bluuebunny/crossref_metadata_2025 huggingface dataset:
Encriptación de datos y avances en la digitalización notarial
Authors: Llopis Benlloch José Carmelo
Published: April 2019

Blockchain es una herramienta criptográfica muy prometedora que, combinada con otras tecnologías emergentes, puede modificar el modo en que algunos servicios jurídicos son prestados. Debemos valorar si los servicios de los notarios pueden ser uno de ellos, y en caso de que sí, cuándo y cómo podría adoptarse blockchain . En este proceso, debemos además identificar los puntos clave de nuestro sistema notarial y, si hay una herramienta mejor para hacerlos más fuerte, utilizarla, como hicimos con la firma electrónica. La pregunta que nos debemos hacer es si blockchain puede ser una de esas herramientas.
Experiencias. De facturas a dinero: revolución financiera y tecnológica para la liquidez corporativa
Authors: Ceruelo Carlos
Published: April 2019

A una breve explicación introductoria a las FinTech y al significado de los nuevos sistemas digitales de financiación de la cadena de suministro, le sigue una exposición de los beneficios concretos que reporta en el mundo de estos sistemas la tecnología implementada por el innovador servicio prestado desde Nettit. Se explica el mecanismo único de ejecución directa de pagos privados en cadena sobre un modelo SCF (Supply Chain Finance) , con una nueva tecnología algorítmica que permite convertir facturas en liquidez y realizar procesos eficientes e instantáneos de compensación de créditos.
Mirando al futuro. El papel de FinTech para el emprendimiento: colaboración universidad y empresa
Authors: Barrio Cruz Óscar del , Ibáñez Jiménez Javier W. , Menéndez Andrés Moisés
Published: April 2019

FinTech genera ríos de tinta física y, sobre todo, digital, en los últimos años, y especialmente en España desde 2016. En el plano de la práctica empresarial han aparecido miles y miles de empresas innovadoras o start-ups en todas las regiones del planeta. Se trata en este caso de impresas dedicadas a la innovación en distintos terrenos del sector financiero que, a través del uso de la tecnología digital, pretenden cubrir procesos concretos de negocio financiero (por ejemplo, pagos a distancia, crédito sin intermediarios, refinanciación con intermediados capturados digitalmente, asesoría financiera automatizada, información relacionada con las finanzas distribuida por vía telemática...) de una manera cualitativamente más ágil y eficiente que desempeñada por los operadores tradicionales (bancos, financieras, entidades de medios de pago...).
La democracia (liberal) sostenible como refuerzo de la teoría de la paz democrática
Authors: Abad Quintanal Gracia
Published: April 2019

En los últimos 10 años hemos asistido a un descenso de la confianza de los ciudadanos en la democracia. Este proceso, vinculado a la crisis económica, ha frenado el ritmo de democratización que vivía el mundo desde hace décadas. Si continua esta tendencia podría ponerse en peligro los axiomas de la Teoría de la Paz Democrática y convertir al mundo en un lugar aun menos pacífico. Para evitar este proceso la democracia debe atender no solo a la dimensión política sino también a la social, convirtiendo a la democracia en un sistema político más sostenible.
La pobreza energética en la Unión Europea y el Reino Unido
Authors: Larrea Basterra Macarena
Published: April 2019

La pobreza energética es una realidad en Europa a pesar de que haya países donde no se reconozca, hasta el punto de no contar con una definición para ella. Sin embargo, su identificación a nivel comunitario está avanzando y resulta conveniente avanzar hacia un mecanismo de medición homogéneo. El Reino Unido por su parte, podría considerarse líder en esta materia dada la involucración tanto del Gobierno Central como de las naciones en la medición de la pobreza energética y en el desarrollo de medidas y planes para su erradicación. La eficiencia energética se ha convertido en uno de los principales pilares de estos planes.
Evolución de la medición del riesgo financiero en los últimos 40 años: una panorámica con especial mención en la banca
Authors: Coronado Vaca María , Carabias López Susana
Published: April 2019

El objetivo de este artículo es ofrecer una panorámica de la evolución de la medición y gestión del riesgo financiero en los últimos 40 años, con especial mención a la banca. Tras una etapa basada en los principios de la Modern Portfolio Theory (MPT), hace 25 años se produce una revolución con la introducción del Value-at-Risk (VaR). Desde entonces, la introducción de nuevas medidas cuantitativas, con complejidad matemática creciente, no se ha detenido, en una interacción continua entre académicos, profesionales y reguladores, como respuesta a las sucesivas crisis financieras y bancarias. Entre ellas, destacan las medidas coherentes del riesgo (concretamente el Expected Shortfall), espectrales y basadas en expectiles. Se concluye que el VaR y el Expected Shortfall (ES) continúan siendo, a pesar de sus limitaciones, las dos medidas más utilizadas tanto desde el punto de vista interno de los bancos, como por parte del regulador y supervisor de su solvencia. Finalmente, se plantean algunas de las líneas de investigación en este campo que tratan de abordar los retos en el futuro de la medición del riesgo financiero en banca.
La irrupción de las finanzas conductuales
Authors: Martínez Morán Pedro César
Published: April 2019

La hipótesis de la racionalidad como elemento explicativo de la toma de decisiones de inversión es puesta en duda. Diversos autores incorporan premisas de la psicología y otras ciencias sociales que matizan el comportamiento de los agentes económicos. Las decisiones financieras son entendidas como procesos complejos, personales y sociales. Están sujetas al influjo del entorno, dirigidas por métodos de valoración subjetivos y prejuicios cognitivos, penalizadas por la falta de conocimiento y, sobre todo, influidas por la asimetría psicológica de las pérdidas respecto a las ganancias. Las finanzas conductuales irrumpen como paradigma descriptivo del comportamiento de los seres humanos cuando toman decisiones de inversión.
Sharp Singular Trudinger–Moser Inequalities Under Different Norms
Authors: Lam Nguyen , Lu Guozhen , Zhang Lu
Published: April 2019

The main purpose of this paper is to prove several sharp singular Trudinger–Moser-type inequalities on domains in

ℝ
N

{\mathbb{R}^{N}}

with infinite volume on the Sobolev-type spaces

D

N
,
q

⁢

(

ℝ
N

)

{D^{N,q}(\mathbb{R}^{N})}

,

q
≥
1

{q\geq 1}

, the completion of

C
0
∞

⁢

(

ℝ
N

)

{C_{0}^{\infty}(\mathbb{R}^{N})}

under the norm

∥

∇
⁡
u

∥

N

+

∥
u
∥

q

{\|\nabla u\|_{N}+\|u\|_{q}}

. The case

q
=
N

{q=N}

(i.e.,

D

N
,
q

⁢

(

ℝ
N

)

=

W

1
,
N

⁢

(

ℝ
N

)

{D^{N,q}(\mathbb{R}^{N})=W^{1,N}(\mathbb{R}^{N})}

) has been well studied to date. Our goal is to investigate which type of Trudinger–Moser inequality holds under different norms when q changes. We will study these inequalities under two types of constraint: semi-norm type

∥

∇
⁡
u

∥

N

≤
1

{\|\nabla u\|_{N}\leq 1}

and full-norm type

∥

∇
⁡
u

∥

N
a

+

∥
u
∥

q
b

≤
1

{\|\nabla u\|_{N}^{a}+\|u\|_{q}^{b}\leq 1}

,

a
>
0

{a>0}

,

b
>
0

{b>0}

. We will show that the Trudinger–Moser-type inequalities hold if and only if

b
≤
N

{b\leq N}

. Moreover, the relationship between these inequalities under these two types of constraints will also be investigated. Furthermore, we will also provide versions of exponential type inequalities with exact growth when

b
>
N

{b>N}

.
Aristotle on Secondary Substance
Authors: Mahlan John Robert
Published: April 2019

At the beginning of Categories 5, Aristotle distinguishes between two kinds of substance: primary substance and secondary substance. Primary substances include particular living organisms, inanimate objects, and their parts. Secondary substances are the species and genera of these. This distinction is unique to the Categories, which raises the question of why Aristotle treats species and genera as substances. I argue that Aristotle has two distinct reasons for doing so, and contrast my interpretation with recent alternatives. On my view, species and genera enjoy two kinds of fundamentality – ontological and epistemological – in virtue of which they warrant their status as substances.
Filling gaps or code choice? Code-switching across generations in colloquial Singapore Mandarin
Authors: Lee Cher Leng
Published: April 2019

Singapore is a multiracial, multicultural island nation; three quarters of its population is ethnic Chinese. This paper examines the phenomenon of code-switching between the younger generation and their parents, and grandparents, focusing on the English, Chinese dialect and Malay elements present in this variety of spoken Mandarin. The data is taken from university students who have recorded their conversations with their parents, grandparents, siblings and friends. Many of the older generation in their 70s still speak southern Chinese dialects such as Hokkien, Teochew, Cantonese, Hakka, and Hainanese as well as Bazaar Malay (which was alingua francawith Hokkien). Their spoken Mandarin consists of code-switching with these dialects. The middle generation in their 50s is the generation that is able to communicate both with the older generation and younger generation in the various languages. Their spoken Mandarin consists of English, dialects, and even some Malay. The younger generation in their 20s can hardly understand or speak these dialects as a result of the Speak Mandarin Campaign which was launched in 1979 to replace all dialects with Mandarin. As such, the younger generation’s spoken Mandarin consists mainly of English code-switched elements. This paper argues that code-switching takes place mainly due to convenience to fill in the gaps when younger speakers do not know the Mandarin equivalent of the words in certain domains, given the changes in language policies in the nation. In this case, it is not necessarily a choice of code but rather filling the gaps with the language that they know out of necessity.
Cannabis and amphetamine use and socio-ecological (proximal and distal) factors among school-going adolescents in four countries in the Caribbean and four countries in South America
Authors: Peltzer Karl , Pengpid Supa
Published: April 2019

The study aimed to assess the prevalence of cannabis and amphetamine use and socio-ecological (proximal and distal) factors among adolescents in eight countries of the Americas. We analysed cross-sectional survey data from 44,904 adolescents [mean age 14.6 years, standard deviation (SD) = 1.4] from Argentina, The Bahamas, Barbados, Belize, Bolivia, Chile, Peru and Trinidad and Tobago that participated in the Global School-Based Student Health Survey (GSHS) in 2011–2013. The prevalence of the past month’s cannabis use was 8.3% and lifetime amphetamine use was 3.0%. In adjusted mixed-effects logistic regression analysis older age, male gender, personal attributes (anxiety, suicidal ideation, current tobacco use, current alcohol use, school truancy and sexual risk behaviour) and environmental stressors (having been in a physical fight, hunger, being bullied) were positively and parental support and peer support were negatively associated with the past month’s cannabis and/or lifetime amphetamine use. Measures to prevent and control cannabis and amphetamine use in this adolescent population should include personal attributes (mental health, substance use, school truancy and sexual risk behaviour), environmental stressors and parental and peer support.
Effect of endoscope on the peristaltic transport of a couple stress fluid with heat transfer: Application to biomedicine
Authors: Ramesh K. , Devakar M.
Published: April 2019

In this investigation, we have studied the problem of peristaltic flow with heat transfer through the gap between coaxial inclined tubes where the inner tube is rigid and the outer tube has sinusoidal wave travelling down its wall. The problem has been formulated in cylindrical coordinate system. The equations governing the flow have been simplified under the long wavelength and low Reynolds number assumptions. The exact solution is obtained for the temperature profile. The perturbation solutions for the velocity and pressure gradient are obtained for small couple stress parameter. Pressure difference per wavelength and frictional forces on the tube walls have been computed numerically. Results are demonstrated for various flow parameters. The better pumping results occur in vertical tube, while less pumping is seen in horizontal tube. The size of trapped bolus is small in triangular wave as compared to other waves. The present study has a wide range of applications in bio-medical engineering like the transport phenomenon in peristaltic micro pumps.
Abstimmungen im Bundestag und in der Weimarer Republik: Gewissen oder Strategie?
Authors: Moldovanu Benny
Published: April 2019

In seiner Thünen-Vorlesung vor dem Verein für Socialpolitik im Herbst 2018 hat Benny Moldovanu das Abstimmungsverfahren im Bundestag und in der Weimarer Republik untersucht. Die Analysemethode basiert sowohl auf einer historisch-politischen Evaluation jedes einzelnen Falls als auch auf einer sehr präzisen spieltheoretischen Untersuchung unter Berücksichtigung der neuesten Fortschritte auf den Feldern von Mechanism Design, Social Choice und Informationsökonomie. Eine vergleichsweise einfache Theorie kann schon eine Menge bringen, um die Verwendung bestimmter gesetzgeberischer Verfahren zu erklären und deren Ergebnisse zu beschreiben und vorauszusagen.
Der Ausstieg aus der Kohle: alternativlos oder verantwortungslos?
Authors: Weimann Joachim
Published: April 2019

Der von der Kohlekommission beschlossene Ausstieg aus der Kohleverstromung in Deutschland wirft eine Reihe von Fragen auf. Wie kann die Versorgungssicherheit gewährleistet werden? Welchen Effekt wird der Ausstieg auf die Strompreise haben? Und wie werden sich die parallel dazu beschlossenen Maßnahmen zur Stärkung betroffener Kohlereviere auswirken? Nach Joachim Weimann gilt es indes vor allem, die klimapolitische Eignung des Instrumentes Kohleausstieg zu bewerten. Diese Bewertung muss nach seiner Analyse eher skeptisch ausfallen. Zudem gibt es einen besseren Weg: den Emissionshandel. Dieses Instrument interagiert erstens eng mit dem Kohleausstieg und wäre zweitens geeignet, eine netto höhere Kohlendioxid-Einsparung zu den halben Kosten zu realisieren.
Sharing of Cost Related Information Can Increase Consumer Welfare Under Risk-aversion
Authors: Mungan Murat C.
Published: April 2019

Existing literature suggests that the sharing of firm-specific information related to costs of production among Cournot competitors unambiguously reduces consumer welfare. This article shows that this result does not hold when at least one firm is risk-averse. Perhaps more importantly, if consumers are sufficiently risk-averse allowing information sharing leads to a Pareto improvement.
Changing shape according to strength: Evidence from root allomorphy in Greek
Authors: Revithiadou Anthi , Markopoulos Giorgos , Spyropoulos Vassilios
Published: April 2019

In this article we examine patterns of root allomorphy in Greek that involve vowel alternations and propose aGeneralized Non-linear Affixation(Bermúdez-Otero 2012) analysis according to which these alternations result from the competition between segments that belong, on the one hand, to the vocabulary items of roots and, on the other, to the exponents of functional heads (Voice/Aspect,n). More specifically, we claim that phonological entities have agradientdegree of presence in a structure, that is, are specified with a certain activation strength value underlyingly (Smolensky and Goldrick 2016). As a result, the surface realization of roots is determined by the relevant activation level of the exponents of functional heads they are eventually combined with. From all available exponents, the one that optimally complements the strength value of the vocabulary item of a given root will eventually surface. Our analysis is shown to be theoretically advantageous because it develops a strictly phonological account of allomorphy and, moreover, it captures the attested generalizations without resorting to extensive stem/span listing or to the application of phonologically unrestricted readjustment rules.
Zur Problematik der Ableitung in sozialwissenschaftlichen Aussagensystemen
Authors: Hummell Hans J.
Published: April 2019

Untersucht werden einige in den theoretisch-empirischen Sozialwissenschaften typische Formen von Argumenten im Hinblick auf die (meist implizit gelassenen) Deduktionsregeln. Dabei werden vier Arten von Aussagen - (a) Deterministische Wenn-Dann-Aussagen; (b) Deterministische Je-Desto-Aussagen; (c) Probabilistische Wenn-Dann-Aussagen; (d) Probabilistische Je-Desto-Aussagen - sowie zwei Klassen von Deduktionsregeln (basierend auf den Eigenschaften der Transitivität und Konjunktivität) behandelt. Problematisch sind nur Aussagen der Art (b), (c) und (d). Es wird die These vertreten, daß die meisten der in den Sozialwissenschaften vorgelegten „Argumente“, welche mit solchen Aussagen relativ komplizierter Struktur arbeiten, zur Ableitung jedoch nur für deterministische Wenn-Dann-Aussagen gültige Regeln verwenden, nicht korrekt sind. Zur Lösung wird generell vorgeschlagen, an Stelle einer durch ein technisches Vokabular ergänzten Wortsprache, der ausschließlich die elementare Logik zugrundeliegt, Sprachen mit reicherer logischer Struktur zu verwenden, d.h. zu formalisieren.

In Teil 1 werden zwei Eigenschaften deterministischer Je-Desto-Aussagen aufgezeigt: 1. Im Falle komplexer Wirkungsstrukturen mit Pfaden mit unterschiedlichen Vorzeichen führen „Deduktionen“ in der Wortsprache entweder zu Inkonsistenzen oder keinen nichttrivialen Konklusionen. 2. Bei Aussagen über soziale Kollektive, die durch „Aggregation“ aus Aussagen über Individuen gewonnen werden sollen, folgt bei Verwendung der Je-Desto-Form ebenfalls nichts Für Kollektive. - In Teil 2 sollen probabilistische Aussagen diskutiert werden.
Biocatalytic Synthesis of Polymeric Esters Used as Emulsifiers
Authors: Ortega-Requena S. , Serrano-Arnaldos M. , Montiel M. C. , Máximo M. F. , Bastida J. , Murcia Almagro M. D.
Published: April 2019

Polyglycerol polyricinoleate (PGPR) is a polymeric ester widely used as emulsifier in the food industry. In this work, PGPR biocatalytic synthesis was carried out in a onestep solvent-free enzymatic process using lipase CALB immobilized in Lewatit® Monoplus

MP 64 by adsorption. The optimal immobilization conditions were determined: initial

enzyme concentration of 13 mg of Lowry protein per mL phosphate buffer pH 7, and

ricinoleic acid as a support activator. An immobilized derivative with 35.93 ± 4.90 mg of

Lowry protein per g of dry support was obtained. It was used as a catalyst for PGPR

production in open air and vacuum batch reactors, and the results obtained showed that

only when the reaction equilibrium was shifted towards ester production by means of water removal, the PGPR produced fulfilled the European legislation (acid value ≤ 6 mg of KOH per g of product).
Enhanced Removal of Cr(VI) from Aqueous Solutions Using Poly(Pyrrole)-g-Poly(Acrylic Acid-co- Acrylamide)/Fe3O4 Magnetic Hydrogel Nanocomposite Adsorbent
Authors: Hosseinzadeh Hossein , Tabatabai Asl M. M.
Published: April 2019

In the present work, the structural characterization and chromium adsorption behavior
of a novel poly(pyrrole)-based magnetic hydrogel nanocomposite (MHN) is reported. This product was prepared using free-radical copolymerization of pyrrole (Py), acrylic acid (AA) and acrylamide (AM) monomers, and subsequent in situ synthesis of magnetic Fe3O4 nanoparticles. The structure of MHNs was then characterized by FTIR, SEM, TEM, XRD, UV-Vis and VSM techniques, and a mechanism for the preparation of MHNs is also proposed. The maximum Cr(VI) adsorption capacity (208 mg g–1) was achieved under the optimum conditions that were found to be: AA = 0.25 mol L–1, AM = 1.2 mol L–1, agitation time = 90 min, solution pH = 1.0, ion concentration = 100 mg L–1, adsorbent dose = 50 mg, and temperature = 65 °C. Further, the calculated values of the thermodynamic parameters (ΔH° = 31.33kJ mol–1, ΔS° = 105.67 J K–1 mol–1, ΔG° = –61.33 kJ mol–1) revealed that ion adsorption is a spontaneous and endothermic process. In general, the results indicated that the synthesized MHNs with specific properties can be used in wastewater treatment applications.
Software Sensors for Biomass Concentration Estimation in Filamentous Microorganism Cultivation Process
Authors: Hrnčiřík Pavel , Moucha Tomáš , Mareš Jan , Náhlík Jan , Janáčová Dagmar
Published: April 2019

In this study, the potential of two software sensors for on-line estimation of biomass

concentration during cultivation of filamentous microorganisms is examined. The first

sensor is based on common bioreactor off-gas analyses, and uses the assumption of the biomass concentration linear dependence on the square root of cumulative O2 consumption. Parameters of the semi-empirical data-driven software sensor based on off-gas analysis were calculated from experimental cultivation data using linear regression. The second sensor is based on biocalorimetry, i.e., the on-line calculation of metabolic heat flux from general enthalpy balance of the bioreactor. The software sensor based on biocalorimetry thus essentially represents a model-driven approach, making use of a fundamental process model based on the enthalpy balance around the bioreactor. This approach has been combined with the experimental identification of the specific biomass heat production, which represents the main process-specific parameter of the software sensor based on biocalorimetry. For this sensor, the accuracy requirements on the process variable on-line measurements were also analysed. The experimental data from the pilot-scale antibiotics Nystatin production by a bacterium Streptomyces noursei were used to calculate the specific bioprocess heat production value using linear regression. The achieved results enabled us to propose a new on-line indicator calculated as the ratio of the outputs of both sensors, which can serve as a timely warning of the risk of undesired nutritional conditions of a culture characterized as underfeeding.
The Role of Redox Potential Measurement in Oak Barrel Wine Maturation
Authors: Berovič Marin , Nemanič Julij
Published: April 2019

Redox potential measurement was efficiently used for monitoring the two-year maturation process of cultivar Blau Fränkisch wine in 225-L oak barrels. Redox potential of maturing wine was measured at six levels from the top to the bottom of the barrel. During the process of wine maturation, the formation and heterogeneity of redox layers, as well as the formation of various oxidoreductive zones were indicated. The end of barrel maturation process was represented with homogeneity of all redox zones where no differences in all measured levels were indicated.
Study on Sustainable Recovery and Extraction of Polyhydroxyalkanoates (PHAs) Produced by Cupriavidus necator Using Waste Glycerol for Medical Applications
Authors: Gahlawat Geeta , Soni Sanjeev Kumar
Published: April 2019

The current study shows that Cupriavidus necator has the ability to grow on waste

glycerol as carbon source, and can synthesize a highly thermostable copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate). Batch cultivation on waste glycerol showed accumulation of 6.76 g L–1 biomass containing 4.84 g L–1 poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer with 3-hydroxyvalerate content of 24.6 mol%. A novel recovery strategy was developed for the extraction of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer from Cupriavidus necator using recyclable solvents, i.e., propylene carbonate, butyl acetate, isoamyl alcohol, and ethyl acetate. Propylene carbonate demonstrated the recovery efficiency of 90 % and polymer purity of 95 %, at 120 °C after 30 min. Ethyl acetate exhibited a higher efficiency than butyl acetate in terms of recovering the copolymer from cells. Ethyl acetate extraction demonstrated a recovery yield of 96 % and purity of 93 % at 100 °C. Efficacy of an anionic surfactant, linear alkylbenzene sulfonic acid (LAS), was also tested for extraction, and it showed maximum yield of 84 % and purity of 90 % at 80 °C and pH 5.0. Extraction of copolymer using these solvents could help in replacing generally used chlorinated toxic solvents, such as 1,2 dichloroethane and chloroform. Further, GPC, TGA and DSC analysis revealed that the thermo-physical properties were not significantly affected by the extraction method. However, the molecular weight distribution of the polymer showed a variation depending on the type of solvent used for extraction. Subsequently, endotoxins were removed efficiently to less than 5 EU g–1 of copolymer using alkali at optimized conditions of 6 h digestion time and 2.5 N NaOH concentration for medical applications.
Local gastric RAAS inhibition improves gastric microvascular perfusion in dogs
Authors: Truse Richard , Voß Fabian , Herminghaus Anna , Schulz Jan , Weber Andreas P M , Mettler-Altmann Tabea , Bauer Inge , Picker Olaf , Vollmer Christian
Published: April 2019

During circulatory shock, gastrointestinal microcirculation is impaired, especially via activation of the renin-angiotensin-aldosterone system. Therefore, inhibition of the renin-angiotensin-aldosterone system might be beneficial in maintaining splanchnic microcirculation. The aim of this study was to analyze whether locally applied losartan influences gastric mucosal perfusion (µflow, µvelo) and oxygenation (µHbO2) without systemic hemodynamic changes. In repetitive experiments six anesthetized dogs received 30 mg losartan topically on the oral and gastric mucosa during normovolemia and hemorrhage (−20% blood volume). Microcirculatory variables were measured with reflectance spectrometry, laser Doppler flowmetry and incident dark field imaging. Transpulmonary thermodilution and pulse contour analysis were used to measure systemic hemodynamic variables. Gastric barrier function was assessed via differential absorption of inert sugars. During normovolemia, losartan increased gastric µflow from 99 ± 6 aU to 147 ± 17 aU and µvelo from 17 ± 1 aU to 19 ± 1 aU. During hemorrhage, losartan did not improve µflow. µvelo decreased from 17 ± 1 aU to 14 ± 1 aU in the control group. Application of losartan did not significantly alter µvelo (16 ± 1 aU) compared to the control group and to baseline levels (17 ± 1 aU). No effects of topical losartan on macrohemodynamic variables or microcirculatory oxygenation were detected. Gastric microcirculatory perfusion is at least partly regulated by local angiotensin receptors. Topical application of losartan improves local perfusion via vasodilation without significant effects on systemic hemodynamics. During mild hemorrhage losartan had minor effects on regional perfusion, probably because of a pronounced upstream vasoconstriction.
Variaciones previsibles del ingreso y su efecto sobre el consumo. Un análisis para la economía colombiana
Authors: Ronderos Nicolas
Published: April 2019

En este trabajo se realiza una revisión de las teorías que explican los determinantes del consumo de los hogares. Con base en variaciones estacionales del ingreso de la economía colombiana se realiza una estimación del ingreso previsible. Utilizando un modelo VAR(p) se encuentra evidencia a favor de la relación entre ingreso previsible hacia el consumo de los hogares, se apoya la llamada hipótesis de exceso de sensibilidad del consumo (Flavin, 1981). Se concluye que para la economía colombiana los consumidores no incorporan toda la información disponible para establecer su senda de gastos. Por lo cual, las variaciones previsibles en el ingreso disponible, causadas por cambios en el nivel de impuestos o subsidios, generan variaciones adicionales en las compras agregadas de los hogares.
Caracterización de los negocios barriales en los barrios del borde oriental de la comuna 10 de Medellín
Authors: Londoño Toro Carlos Mario
Published: April 2019

Esta investigación se diseñó con el objetivo de describir las características socioeconómicas de los negocios barriales del sector de la ciudad de Medellín, en el estudio se definieron 5 barrios: Los Ángeles, Boston, Bomboná N.° 1, Las Palmas y San Diego; a partir de la aplicación de un instrumento de encuesta. Las dimensiones de análisis involucradas en el estudio fueron: características generales de los negocios, la cual agrupa las tipologías de negocios, estrato socioeconómico y condiciones locativas; en segundo lugar, se analizaron procesos comerciales relacionados con el tamaño de la oferta comercial y relacionamiento con los clientes; la tercera parte estudió los procesos financieros relacionados con la generación de ingresos y tenencia de productos financieros; la cuarta parte caracterizó el talento humano en cuanto a número y composición familiar, así como las condiciones sociodemográficas de los microempresarios; la última dimensión se enfocó en el estudio de los procesos de formalidad o informalidad del negocio a partir de la tenencia de cámara de comercio, acceso a seguridad social y manejo de procesos contables. A partir de los resultados de 1582 encuestas aplicadas, se concluyó que los negocios barriales más representativos son aquellos que proveen bienes y servicios básicos para los hogares, son negocios que tienen debilidades estructurales relacionadas con escasa oferta comercial, baja capacidad de generar ingresos, tamaño reducido y operación bajo grados de informalidad relativamente altos.
Redes que se construyen dentro de la comunidad indígena Embera desplazada en Bogotá (Colombia): caso del alojamiento Embera en Santafé
Authors: Sánchez Delgado María Camila
Published: April 2019

¿Cuáles son las redes con que cuentan las familias indígenas en situación de desplazamiento en Bogotá (Colombia), qué sentidos construyen sobre ellas y cómo contribuyen a su vida cotidiana? Son las preguntas en las que se basa esta investigación que busca, en primera instancia, identificar y observar las redes ya existentes y aquellas que un grupo de familias indígenas tejen en su condición de desplazamiento para reconocer los sentidos que construyen sobre estas. Se lograron evidenciar lo sentidos de las redes que están dentro de esta comunidadindígena desplazada, y algunas otras que toman fuerza en el desarrollo de su cotidianidad
Contribución de las mujeres en las revistas de sociología colombianas 1959-2000
Authors: García Jurado Mayra Alejandra
Published: April 2019

La contribución de las mujeres en la producción de conocimiento científico ha sido un fenómeno poco reconocido en la comunidad académica, en el caso de la sociología se menciona de forma constante el trabajo realizado por los “padres fundadores” y poco se habla del desarrollo del conocimiento sociológico realizado por mujeres, a pesar de que sus contribuciones se evidencian desde el siglo XIX; se pretende con el presente estudio realizar un análisis documental y bibliométrico de la producción científica de las mujeres sociólogas colombianas entre los años 1959 y 2000, tomando como referencia las dos únicas instituciones nacionales (Universidad Santo Tomás y Universidad Nacional de Colombia) que realizaron publicaciones y permanecieron activas en dicho periodo. Se encuentra que existe poca representación de las mujeres en la producción sociológica, sin embargo estuvieron activas en la totalidad del periodo de tiempo delimitado, siendo su mayor contribución el desarrollo conceptual de la disciplina.
Kaip meniniai tyrimai gali padėti atsakyti į auditorijų įsitraukimo klausimus?
Authors: Balevičiūtė Ramunė , Sokolovaitė Milda
Published: April 2019

[full article and abstract in Lithuanian; abstract in English]

There is an increasing interest in audience engagement and the possibilities of its research in contemporary performance practice. One of the possibilities that can be used in conducting such a study is a practice-led type of research, commonly known as artistic research. The distinguishing quality of this type of research, which has been finding its place in academia throughout the last few decades, is that it uses artistic practice to generate new knowl­edge. This article analyzes the possibilities of such research from the point of view of the aesthetics of performativity, which focuses on works that explore audience engagement rather than representation. While analyzing examples of performance and theater art works, it tackles the issue of how artistic research can assist in answering audience engagement questions.
Chemical industry and value-added trade – A comparative study on Hungary and Poland
Authors: Folfas Pawel , Udvari Beáta
Published: April 2019

Nowadays, global production networks (GPN) and global value chains (GVC) play an important role in the world economy intensifying the trade and production networks and resulting in products having value-added in different countries. The analysis of how many intermediate products a country imports in order to produce a product and of how many products a country exports to another country in order to produce new products draws the attention to value-added trade. In the present study, we compare the Hungarian and Polish value-added trade of chemicals and chemical products. We use the OECD-WTO data of value-added trade, which is based on an input-output table. By calculating numerous indices, we reveal that the domestic value-added of chemicals and chemical products in the two countries was relatively low and should be increased by adequate economic policy.
The impact of bacterial cultures on changes in contents of PCB congeners in yoghurt and bioyoghurt
Authors: Witczak Agata , Mituniewicz-Małek Anna
Published: April 2019

Persistent organic pollutants, including polychlorinated biphenyls, may pose serious health hazard to consumers due to their lipophilic character as well as their high stability and toxicity. They are common in milk and also in dairy products. Therefore, to provide consumers with
food of the lowest possible level of pollutants, it is important to estimate the influence of technological processes in milk and dairy products manufacture on changes in the contents of toxic PCB congeners. The PCB congeners content was determined using gas chromatography with mass spectrometry. Our study showed that yoghurt starter cultures turned
out to be an effective tool in decreasing the toxicity equivalent of yoghurts. The presence of additional two starter cultures of bacteria Lactobacillus acidophilus and Bifidobacterium sp. In the A.B.T. bioyoghurt starter culture was most likely the reason of the highest efficiency of this culture to reduce the value of toxicity equivalent (TEQPCB) in bioyoghurts (reduction by nearly 50 %). However, none of the
four tested starter cultures of yoghurts and bioyoghurts ensured complete biodegradation of any of the tested PCB congeners. These cultures contributed to a distinct reduction in contents of the PCB congeners in the finished products and, simultaneously, to a significant
increase in PCB 28 and PCB 77, which may result from the degradation of
more chlorinated congeners. In consequence it can improve the quality of fermented dairy products.
Potential of bovine kappa - casein as biomarker for detection of adulteration of goat’s milk with cow’s milk
Authors: Jamnik Polona , Volk Helena , Ogrinc Nives , Jeršek Barbara
Published: April 2019

Using two-dimensional (2-D) electrophoresis it was shown that bovine kappa-casein could be an appropriate biomarker of adulteration of goat’s
milk with cow’s milk not only in raw milk, but also for milk thermally processed by pasteurization or treated with ultra-high-temperature. The presence of cow’s milk in goat’s milk was detected at level of 2 %. Furthermore, position of bovine kappa-casein spots on 2-D gels remained unchanged even with samples from two different geographical origins, Belgium and Slovenia. These results show that neither thermal processing
nor different geographical area seem to affect the position of bovine kappa-casein spots on 2-D gels.
Improved Characteristics of InGaN Multi-Quantum-Well Laser Diodes Grown on Laterally Epitaxially Overgrown GaN on Sapphire
Authors: Hansen Monica , Fini Paul , Zhao Lijie , Abare Amber , Coldren Larry A. , Speck James S. , DenBaars Steven P.
Published: April 2019

InGaN multi-quantum-well laser diodes have been fabricated on fully-coalesced laterally epitaxially overgrown (LEO) GaN on sapphire. The laterally overgrown ‘wing’ regions as well as the coalescence fronts contained few or no threading dislocations. Laser diodes fabricated on the low-dislocation-density wing regions showed a reduction in threshold current density from 8 kA/cm2 to 3.7 kA/cm2 compared the those on the high-dislocation ‘window’ regions. Laser diodes also showed a two-fold reduction in threshold current density when comparing those on the wing regions to those fabricated on conventional planar GaN on sapphire. The internal quantum efficiency also improved from 3% for laser diodes on conventional GaN on sapphire to 22% for laser diodes on LEO GaN on sapphire.
Pendeo-epitaxial Growth and Characterization of GaN and related Materials on 6H-SiC(0001) and Si(111) Substrates
Authors: Davis Robert F. , Gehrke T. , Linthicum K.J. , Zheleva T. S. , Rajagopal P. , Zorman C. A. , Mehregany M.
Published: April 2019

Discrete and coalesced monocrystalline GaN and AlxGa1−xN layers grown via Pendeoepitaxy (PE) [1] originated from side walls of GaN seed structures containing SiNx top masks have been grown via organometallic vapor phase deposition on GaN/AlN/6HSiC(0001) and GaN(0001)/AlN(0001)/3C-SiC(111)/Si(111) substrates. Scanning and transmission electron microscopies were used to evaluate the external microstructures and the distribution of dislocations, respectively. The dislocation densities in the PE grown films was reduced by at least five orders of magnitude relative to the initial GaN seed layers. Tilting in the coalesced GaN epilayers was observed via X-ray diffraction. A tilt of 0.2° was confined to areas of mask overgrowth; however, no tilting was observed in the material suspended above the SiC substrate. The strong, low-temperature PL band-edge peak at 3.45 eV with a FWHM of 17 meV was comparable to that observed in PE GaN films grown on 6H-SiC(0001). The band-edge in the GaN grown on AlN(0001)/SiC(111)Si(111) substrates was shifted to a lower energy by 10 meV, indicative of a greater tensile stress.
Mass Transport, Faceting and Behavior of Dislocations in GaN
Authors: Nitta S. , Kashima T. , Kariya M. , Yukawa Y. , Yamaguchi S. , Amano H. , Akasaki I.
Published: April 2019

The behavior of threading dislocations during mass transport of GaN was investigated in detail by transmission electron microscopy. Mass transport occurred at the surface. Therefore, growing species are supplied from the in-plane direction. The behavior of threading dislocations was found to be strongly affected by the mass transport process as well as the high crystallographic anisotropy of the surface energy of the facets particular to GaN.
Polarity Determination for Mocvd Growth of GaN on Si(111) by Convergent Beam Electron Diffraction
Authors: Zhao L. , Marchand H. , Fini P. , Denbaars S. P. , Mishra U. K. , Speck J. S.
Published: April 2019

The polarity of laterally epitaxially overgrown (LEO) GaN on Si(111) with an AlN buffer layer grown by MOCVD has been studied by convergent beam electron diffraction (CBED). The LEO GaN was studied by cross-section and plan-view transmission electron microscopy (TEM). The threading dislocation density is less than 108cm−2and no inversion domains were observed. CBED patterns were obtained at 200 kV for the <100> zone. Simulation was done by many-beam solution with 33 zero-order beams. The comparison of experimental CBED patterns and simulated patterns indicates that the polarity of GaN on Si(111) is Ga face.
Integration of PLZT and BST Family Oxides with GaN
Authors: Osinsky Andrei V. , Fuflyigin Vladimir N. , Wang Feiling , I.Vakhutinsky Peter , E.Norris Peter
Published: April 2019

Recent advances in the processing of complex-oxide materials has allowed us to monolithically grow ferroelectrics of lead lanthanum zirconate titanate (PLZT) and barium strontium titanate (BST) systems on a GaN/sapphire structure. High quality films of PLZT and BST were grown on GaN/c-Al2O3 in a thickness range of 0.3-5 µm by a solgel technique. Field-induced birefringence, as large as 0.02, was measured from a PLZT layer grown on a buffered GaN/sapphire structure. UV illumination was found to result in more symmetrical electrooptic hysteresis loop. BST films on GaN demonstrated a low frequency dielectric constant of up to 800 with leakage current density as low as 5.5⋅10−8A/cm2.
Surface Morphology of GaN: Flat versus Vicinal Surfaces
Authors: Xie M.H. , Seutter S.M. , Zheng L.X. , Cheung S.H. , Ng Y.F. , Wu Huasheng , Tong S.Y.
Published: April 2019

The surface morphology of GaN films grown by molecular beam epitaxy (MBE) is investigated by scanning tunneling microscopy (STM). A comparison is made between flat and vicinal surfaces. The wurtzite structure of GaN leads to special morphological features such as step pairing and triangularly shaped islands. Spiral mounds due to growth at screw threading dislocations are dominant on flat surfaces, whereas for vicinal GaN, the surfaces show no spiral mound but evenly spaced steps. This observation suggests an effective suppression of screw threading dislocations in the vicinal films. This finding is confirmed by transmission electron microscopy (TEM) studies. Continued growth of the vicinal surface leads to step bunching that is attributed to the effect of electromigration.
Effect of the Doping and the Al Content on the Microstructure and Morphology of Thin AlxGa1−xN Layers Grown by MOCVD
Authors: Mazur J.H. , Benamara M. , Liliental-Weber Z. , Swider W. , Washburn J. , Eiting C.J. , Dupuis R. D.
Published: April 2019

AlxGa1−xN {x=30% (doped and undoped), 45% (doped)} thin films were grown by MOCVD on ∼2 μm thick GaN layer using Al2O3 substrate. These films were designed to be the active parts of HFETs with nsμ product of about 1016(Vs)-1. The layers were then studied by means of transmission electron microscopy (TEM) techniques. In this paper, it is shown that the AlxGa1−xN layer thickness was non-uniform due to the presence of V-shaped defects within the AlxGa1−xN films. The nucleation of these V-shaped defects has taken place about 20 nm above the AlxGa1−xN/GaN interface. Many of these V-shaped defects were associated with the presence of the threading dislocations propagating from the GaN/Al2O3 interface. We show that the density of these V-shaped defects increases with the doping level and also with the Al mole fraction in the films. The formation mechanism of the V-shaped defects seems to be related to the concentration of dopants or other impurities at the ledges of the growing film. This suggestion is supported by high resolution TEM analysis. The growth front between the V-shaped defects in the lower Al concentration thin films was planar as compared with the three-dimensional growth in the doped, higher Al concentration film. This interpretation of the origin of the V-shaped defects is consistent with the observed lowering of the Schottky barrier height in n-doped AlGaN/Ni Schottky diodes.
Efficient Acceptor Activation in AlxGa1−xN/GaN Doped Superlattices
Authors: Goepfert I. D. , Schubert E. F. , Osinsky A. , Norris P. E.
Published: April 2019

Mg-doped superlattices consisting of uniformly doped AlxGa1−xN and GaN layers are analyzed by Hall-effect measurements. Acceptor activation energies of 70 meV and 58 meV are obtained for superlattice structures with an Al mole fraction of x = 0.10 and 0.20 in the barrier layers, respectively. These energies are significantly lower than the activation energy measured for Mg-doped GaN thin films. At room temperature, the doped superlattices have free hole concentrations of 2 × 1018 cm−3 and 4 × 1018 cm−3 for x = 0.10 and 0.20, respectively. The increase in hole concentration with Al content of the superlattice is consistent with theory. The room temperature conductivity measured for the superlattice structures are 0.27 S/cm and 0.64 S/cm for an Al mole fraction of x = 0.10 and 0.20, respectively.
MOVPE Growth of Quaternary (Al,Ga,In)N for UV Optoelectronics
Authors: Han Jung , Figiel Jeffrey J. , Petersen Gary A. , Myers Samuel M. , Crawford Mary H. , Banas Michael A. , Hearne Sean J.
Published: April 2019

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.
Electrical Measurements in GaN: Point Defects and Dislocations
Authors: Look David C. , Fang Zhaoqiang , Polenta Laura
Published: April 2019

Defects can be conveniently categorized into three types: point, line, and areal. In GaN, the important point defects are vacancies and interstitials; the line defects are threading dislocations; and the areal defects are stacking faults. We have used electron irradiation to produce point defects, and temperature-dependent Hall-effect (TDH) and deep level transient spectroscopy (DLTS) measurements to study them. The TDH investigation has identified two point defects, an 0.06-eV donor and a deep acceptor, thought to be the N vacancy and interstitial, respectively. The DLTS study has found two point-defect electron traps, at 0.06 eV and 0.9 eV, respectively; the 0.06-eV trap actually has two components, with different capture kinetics. With respect to line defects, the DLTS spectrum in as-grown GaN includes an 0.45-eV electron trap, which has the characteristics of a dislocation, and the TDH measurements show that threading-edge dislocations are acceptor-like in n-type GaN. Finally, in samples grown by the hydride vapor phase technique, TDH measurements indicate a strongly n-type region at the GaN/Al2O3 interface, which may be associated with stacking faults. All of the defects discussed above can have an influence on the dc and/or ac conductivity of GaN.
Pulsed-laser-deposited AlN films for high-temperature SiC MIS devices
Authors: Vispute R. D. , Patel A. , Baynes K. , Ming B. , Sharma R. P. , Venkatesan T. , Scozzie C. J. , Lelis A. , Zheleva T. , Jones K. A.
Published: April 2019

We report on the fabrication of device-quality AlN heterostructures grown on SiC for high-temperature electronic devices. The AlN films were grown by pulsed laser deposition (PLD) at substrate temperatures ranging from 25 °C (room temperature) to 1000 °C. The as-grown films were investigated using x-ray diffraction, Rutherford backscattering specttroscopy, ion channeling, atomic force microscopy, and transmission electron microscopy. The AlN films grown above 700 °C were highly c-axis oriented with rocking curve FWHM of 5 to 6 arc-min. The ion channeling minimum yields near the surface region for the AlN films were ∼2 to 4%, indicating their high degree of crystallinity. TEM studies indicated that AlN films were epitaxial and single crystalline in nature with a large number of stacking faults as a results of lattice mismatch and growth induced defects. The surface roughness for the films was about 0.5 nm, which is close to the unit cell height of the AlN. Epitaxial TiN ohmic contacts were also developed on SiC, GaN, and AlN by in-situ PLD. Epitaxial TiN/AlN/SiC MIS capacitors with gate areas of 4 * 10−4 cm2 were fabricated, and high-temperature current-voltage (I-V) characteristics were studied up to 450 °C. We have measured leakage current densities of low 10−8 A/cm2 at room temperature, and have mid 10−3 A/cm2 at 450°C under a field of 2 MV/cm.