bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel study of the morphology and effective density of externally mixed black carbon aerosols in ambient air using a size-resolved single-particle soot photometer (SP2)
Authors: Wu Yunfei , Xia Yunjie , Huang Rujin , Deng Zhaoze , Tian Ping , Xia Xiangao , Zhang Renjian
Published: December 2018

Abstract. The morphology of externally mixed black carbon (extBC) aerosols, an important factor affecting radiative forcing, was studied by a tandem method coupling a differential mobility diameter (DMA) with a single-particle soot photometer (SP2). Ambient particles were selected by the DMA, and the size-resolved extBC particles were distinguished from those of a thick coating (internally mixed) and quantified by the SP2. Time differences between the DMA size selection and the SP2 measurement were processed previously, as well as the effects of multicharged particles. Based on the mass-mobility relationship, the fractal dimension of the extBC particles was obtained, with a value of 2.36 ± 0.04. This value is comparable with those of diesel exhaust particles, implying a predominant contribution of vehicle emissions to the ambient extBC in urban Beijing. The effective densities (ρeff) of the extBC in the mobility diameter range of 140–750 nm were also derived, with values gradually decreasing from 0.34 g cm−3 at 140–160 nm to 0.12 g cm−3 at 700 nm. The ρeff values were generally lower than those measured using the DMA-aerosol particle mass analyzer (APM) system. This was most likely due to the lower BC masses determined by the SP2 compared to those from the APM, since the SP2 measured the mass of pure refractory BC instead of the entire BC aggregate consisting of both refractory BC and nonrefractory components measured by the APM.
High accuracy UAV photogrammetry of ice sheet dynamics with no ground control
Authors: Chudley Thomas R. , Christoffersen Poul , Doyle Samuel H. , Abellan Antonio , Snooke Neal
Published: December 2018

Abstract. Unmanned Aerial Vehicles (UAVs) and Structure from Motion with Multi-View Stereo (SfM-MVS) photogrammetry are increasingly common tools for geoscience applications, but final product accuracy can be significantly diminished in the absence of a dense and well-distributed network of ground control points (GCPs). This is problematic in inaccessible or hazardous field environments, including highly crevassed glaciers, where implementing suitable GCP networks would be logistically difficult if not impossible. To overcome this challenge, we present an alternative geolocation approach known as GNSS-supported aerial triangulation (GNSS-AT). Here, an on-board carrier-phase GNSS receiver is used to determine the location of photo acquisitions using kinematic differential carrier-phase positioning. The camera positions can be used as the geospatial input to the photogrammetry process. We describe the implementation of this method in a low-cost, custom-built UAV, and apply the method in a glaciological setting at Store Glacier in West Greenland. We validate the technique at the calving front, achieving topographic uncertainties of ±0.07 m horizontally and ±0.14 m vertically when flying at an altitude of ~ 450 m a.s.l. This compares favourably with previous GCP-derived uncertainties in glacial environments, and allowed us to apply the SfM-MVS photogrammetry at an inland study site where ice flows at 2 m day−1 and where stable ground control is not available. Here, we were able to produce, without the use of GCPs, the first UAV-derived velocity fields of an ice sheet interior. Given the growing use of UAVs and SfM-MVS in glaciology and the geosciences, GNSS-AT will be of interest to those wishing to use UAV photogrammetry to obtain high-precision measurements of topographic change in contexts where GCP collection is logistically constrained.
Relación palabra-gráfico en un género profesional de la economía: el Informe Mensual de Estadísticas Monetarias y Financieras
Authors: Molina Marco , Vásquez-Rocca Liliana , Parodi Giovanni
Published: December 2018

Los estudios desde una perspectiva multimodal, como nuevo paradigma, implican que la investigación debe contemplar que los significados no sólo surgen a partir de las palabras, sino que deben considerarse todos los artefactos multisemióticos presentes en un texto, por ejemplo, gráficos y tablas. Los sistemas semióticos se han desarrollado, históricamente, en una sociedad, por lo tanto, su uso es situado. Por otro lado, los estudios sobre descripción de géneros discursivos se han centrado preferentemente en los académicos y, en menor medida, en los géneros profesionales. Buscando aportar a este vacío, la presente investigación describe la forma en que se construyen los significados en el género profesional de la economía denominado Informe Mensual de Estadísticas Monetarias y Financieras (IMEMF). Para lograr este objetivo, se utilizó una metodología cualitativa centrada en la descripción complementaria de tres análisis: organización retóricofuncional, artefactos multisemióticos y relaciones intersemióticas. Estos análisis, de forma integrada, permitieron observar las características multisemióticas que presenta el IMEMF, logrando así evidenciar los sistemas semióticos que intervienen en la construcción de significados. Los resultados revelan que los sistemas preponderantes en este género son el sistema gráfico-visual en conjunto con el sistema verbal y que su modo de organización discursiva predominante es el explicativo.
Características interaccionales de algunos marcadores secuenciales del español: un estudio conversacional de partículas lingüísticas
Authors: Vázquez Carranza Ariel
Published: December 2018

El presente artículo utiliza datos provenientes de conversaciones cotidianas y aplica el método del análisis conversacional para reportar algunas características interaccionales de seis partículas lingüísticas (no, pues, oye, o sea, ah y ay) o marcadores secuenciales, como se les define aquí. Los marcadores secuenciales tienen una función deíctica y de inicio, i.e., hacen referencia al habla anterior o bien inician una nueva actividad interaccional. Por sí mismos, los marcadores constituyen unidades de construcción de turno ya que proyectan momentos pertinentes para la transición del turno. Los marcadores realizan y constituyen acciones sociales interaccionales. El estudio conversacional de estos elementos lingüísticos muestra aspectos lingüístico-culturales de los hablantes. Se sugiere que este tipo de partículas lingüísticas puede ser parte de la “mecánica” universal de la interaccional humana.
A linguagem e a vida: reflexões acerca de língua e literatura
Authors: Neumann Daiane
Published: December 2018

O presente texto objetiva apresentar uma leitura do capítulo “Vista d’olhos sobre o desenvolvimento da linguística”, de Émile Benveniste, publicado em Problemas de Linguística Geral I. Essa reflexão busca atentar para a particularidade da leitura feita pelo linguista acerca do pensamento saussuriano, bem como para o que propõe Benveniste, enquanto sucessor dessa linguística já existente. Na segunda parte do texto, são apresentadas reflexões que envolvem língua e literatura e que se propõem como uma continuidade do pensamento benvenistiano, sustentadas, em grande parte, pela poética do discurso de Henri Meschonnic.
The Influence of E-Commerce in Changing Competition in Regulated Industries: An Analysis in the Italian Sports Betting Market
Authors: Calvosa Paolo
Published: December 2018

The effect of the Internet and e-commerce on industry competition has been widely discussed in economic-managerial literature. Most of the studies focused on the analysis of the impact of Internet technologies on specific industry structural factors – in particular on sectoral price levels –, but no sufficient empirical evidence based on overall industry change is yet available. The aim of this work is to analyze the influence of e-commerce on the transformation of the industrial structure and competition in a regulated market, that of Italian sports betting. This market, because the effect of a process of legalization of on-line sports betting that started in 2006, has been interested by a continuous shift of purchases of sport bets, ranging from the traditional sales channels to digital ones. This has contributed in creating an on-line gambling sector among the most developed and consolidated in the world. From a methodological point of view, firstly the data from a series of secondary sources was processed in order to examine the main changes in the Italian sports betting market induced by the legalization of on-line gambling. Secondly, the data and information collected through specific empirical investigations was used to examine the impact of Internet betting on gambling operators’ business models and on players’ gambling behavior in the Italian market. The results of the analysis has shown that the development of Internet technologies and of e-commerce has had, on the one hand, a positive influence on the growth of the sales in the Italian sports betting market; and on the other hand, has impacted on a series of structural factors in the sector – entry barriers, number of competitors, geographical opening of the market, levels of pricing, average profit margins – in such a way as to determine an increase in industry competition. In particular, use by foreign companies of the electronic distribution channel as a ‘mode of entry’ into different geographical markets is causing the development of competition that goes beyond national borders, reducing the strongly domestic oligopolistic structure that has always characterized the Italian sports betting industry.
A New Class of Generalized Weibull-G Family of Distributions: Theory, Properties and Applications
Authors: Mashabe Baitshephi , Oluyede Broderick O. , Fagbamigbe Adeniyi F. , Makubate Boikanyo , Krishnannair Syamala
Published: December 2018

We propose a generalized class of distributions called the Webull-G Power Series (WGPS) family of distributions and its sub-model Weibull-G logarithmic (WGL) distributions. Structural properties of the WGPS family of distributions and its sub-model WGL distribution including hazard function, moments, conditional moments, order statistics, R´enyi entropy and maximum likelihood estimates are derived. A simulation study to examine the bias, mean square error of the maximum likelihood estimators for each parameter is presented. Finally, real data examples are presented to illustrate the applicability and usefulness of the proposed model.
Theoretical Approach in Vp/Vs Prediction from Rock Conductivity in Gas Saturating Shaly Sand
Authors: Mendrofa Denny MF.
Published: December 2018

Most of study in Oil and Gas Industry are studying Vp/Vs behaviour against hydrocarbon presence in a porous rock. Vp/Vs number is commonly used to model Amplitude Variation against Offset response of a gas sand which allow us be able to discriminate it from the water sand. The model is built in term to match the synthesized Vp/Vs against the observed Vp/Vs which actually correspond to elastic property of porous and fluid saturating rocks. This study is aimed to find correlation between elastic property and conductivity of saturated rocks, especially reservoir in this study is found as a shaly sand unit, a turbidite sand deposit in Kutai Basin, East Kalimantan. The correlation between elastic property and conductivity properties are rarely discussed in many studies, however this study gives a new insight and evidence of how elastic and the inverse of conductivity (resistivity) properties are correlating both ways formulized theoretically with a support from Gassmann and Archie equations. In this study, more realistic condition is accomplished by taking clay mineral into account in sand unit and hence impact to Vp/Vs derivation from resistivity. Furthermore, sand-shale texture is considered important when this study giving a significant discrepancy of how clay mineral is distributed in sand unit and impacted to Vp/Vs and resistivity values. Thomas-Stieber diagram is useful when defining a disperse and/or laminate distribution of shale in the observed porous sand.
Response to Extreme Energy Price Changes: Evidence from Ukraine
Authors: Alberini Anna , Khymych Olha , Ščasný Milan
Published: December 2018

Large but temporary price increases are sometimes deployed on days when the demand for electricity is extremely high due to exceptionally warm or cold weather. But what happens when the extreme price changes are permanent? Between January 2013 and April 2016, natural gas and electricity prices in Ukraine increased dramatically (up to 300% of the initial rates). We exploit variation in tariffs over time and across customers to estimate the price elasticity of electricity demand using a panel dataset with monthly meter readings from households in Uzhhorod in Ukraine. The price elasticity of electricity demand is -0.2 to -0.5, with the bulk of our estimates around -0.3. The elasticity becomes up to 50% more pronounced over the first three months since prices change. We find only limited evidence that persons who are attentive about their consumption levels, their bills, or the tariffs are more responsive to the price changes.
Gemoderniseerde voordeelsontneming
Authors: de Zanger W.S.
Published: December 2018

Gemoderniseerde voordeelsontneming

De modernisering van het Wetboek van Strafvordering zal ook het proces ter ontneming van wederrechtelijk verkregen voordeel aanpassen. Deze wetgevingsoperatie zal de ontnemingsmaatregel grotendeels ontdoen van zijn bijzondere karakter. Zo komt het strafrechtelijk financieel onderzoek te vervallen en wordt voorgesteld de oplegging van de ontnemingsmaatregel als hoofdregel in het reguliere strafproces te laten plaatsvinden. Deze bijdrage brengt in kaart welke wijzigingen worden voorgesteld en hoe die moeten worden beoordeeld. Geconcludeerd wordt dat de moderniseringsplannen kunnen worden onderschreven, maar wel nader dienen te worden doordacht.
Wie moderniseert de bijzondere strafvordering?
Authors: Sackers H.J.B.
Published: December 2018

Wie moderniseert de bijzondere strafvordering?

Bij de modernisering van het Wetboek van Strafvordering blijven de strafprocessuele bevoegdheden uit het bijzondere strafrecht vooralsnog buiten beeld. Gegeven de bijzondere aard van deze bevoegdheden, de wisselende verdenkingsgraad en de complexe verhouding met de commune strafvordering, wordt bepleit aandacht te schenken aan de vraag of een modernisering van met name de bevoegdheden inzake de inbeslagneming, de doorzoeking en het onderzoek aan de kleding uit de Opiumwet en de Wet wapens en munitie gewenst is.
Compliance als transactievoorwaarde bij banken
Authors: Huisman W.
Published: December 2018

Compliance als transactievoorwaarde bij banken

De transactie met ING was een van de meest opvallende gebeurtenissen in de sfeer van het bijzonder strafrecht en de strijd tegen financieel-economische criminaliteit van het afgelopen jaar. Dit artikel bespreekt verschillende redenen waarom dit een belangrijke casus is. Naast de hoogte van het bedrag en de onderliggende criminaliteit, gaat dit artikel in op het strafrechtelijk aansprakelijk stellen van systeembanken en de te verwachten effectiviteit van verbetering van compliancemanagement als transactievoorwaarde.
Komt een 112-melding bij de politie
Authors: Wierdsma André , van Strien Yvette , den Hollander Philip , van Reijsen Aram
Published: December 2018

Triage of mentally disordered persons in telephone calls to the police emergency control room

National thematic projects and local authorities aim to improve shelter and transport facilities for mentally disordered non-offenders. A pilot project in the south-western part of the Netherlands investigated the efficiency of psychiatric expertise in the triage process of the police emergency control room.

To evaluate incoming emergency telephone calls in terms of the type of mentally disordered behavior, the sort and degree of dangerousness, and the urgency and type of response required.

Between November 2016 and January 2017 social psychiatric nurses did weekend shifts on the emergency control room. Incoming telephone calls concerning public nuisance or disordered behavior were administered using the triage tool developed by the Dutch Association of Mental Health and Addiction Care. Nurses had access to regional information systems and were explicitly allowed to follow up on cases where continuity of care was an issue.

A total of 155 calls were evaluated producing a representative image of calls concerning mentally disordered behaviour. Results show that this type of emergency calls is not overly frequent, in many cases not extremely urgent (response time target >1 hour: 67%), and about 65% could be followed up by the general practice centre or specialised (psychiatric) healthcare services. More than half (55%) of the emergency calls involved people previously in contact with psychiatric services. Most common types of danger were public disorder (28%) and suicide risk (21%). However, in 29% of cases type of danger was unclear and 14-20% of the triage tool was inconclusive.

Triage by mental health specialists at the police emergency control room is not efficient because many cases are not very urgent and information quality is often too low to preclude street-triage. Yet screening and follow up of mentally disturbed persons can be improved by close collaboration between control room and psychiatric services.
The Work of the Piarist Order in South Moravia in the 19th Century
Authors: Jireček Miroslav
Published: December 2018

This paper1 aims to give an account of the work of the Piarist Order in South Moravia in the 19th century. Attention is devoted principally to education which was (and remains) the fundamental area of interest to the Piarist Order. The Piarists operated in Mikulov, Strážnice, Hustopeče and Kyjov in South Moravia in the 19th century. They also worked for a certain time at the Episcopal Philosophical Institute in Brno. This paper shows the diversity of the activities of the order in the first half of the 19th century and its subsequent decline in the second half of the century. The causes of this decline are summarised.
Impact of agricultural farms on the environment of the Puck Commune: Integrated agriculture calculator – CalcGosPuck
Authors: Dzierzbicka-Glowacka Lidia A , Pietrzak Stefan , Dybowski Dawid , Białoskórski Michał , Marcinkowski Tadeusz , Rossa Ludmiła , Urbaniak Marek , Majewska Zuzanna , Juszkowska Dominika , Nawalany Piotr , Pazikowska-Sapota Grażyna , Kamińska Bożena , Selke Bartłomiej , Korthals Paweł , Puszkarczuk Tadeusz
Published: December 2018

Background. Leaching of nutrients from agricultural areas is the main cause of water pollution and eutrophication of the Baltic Sea. A variety of remedial actions to reduce nitrogen and phosphorus losses from agricultural holdings and cultivated fields have been taken in the past. However, knowledge about the risk of nutrient leaching has not yet reached many farmers operating in the water catchment area of the Baltic Sea.

Methods. The nutrient balance method known as "at the farm gate" involves calculating separate balances for nitrogen (N), phosphorus (P) and potassium (K). After estimating all the components of the nutrient balance, the total balance for NPK is calculated and the data obtained is expressed as the ratio of total change (surplus) to the area of arable land on a farm. In addition, the nutrient usage efficiency on a farm is also calculated. An opinion poll was conducted in 2017 on 31 farms within the commune of Puck which is approximately 3.6 percent of all farms located in this commune. The area of the farms is variable ranging from 5 – 130 ha with an average of 45.82 ha including areas of arable and grass land. The former are on average 30.79 ha with a range of 4.45 to 130 ha while the latter has an average area of 12.77 ha and ranges from 0 to 53 ha.

Results. The average consumption of mineral fertilizer in the sample population of farms was 114.9 kg N, 9.3 kg P, and 22.9 kg K∙ha-1of agricultural land (AL), respectively. N surplus in the sample farms being ranged from -23.3 to 254.5 kg N∙ha-1AL while nutrient use efficiency ranged from 0.40 to 231.3 percent. In comparison, P surplus in the sample farms was 5.0 kg P∙ha-1AL with the P use efficiency of 0.4-266.5 percent.

Discussion. Individual N fertilizer consumption in the tested farms was higher than the average usage across Poland and in the Pomeranian Voivodeship, compared to the lower consumption of potassium fertilizers. Phosphorus fertilizer consumption was higher than in the Pomeranian Voivodeship, but lower compared to the entire country. Generally, on the basis of designated research indicators of farm pressures on water quality concentrations of total nitrogen and total phosphorus were obtained. CalcGosPuck (an integrated agriculture calculator) will help to raise farmers’ awareness about NPK flow on farm scale and thus to improve nutrient management.
An automatic seating plan algorithm
Authors: Lindorff-Larsen Kresten
Published: December 2018

An appropriate seating plan is an important prerequisite for any good party be it a formal wedding or an informal dinner. Yet anyone who has designed a seating plan knows that it can prove frustratingly difficult to find a solution that solves the large number of formal, physical and personal constraints associated. Here I present a flexible algorithm for automating the task. The algorithm matches guests to seats taking into account constraints provided through a dissimilarity matrix calculated, for example, using answers to questions designed to classify personality, as well as other formal or informal constraints.
Behavior problems and personality in Korean high school students
Authors: Lee Soo Jin , Park Soo Hyun , Cloninger C Robert , Chae Han
Published: December 2018

Introduction

Extant studies have examined the effect of psychological characteristics on clinical features that define behavior problems. The purpose of this study was to analyze the effects of temperament and character as both individual factors and complex profiles on behavior problems in a community sample of adolescents.

Methods

Behavior problems and personality of 670 Korean high school students were measured with the Youth Self-Report (YSR) and Junior version of the Temperament and Character Inventory (JTCI). Stepwise regression analysis analyzed the effects of JTCI character and temperament traits on YSR Total, Internalizing and Externalizing subscale scores, and Profile Analysis examined differences of JTCI personality profiles among three latent YSR subscale profiles acquired from Latent Profile Analysis.

Results

Seven subscales of the JTCI explained 38% of the YSR total degree of behavior problems, and JTCI Novelty-Seeking and Harm-Avoidance were found to account for vulnerability while JTCI Reward-Dependence and Self-Directedness explained resilience to behavior problems. There were three distinct latent YSR profile groups based on nine YSR subscales, and low behavior problem group showed a resilient personality profile characterized by low Novelty-Seeking and Harm-Avoidance and high Reward-Dependence, Persistence, Self-Directedness and Cooperativeness while high behavior problem group exhibited a vulnerable personality profile of the opposite tendency.

Discussion

Temperament and character explained behavior problems of Korean high school students as both individual personality traits and a complex personality profile. The results and implications of this study were examined in regard to mental health of adolescents, and the importance of education in the development of mature personality are discussed.
Análisis comparativo de los marcadores de compromiso en los comentarios sobre noticias digitales en España y Chile
Authors:   Universidad de Chile, Moya Muñoz Patricio , Carrió-Pastor María Luisa ,   Universitat Politècnica de València (España)
Published: December 2018

El propósito de esta investigación es analizar y comparar los marcadores de compromiso utilizados en los comentarios sobre las noticias de los periódicos digitales El País, publicado en España, y Emol, publicado en Chile, utilizados en dos ámbitos temáticos distintos, la política y los deportes. En este estudio los marcadores de compromiso han sido considerados como parte del modelo de análisis del metadiscurso interpersonal; es decir, son elementos que involucran explícitamente a los lectores, ya sea para captar su atención o incluirlos como participantes del discurso (Hyland, 2005a). Para su análisis, se recopiló un corpus compuesto de 2.400 comentarios digitales a noticias, que fueron etiquetados manualmente con la herramienta UAM Corpus Tool con el fin de identificar los mecanismos empleados como marcadores de compromiso. Los resultados señalaron que los comentaristas del diario Emol y los de El País utilizaron un número similar de marcadores de compromiso; por otro lado, tampoco identificamos variación significativa en el uso de estos marcadores en los dos ámbitos temáticos, aunque en ambos periódicos se utilizaron más en los comentarios sobre noticias políticas.
Hypoxia‐inducible factor‐2α directly promotes BCRP expression and mediates the resistance of ovarian cancer stem cells to adriamycin
Authors: He Miao , Wu Huizhe , Jiang Qian , Liu Yinuo , Han Li , Yan Yuanyuan , Wei Binbin , Liu Fangxiao , Deng Xiaolan , Chen Huiying , Zhao Lin , Wang Min , Wu Xin , Yao Weifan , Zhao Haishan , Chen Jianjun , Wei Minjie
Published: December 2018

Ovarian cancer stem cells (OCSCs) are sources of tumor chemoresistance and recurrence. A hypoxic microenvironment contributes to the chemoresistance of cancer stem cells (CSCs), but the underlying mechanism is not fully understood yet. Here, we show that increased HIF‐2α expression is associated with enhanced stemness of OCSCs and poor outcomes in ovarian cancer patients. OVCAR‐3 and CAOV‐3 sphere‐forming (OVCAR‐3 S and CAOV‐3 S) cells with OCSC‐like properties showed strong resistance to adriamycin (ADR). Hypoxia (1% O2) induced high expression of both HIF‐1α and especially HIF‐2α, and increased the resistance of OVCAR‐3 S and CAOV‐3 S cells to ADR. Notably, treatment with ADR further increased the expression of HIF‐2α, but not that of HIF‐1α. Knockdown of HIF‐2α expression substantially attenuated the resistance of OVCAR‐3 S and CAOV‐3 S cells to ADR, and the HIF‐2α overexpression had the opposite effect. Furthermore, in mouse models xenografted with OCSCs, HIF‐2α depletion significantly inhibited tumor growth and sensitized OCSCs to ADR in vivo. Mechanistically, HIF‐2α directly promotes transcription/expression of BCRP, a gene encoding a transporter protein responsible for pumping drugs (e.g., ADR) out of cells, which in turn increases drug resistance due to increased drug transportation. Collectively, our studies reveal a novel drug‐resistant mechanism in ovarian cancer by which hypoxia (and ADR treatment)‐induced HIF‐2α overexpression endows OCSCs with resistance to ADR by promoting BCRP expression and ADR transportation. Therefore, targeting the HIF‐2α/BCRP axis holds therapeutic potential for treating drug‐resistant ovarian cancer.
Putting evidence‐based claims to the test: A multi‐site classroom study of retrieval practice and spaced practice
Authors: Gurung Regan A.R. , Burns Kathleen
Published: December 2018

Retrieval practice and spacing out studying help increase learning. Introductory Psychology students at nine colleges/universities took quizzes with more (RP+) or less (RP−) retrieval practice and more (SP+) or less (SP−) spacing between quizzes. We compared (N = 351) scores on class exams and on a standardized test. We also measured key student variables (e.g., depth of processing). GPA predicted a significant portion of variance in exam scores, R2 = 0.05, F(1, 204) = 10.84, p = 0.001. We found a main effect for retrieval practice and a significant retrieval by spacing practice interaction, R2 = 0.28, F(3, 201) = 27.38, p < 0.001. Students using SP+, as well as those with SP− and RP−, scored higher than students using SP− and RP+. In practice, closer attention needs to be paid to quiz and exam content overlap and the duration within which repetition is used.
Comprehensive Pyro‐Phototronic Effect Enhanced Ultraviolet Detector with ZnO/Ag Schottky Junction
Authors: Wang Ying , Zhu Laipan , Feng Yunjie , Wang Zhaona , Wang Zhong Lin
Published: December 2018

As a coupling effect of pyroelectric and photoelectric effect, pyro‐phototronic effect has demonstrated an excellent tuning role for fast response p–n junction photodetectors (PDs). Here, a comprehensive pyro‐phototronic effect is utilized to design and fabricate a self‐powered and flexible ultraviolet PD based on the ZnO/Ag Schottky junction. By using the primary pyroelectric effect, the maximal transient photoresponsivity of the self‐powered PDs can reach up to 1.25 mA W−1 for 325 nm illumination, which is improved by 1465% relative to that obtained from the steady‐state signal. The relative persistent secondary pyroelectric effect weakens the height of Schottky barrier, leading to a reduction of the steady‐state photocurrent with an increase in the power density. When the power density is large enough, the steady‐state photocurrent turns into a reverse direction. The corresponding tuning mechanisms of the comprehensive pyro‐phototronic effect on transient and steady‐state photocurrent are revealed based on the bandgap diagrams. The results may help us to further clarify the mechanism of the pyro‐phototronic effect on the photocurrent and also provide a potential way to optimize the performance of self‐powered PDs.
Controllable Growth of Graphene on Liquid Surfaces
Authors: Liu Jinxin , Fu Lei
Published: December 2018

Controllable fabrication of graphene is necessary for its practical application. Chemical vapor deposition (CVD) approaches based on solid metal substrates with morphology‐rich surfaces, such as copper (Cu) and nickel (Ni), suffer from the drawbacks of inhomogeneous nucleation and uncontrollable carbon precipitation. Liquid substrates offer a quasiatomically smooth surface, which enables the growth of uniform graphene layers. The fast surface diffusion rates also lead to unique growth and etching kinetics for achieving graphene grains with novel morphologies. The rheological surface endows the graphene grains with self‐adjusted rotation, alignment, and movement that are driven by specific interactions. The intermediary‐free transfer or the direct growth of graphene on insulated substrates is demonstrated using liquid metals. Here, the controllable growth process of graphene on a liquid surface to promote the development of attractive liquid CVD strategies is in focus. The exciting progress in controlled growth, etching, self‐assembly, and delivery of graphene on a liquid surface is presented and discussed in depth. In addition, prospects and further developments in these exciting fields of graphene growth on a liquid surface are discussed.
Promoting Electrocatalysis upon Aerogels
Authors: Cai Bin , Eychmüller Alexander
Published: December 2018

Electrocatalysis plays a prominent role in renewable energy conversion and storage, enabling a number of sustainable processes for future technologies. There are generally three strategies to improve the efficiency (or activity) of the electrocatalysts: i) increasing the intrinsic activity of the catalyst itself, ii) improving the exposure of active sites, and iii) accelerating mass transfer during catalysis (both reactants and products). These strategies are not mutually exclusive and can ideally be addressed simultaneously, leading to the largest improvements in activity. Aerogels, as featured by large surface area, high porosity, and self‐supportability, provide a platform that matches all the aforementioned criteria for the design of efficient electrocatalysts. The field of aerogel synthesis has seen much progress in recent years, mainly thanks to the rapid development of nanotechnology. Employing precursors with different properties enables the resulting aerogel with targeted catalytic properties and improved performances. Here, the design strategies of aerogel catalysts are demonstrated, and their performance for several electrochemical reactions is reviewed. The common principles that govern electrocatalysis are further discussed for each category of reactions, thus serving as a guide to the development of future aerogel electrocatalysts.
Chirality‐Assisted High‐Efficiency Metasurfaces with Independent Control of Phase, Amplitude, and Polarization
Authors: Xu He‐Xiu , Hu Guangwei , Han Lei , Jiang Menghua , Huang Yongjun , Li Ying , Yang Xinmi , Ling Xiaohui , Chen Liezun , Zhao Jianlin , Qiu Cheng‐Wei
Published: December 2018

Simultaneously independent control of phase, amplitude, and polarization is pivotal yet challenging for manipulating electromagnetic waves by transmissive metasurfaces. Huygens' metasurface affords a high‐efficiency recipe primarily by engineering phase‐only meta‐atoms, restricting itself from realizing unprecedentedly complex functions of the transmission beam. Here, a 3D chirality‐assisted metasurface concept relying on integrated magnetoelectric meta‐atoms is proposed. It empowers the completely decoupled and arbitrary control of phase and amplitude at large incident angles and arbitrary polarizations. This strategy thus facilitates very sophisticated beam manipulations at close‐to‐unity cross‐polarized efficiency via trilayer integrated resonators with mutual twist. The prescribed phase coverage can be determined by geometrical footprints of the unit cell, while the global azimuthal twist unlocks the capability of tuning amplitudes without affecting the phase. The concept and significance of it are validated to implement several proof‐of‐prototype demanding functionalities by thin metasurfaces of λo/12, which generate self‐accelerating diffraction‐free Airy beams, lateral and axial dual focusing, and even specific multiplexed beam shaping, respectively. This finding opens up an alternative way in very fine control of light with minimalist complexity and advanced performance. It can stimulate novel and high‐performance versatile photonic metadevices, thanks to the fully independent control of phase, amplitude, and polarization.
Enantioselective Bio‐Hydrolysis of Geranyl‐Derived rac‐Epoxides: A Chemoenzymatic Route to trans‐Furanoid Linalool Oxide
Authors: van Lint Matthijs J. , Gümüs Aysegül , Ruijter Eelco , Faber Kurt , Orru Romano V. A. , Hall Mélanie
Published: December 2018

In contrast to many chemical dihydroxylation methods, enzymatic epoxide hydrolysis provides an environmentally benign route to vicinal diols, which are important intermediates in the synthesis of fine chemicals and pharmaceuticals. Using epoxide hydrolases, enantiopure diols are accessible under mild conditions. In order to assess the selectivity of epoxide hydrolases on geraniol‐derived oxiranes, a range of derivatives were screened against a large variety of enzyme preparations. For nearly all substrates, a matching hydrolase with excellent enantioselectivity (≥95% ee) could be found. In addition, a chemoenzymatic approach for the stereoselective synthesis of furanoid linalool oxide was developed. Combination of enzymatic enantioselective hydrolysis with stereoselective Tsuji‐Trost reaction granted diastereoselective access to trans‐(2R,5R)‐configured linalool oxide with high diastereomeric and enantiomeric excess (97% de and 97% ee).

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Palladium Catalyzed Controllable Mono‐ or Di‐Allylic Substitution Reaction of Benzothiazolylacetate with Allylic Alcohols
Authors: Yan Peipei , Pan Shulei , Hu Jinjin , Lu Limei , Zeng Xiaofei , Zhong Guofu
Published: December 2018

A Pd(PPh3)4/acid catalyzed highly efficient and mono‐ or di‐selective allylic substitution reaction of benzothiazolylacetate and allylic alcohols has been developed. The mono‐ and di‐selectivities could be efficiently controlled by changing the reaction solvent and temperature, affording various mono‐ and di‐allylated products in good to excellent yields and selectivities. Both linear and branched allylic alcohols as well as allyl alcohol could all be well tolerated in the reaction.

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The Impact of Video Laryngoscopy on the Clinical Learning Environment of Emergency Medicine Residents: A Report of 14,313 Intubations
Authors: Monette Derek L. , Brown Calvin A. , Benoit Justin L. , McMullan Jason T. , Carleton Steven C. , Steuerwald Michael T. , Eyre Andrew , Pallin Daniel J. ,   the NEAR III Investigators
Published: December 2018

Background

The introduction of video laryngoscopy (VL) may impact emergency medicine (EM) residents' intubation practices.

Methods

We analyzed 14,313 intubations from 11 EM training sites, July 1, 2002, to December 31, 2012, assessing the likelihood of first‐attempt success and likelihood of having a second attempt, by rank and device. We determined whether direct laryngoscopy (DL) first‐attempt success decreased as VL became more prevalent using a logistic regression model with proportion of encounters initiated with VL at that center in the prior 90 and 365 days as predictors of DL first‐attempt success.

Results

First‐attempt success by PGY‐1s was 71% (95% confidence interval [CI] = 63% to 78%); PGY‐2s, 82% (95% CI = 78% to 86%); and PGY‐3+, 89% (95% CI = 85% to 92%). Residents' first‐attempt success rate was higher with the C‐MAC video laryngoscope (C‐MAC) versus DL, 92% versus 84% (risk difference [RD] = 8%, 95% CI = 4% to 11%), but there was no statistical difference between the GlideScope video laryngoscope (GVL) and DL, 80% versus 84% (RD = −4%, 95% CI = −10% to 1%). PGY‐1s were more likely to have a second intubation attempt after first‐attempt failure with VL versus DL: 32% versus 18% (RD = 14%, 95% CI = 5% to 23%). DL first‐attempt success rates did not decrease as VL became more prevalent.

Conclusions

First‐attempt success increases with training. Interns are more likely to have a second attempt when using VL. The C‐MAC may be associated with increased first‐attempt success for EM residents compared with DL or GVL. The increasing prevalence of VL is not accompanied by a decrease in DL success.
Competition of C‐C bond formation and C‐H bond formation For acetylene hydrogenation on transition metals: A density functional theory study
Authors: Zhao Zhi‐Jian , Zhao Jiubing , Chang Xin , Zha Shenjun , Zeng Liang , Gong Jinlong
Published: December 2018

Selective hydrogenation of acetylene is an important reaction for production of polymer grade ethylene. The green oil formation has great influence on the selectivity and activity of acetylene selective hydrogenation. This article describes a density functional theory study on the C + H hydrogenation reaction and C + C coupling reaction on the (111) surface of Ag, Cu, Pd, Pt, Rh, and Ir. The activity of acetylene selective hydrogenation is examined by the effective barrier for ethylene formation. A comparison between the reaction barrier of ethylene hydrogenation and desorption is used to identify the selectivity for ethylene formation. The barriers of three pathways for 1,3‐butadiene formation suggest that acetylene and vinyl coupling reaction is the favorable pathway. The stability of catalysts is evaluated by the selectivity of 1,3‐butadiene, which follows the order of Pt(111) > Ir(111) > Rh(111) > Pd(111) > Cu(111) > Ag(111). Furthermore, the relationship between acetylene adsorption energy and effective barrier of ethylene formation and 1,3‐butadiene formation has been established to well understand the catalytic properties of different metals. © 2018 American Institute of Chemical Engineers AIChE J, 65: 1059–1066, 2019
Pneumococcal vaccination for welders: Global deployment within a multi‐national corporation
Authors: Donoghue A. Michael , Wesdock James C.
Published: December 2018

Background

Lobar pneumonia is an occupational disease of welders. This is the first report of global deployment of a pneumococcal vaccination program for welders within a multi‐national corporation.

Methods

Global webinars were conducted to introduce the program. Communication packages translated into all location languages were deployed. All employee welders who had not previously been vaccinated were offered a free single dose of pneumococcal polysaccharide vaccine (PPV23) by on‐site location medical centers during normal working hours. Numbers of vaccinated welders were reported by each location each month.

Results

Twelve months after starting the program, 241 of 767 welders have been vaccinated (31%) across six countries.

Conclusions

Global deployment of pneumococcal vaccination for welders can be successfully undertaken by a multi‐national corporation. Adoption of this practice by corporations could reduce the incidence and mortality of pneumonia among welders globally.
Active Edge‐Site‐Rich Carbon Nanocatalysts with Enhanced Electron Transfer for Efficient Electrochemical Hydrogen Peroxide Production
Authors: Sa Young Jin , Kim Jae Hyung , Joo Sang Hoon
Published: December 2018

A highly efficient, metal‐free carbon nanocatalyst is presented that possesses abundant active, oxygenated graphitic edge sites. The edge site‐rich nanocarbon catalyst exhibits about 28 times higher activity for H2O2 production than a basal plane‐rich carbon nanotube with a H2O2 selectivity over 90 %. The oxidative treatment further promotes the H2O2 generation activity to reach close to the thermodynamic limit. The optimized nanocarbon catalyst shows a very high H2O2 production activity, surpassing previously reported catalysts in alkaline media. Moreover, it can stably produce H2O2 for 16 h with Faradaic efficiency reaching 99 % and accumulated H2O2 concentration of 24±2 mm. Importantly, we find that the heterogeneous electron transfer kinetics of the carbon‐based catalyst is closely related to the electrocatalytic activity, suggesting that first outer‐sphere electron transfer to O2 is an important step governing the H2O2 production rate.
Spontaneous Symmetry Breaking in the Formation of Supramolecular Polymers: Implications for the Origin of Biological Homochirality
Authors: Karunakaran Suneesh C. , Cafferty Brian J. , Weigert‐Muñoz Angela , Schuster Gary B. , Hud Nicholas V.
Published: December 2018

Aqueous solutions of the achiral, monomeric, nucleobase mimics (2,4,6‐triaminopyrimidine, TAP, and a cyanuric acid derivative, CyCo6) spontaneously assemble into macroscopic homochiral domains of supramolecular polymers. These assemblies exhibit a high degree of chiral amplification. Addition of a small quantity of one handedness of a chiral derivative of CyCo6 generates exclusively homochiral structures. This system exhibits the highest reported degree of chiral amplification for dynamic helical polymers or supramolecular helices. Significantly, homochiral polymers comprised of hexameric rosettes with structural features that resemble nucleic acids are formed from mixtures of cyanuric acid (Cy) and ribonucleotides (l‐, d‐pTARC) that arise spontaneously from the reaction of TAP with the sugars. These findings support the hypothesis that nucleic acid homochirality was a result of symmetry breaking at the supramolecular polymer level.
Siliziumtris(perchloro)dioxolen: ein neutrales Triplett‐Diradikal
Authors: Maskey Rezisha , Wadepohl Hubert , Greb Lutz
Published: December 2018

Die Umsetzung von ortho‐Chinonen mit Siliciumtetraiodid führt zu neutralen Siliziumtrisdioxolenen in hoher Ausbeute, wodurch die noch unbekannte oxidierte Form von Triscatecholatosilikat‐Dianionen und das erste Beispiele von offenschaligen Semichinolaten die über ein einziges Nichtmetallzentrum verbrückt sind, zugängig werden. Siliziumtris(perchloro)dioxolen ist ein stabiles Diradikal mit einem Triplett‐Grundzustand, der durch Röntgen‐Kristallstrukturanalyse, IR‐, Resonanzraman‐, UV/VIS‐, (VT)EPR‐Spektroskopie und Kohn‐Sham‐Broken‐Symmetry‐Rechnungen gestützt wird. Vorläufige Ergebnisse legen nahe, dass der bevorzugte magnetische Zustand durch Wahl der Substituenten verändert werden kann.
Palladium‐Catalyzed Intermolecular [4+1] Spiroannulation by C(sp3)−H Activation and Naphthol Dearomatization
Authors: Tan Bojun , Bai Lu , Ding Pin , Liu Jingjing , Wang Yaoyu , Luan Xinjun
Published: December 2018

A novel palladium‐catalyzed [4+1] spiroannulation was developed by using a C(sp3)−H activation/naphthol dearomatization approach. This bimolecular domino reaction of two aryl halides was realized through a sequence of cyclometallation‐facilitated C(sp3)−H activation, biaryl cross‐coupling, and naphthol dearomatization, thus rendering the rapid assembly of a new class of spirocyclic molecules in good yields with broad functional‐group tolerance. Preliminary mechanistic studies indicate that C−H cleavage is likely involved in the rate‐determining step, and a five‐membered palladacycle was identified as the key intermediate for the intermolecular coupling.
Towards the 150th Anniversary of the Markovnikov Rule
Authors: Beletskaya Irina P. , Nenajdenko Valentine G.
Published: December 2018

The Markovnikov rule, known to every student of organic chemistry, was formulated 150 years ago, in 1869. During its long history (almost as long as the history of organic chemistry itself), attitudes towards this famous statement of chemical reactivity have evolved from indifference up to the 1930s, through common acceptance as a useful educational paradigm with marginal use in research up to the 1990s, to its vigorous relaunch as an important designation of regioselectivity in the last few decades. The unexpected new popularity of the classical rule is accounted for by the rapid expansion in catalytic addition reactions and their critical importance as highly effective atom‐economical, regioselective methods in modern organic synthesis. A historical outline of the life and achievements of Vladimir Markovnikov is included to reveal the very wide scope of his interests as well as his prophetic predictions on structure, reactivity, selectivity, stereochemistry, and other key issues of organic chemistry.
Silicon Tris(perchloro)dioxolene: A Neutral Triplet Diradical
Authors: Maskey Rezisha , Wadepohl Hubert , Greb Lutz
Published: December 2018

The reaction of ortho‐quinones with silicon tetraiodide leads to neutral silicon trisdioxolenes in high yield, delivering the unknown oxidized form of triscatecholatosilicate dianions and the first example of open‐shell semiquinonates connected via a single non‐metal center. Silicon tris(perchloro)dioxolene is a stable diradical with a triplet ground state, as supported by X‐ray diffraction; IR, resonance Raman, UV/Vis, and (VT)EPR spectroscopy; and Kohn–Sham broken‐symmetry computations. Preliminary results suggest that the preferred magnetic ground state can be altered through variation of the substituents.
Green synthesis of Cu/zirconium silicate nanocomposite by using Rubia tinctorum leaf extract and its application in the preparation of N‐benzyl‐N‐arylcyanamides
Authors: Nasrollahzadeh Mahmoud , Sajjadi Mohaddeseh , Sajadi S. Mohammad
Published: December 2018

A simple and convenient protocol was established for the synthesis of the N‐benzyl‐N‐arylcyanamides through N‐benzylation of a wide variety of arylcyanamides using copper nanoparticles immobilized on natural zirconium silicate as a novel and green heterogeneous catalyst. In this study, we showed a novel, cost efficient, convenient and simple method for green synthesis of Cu/zirconium silicate nanocomposite by using Rubia tinctorum leaf extract as capping and reducing agent. The structure of the novel catalyst was successfully characterized using a number of micro/spectroscopic techniques such as XRD, FESEM, BET, EDS, TEM, FT‐IR and elemental mapping. TEM micrographs of obtaining biocatalyst revealed mostly spherical particles with an average diameter of about 15–25 nm on the surface of natural support. The prepared catalyst was used in the N‐benzylation of a variety of arylcyanamides with benzyl bromide and showed high activity and stability for the efficient synthesis of N‐benzylarylcyanamides in good yields. Remarkably, the catalyst can be easily recovered from the reaction medium and reused up to five runs without losing its catalytic activity.