлерного м’яса є Бразилія, США, країни Євросоюзу, Таїланд і Китай. Визначено, що найбільшими імпортерами бройлерного м’яса на світовому ринку є Японія, Мексика, Саудівська Аравія. Україна займає сьому позицію в світі за обсягами експорту бройлерного м’яса. Українські виробники у 2016 р. збільшили експортні поставки м’яса птиці майже на 80 тис. т. Основний вектор поставок був спрямований на азійсько-африканський ринок. Обсяги імпорту курячого м’яса в Україну також зросли трохи більше, як на 20 тис. т. В Україну ввозиться здебільшого дешева низькоякісна продукція.
Lithium Dendrite Growth Control Using Local Temperature Variation
Authors: Aryanfar Asghar , Colussi Agustín J , Hoffmann Michael R.
Published: May 2017

We have quantified lithium dendrite growth in an optically accessible symmetric Li-metal cell, charged under imposed temperatures on the electrode surface. We have found that the dendrite length measure is reduced up to 43% upon increasing anodic temperature of about 50°C. We have deduced that imposing higher temperature on the electrode surface will augment the reduction rate relative to dendritic peaks and therefore lithium holes can draw near with the sharp deposited tips. We have addressed this mechanism via fundamentals of electrochemical transport.
The Effect of Structural Defects on the Laser Damage Threshold of KH2PO4 Single Crystals.
Authors: Garnov S. V. , Kolybayeva M. I. , Puzikov V. M. , Salo V. I.
Published: May 2017

The effect of the crystal structure defects of different origin (dislocations, stresses, impurities, liquid phase inclusions) on the bulk laser damage threshold in big-size KDP crystals has been studied in the present paper. The quantitative dependence of the bulk laser damage threshold value on the internal stresses, density of dislocations and impurity concentration in crystals has been found.
Spectroscopy, Modelling and Laser Operation of Holmium Doped Laser Crystals
Authors: Kalisky Y. , Rotman S. R. , Boulon G. , Pedrini C. , Brenier A.
Published: May 2017

Spectroscopic studies using laser induced fluorescence and numerical modelling of energy transfer and back transfer mechanism are reported in Er:Tm:Ho:YLF, Cr:Tm:Ho:YAG and Cr:Tm:YAG laser crystals at various temperatures (10 K-300 K). Direct energy transfer from Tm3+ excited states to Ho3+5I7 emitting level was observed and analyzed both in YAG and YLF. Further analysis of Cr3+ and Tm3+ time-dependent emission curves indicate a strong correlation of chromium-thulium pairs. Pulsed operation of holmium laser at high temperature will be presented.
First Order Quasi-Phase-Matched Second-Harmonic Generation in LiTaO3 Utilizing a Periodic Domain Inversion Created by an External Stress
Authors: Strasser Thomas A. , Raj Rishi
Published: May 2017

First order quasi-phase-matching in a proton exchanged LiTaO3 channel waveguide structure is reported, where the periodic domain inversion is created by the application of a periodic compressive stress near the Curie temperature. The processing conditions, driving force, and effects on resulting domain structure is reported, including the observation of domain structures with periods as small as 0.36 μm. A waveguide second-harmonic generation structure with a periodic 3.45 μm domain inversion structure is fabricated and evaluated to quasi-phase-match 420 nm blue light with 840 nm output available from standard laser diode sources.
Blue Light by Second Harmonic Generation in Epitaxial PbTiO3 Thin Film Waveguide
Authors: Hsu Wei-Yung , Raj R.
Published: May 2017

Epitaxial PbTiO3 thin films have been grown on MgO substrate. The as grown PbTiO3 thin films were multi-domain with the existence of a-domain and c-domain. The amount of adomain can be reduced with the application SrTiO3 transitional layer, which also improve the crystalline quality and thus the nonlinear optical properties. Blue light generation in the PbTiO3/SrTiO3/MgO heterostructure was demonstrated based on waveguide mode dispersion.
An Intuitive Method for the Determination of Crystal-Field Parameters in Laser Crystals
Authors: Anderson Frederick G. , Weidner H. , Summers P. L. , Peale R. E. , Chai B. H. T.
Published: May 2017

Expanding the crystal field in terms of operators that transform as the irreducible representations of the Td group leads to an intuitive interpretation of the crystal-field parameters. We apply this method to the crystal field experienced by Nd3+ dopants in the laser crystals YLiF4, YVO4, and KLiYF5.
Growth Studies of YVO4 Crystals: I. Aspects of Oxygen Deficiency
Authors: Erdei Sandor , Ainger F. W.
Published: May 2017

During crystal growth of yttrium orthovanadate (YVO4) from the Y-V-O melt system, strong incongruent vanadium oxide vaporization occurs, causing changes in both oxygen and Y/V stoichiometry and resulting in significant color centers and inclusion problems in the crystal. Oxygen deficiency is an inherent problem in melt grown YVO4 crystals, and this work seeks to clarify this phenomenon. Lattice parameter decrease was observed in oxygen deficient YVO4-x fibers grown by the laser heated pedestal growth (LHPG) technique. Although post-growth annealing in O2 atmosphere can eliminate the black color centers in the fibers, it causes anisotropic lattice distortions within the crystal. Consequently, preventing the formation of oxygen deficient YVO4-x holds the most promise for production of scattering free YVO4 crystals. Since the complete suppression of incongruent vaporization is very difficult during high temperature growth procedure, utilization of a proper flux system having a low melting temperature “compensating phase” for collecting non-pentavalent vanadium oxides is recommended to achieve directly-grown oxygen deficiency free yttrium orthovanadate crystals.
Room Temperature CW Laser Efficiency Yb3+−Er3+ and Tm3+ Doped Silicates in the Infrared Region
Authors: Borel C. , Souriau J. C , Wyon Ch. , Li C. , Moncorge R.
Published: May 2017

This paper reports the main spectroscopic characterizations and laser experiments carried out on two new crystal hosts: the! yttrium orthosilicate Y2SiO5 and the silicate oxyapatite Sr2Y8(SiO4)6O2 (hereafter noted SYS), doped with Ytterbium and Erbium for a 1,55 μm laser emission and with Thulium for a 2 μm emission. Four new lasers have been demonstrated at 1,554 μm, 1,576 μm, 1,99 μm and 2,05 μm for respectively Yb,Er:SYS; Yb,Er:Y2SiO5; Tm:SYS and Tm:Y2SiO5. If for the Yb,Er codoped materials laser performances are still poor compared with the Yb,Er phosphate glass, the Tm doped materials exhibit laser performances similar to the Tm:YAG and look very promising.
Luminescence Behavior of Organo-Ruthenium Complexes Entrapped Within Sol-Gel Hosts
Authors: Matthews Lowell R. , Wang Xiao-Jun , Knobbe E. T.
Published: May 2017

Compounds of europium(III) and ruthenium(II) are of interest for potential optical source applications in the red portion of the visible spectrum. Our previous work showed that the organo-europium complex tris(4,4,4-trifluoro-l-(2′-thienyl)-l,3-butanedionato-O, O′)europium( III), Eu(ttfa)3, demonstrated superior fluorescence properties to salts like europium(III) chloride when doped into sol-gel materials. The ruthenium complex tris(2,2′- bipyridyl)ruthenium(II) chloride, ‘Ru(bpy)3’Cl2, also shows strong fluorescence when doped into sol-gel materials.

Luminescence behavior of the ‘;Ru(bpy)3’Cl2 complex has been investigated as a function of matrix composition using three sol-gel-derived hosts: silica, an acrylate ORMOSIL, and an epoxide ORMOSIL. Luminescence characteristics have also been studied as a function of fluorophore concentration. Fluorescence lifetime, excitation and emission spectra, and quantum efficiency values have been determined.
Influence of Real Structure on Characteristics of KTA Elements.
Authors: Isaenko Ludmila I. , Pylneva N. A. , Mashkovzhev R. I. , Turikov V. I.
Published: May 2017

The specftral features of KTA samples, grown from melt solution of var ious solvent impurity composition and treated in various conditions are represented.
Intraband Absorption in P-Type InGaAs at FIR Frequencies
Authors: Zhang Xiangkun , Liao Phengpiao , Afzali-Kushaa Ali , Haddad George I.
Published: May 2017

Intraband absorption in p-type In.53Ga.47 As has been measured at FIR frequencies (40–240 cm−1). It is found that the absorption in p-type InGaAs, which is associated with transitions between the light- and heavy-hole valence bands, is very strong. The absorption coefficient is as high as 103–104 cm−1. It increases with the doping concentration but decreases with the frequency of the incident radiation and temperature.
Idea on Momentum Effect of Gaseous Beam Particles on Epitaxial Crystal Stiffness as to Thin Film Growth Such as Metal Organic Chemical Vapor Deposition Growth and Molecular Beam Growth
Authors: Saito Yasuyuki
Published: May 2017

The author reports on idea of momentum effect of gaseous beam particles as to thin film epitaxial crystal growth such as molecular beam epitaxial growth or metal organic chemical vapor deposition epitaxial growth on stiffness of epitaxial growth thin film. The author presented that liquid glass encapsulation squeeze compression effect of liquid-glass-encapsulation Czochralski technique (LEC) crystal growth [Y.Saito, presented at the 10th Int. Conf. on Crystal Growth, 1992], third element different from crystal matrix elements [Y.Saito, presented at the 9th Int. Conf. on Ternary and Multinary Compounds, 1993], light momentum pressure of substance cooling thermal cycle [Y.Saito, presented at the 1st Int.Symposium on Laser and Optoelectronics Technology & Applications, 1993] can yield firmly binded bonds of substance elements. On the other hand, collisions of particles sputtered from solid target slabs [Y.Saito, presented at the 2nd Int.Symposium on Sputtering & Plasma Processes, 1993] or accelerated ions or particles evaporated from molten metals with themselves on the thin films can yield binded bonds. It was shown that internal compression in a crystal by ion implantation in crystal cell lattices can make the refractory state to gas phase chemical attack.[Y.Saito, in the Materials Research Society Symposium Proc. Vol. 279, pp. 135–140.] From these results, we can consider momentum effect at collision on binding state. After collision binding, internal compression by thermal transition variation in a multilayer structure during cooling thermal cycle influences binding stiffness.
Characterization of Ce-Doped LaPO4 by X-Ray Absorption Spectroscopy
Authors: Shuh D. K. , Terminello L. J. , Boatner L. A. , Abraham M. M. , Perry D.
Published: May 2017

X-ray Absorption Spectroscopy (XAS) of the Rare Earth (RE) 3d levels yields sharp peaks near the edges as a result of strong, quasi-atomic 3d104fn→3d94fn+1 (M4,5) transitions that contain a wealth of spectroscopic features. XAS is a useful technique for the characterization of 4f-occupancy, 4f-hybridization, and valence in RE-containing materials. The XAS measurements of the single crystal RE-orthophosphates, as well as a range of Ce- doped (˜l–30%) LaPO4 hosts were performed at the 3d edge in the total electron yield mode at beamline 8–2 at the Stanford Synchrotron Radiation Laboratory (SSRL). The XAS spectra of the RE ions in the orthophosphate matrix generally resemble that of the corresponding RE metal and emphasize the major contribution of the trivalent state to the electronic transitions occurring at the 3d edge. There is no energy shift of the La and Ce absorption peaks with Ce doping and furthermore, no additional transitions are observed in either spectral region. However, accompanying the Ce doping there is a significant narrowing of the La absorption peak full width half maximum that contrasts to the Ce features that exhibit no contraction. The La and Ce spectra indicate that the Ce-doping of LaPO4 is purely substitutional.
Dihexyl-Fluorene-co-3,4 Ethylenedioxythiophene Copolymers for OLEDs
Authors: Stéphan Olivier , Tran-Van Francois , Contat Jérome , Dubois Angélique , Chevrot Claude
Published: May 2017

We report synthesis, and optical properties, of dihexyl-fluorene-co-3,4-ethylene- dioxythiophene (DHF-co-EDOT) random copolymers obtained from mixture, in various ratios, of the two corresponding dibrominated monomers. Infra-red studies coupled with 1H NMR clearly indicate, as expected, that the amount of each monomer unit in the materials is strongly connected to the feed composition. It clearly appears that even a low 3,4-ethylene- dioxythiophene (EDOT) content, i.e. 15 %, within a poly(dihexyl fluorene) main chain induces significant changes in the electronic properties of the corresponding material, denoted COPO1, compared with the fluorene-based homopolymer. Higher EDOT contents lead to less soluble copolymers which are not or only to a slight extent suitable to investigate their use as luminescent semiconducting ∼-conjugated materials in Organic Light-Emitting Diodes (OLEDs). Green organic light emitting devices based on COPO1, exhibiting no significant spectral evolution, have been demonstrated and showed improved hole-injection properties when compared to the ones using poly(dihexyl fluorene). The use of an additional PEDOT- PSS layer on the ITO anode has also been investigated leading to improved operating lifetime.
Light-Induced Enhancement of Rectification by Monolayer of Hexadecylquinolinium Tricyanoquinodimethanide Between Al Electrodes
Authors: Xu Tao , Metzger Robert M.
Published: May 2017

Photoinduced changes in electrical rectification were measured for a 5-layer Langmuir-Blodgett multilayer of hexadecylquinolinium tricyanoquinodimethanide, sandwiched between opaque and semitransparent Al electrodes, as a function of bias and wavelength. The current increases with the light intensity, but this may be simply due to heating of the sample, rather than to a photon-induced enhancement of the rectification.
Self-Organization of Nitrogen-Containing Polymeric Supramolecules in Thin Films
Authors: Knaapila Matti , Torkkeli Mika , Mäkelä Tapio , Horsburgh Lockhart , Lindfors Klas , Serimaa Ritva , Kaivola Matti , Monkman Andrew P. , Brinke Gerritten , Ikkala Olli
Published: May 2017

Rigid rod-like poly(2,5-pyridinediyl), semi-rigid polyaniline and flexible poly(4- vinylpyridine) are nitrogen-containing polymers that with selected amphiphilic oligomers form self-organized comb-shaped supramolecules due to protonation, hydrogen bonding and polar- nonpolar effects combined. Luminescent or conductive ordered structures are demonstrated in thin films. The structures are characterized using small-angle x-ray scattering (SAXS) and grazing-incidence small-angle x-ray scattering (GISAXS). The uniformity is studied using atomic force microscopy and scanning near-field optical microscopy (SNOM).
Low Driving Voltage of Organic Light-Emitting Diodes Using p-Doping Starburst Amine as Hole Transporter
Authors: Zhou Xiang , Nollau Andreas , Blochwitz Jan , Pfeiffer Martin , Fritz Torsten , Leo Karl
Published: May 2017

We investigate the electrical properties and the OLED application of controlledly doped amorphous hole transporters. Thin films of starburst amine, 4,4',4“-tris(N,N-diphenyl- amino) triphenylamine (TDATA), doped by a fully fluorinated form of tetracyano- quinodimethane (F4-TCNQ), are characterized in situ by temperature dependent conductivity and Seebeck measurements. The conductivity and hole concentration increase with dopant concentration and are many orders of magnitude higher than those of undoped material. OLED devices with the layer sequence ITO/TDATA(200 nm)/Alq3(65 nm)/LiF(1 nm)/Al were fabricated. The use of p-doped TDATA thin films with high bulk conductivity and hole concentration reduces the resistance of the devices and leads to a thinner space charge layer which facilitates injection of holes from the ITO anode.
Optically Induced Dynamics of Isocyanate Organic Films Containing Azobenzene Chromophores
Authors: Kim Mi Jeong , Seo Eun-Mi , Shin Yeong-Deuk , Lee Jae-Suk , Kim Dong-Yu
Published: May 2017

The photophysical formation of surface relief grating (SRG) was compared between isocyanate-based polymeric and non-polymeric thin films of low molecular weight organics containing azobenzene group. The non-polymeric film forms faster and more efficient surface grating formation than the polymeric film when exposed to an interference pattern of polarized Ar+ laser beams at 488 nm. However, the polymeric materials exhibited higher stability of SRG and orientation of azobenzenes than non-polymeric ones. The relation between the rate of photoinduced surface modulation and orientation of azobenzenes is discussed.
Influence of Device Configuration on External Quantum Efficiency in Organic Light-Emitting Devices
Authors: Yahiro Masayuki , Tsutsui Tetsuo
Published: May 2017

The external quantum efficiency in conventional double-layer type organic light-emitting devices with different layer thickness was carefully evaluated. From the measurements of luminance and emission spectra, external quantum efficiency (uncorrected) was obtained.

The correction due to the modification of spatial emission distribution was added from the measurements of spatial emission patterns. The external quantum efficiency, both uncorrected and corrected, showed strong dependency on the distance between a metal electrode and an emissive region. This variation was ascribed to the change of coupling-out efficiency. Independent experimental evaluations of apparent couple-out efficiency using an integrating sphere supported this interpretation.
Enhanced Blue Light Emission From Sexiphenyl Heterostructure EL Device
Authors: Ohmori Yutaka , Tsukagawa Takahisa , Kajii Hirotake
Published: May 2017

Enhanced electroluminescence (EL) from vapor deposited p-sexiphenyl (6p) layer has been observed utilizing heterostructure of p-sexiphenyl emissive layer and N,N'-diphenyl-N,N'-(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) hole transporting layer. The EL device consists of an indium-tin oxide (ITO) anode, a hole transporting layer, an emissive layer, and a magnesium containing silver cathode. A heterostructure device with 50 nm-thick p-sexiphenyl and 60 nm-thick TPD shows the enhanced emission from the p-sexiphenyl emissive layer. The electroluminescence from the device shows the emission peak centered at 420 nm. The p-sexiphenyl/TPD heterostructure device emits 2 orders of magnitude higher intensity than the conventional single layer of p-sexiphenyl device. The mechanism of enhanced emission from the heterostructure device has been discussed utilizing energy band diagrams of these materials.
Enhanced Electroluminescence of Urethane Containing Processable Polythiophene Derivative by Addition of Dye Molecules
Authors: Kaur Amarjeet , Cazeca Mario J. , Chittibabu Kethinni G. , Kumar Jayant , Tripathy Sukant K.
Published: May 2017

Organic electroluminescent (EL) diodes based on fluorescent dyes and conducting polymers have attracted the interest of researchers, mainly because of their emission in the visible region and for application to large area portable flat panel display devices, driven at low voltages. Therefore, for the development of higher efficiency polymer EL diodes, the optimal combination of the merits of organic fluorescent dye molecules with that of conjugated polymer is an important approach. We report electroluminescence studies of polymer light emitting diodes (p-LEDs) fabricated with poly[2-(3-thienyl)ethanol n-butoxy carbonylmethyl urethane] (PURET) and its composite with 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H pyran (DCM) dye. These materials have been chosen in view of the fact that PURET exhibits a small overlap between emission and absorption spectra whereas DCM has a good efficiency of trapping both electrons as well as holes. Polyaniline has been utilized as hole injecting layer whereas tris-8-hydroxyquinoline-aluminum as electron injecting layer. Enhanced electroluminescence with bright yellow color has been observed in p-LEDs by the addition of dye.
Reversible Thermochromic Transition between Different J-Aggregate States of Amphiphilic Merocyanine Dye Crystallites
Authors: Kato Noritaka , Shin Yasuaki , Uesu Yoshiaki
Published: May 2017

On the subphase, which contains Cd2+ and Mg2+ ions, two-dimensional (2D) J-aggregate crystallites of merocyanine dye molecules exhibit a thermochromic transition. The J-aggregate absorption band of the low (LT) and high temperature (HT) phases are located at 620 and 595 nm, respectively. In order to clarify the in-plane structure of the 2D J-aggregate crystallites, grazing incident X-ray diffraction measurements were performed on the Langmuir-Blodgett multi-layers which consisted of the monolayers of LT and HT phases. It was revealed that the in-plane arrangement of the dye molecules is slightly different in the J-aggregate crystallites of LT and HT phases.
Spectroelectrochemical Raman Study of two α,α'-End Capped Sexithiophenes: The Effect of the Introduction of a Polarisable Sulfur Atom in the Side Chain
Authors: Casado J. , Katz H. E. , Hernández V. , López Navarrete J.T.
Published: May 2017

In this paper, the vibrational FT-Raman spectra obtained at different anodic potentials chosen in the oxidation and reduction branches of the voltamperometric waves of two α,α'-sexithiophenes end capped with n-hexyl and n-thiohexyl groups are investigated. In order to analyze the evolution of the atomic charges and bonth lengths on going from the neutral to the doped species some theoretical calculations have been carried out.