bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐resolution projections of evapotranspiration and water availability for Europe under climate change
Authors: Dezsi Ştefan , Mîndrescu Marcel , Petrea Dănuţ , Rai Praveen Kumar , Hamann Andreas , Nistor Mărgărit‐Mircea
Published: April 2018

Evapotranspiration plays an essential role in estimating water balance, runoff and effective precipitation. To determine historical and projected water availability for Europe, we contribute high‐resolution (1 km) estimates of monthly and annual potential evapotranspiration (ET0) and actual evapotranspiration (AET0). In the ET0 calculation, the monthly and annual heat index I and annual α parameter were estimated following the Thornthwaite method, and AET0 was calculated using the Budyko approach. The variables were estimated for a climate normal period that largely precedes an anthropogenic warming signal (1961–1990), and for two CMIP5 multi‐model future projections (2011–2040 and 2041–2070). We project widespread and relatively uniform ET0 increases of around 50–100 mm by the 2020s and 75–125 mm by the 2050s for most of Europe. These values imply important changes that may affect runoff and groundwater recharge. AET0 was identified as important driver of water availability with more regional variability. Spatial mapping of changes relative to the normal baseline imply that all except northern parts of Europe are vulnerable to water deficits, with pronounced decrease expected in southern Europe. We provide high‐resolution maps and data as an important tool for future natural resources management and climate change mitigation planning.
Synthesis of Natural Tea‐Saponin‐Based Succinic Acid Sulfonate as Anionic Foaming Agent
Authors: Fan Zexia , Deng Zhiyu , Wang Tengfei , Yang Weipeng , Wang Kun
Published: April 2018

Tea saponin (TS) is a relatively inexpensive natural nonionic surfactant extracted from parts of tea plants, which can be modified into an anionic surfactant to achieve better surface activity. In this paper, the synthesis of TS‐based succinic acid sulfonate as an anionic foaming agent is described. TS used as the hydrophobic source was modified by maleic anhydride (MAH) and then reacted with sodium bisulfite. Orthogonal experiment of a 2‐step reaction was designed and performed, resulting in 9 kinds of succinic acid tea‐saponin sulfonate (STS). 4‐Dimethylaminopyridine and tetrabutylammonium bromide were, respectively, used as catalyst for the esterification with MAH and the sulfonation with sodium bisulfite. During the synthesis process, N,N‐dimethylformamide was employed as the solvent and ethyl acetate as the extractant. The molecular structure of STS was confirmed by infrared spectroscopy and mass spectrometry. The foaming property of STS was investigated through comparison with different kinds of common surfactants. The results show great prospects of these environmentally friendly anionic surfactants.
Comparative Investigation of Dynamic Foam Behavior of Air–Water and CO2–Water Systems
Authors: Bathe Ganesh A. , Bhagat Mandar S. , Chaudhari Bhushan L.
Published: April 2018

The purpose of this study was to understand and compare the dynamic foam behavior of the surfactant Tween‐20 in air–water and CO2–water systems. The foam height in the CO2–water system was less than that in the air–water system, but the foam stability was better in the CO2–water system. The effect of temperature on axial dye displacement and foam bubble size was studied, where the foam generation ability of the surfactant was directly proportional to the temperature, while the foaminess was inversely proportional. The observed highest foam volume for the air–water system was 3922 ± 181 cm3 and for the CO2–water system 3195 ± 181 cm3 at 5.0 g L–1 of surfactant at air flow rate of 1 liter per minute (LPM) at 52 °C. The half‐life for the air–water and the CO2–water system was 110 and 40 s, respectively, at 5.0 g L–1 of surfactant at the air flow rate of 1 LPM and 28 °C. In wet foam, the liquid holdup range for the air–water system was 0.38–0.52% and for the CO2–water system 0.51–0.72% in the concentration range 1.0–5.0 g L–1 at 1 LPM gas flow rate.
Effects of high‐power ultrasound on microflora, enzymes and some quality attributes of a strawberry drink
Authors: Chen Liyi , Bi Xiufang , Cao Xiamin , Liu Lei , Che Zhenming
Published: April 2018

BACKGROUND

The objective of the present work was to study the effect of high‐power ultrasound (HPU) on the microflora, enzymes and some quality attributes of a strawberry drink and to provide a theoretical basis for strawberry drink processing conducive to the development of more nutritious and healthier strawberry drinks.

RESULTS

Fresh strawberry drink was subjected to HPU treatment at 20 kHz (242, 605 and 968 W cm−2) for 2, 4, 6, 8 and 10 min in an ice bath. Results showed that polyphenol oxidase (PPO), pectin methyl esterase (PME) and β‐glucosidase activities were decreased by 44.90, 89.11 and 84.71% respectively at 968 W cm−2 for 10 min. Lower L*, a* and b* values and higher browning degree (BD) were observed in HPU‐treated samples, resulting in a significant increase in ΔE value (P < 0.05). HPU treatment caused loss of viscosity and turbidity, while total soluble solids (TSS) and pH of the strawberry drink were stable. Total phenol content and antioxidant capacity increased while anthocyanin content decreased compared with untreated samples. Total aerobic bacteria (TAB) and molds and yeasts (M&Y) were reduced by 2.07 and 1.13 log10 cycles respectively at 968 W cm−2 for 10 min.

CONCLUSIONS

HPU can effectively achieve the effect of pasteurization and maintain the nutrients of strawberry drink. © 2018 Society of Chemical Industry
Estimating wind turbine fatalities using integrated detection trials
Authors: Smallwood K. Shawn , Bell Douglas A. , Walther Erika L. , Leyvas Elizabeth , Standish Skye , Mount Joanne , Karas Brian
Published: April 2018

Fatality monitoring at wind projects requires carcass detection trials to adjust fatality estimates for the proportion of fatalities not found. However, detection trials vary greatly in metric, duration, carcass monitoring schedule, species, number placed, state of decomposition, whether placed within or outside search areas, and other factors. We introduce a new approach for estimating fatalities by quantifying overall detection rates rather than separate rates for searcher detection error and carcass persistence, and by leaving placed and found fatality carcasses undisturbed throughout monitoring. We placed 2 fresh‐frozen bird carcasses weekly at random sites within fatality search areas and on randomized days Monday–Friday at Sand Hill and Santa Clara wind projects, Altamont Pass Wind Resource Area, California, USA. To estimate detection rates, we used logit regression to fit detection outcomes on body mass, which served as an axis of similitude between placed trial carcasses and fatality finds. Adjusted carcass placement rates among species detected by searchers regressed on true placement rates with a slope of 1.0 so long as sufficient numbers of trial carcasses were placed, thus validating our approach as an unbiased estimator. Our approach generally estimated lower fatality rates than did conventional approaches, the latter of which demonstrated biases in searcher detection rates and carcass persistence rates whether based on proportion of carcasses remaining or mean days to removal. Our approach also revealed detection errors that highlight the difficulty of finding and identifying the remains of dead animals, and which warrant routine reporting. Despite averaging only a 5‐day search interval on intensively grazed annual grasslands where ground visibility was usually high, our experienced fatality monitors averaged 4.3 searches/first carcass detection, failed to detect 25% of 75 species represented by placed carcasses, and misidentified carcasses to species among 44% of species detected. Estimates of time since death also suffered bias and large error. Our approach more realistically simulates carcass detection probabilities associated with fatality monitoring, is less costly, facilitates hypothesis testing, eliminates multiple sources of error and bias suspected of conventional methods, and enables quantification of errors in estimated time since death, species identifications, and false negative findings. © 2018 The Wildlife Society.
Isoconversional Kinetics of Thermal Processes in Mixtures Based on Metakaolin and Sodium Hydroxide
Authors: Prokof'ev Valery Yu. , Gordina Natalya E. , Khramtsova Alexandra P. , Konstantinova Ekaterina M. , Voynova Viktoriya V.
Published: April 2018

This study investigated the thermal behavior of the mixtures 6Al2Si2O7: 12NaOH and 6Al2Si2O7: 12NaOH: 2Al2O3 which are designed for synthesis of LTA (Linde type A) zeolite. XRD, SEM, and Synchronous thermal analysis (STA) have been used. It was found that after evaporating suspensions, molding pellets, and drying, small amounts of LTA and sodium hydroaluminates have been formed in the sample. The removal of crystallization water occurs on heating up to 400°C. In the temperature range from 400 to 850°C, Na6Al4Si4O17 and Na8Al4Si4O18 are synthesized by interaction of metakaolin with sodium hydroxide. The formation of mullite and nepheline is also observed. It was shown that preactivation of powders in the vibratory mill allows reducing the starting temperature of synthesis at 50–100°C. For the range 400–850°C using Ozawa–Flynn–Wall analysis, the values of apparent activation energy and preexponential factor have been calculated. It was established that the apparent activation energy for mixtures without preactivation made 200–290 kJ mol−1. After preactivation, E values decreased to 130–170 kJ mol−1. Also it was shown that alumina excess inhibits nepheline and mullite formation.
Has the management of pediatric mucoepidermoid carcinoma of the parotid gland changed?
Authors: Janz Tyler A. , Camilon P. Ryan , Nguyen Shaun A. , Levi Jessica R. , Lentsch Eric J.
Published: April 2018

Objectives/Hypothesis

To examine the evolving changes in management of pediatric mucoepidermoid carcinoma of the parotid gland.

Study Design

Retrospective analysis of a large population database.

Methods

Pediatric patients in the Surveillance, Epidemiology, and End Results database were included from 1973 to 2014 based on a diagnosis of mucoepidermoid carcinoma of the parotid gland using the International Classification of Diseases for Oncology, Third Edition codes: C07.9: parotid gland and 8430/3: mucoepidermoid carcinoma. Patients were included from ages 0 to 18 years. Patients were categorized into 5‐ or 6‐year cohorts based on their year of diagnosis. Two‐year and 5‐year survival was calculated using actuarial or life‐table analysis.

Results

One hundred sixty‐nine pediatric cases were identified. Eighty of the 169 cases (47.4%) were diagnosed from 2005 to 2014. The number of cases increased steadily across cohorts over time since 1995. Pediatric patients tended to be diagnosed in adolescence (mean age: 13.4 years, range: 3.0–18.0 years). Most patients received surgical management as a part of their case (95.3% of total cohort). The 5‐year disease‐specific survival was > 90% for each cohort.

Conclusions

The age‐adjusted incidence rate of pediatric mucoepidermoid carcinoma of the parotid gland remains low and is not greatly changing. This cancer is most likely diagnosed in adolescence affecting both male and female patients equally. Analysis of cases since 1973 revealed that most patients continue to receive surgical care. Survival for these pediatric patients continues to remain excellent. Healthcare providers should note these updates in pediatric mucoepidermoid carcinoma of the parotid gland as effective diagnosis and management continues to lead to good survival outcomes.

Level of Evidence

4 Laryngoscope, 128:2408–2414, 2018
Pediatric oncology as a Learning Health System: Ethical implications for best available treatment protocols
Authors: van der Graaf Rieke , Dekking Sara A. , de Vries Martine C. , Zwaan Christian Michel , van Delden Johannes J.M.
Published: April 2018

Introduction

Pediatric oncology is often considered as a field in which research and care are highly integrated. We believe that this integration can be seen as a so‐called Learning Health System, a system in which research is considered an important means to continuously improve the practice of care. In order to substantiate our assumption of pediatric oncology as an LHS, we will analyze so‐called “best available treatment protocols.” These protocols always contain research elements, even if themain goal of these protocols is to treat children diagnosed with cancer.

Methods

We will analyze the implications for ethical review and informed consent if these protocols had to function as exponents of pediatric oncology an LHS.

Results

An analysis of best available treatment protocols teaches us how these protocols integrate care and research and how these protocols can be seen as exponents of a system where care and research need no longer be sharply distinct practices.

Discussion

Further intervention in the field of pediatric oncology is essential to also meet the requirements for an ethically responsible LHS.

Conclusion

Best available treatment protocols, which combine research and care, can be seen as examples of pediatric oncology as an LHS. However, in order to prevent that research elements in these protocols will be overlooked, we will have to find new ways to accommodate for the oversight of these protocols, such as multifaceted review and risk‐adapted approaches. Moreover, informed consent process must be changed in order for patients to understand how care and research are integrated in these protocols.
Design, Preparation, and Characterization of Thermoresponsive Hybrid Nanogels Using a Novel Ulvan‐Acrylate Crosslinker as Potential Carriers for Protein Encapsulation
Authors: Morelli Andrea , Puppi Dario , Cheptene Victoria , Disgraziati Dunia , Ruggeri Giacomo , Chiellini Federica
Published: April 2018

The aim of the present study is the design and development of thermoresponsive nanogels based on ulvan, a sulphated heteropolysaccharide of algal origins with unique biological and chemical properties. Hybrid nanogels are successfully synthesized by means of UV‐initiated radical copolymerization ofN‐vinylcaprolactam with an ulvan derivate as a novel crosslinker. In nanogels, the ulvan‐grafted poly(N‐vinylcaprolactam) chains represent the thermoresponsive component. The most promising candidates, selected after a thorough physical–chemical characterization of nanogels in terms of size and responsivity to thermal variation at physiological conditions, are loaded with bovine serum albumin (BSA) as model bioactive compound. The developed nanogels display BAS loading efficiency values similar to those obtained by using synthetic crosslinkers, and thus indicating the suitability of the developed ulvan‐acrylate to act as novel macromolecular crosslinker for thermoresponsive nanogels preparation.
Synthesis and Enhanced Photofluorescence of Pyrazoline‐Ester Copolymers from Bisdiazoacetates and Diacrylates
Authors: Cao Ting , Chen Cheng , Liu Li Jian
Published: April 2018

Photofluorescent pyrazoline‐ester copolymer is synthesized from bisdiazoacetate and diacrylate through two tandem 1,3‐dipolar cycloadditions at room temperature. The first 1,3‐dipolar cycloaddition takes place between bisdiazoacetate and diacrylate, and produces the diazoacetate and acrylate‐terminated pyrazoline monomer that undergoes second 1,3‐dipolar cycloaddition further to form pyrazoline‐ester copolymer in excellent yield (up to 90%) with number‐average molecular weights (Mn) in the range of 6100–17900 g mol−1. The optimized bisdiazo and dialkene are 1,4‐cyclohexanedimethyl bisdiazoacetate and 1,6‐hexanediol diacrylate, from which the pyrazoline‐ester copolymer with Mn 17900 g mol−1 is obtained in 97% yield and the maximum emission intensity (I/N) is enhanced to be as high as 19 × 104 a.u.. The pyrazoline‐ester copolymers are down/upconversion fluorescence materials, which emit 320–330 nm UV light through the excitation of both mid‐UV and visible light, and could find wide application in the optical field.
Rolling of 3D Printed Dual‐Layer Beam into a Cylinder by Ethanol Absorption
Authors: Choi Woorim , Kim Tae‐Young , Lee Yong‐Gu
Published: April 2018

4D printing is an extension to 3D printing whereby a printed shape programmatically undergoes shape transformation through external stimulations. There is an increasing interest in this field because of its potential applications. However, many demonstrated shape transformations work on simple and limited geometrical shapes. In this work, the formation of a cylinder from a printed flat dual‐layer beam when exposed to ethanol is demonstrated. The newly formed cylinder retains its shape even when the ethanol is removed through the use of a locking mechanism. The proposed method can be used for building medical stents or various sensors and actuators that require cylindrical shapes.
Effects of functional green advertising on self and others
Authors: Mo Ziying , Liu Matthew Tingchi , Liu Yongdan
Published: April 2018

This study examines the effects of a functional green advertising promoting the environmental advantages of a product. It presents the results of three experiments designed to (a) explore consumers’ perceptions of a functional green ad's effects on themselves and others, (b) determine how those perceptions are influenced by consumer environmental concern, and (c) examine how individualism–collectivism relates to self–other effect perceptions. Findings indicate that (a) consumers believe that functional green advertising exerts a stronger influence on others’ purchase decisions than on their own purchase decisions; (b) the self–other difference is more salient among consumers with high environmental concern; (c) in the individualistic culture, the perceived effectiveness on self, not on others, predicts consumers’ support for the regulation of functional green ads, while this effect is reversed when consumers are in collectivistic cultures. The study's findings extend several lines of research, including the literature on green advertising and the third‐person effect.
A spatiotemporal Evaluation of Atlantic Sea Scallop Placopecten magellanicus Habitat in the Gulf of Maine Using a Bioclimate Envelope Model
Authors: Torre Michael P. , Tanaka Kisei R. , Chen Yong
Published: April 2018

A bioclimate envelope model was developed to evaluate the impacts of climate variability on spatiotemporal availability of suitable habitat for the Atlantic sea scallop Placopecten magellanicus in the Gulf of Maine (GOM). Bioclimate envelopes were established through habitat suitability indices (HSIs) based on bottom temperature, bottom salinity, current velocity, depth, and bottom composition. The relationship between Atlantic sea scallop abundance and each environmental variable was quantified using suitability indices, which were generated based on standardized scallop abundance sampled over 10 years of dredge survey data. Boosted regression tree models were used to determine the relative importance of each environmental variable to scallop abundance, thereby establishing a weighting scheme within the HSI. A regional circulation model was coupled with the weighted HSI to hindcast spatiotemporal dynamics of suitable habitat for Atlantic sea scallop in coastal and offshore waters of the GOM from 1978 to 2013. Higher habitat suitability was found along inshore areas compared with offshore areas. Model predictions indicated an increasing trend in habitat suitability in inshore waters since 1978 and decreasing habitat suitability in offshore waters. This research provides a novel modeling framework with which to enhance research and management of commercially valuable Atlantic sea scallop stocks over broad spatiotemporal scales in the climatically altered GOM.
Smoldering Multiple Myeloma Associated Leukoencephalopathy Presenting with Holmes Tremor, Ataxia, and Pyramidal Syndrome
Authors: Aquino Camila Catherine , Connolly Barbara , Lang Anthony E.
Published: April 2018

View Supplementary Video 1
Activity and selectivity cliffs for DPP‐IV inhibitors: Lessons we can learn from SAR studies and their application to virtual screening
Authors: Ojeda‐Montes María José , Gimeno Aleix , Tomas‐Hernández Sarah , Cereto‐Massagué Adrià , Beltrán‐Debón Raúl , Valls Cristina , Mulero Miquel , Pujadas Gerard , Garcia‐Vallvé Santiago
Published: April 2018

The inhibition of dipeptidyl peptidase‐IV (DPP‐IV) has emerged over the last decade as one of the most effective treatments for type 2 diabetes mellitus, and consequently (a) 11 DPP‐IV inhibitors have been on the market since 2006 (three in 2015), and (b) 74 noncovalent complexes involving human DPP‐IV and drug‐like inhibitors are available at the Protein Data Bank (PDB). The present review aims to (a) explain the most important activity cliffs for DPP‐IV noncovalent inhibition according to the binding site structure of DPP‐IV, (b) explain the most important selectivity cliffs for DPP‐IV noncovalent inhibition in comparison with other related enzymes (i.e., DPP8 and DPP9), and (c) use the information deriving from this activity/selectivity cliff analysis to suggest how virtual screening protocols might be improved to favor the early identification of potent and selective DPP‐IV inhibitors in molecular databases (because they have not succeeded in identifying selective DPP‐IV inhibitors with IC50 ≤ 100 nM). All these goals are achieved with the help of available homology models for DPP8 and DPP9 and an analysis of the structure–activity studies used to develop the noncovalent inhibitors that form part of some of the complexes with human DPP‐IV available at the PDB.
A 3D individual‐based model to investigate the spatially heterogeneous response of bacterial biofilms to antimicrobial agents
Authors: Machineni Lakshmi , Reddy Ch. Tejesh , Nandamuri Vandana , Pawar Parag D.
Published: April 2018

The response of bacterial biofilms to treatment with antimicrobial agents is often characterized by the emergence of recalcitrant cellular microcolonies. We present an individual‐based model to investigate the biophysical mechanisms of the selective resistance that arises within the biofilm and leads to a spatially heterogeneous response upon treatment with antibiotics. The response occurs in 3 distinct phases. In the first phase, the subpopulation of metabolically active cells diminishes due to antibiotic‐induced cell death. Subsequently, in the second phase, increased nutrient availability allows dormant cells in the lower layers of the biofilm to transform into metabolically active cells. In the third phase, survival of the biofilm is governed by the interplay between 2 contrasting factors: (1) rate of antibiotic‐induced cell death and (2) rate of transformation of dormant cells into active ones. Metabolically active cells at the distal edge of the biofilm sacrifice themselves to protect the dormant cells in the interior by (1) reducing local antibiotic concentrations and (2) increasing nutrient availability. In the presence of quorum sensing, biofilms exhibit increased tolerance compared with the quorum sensing–negative strains. Extracellular polymeric substance (EPS) forms a protective layer at the top of the biofilm, thereby limiting antibiotic penetration. The surviving cells, in turn, produce EPS resulting in a feedback‐like mechanism of resistance. Whereas resistance in QS− biofilms occurs because of transformation of dormant cells into metabolically active cells, this transformation is less pronounced in QS+ biofilms, and resistance is a consequence of the sequestration of the antibiotic by EPS.
Effect of negligence and length of time delay in spontaneous behavioural changes for the response to epidemics
Authors: Kassa Semu Mitiku , Workineh Yetwale Hailu
Published: April 2018

It is understood that public health education and informal communications can impact on perceptions of disease threat, which could result in influencing behaviour of individuals to take any possible self‐protective measures. On the other hand, the information about the actual status of the disease dynamics, on which the public health education is based, can be known only after its data are collected and processed. This may take a significant amount of time, and therefore, there is a time gap between what the public knows about the prevalence of the disease and the actual distribution of the disease in the population. Furthermore, there is a memory decay and negligence from the side of the population in applying protective mechanisms as the disease becomes endemic. In this paper, a mathematical model for human disease epidemics that takes a change in human behaviour and effect of negligence into account is formulated and analysed. The model investigates the effect of negligence (from the side of the population) and time lag (in disclosing the actual prevalence of the disease) in the dynamics and control of the disease. The numerical results show that the length of the delay has a significant impact on the control strategy rather than on the dynamics without control. In addition, announcing the prevalence value once every time it is updated and keeping that value constant has the same effect on the dynamics as compared with updating the same continuously. Moreover, it is also shown that the negligence parameter significantly affects the overall prevalence of the disease.
Positive homoclinic solutions of n‐th order difference equations with sign‐changing Green's function
Authors: Cabada Alberto , Dimitrov Nikolay D.
Published: April 2018

In this paper we, consider an n‐th order nonlinear difference equation with parameter dependence. An exhaustive study of the related Green's function is done. The exact expression of the function is given. The range of parameter for which either it has constant sign or it changes sign is obtained. Some existence results for the nonlinear problem are deduced by using the classical Krasnosel'skii's fixed point theorem on cones and fixed point index theory.
Finite‐time stability of a class of oscillating systems with two delays
Authors: Cao Xiaokai , Wang JinRong
Published: April 2018

In this paper, we study finite‐time stability of an oscillating system with 2 delays. To derive a bounded of state vector, we use a representation of explicit solution involving 2‐delayed matrix polynomial of 2 indices after deriving some fundamental estimates for such delayed matrix polynomial of 2 indices. A sufficient condition is given. Finally, an example is given to demonstrate the application of the main result.
VMAT optimization with dynamic collimator rotation
Authors: Lyu Qihui , O'Connor Daniel , Ruan Dan , Yu Victoria , Nguyen Dan , Sheng Ke
Published: April 2018

Purpose

Although collimator rotation is an optimization variable that can be exploited for dosimetric advantages, existing Volumetric Modulated Arc Therapy (VMAT) optimization uses a fixed collimator angle in each arc and only rotates the collimator between arcs. In this study, we develop a novel integrated optimization method for VMAT, accounting for dynamic collimator angles during the arc motion.

Methods

Direct Aperture Optimization (DAO) for Dynamic Collimator in VMAT (DC‐VMAT) was achieved by adding to the existing dose fidelity objective an anisotropic total variation term for regulating the fluence smoothness, a binary variable for forming simple apertures, and a group sparsity term for controlling collimator rotation. The optimal collimator angle for each beam angle was selected using the Dijkstra's algorithm, where the node costs depend on the estimated fluence map at the current iteration and the edge costs account for the mechanical constraints of multi‐leaf collimator (MLC). An alternating optimization strategy was implemented to solve the DAO and collimator angle selection (CAS). Feasibility of DC‐VMAT using one full‐arc with dynamic collimator rotation was tested on a phantom with two small spherical targets, a brain, a lung and a prostate cancer patient. The plan was compared against a static collimator VMAT (SC‐VMAT) plan using three full arcs with 60 degrees of collimator angle separation in patient studies.

Results

With the same target coverage, DC‐VMAT achieved 20.3% reduction of R50 in the phantom study, and reduced the average max and mean OAR dose by 4.49% and 2.53% of the prescription dose in patient studies, as compared with SC‐VMAT. The collimator rotation co‐ordinated with the gantry rotation in DC‐VMAT plans for deliverability. There were 13 beam angles in the single‐arc DC‐VMAT plan in patient studies that requires slower gantry rotation to accommodate multiple collimator angles.

Conclusions

The novel DC‐VMAT approach utilizes the dynamic collimator rotation during arc delivery. In doing so, DC‐VMAT affords more sophisticated intensity modulation, alleviating the limitation previously imposed by the square beamlet from the MLC leaf thickness and achieves higher effective modulation resolution. Consequently, DC‐VMAT with a single arc manages to achieve superior dosimetry than SC‐VMAT with three full arcs.
Robin‐Neumann transmission conditions for fluid‐structure coupling: Embedded boundary implementation and parameter analysis
Authors: Cao Shunxiang , Main Alex , Wang Kevin G.
Published: April 2018

Partitioned procedures are appealing for solving complex fluid‐structure interaction (FSI) problems, as they allow existing computational fluid dynamics (CFD) and computational structural dynamics algorithms and solvers to be combined and reused. However, for problems involving incompressible flow and strong added‐mass effect (eg, heavy fluid and slender structure), partitioned procedures suffer from numerical instability, which typically requires additional subiterations between the fluid and structural solvers, hence significantly increasing the computational cost. This paper investigates the use of Robin‐Neumann transmission conditions to mitigate the above instability issue. Firstly, an embedded Robin boundary method is presented in the context of projection‐based incompressible CFD and finite element–based computational structural dynamics. The method utilizes operator splitting and a modified ghost fluid method to enforce the Robin transmission condition on fluid‐structure interfaces embedded in structured non–body‐conforming CFD grids. The method is demonstrated and verified using the Turek and Hron benchmark problem, which involves a slender beam undergoing large transient deformation in an unsteady vortex‐dominated channel flow. Secondly, this paper investigates the effect of the combination parameter in the Robin transmission condition, ie, αf, on numerical stability and solution accuracy. This paper presents a numerical study using the Turek and Hron benchmark problem and an analytical study using a simplified FSI model featuring an Euler‐Bernoulli beam interacting with a two‐dimensional incompressible inviscid flow. Both studies reveal a trade‐off between stability and accuracy: smaller values of αf tend to improve numerical stability, yet deteriorate the accuracy of the partitioned solution. Using the simplified FSI model, the critical value of αf that optimizes this trade‐off is derived and discussed.
A continuation method for rigid‐cohesive fracture in a discontinuous Galerkin finite element setting
Authors: Hirmand M. Reza , Papoulia Katerina D.
Published: April 2018

An energy minimization formulation of initially rigid cohesive fracture is introduced within a discontinuous Galerkin finite element setting with Nitsche flux. The finite element discretization is directly applied to an energy functional, whose term representing the energy stored in the interfaces is nondifferentiable at the origin. Unlike finite element implementations of extrinsic cohesive models that do not operate directly on the energy potential, activation of interfaces happens automatically when a certain level of stress encoded in the interface potential is reached. Thus, numerical issues associated with an external activation criterion observed in the previous literature are effectively avoided. Use of the Nitsche flux avoids the introduction of Lagrange multipliers as additional unknowns. Implicit time stepping is performed using the Newmark scheme, for which a dynamic potential is developed to properly incorporate momentum. A continuation strategy is employed for the treatment of nondifferentiability and the resulting sequence of smooth nonconvex problems is solved using the trust region minimization algorithm. Robustness of the proposed method and its capabilities in modeling quasistatic and dynamic problems are shown through several numerical examples.
Low‐trust bureaucracy: Understanding the Mexican bureaucratic experience
Authors: Peeters Rik , Trujillo Jiménez Humberto , O'Connor Elizabeth , Ogarrio Rojas Pascual , González Galindo Michele , Morales Tenorio Daniela
Published: April 2018

Latin American bureaucracies are notorious for their inefficiency and opacity, yet there is very little empirical research done on what exactly constitutes the “bureaucratic experience” for citizens and what the costs of bureaucratic dysfunction are. To improve our understanding of this topic, 5 cases of Mexican citizens' encounters with public bureaucracies are used to develop the notion of “low‐trust bureaucracy”: public organisations in which access to services is unreliable and the levels of control towards both citizens and bureaucrats are excessive. This bottom‐up analysis of administrative practices contributes to our understanding of the ineffectiveness of government programmes and services, but also of how bureaucracies in developing countries amplify social inequality rather than function as a social equaliser. Furthermore, this article adds new insights to the existing understanding of administrative burdens as a result of either political tactics or mere benign neglect. The data presented here suggest that structural and intractable characteristics of the broader administrative context, such as authoritarian legacies, can produce behavioural patterns that shift bureaucratic attention away from a fair and efficient service provision.
Defect Structures, Electronic Properties, UV–Vis, and EPR Parameters for Rh2+ Centers in LiD: A DFT Study
Authors: Wu Li‐Na , Wu Shao‐Yi , Liu Xu‐Sheng , Zhong Si‐Ying , Zhang Fu
Published: April 2018

The defect structures and electronic properties of orthorhombic elongated (OE) and tetragonal compressed (TC) Rh2+ centers in LiD are theoretically studied using Density Functional Theory (DFT) with the periodic CP2K program. The calculations demonstrate obvious differences in defect structure between the two centers. OE center with one next nearest neighbor (nnn) cation vacancy (VLi) in [100] axis shows the Jahn‐Teller elongation of about 0.076 Å along [001] axis, whereas TC center with one nnn VLi in [001] axis exhibits a compression of about 0.049 Å along this direction. The ligand between the central Rh2+ and the VLi is found to move away from the VLi by about 0.038 or 0.035 Å for O­­E or TC center. The larger magnitude of the overlap population (≈ −0.5907 or −0.5494 e) of the RhD bonds in OE or TC center than that (≈0.2373 e) of the host LiD bonds in pure LiD indicates much stronger covalency of the former. The simulated UV–Vis and electron paramagnetic resonance (EPR) spectra with the embedded cluster model in ORCA code are consistent with the experimental data. The present results are discussed and compared with those of the previous perturbation calculations.
Colossal Dielectric Behavior and Dielectric Relaxation of (Li, Fe) Co‐Doped ZnO Ceramics
Authors: Wu You , Li Jun , Bai Han , He San , Hong Yang , Shi Kouzhong , Zhou Zhongxiang
Published: April 2018

The co‐doped ceramics (Fe0.5Li0.5)xZn1−xO (x = 0.005, 0.01, 0.015) (abbreviated as FL‐0.005, FL‐0.01, and FL‐0.015) as well as the Fe‐only and Li‐only (abbreviated as Fe‐0.01 and Li‐0.01) doped samples are prepared by a solid‐state reaction method to investigate their colossal dielectric property for the first time. The permittivity value (ɛ′ ≈ 2.05 × 104 at 20 °C, 1 kHz with tanδ ≈0.61) is the highest in co‐doped ZnO ceramics reported so far. The colossal permittivity is brought out by the step‐like dielectric abnormities over which ɛ′ goes up steeply (≈101–≈104) resulting from the mix‐valent ions of Fe2+/Fe3+, while the grain boundaries tend to make the dominant contribution at elevated temperature above the step‐like abnormity. The defect‐dipole (Li+–Fe3+) can localize the electrons to a certain extent in the ZnO matrix inducing effective suppression of the dielectric loss. The sample FL‐0.01 exhibits the optimal colossal dielectric property and as x goes up further, the dielectric loss tends to increase obviously. This work provides a new routine to design optimal colossal dielectric materials and related devices for research and applications.
Mesoscale rainfall patterns observed around wetlands in sub‐Saharan Africa
Authors: Taylor Christopher M. , Prigent Catherine , Dadson Simon J.
Published: April 2018

Wetlands are dynamic components of the landscape, responding to local and upstream rainfall, river flow and groundwater variability, and to water management. At the same time, in regions of strong evaporative demand, wetlands can present very strong land surface heterogeneity to the atmosphere, driving marked gradients in sensible and latent heat fluxes. At certain times of year, wetlands can therefore potentially provide a land surface feedback on rainfall. Here we assess the influence of wetlands on rainfall across sub‐Saharan Africa (SSA). Using a well‐established multi‐satellite based product of wetland extent with monthly temporal resolution, we find significant wetland coverage (>10%) occurs at some point in the 15‐year dataset for about 22% of SSA. We analyse rainfall patterns in the vicinity of major wetlands using satellite data, and find a consistent signal across SSA of locally suppressed rainfall over the wetlands as compared to nearby drier areas. This signal contrasts with a simple atmospheric water balance perspective which would suggest increased rain in response to increased local evaporation. The observed signal is strongest during the afternoon and weakens overnight. Using cloud‐top temperature data from the Sahel, we find that afternoon convective initiation is favoured close to wetlands, consistent with forcing by a thermally induced circulation from gradients in sensible heat fluxes. We also find that in this region, where the vast majority of rainfall is associated with remotely triggered Mesoscale Convective Systems (MCS), convection weakens when these systems pass over wetlands. From this study, we conclude that wetlands across the range of climate zones spanning SSA influence rainfall patterns locally, and where MCS are an important component of rainfall, this influence can extend over a larger region, associated with the tracks of long‐lived MCS.
Die Einführung der Direct Strength Method zur Bemessung von kaltgeformten Stahlprofilen nach EN1993‐1‐3
Authors: Clasen Sascha , Brune Bettina
Published: April 2018

Herrn Prof. Dr.‐Ing. habil. Joachim Lindner zur Vollendung seines 80. Lebensjahres gewidmet

Kaltgeformte, dünnwandige Profile des Stahlleichtbaus sind vielseitig einsetzbar, unterliegen bei einwirkenden Druck‐ und Biegebeanspruchungen jedoch lokalen und globalen Stabilitätsgefährdungen. Das Bemessungsverfahren der europäischen Normung EN 1993‐1‐3 stützt sich zur Beurteilung des lokalen Beulens und der Forminstabilität auf die Methode der wirksamen Breiten. Diese Art der Bemessung ist zeitaufwändig und fehleranfällig, zudem sind die Bemessungsergebnisse oft konservativ. In diesem Beitrag wird ein neues, praxisnahes Bemessungsmodell vorgestellt, das die bewährten europäischen Regelungen zum globalen Stabilitätsnachweis mit der in der nordamerikanischen Norm AISI Standard 100 beschriebenen Direct Strength Method (DSM) für die lokale Stabilitätsanalyse des kaltgeformten Stahlquerschnitts kombiniert. Anhand von Vergleichsrechnungen an einfachsymmetrischen Querschnitten lässt sich aufzeigen, dass diese neue Methode große Potenziale zur Effizienzsteigerung bei der Bemessung von Kaltprofilen bietet, zugleich aber auch die Wirtschaftlichkeit der Leichtbauprofile verbessert. Bis das Verfahren die europäische Normung jedoch sinnvoll ergänzen kann, sind weitere Versuche und Vergleichsrechnungen durchzuführen sowie tiefergehende Fragestellungen zu beantworten.
Rekonstruktion und Neunutzung der Messehalle 15 auf dem Gelände der Alten Messe in Leipzig
Authors: Ritter Jens
Published: April 2018

Dem 90. Jahrestag der Erstausgabe der Zeitschrift DER STAHLBAU gewidmet

Vor 90 Jahren, im April 1928, erschien erstmalig die Zeitschrift DER STAHLBAU. Der erste Fachartikel in der ersten Ausgabe widmete sich der Konstruktion und dem Bau der Messehalle 7 (heute Messehalle 15) auf dem Gelände der Technischen Messe in Leipzig. Die Halle hielt zum Zeitpunkt ihrer Errichtung mit 100 m freier Spannweite einen Rekord. Nach einer wechselvollen Geschichte wird das denkmalgeschützte Bauwerk aktuell rekonstruiert und einer neuen Nutzung zugeführt. Dieser Beitrag beschreibt die Bau‐ und Nutzungsgeschichte der Messehalle sowie die Planung der Neunutzung. Besondere Berücksichtigung findet die Überprüfung und die Nachrechnung der historischen Stahlkonstruktion. Zugleich soll damit die Bedeutung dieser Zeitschrift für die in Wissenschaft und Stahlbaupraxis tätigen Ingenieurinnen und Ingenieure hervorgehoben werden.
Influence and mechanism of pressure on SF6 decomposition components of gas‐insulated switchgear under positive DC partial discharge
Authors: Cao Zhengqin , Tang Ju , Miao Yulong , Zhu Ning , Yao Qiang , Zeng Fuping
Published: April 2018

To clarify the influence of pressure on SF6 decomposition under positive DC partial discharge (PD), SF6‐positive DC partial discharge decomposition experiments at different pressures were carried out. We found that the contents of SF6 primary decomposition products are proportional to . Keeping the chamber volume and external temperature constant, the difference of air chamber pressure means that the electronic mean free path is different. So, different pressures make a difference in the energy of free electrons obtained in a single flight, which results in the difference in the reaction rates of SF6 primary decomposition and further influences the formation of SF6 PD characteristic decomposition components. © 2018 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Using Websites to Recruit Franchisee Candidates
Authors: López-Fernández Begoña , Perrigot Rozenn
Published: April 2018

Unlike other interorganizational relationships, such as joint ventures, franchisors commonly display information on their websites with the objective of attracting franchisee entrepreneurs and having them sign standardized contracts. This paper analyses, for the first time, how franchise brands disclose both functional and symbolic benefits and their effect on franchise chain growth. Our empirical study, based on an in-depth analysis of 106 websites, suggests that both types of benefits are intertwined in advertising franchise opportunities. Information on financial requirements, contact facilities and recruiting processes are positively related to franchise chain growth, whereas information on business potential (financial expectations) is negatively related to growth. Moreover, information on continuous assistance is relevant for service-type franchisee candidates. Finally, our observations show that information available in all the categories is far from exhaustive and that influential information is frequently absent from franchisor websites.
Benefit-Cost Analysis in EU Chemicals Legislation: Experiences from over 100 REACH Applications for Authorisation
Authors: Georgiou Stavros , Rheinberger Christoph M. , Vainio Matti
Published: April 2018

In this paper we review the benefit-cost analyses (BCAs) made to support applications for authorisations under the EU’s REACH Regulation on hazardous chemicals. Experiences from over 100 cases suggest that there are a number of informational and methodological challenges to overcome in these BCAs. In particular, we find that many REACH applicants have had problems explaining the societal relevance of the regulatory impacts expected to affect them and other market actors. Adapting the framework for regulatory impact assessment proposed by Dudley et al. [(2017). Consumer’s Guide to Regulatory Impact Analysis: Ten Tips for Being an Informed Policymaker. Journal of Benefit-Cost Analysis, 8, 187–204], we discuss these impacts from a welfare economics perspective and make suggestions on how to improve current practices in BCA applied to chemicals risk management. From this discussion we then distill a number of topics that deserve more attention in applied BCAs under the REACH Regulation.
Meccano Magazine: boys’ toys and the popularization of science in early twentieth-century Britain
Authors: BOWLER PETER J.
Published: April 2018

Meccano Magazine began publishing in 1916 to advertise the popular children's construction set. By the 1920s it had expanded into a substantial, well-illustrated monthly that eventually achieved a circulation of seventy thousand. Under the editorship of the popular-science writer Ellison Hawks it now devoted approximately half of its pages to real-life technology and some natural science. In effect, it became a popular-science magazine aimed at teenage and pre-teen boys. This article explores Hawks's strategy of exploiting interest in model building to encourage interest in science and technology. It surveys the contents of the magazine and shows how it developed over time. It is argued that the material devoted to real-life science and technology was little different to that found in adult popular-science magazines of the period, raising the possibility that Meccano Magazine’s large circulation may explain the comparative lack of success of the adult publications.
How autonomy is understood in discussions on the ethics of nudging
Authors: VUGTS ANASTASIA , VAN DEN HOVEN MARIËTTE , DE VET EMELY , VERWEIJ MARCEL
Published: April 2018

Nudging is considered a promising approach for behavioural change. At the same time, nudging has raised ethical concerns, specifically in relation to the impact of nudges on autonomous choice. A complexity is that in this debate authors may appeal to different understandings or dimensions of autonomy. Clarifying the different conceptualisations of autonomy in ethical debates around nudging would help to advance our understanding of the ethics of nudging. A literature review of these considerations was conducted in order to identify and differentiate between the conceptualisations of autonomy. In 33 articles on the ethics of nudging, we identified 280 autonomy considerations, which we labelled with 790 unique autonomy codes and grouped under 61 unique super-codes. Finally, we formulated three general conceptualisations of autonomy. Freedom of choice refers to the availability of options and the environment in which individuals have to make choices. Agency involves an individual's capacity to deliberate and determine what to choose. Self-constitution relates to someone's identity and self-chosen goals. In the debate about the ethics of nudging, authors refer to different senses of autonomy. Clarifying these conceptualisations contributes to a better understanding of how nudges can undermine or, on the other hand, strengthen autonomy.