bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, Characterization, Corrosion Resistance and In-Vitro Bioactivity Behavior of Biodegradable Mg–Zn–Mn–(Si–HA) Composite for Orthopaedic Applications
Authors: Prakash Chander , Singh Sunpreet , Gupta Munish Kumar , Mia Mozammel , Królczyk Grzegorz , Khanna Navneet
Published: September 2018

Recently, magnesium (Mg) has gained attention as a potential material for orthopedics devices, owing to the combination of its biodegradability and similar mechanical characteristics to those of bones. However, the rapid decay rate of Mg alloy is one of the critical barriers amongst its widespread applications that have provided numerous research scopes to the scientists. In this present, porous Mg-based biodegradable structures have been fabricated through the hybridization of elemental alloying and spark plasma sintering technology. As key alloying elements, the suitable proportions of silicon (Si) and hydroxyapatite (HA) are used to enhance the mechanical, chemical, and geometrical features. It has been found that the addition of HA and Si element results in higher degree of structural porosity with low elastic modulus and hardness of the Mg–Zn–Mn matrix, respectively. Further, addition of both HA and Si elements has refined the grain structure and improved the hardness of the as-fabricated structures. Moreover, the characterization results validate the formation of various biocompatible phases, which enhances the corrosion performance and biomechanical integrity. Moreover, the fabricated composites show an excellent bioactivity and offer a channel/interface to MG-63 cells for attachment, proliferation and differentiation. The overall results of the present study advocate the usefulness of developed structures for orthopedics applications.
Modulating Surface Morphology Related to Crystallization Speed of Perovskite Grain and Semiconductor Properties of Optical Absorber Layer under Controlled Doping of Potassium Ions for Solar Cells
Authors: Ling Tao , Zou Xiaoping , Cheng Jin , Yang Ying , Ren Haiyan , Chen Dan
Published: September 2018

Perovskite thin films with excellent optical semiconductor and crystallization properties and superior surface morphology are normally considered to be vital to perovskite solar cells (PSCs). In this paper, we systematically survey the process of modulating surface morphology and optical semiconductor and crystallization properties of methylammonium lead iodide film by controlling doping of K+ for PSC prepared in air and propose the mechanism of large K+-doped perovskite grain formation related to crystallization speed. The increase in the crystallization speed leads to the production of large grains without localized-solvent-vapor (LSV) pores via moderate doping of K+, and the exorbitant crystallization speed induces super large grains with LSV pores via excessive doping of K+. Furthermore, the semiconductor properties (absorption band edge wavelength, PL emission peak wavelength, energy band gap) of perovskite film can be significantly tuned by controlled doping of K+. The investigation of the detailed process of modulating surface morphology and semiconductor properties of perovskite thin film by controlled doping of K+ may provide guidance and pave the way for superior component design of absorption materials for cost-efficient PSCs.
Time in Quantum Mechanics and the Local Non-Conservation of the Probability Current
Authors: Modanese Giovanni
Published: September 2018

In relativistic quantum field theory with local interactions, charge is locally conserved. This implies local conservation of probability for the Dirac and Klein–Gordon wavefunctions, as special cases; and in turn for non-relativistic quantum field theory and for the Schrödinger and Ginzburg–Landau equations, regarded as low energy limits. Quantum mechanics, however, is wider than quantum field theory, as an effective model of reality. For instance, fractional quantum mechanics and Schrödinger equations with non-local terms have been successfully employed in several applications. The non-locality of these formalisms is strictly related to the problem of time in quantum mechanics. We explicitly compute, for continuum wave packets, the terms of the fractional Schrödinger equation and the non-local Schrödinger equation by Lenzi et al. that break local current conservation. Additionally, we discuss the physical significance of these terms. The results are especially relevant for the electromagnetic coupling of these wavefunctions. A connection with the non-local Gorkov equation for superconductors and their proximity effect is also outlined.
Effect of Regular Exercise and Functional Beverages on Changes in Body Weight and Waist Circumference in Healthy Japanese Subjects
Authors: Ide Kazuki , Takeuchi Masato , Seki Tomotsugu , Kawakami Koji
Published: September 2018

Background and objectives: The effects on anthropometry of several lipid-related foods for specified health uses (FOSHU) approved in Japan are not well known. We examined the effects of regular exercise and lipid-related FOSHU beverages on changes in body weight (BW) and waist circumference (WC) among factory and office workers. Materials and Methods: A total of 3002 subjects aged 20 years or older (2497 men and 505 women) received health check-ups in 2015 and 2016 and completed a lifestyle questionnaire. The association between regular exercise or lipid-related FOSHU beverage intake and changes in BW or WC were evaluated using trend test and linear regression analysis. Results: Regular exercise (≥1/week) was reported by 774 subjects (25.8%), and regular consumption of lipid-related FOSHU beverages (≥1/week) was reported by 1168 subjects (38.9%). The significant association between lipid-related FOSHU beverage intake and changes in BW was only observed among subjects with regular exercise (p for trend = 0.042). In the multivariable analysis, sex, older age, baseline weight, baseline body mass index (BMI), and regular exercise behavior were significantly associated with smaller changes in BW (p < 0.05). In WC, only the baseline values of WC and BMI were associated with one-year changes of WC. Conclusions: The combination of regular exercise and lipid-related FOSHU may be effective in maintaining BW.
Antioxidant and Antimicrobial Properties of Rosemary (Rosmarinus officinalis, L.): A Review
Authors: Nieto Gema , Ros Gaspar , Castillo Julián
Published: September 2018

Nowadays, there is an interest in the consumption of food without synthetic additives and rather with the use of natural preservatives. In this regard, natural extracts of the Lamiaceae family, such as rosemary, have been studied because of its bioactive properties. Several studies have reported that rosemary extracts show biological bioactivities such as hepatoprotective, antifungal, insecticide, antioxidant and antibacterial. It is well known that the biological properties in rosemary are mainly due to phenolic compounds. However, it is essential to take into account that these biological properties depend on different aspects. Their use in foods is limited because of their odour, colour and taste. For that reason, commercial methods have been developed for the preparation of odourless and colourless antioxidant compounds from rosemary. Owing to the new applications of natural extracts in preservatives, this review gives a view on the use of natural extract from rosemary in foods and its effect on preservative activities. Specifically, the relationship between the structure and activity (antimicrobial and antioxidant) of the active components in rosemary are being reviewed.
Contact Fatigue Failure Analysis of Helical Gears with Non-Entire Tooth Meshing Tests
Authors: Zhao Fuqiang , Ding Xiaofeng , Fan Xiaoyu , Cui Renjie , Li Yugui , Wang Tie
Published: September 2018

This study presents an experimental approach based on partial tooth meshing contact fatigue with constant amplitude and different lengths of load cycles. To achieve this, 20CrH helical gears were considered, limiting the region of interest to one-third of the tooth to accelerate crack initiation and propagation. Different factors, such as number of fatigue cycles, tooth flank morphology, residual stress, hardness, and microstructure evolution under fatigue, were considered. The ultimate goal was to relate these variations with the observed failure modes. The results showed that with increasing cycle number, the residual stress at the same position in the meshing zone of the tooth flank increased first and then decreased. The residual stress values at the lower position of the pitch circle were larger than that of the addendum and dedendum. After cyclic loading, the content of the twin martensite within the microstructure below the pitch circle decreased and the corresponding hardness value of the tooth flank was reduced. After long-term cyclic loading, the precipitated phases aggregated and grew and the discontinuous distribution hindered the grain boundary slip. The dislocation density increased, and the pile-up of dislocation resulted in stress concentration at the grain boundary and the phase boundary, which induced the initiation of fatigue crack of the tooth flank.
Gold Catalyzed Multicomponent Reactions beyond A3 Coupling
Authors: Visbal Renso , Graus Sara , Herrera Raquel P. , Gimeno M. Concepción
Published: September 2018

The preparation of complex architectures has inspired the search for new methods and new processes in organic synthesis. Multicomponent reactions have become an interesting approach to achieve such molecular diversity and complexity. This review intends to illustrate important gold-catalyzed examples for the past ten years leading to interesting skeletons involved in biologically active compounds.
Reviews of Social Embodiment for Design of Non-Player Characters in Virtual Reality-Based Social Skill Training for Autistic Children
Authors: Moon Jewoong
Published: September 2018

The purpose of this paper is to review the scholarly works regarding social embodiment aligned with the design of non-player characters in virtual reality (VR)-based social skill training for autistic children. VR-based social skill training for autistic children has been a naturalistic environment, which allows autistic children themselves to shape socially-appropriate behaviors in real world. To build up the training environment for autistic children, it is necessary to identify how to simulate social components in the training. In particular, designing non-player characters (NPCs) in the training is essential to determining the quality of the simulated social interactions during the training. Through this literature review, this study proposes multiple design themes that underline the nature of social embodiment in which interactions with NPCs in VR-based social skill training take place.
The Antisecretory Factor in Plasma and Breast Milk in Breastfeeding Mothers—A Prospective Cohort Study in Sweden
Authors: Gustafsson Anna , Granström Elisabeth , Stecksén-Blicks Christina , West Christina E. , Silfverdal Sven-Arne
Published: September 2018

Inflammation and infection postpartum threaten the mother and her infant. Human milk provides a defense for the infant, but inflammatory complications like mastitis may lead to the cessation of breastfeeding. Antisecretory factor (AF) has a role in the regulation of secretory processes and inflammation. The objective of the study was to describe AF-levels in plasma and breast milk, and in relation to breast complications. Breastfeeding mothers (n = 95) were consecutively recruited at a Well Baby Clinic in Umeå, Sweden. At inclusion four weeks postpartum, samples of venous blood (10 mL) and breast milk (10 mL) were collected. Active AF was analyzed with ELISA using a monoclonal antibody mAb43, and was detected in all samples of plasma and breast milk with a positive correlation (Spearman coefficient = 0.40, p < 0.001; Pearson correlation = 0.34, p < 0.01). High AF-levels in plasma correlated with high AF-levels in breast milk. The results suggest a co-regulation between active AF in plasma and breastmilk, and/or a local regulation of AF in the breast. Further studies are needed to determine the pathways for the activation of AF-levels in breast milk and plasma.
Maternal Administration of Probiotic or Prebiotic Prevents Male Adult Rat Offspring against Developmental Programming of Hypertension Induced by High Fructose Consumption in Pregnancy and Lactation
Authors: Hsu Chien-Ning , Lin Yu-Ju , Hou Chih-Yao , Tain You-Lin
Published: September 2018

Excessive intake of fructose is associated with hypertension. Gut microbiota and their metabolites are thought to be associated with the development of hypertension. We examined whether maternal high-fructose (HF) diet-induced programmed hypertension via altering gut microbiota, regulating short-chain fatty acids (SCFAs) and their receptors, and mediating nutrient-sensing signals in adult male offspring. Next, we aimed to determine whether early gut microbiota-targeted therapies with probiotic Lactobacillus casei and prebiotic inulin can prevent maternal HF-induced programmed hypertension. Pregnant rats received 60% high-fructose (HF) diet, with 2 × 108 CFU/day Lactobacillus casei via oral gavage (HF+Probiotic), or with 5% w/w long chain inulin (HF+prebiotic) during pregnancy and lactation. Male offspring (n = 7–8/group) were assigned to four groups: control, HF, HF+Probiotic, and HF+Prebiotic. Rats were sacrificed at 12 weeks of age. Maternal probiotic Lactobacillus casei and prebiotic inulin therapies protect against hypertension in male adult offspring born to fructose-fed mothers. Probiotic treatment prevents HF-induced hypertension is associated with reduced plasma acetate level and decreased renal mRNA expression of Olfr78. While prebiotic treatment increased plasma propionate level and restored HF-induced reduction of Frar2 expression. Maternal HF diet has long-term programming effects on the adult offspring’s gut microbiota. Probiotic and prebiotic therapies exerted similar protective effects on blood pressure but they showed different mechanisms on modulation of gut microbiota. Maternal HF diet induced developmental programming of hypertension, which probiotic Lactobacillus casei or prebiotic inulin therapy prevented. Maternal gut microbiota-targeted therapies could be reprogramming strategies to prevent the development of hypertension caused by maternal consumption of fructose-rich diet.
Magnetogels: Prospects and Main Challenges in Biomedical Applications
Authors: Veloso Sérgio R. S. , Ferreira Paula M. T. , Martins J. A. , Coutinho Paulo J. G. , Castanheira Elisabete M. S.
Published: September 2018

Drug delivery nanosystems have been thriving in recent years as a promising application in therapeutics, seeking to solve the lack of specificity of conventional chemotherapy targeting and add further features such as enhanced magnetic resonance imaging, biosensing and hyperthermia. The combination of magnetic nanoparticles and hydrogels introduces a new generation of nanosystems, the magnetogels, which combine the advantages of both nanomaterials, apart from showing interesting properties unobtainable when both systems are separated. The presence of magnetic nanoparticles allows the control and targeting of the nanosystem to a specific location by an externally applied magnetic field gradient. Moreover, the application of an alternating magnetic field (AMF) not only allows therapy through hyperthermia, but also enhances drug delivery and chemotherapeutic desired effects, which combined with the hydrogel specificity, confer a high therapeutic efficiency. Therefore, the present review summarizes the magnetogels properties and critically discusses their current and recent biomedical applications, apart from an outlook on future goals and perspectives.
Limitations of Viscoelastic Constitutive Models for Carbon-Black Reinforced Rubber in Medium Dynamic Strains and Medium Strain Rates
Authors: Carleo Francesca , Barbieri Ettore , Whear Roly , Busfield James J. C.
Published: September 2018

Modelling the viscoelastic behavior of rubber for use in component design remains a challenge. Most of the literature does not consider the typical regimes encountered by anti-vibration devices that are deformed to medium dynamic strains (0.5 to 3.5) at medium strain rates (0.5/s to 10/s). Previous studies have either focused on the behaviour at small strains and small strain rates or in fast loading conditions that result in low cycle fatigue or tearing phenomena. There is a lack of understanding of the dynamic response of natural rubber suspension components when used in real vehicle applications. This paper presents a review of popular viscoelastic nonlinear constitutive models and their ability to model the mechanical behaviour of typical elastomer materials such as Natural Rubber (NR) incorporating different PHR (Parts per Hundred Rubber, XX) of carbon black. The range of strain and strain rate are typical for the materials used in rubber suspensions when operating in severe service operating conditions, such as over rough terrain or over pot-holes. The cyclic strain is applied at different amplitudes and different strain rates in this medium strain range. Despite the availability of many models in the literature, our study reports that none of the existing models can fit the data satisfactorily over a wide range of conditions.
Electrocomposite Developed with Chitosan and Ionic Liquids Using Screen-Printed Carbon Electrodes Useful to Detect Rutin in Tropical Fruits
Authors: Muñoz Lili , Arancibia Verónica , García-Beltrán Olimpo , Nagles Edgar , Hurtado John J.
Published: September 2018

This work reports the development of a composite of the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BP4) and chitosan (CS) described in previous reports through a new method using cyclic voltammetry with 10 cycles at a scan rate of 50.0 mV s−1. This method is different from usual methods such as casting, deposition, and constant potential, and it allows the development of an electroactive surface toward the oxidation of rutin by stripping voltammetry applied to the detection in tropical fruits such as orange, lemon, and agraz (Vaccinium meridionale Swartz), with results similar to those reported in previous studies. In addition, the surface was characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and Raman spectroscopy. The limit of detection was 0.07 µmol L−1 and the relative standard deviation (RSD) of 10 measurements using the same modified electrode was 0.86%. Moreover, the stability of the sensor was studied for six days using the same modified electrode, where the variation of the signal using a known concentration of rutin (RT) was found to be less than 5.0%. The method was validated using a urine chemistry control spiked with known amounts of RT and possible interference was studied using ten substances including organic and biological compounds, metal ions, and dyes. The results obtained in this study demonstrated that this electrodeveloped composite was sensitive, selective, and stable.
On the Effects of InSAR Temporal Decorrelation and Its Implications for Land Cover Classification: The Case of the Ocean-Reclaimed Lands of the Shanghai Megacity
Authors: Ma Guanyu , Zhao Qing , Wang Qiang , Liu Min
Published: September 2018

In this work, we focused on the ocean-reclaimed lands of the Shanghai coastal region and we evidenced how, over these areas, the interferometric synthetic aperture radar (InSAR) coherence maps exhibit peculiar behavior. In particular, by analyzing a sequence of Sentinel-1 SAR InSAR coherence maps, we found a significant coherence loss over time in correspondence to the ocean-reclaimed platforms that are substantially different from the coherence loss experienced in naturally-formed regions with the same type of land cover. We have verified whether this is due to the engineering geological conditions or the soil consolidation subsidence in ocean-reclaimed region. In this work, we combine the information coming from InSAR coherence maps and the retrieved temporal decorrelation model with that obtained by using optical Sentinel-2 data, and we performed land cover classification analyses in the zone of the Pudong International Airport. To estimate the accuracy of utilizing InSAR coherence information for land cover classification, in particular, we have analyzed what causes the difference of the InSAR coherence loss with the same type of land cover. The presented results show that the coherence models can be useful to distinguish roads and buildings, thus enhancing the accuracy of land cover classification compared with that allowable by using only Sentinel-2 data. In particular, the accuracy of classification increases from 75% to 86%.
Innovative Blockchain-Based Approach for Sustainable and Credible Environment in Food Trade: A Case Study in Shandong Province, China
Authors: Mao Dianhui , Hao Zhihao , Wang Fan , Li Haisheng
Published: September 2018

Agri-food trade has a profound impact on social stability and sustainable economic development. However, there are several technological problems in current agricultural product transactions. For example, it is almost impossible to improve the efficiency of transactions and maintain market stability. This paper designs a novel Food Trading System with COnsortium blockchaiN (FTSCON) to eliminate information asymmetry in the food trade, in order to establish a sustainable and credible trading environment, the system uses consortium blockchain technology to meet the challenge of different authentications and permissions for different roles in food trade. Meanwhile, we have used the online double auction mechanism to eliminate competition. We also have designed a improved Practical Byzantine Fault Tolerance (iPBFT) algorithm to improve efficiency. In addition, a case study based on a series of data from Shandong Province, China indicate that the FTSCON can achieve profit improvement of merchants. Therefore, the proposed system proved to have high commercial value.
Impacts of Gratifications on Consumers’ Emotions and Continuance Use Intention: An Empirical Study of Weibo in China
Authors: Gogan Ives Chacourre Wangninanon , Zhang Ziqiong , Matemba Elizabeth Damian
Published: September 2018

Recently, several studies on information systems have applied the Uses and Gratifications theory to investigate individual use of social media, and have reported the role of different gratifications in predicting users’ behaviors. However, no attention was given to the influence of these gratifications on users’ emotional states (satisfaction and emotional commitment). To address this research gap, the current study integrates the Uses and Gratifications theory and the Stimulus-Organism-Response theory to provide a theoretical background for the impacts of gratification on consumers’ emotional states and continuance use intention. The study has proposed a theoretical model that was tested on data collected from 252 Sina Weibo users in China. The results revealed that social gratification is the most important factor influencing users’ satisfaction and emotional commitment. In addition, we report the roles that user satisfaction and emotional state provide in predicting users’ continuance intention. The theoretical and practical implications of the proposed theory are also discussed.
Mycetoma: The Spectrum of Clinical Presentation
Authors: Fahal Ahmed Hassan , Suliman Suliman Hussein , Hay Roderick
Published: September 2018

Mycetoma is a chronic infection, newly designated by the World Health Organization (WHO) as a neglected tropical disease, which is endemic in tropical and subtropical regions. It follows implantation of infectious organisms, either fungi (eumycetomas) or filamentous bacteria (actinomycetomas) into subcutaneous tissue, from where infection spreads to involve skin, bone and subcutaneous sites, leading to both health related and socioeconomic problems. In common with other NTDs, mycetoma is most often seen in rural areas amongst the poorest of people who have less access to health care. The organisms form small microcolonies that are discharged onto the skin surface via sinus tracts, or that can burrow into other adjacent tissues including bone. This paper describes the clinical features of mycetoma, as early recognition is a key to early diagnosis and the institution of appropriate treatment including surgery. Because these lesions are mostly painless and the majority of infected individuals present late and with advanced disease, simplifying early recognition is an important public health goal.
Structure Damage Identification Based on Regularized ARMA Time Series Model under Environmental Excitation
Authors: Zhang Xuan , Li Dongsheng , Song Gangbing
Published: September 2018

In this paper, a non-modal parametric method to identify structural damage using a regularized autoregressive moving average time series model under environmental excitation is proposed in combination with the virtual impulse response function. This method can use the structural vibration response to determine the damage caused to the structure during environmental excitation. Firstly, the virtual impulse response function is obtained by using the structural vibration response. Then, a regularized ARMA time series model is used to fit the virtual impulse response function. Based on the change of auto-regression coefficients in the regularization model under different damage cases, the structural damage is identified. The authors derive the regularization equation of an ARMA time series model to solve the problems in a time series model and obtain the regularization coefficient. Finally, this method is applied to a three-degrees-of-freedom chain structure and a three-floor shear structure of the Los Alamos National Laboratory (LANL). The experimental results show that the method based on the regularized ARMA time series model under environmental excitation can effectively identify the structural damage, which is a reliable method for damage identification. The regularized ARMA time series model can accurately extract signal features and has invaluable application prospects in the field of structural health monitoring.
Assessing Regional Climate Models (RCMs) Ensemble-Driven Reference Evapotranspiration over Spain
Authors: Giménez Patricia Olmos , García-Galiano Sandra G.
Published: September 2018

The present work applies a novel methodology of combining multiple Regional Climate Models (RCMs) (or ensemble) that are based on the seasonal and annual variability of temperatures over Spain, which allows for the quantification and reduction of uncertainty in the projections of temperature based-potential evapotranspiration. Reference evapotranspiration (ETo) is one of the most important variables in water budgets. Therefore, the uncertainties in the identification of reliable trends of reference evapotranspiration should be taken into account for water planning and hydrological modeling under climate change scenarios. From the results over Spain, the RCMs ensemble reproduces well the yearly and seasonal temperature observed dataset for the time reference period 1961–1990. An increase in the ensemble-driven ETo for time period 2021–2050 over Spain is expected, which is motivated by an increase in maximum and minimum temperature, with the consequent negative impacts on water availability.
In-Situ and Numerical Investigation of Groundwater Inrush Hazard from Grouted Karst Collapse Pillar in Longwall Mining
Authors: Ma Dan , Cai Xin , Li Qiang , Duan Hongyu
Published: September 2018

Groundwater inrush is a typical hydrologic natural hazard in mining engineering. Since 2000 to 2012, there have been 1110 types of mine groundwater inrush hazards with 4444 miners died or missing. As a general geological structure in the northern China coalfields, the karst collapse pillar (KCP) contains a significant amount of granular rocks, which can be easily migrated under high hydraulic pressure. Therefore, the KCP zone acts as an important groundwater inrush pathway in underground mining. Grouting the KCP zone can mitigate the risk of groundwater inrush hazard. However, the fracture or instability of the coal pillar near KCP can cause the instability of surrounding rock and even groundwater inrush hazard. To evaluate the risk of groundwater inrush from the aquifer that is caused by coal pillars instability within grouted KCP in a gob, an in-situ investigation on the deformation of the surrounding strata was conducted. Besides, a mechanical model for the continuous effect on the coal pillar with the floor-pillar-roof system was established; then, a numerical model was built to evaluate the continuous instability and groundwater inrush risk. The collective energy and stiffness in the floor-pillar-roof system are the two criterions for judging the stability of the system. As a basic factor to keep the stability of floor-pillar-roof system, the collective energy in coal pillar is larger than that in floor-roof system. Moreover, if the stiffness of floor-roof or coal pillar meets a negative value, the system will lose stability; thus, the groundwater inrush pathway will be produced. However, if there is a negative value occurring in floor-pillar-roof system meets, it indicates that the system structure is situated in a damage state; a narrower coal pillar will enlarge the risk of continuous instability in the system, leading to a groundwater inrush pathway easily. Continuous coal pillars show a lower probability of instability. Conversely, the fractured coal pillars have a greater probability of failure. The plastic zone and deformation of the roadway roof in the fractured coal pillar are larger than that of continuous coal pillar, indicating that the continuous coal pillars mitigate the risk of groundwater inrush hazard effectively.
Microspheres as Surrogate Helminth Eggs: A Comparative Labscale Sedimentation Study for Tap- and Wastewater
Authors: Arthur Barbara K. , Nettmann Edith , Rademacher Andrea , Lübken Manfred , Marschner Bernd , Wichern Marc
Published: September 2018

Re-use of water containing helminth eggs during irrigation for agricultural purposes poses health risks, and likewise during research, due to the potential of spreading on contact. Therefore, polystyrene latex microspheres could be used as surrogates for chemical or biological species during colloidal transport. The aim here is to compare the settling velocities of microspheres having varied surface coatings—that is, proteins A, G and A/G; with that of real helminth eggs obtained from literature. The settling velocities of the microspheres were experimentally determined in tap- and wastewater, as well as theoretically in tap water; which was found to be within the range of mean values for those experimentally determined. There were no differences amongst the microspheres types used for settling in wastewater (i.e., A = 0.072 ± 0.02; G = 0.060 ± 0.03; A/G = 0.053 ± 0.01 mm/s). The same applied for settling in tap water (i.e., A = 0.068 ± 0.02; G = 0.047 ± 0.004; A/G = 0.095 ± 0.02 mm/s), except for microsphere G being different from microsphere A/G. All three types of microspheres settled at velocities lower than that of the wastewater particles (=0.118 ± 0.03). T-test analyses of settling velocities of microspheres in both tap- and wastewater, versus that from literature (i.e., Ascaris, Trichuris and Oesophagostomum), showed that microsphere A and A/G may surrogate for Ascaris in tap water, the same as A/G for Oesophagostomum. In wastewater however, both microspheres A and G are a good fit for Trichuris.
Incorporating Surface Convection into a 3D Babcock–Leighton Solar Dynamo Model
Authors: Hazra Gopal , Miesch Mark S.
Published: September 2018

The convective flows observed on the photosphere (e.g., supergranulation, granulation) play a key role in the Babcock–Leighton (BL) process to generate large-scale polar fields from sunspot fields. In most surface flux transport (SFT) and BL dynamo models, the dispersal and migration of surface fields are modeled as an effective turbulent diffusion. Recent SFT models have incorporated explicit, realistic convective flows in order to improve the fidelity of convective transport but, to our knowledge, this has not yet been implemented in previous BL models. We present the first kinematic 3D Flux-Transport/BL model to explicitly incorporate realistic convective flows based on solar observations. Though we describe a means to generalize these flows to 3D, we find that the kinematic small-scale dynamo action they produce disrupts the operation of the cyclic dynamo. The cyclic solution is found by limiting the convective flow to act only on the vertical radial component of the magnetic field. The results obtained are generally in good agreement with the observed surface flux evolution and with non-convective models that have a turbulent diffusivity of the order of 3 × 1012 cm2 s−1 (300 km2 s−1). However, we find that the use of a turbulent diffusivity underestimates the dynamo efficiency, producing weaker mean fields and a shorter cycle than in the convective models. Also, the convective models exhibit bands of mixed polarity in the polar regions that have no counterpart in solar observations, and the poleward migration speed of poloidal flux is determined mainly by the meridional flow and the vertical diffusion.
Unraveling the Complex Structure of AGN-driven Outflows. III. The Outflow Size–Luminosity Relation
Authors: Kang Daeun , Woo Jong-Hak
Published: September 2018

Energetic gas outflows driven by active galactic nuclei (AGNs) are considered as one of the mechanisms by which supermassive black holes affect their host galaxies. To probe the impact of AGN-driven outflows, it is essential to quantify the size of the region under the influence of such outflows. In the third of a series of papers, we present the spatially resolved kinematics of ionized gas for three additional Type 2 AGNs based on Gemini Multi-Object Spectrograph (GMOS) integral field spectroscopy. Along with the six AGNs presented in our previous works and the 14 AGNs with available GMOS-integral field unit data, we construct a sample of 23 luminous Type 2 AGNs at z < 0.2, and kinematically measure the size of ionized gas outflows by tracing the radial decrease of the velocity dispersion of the [O iii] λ5007 emission line. The kinematically measured outflow size ranges from 0.60 to ∼7.45 kpc, depending on AGN luminosity. We find that the size of the photoionized region is larger than the kinematically measured outflow size, while the flux-weighted photoionization size is significantly smaller. Thus, using photoionization size as a proxy for outflow size leads to overestimation or underestimation, and introduces large uncertainties of the mass outflow rate and the energy output rate. We report an outflow size–luminosity relation with a slope of 0.28 ± 0.03, which is shallower than the slope of the correlation between the photoionization size and luminosity.
Galaxy Structure in the Ultraviolet: The Dependence of Morphological Parameters on Rest-frame Wavelength
Authors: Mager Violet A. , Conselice Christopher J. , Seibert Mark , Gusbar Courtney , Katona Anthony P. , Villari Joseph M. , Madore Barry F. , Windhorst Rogier A.
Published: September 2018

Evolutionary studies that compare galaxy structure as a function of redshift are complicated by the fact that any particular galaxy’s appearance depends in part on the rest-frame wavelength of the observation. This leads to the necessity for a “morphological k-correction” between different passbands, especially when comparing the rest-frame optical or infrared (IR) to the ultraviolet (UV). This is of particular concern for high-redshift studies that are conducted in the rest-frame UV. We investigate the effects of this “bandpass shifting” out of the UV by quantifying nearby galaxy structure via concentration, asymmetry, and clumpiness (CAS) parameters. For this study we combine panchromatic data from the UV through the near-IR with Galaxy Evolution Explorer (GALEX) data of 2073 nearby galaxies in the “near-UV” (NUV; ∼230 nm) and 1127 in the “far-UV” (FUV; ∼150 nm), providing the largest study of this kind in the mid- to far-UV. We find a relationship between the CAS parameters and observed rest-frame wavelength that make galaxies appear more late-type at shorter wavelengths, particularly in the UV. The effect is strongest for E/S0 galaxies in the far-UV, which have concentrations and asymmetries that more closely resemble those of spiral and peculiar/merging galaxies in the optical. This may be explained by extended disks containing recent star formation. Here, we also release the CAS values of the galaxies imaged in GALEX NUV and FUV for use in comparisons with deep Hubble Space Telescope imaging and the James Webb Space Telescope in the future.
Turbulent Transport by Diffusive Stratified Shear Flows: From Local to Global Models. III. A Closure Model
Authors: Kulenthirarajah Logithan , Garaud Pascale
Published: September 2018

Being able to account for the missing mixing in stellar radiative zones is a key step toward a better understanding of stellar evolution. Zahn argued that thermally diffusive shear-induced turbulence might be responsible for some of this mixing. In Part I and Part II of this series of papers, we showed that Zahn’s mixing model applies when the properties of the turbulence are local. But we also discovered limitations of the model when this locality condition fails, in particular near the edge of a turbulent region. In this paper, we propose a second-order closure model for the transport of momentum and chemical species by shear-induced turbulence in strongly stratified, thermally diffusive environments (the so-called low Péclet number (LPN) limit), which builds upon the work of Garaud & Ogilvie. Comparison against direct numerical simulations (DNSs) shows that the model is able to predict the vertical profiles of the mean flow and of the stress tensor (including the momentum transport) in diffusive shear flows, often with a reasonably good precision, and at least within a factor of order unity in the worst case scenario. The model is sufficiently simple to be implemented in stellar evolution codes, and all the model constants have been calibrated against DNSs. While significant limitations to its use remain (e.g., it can only be used in the slowly rotating LPN limit), we argue that it is more reliable than most of the astrophysical prescriptions that are used in stellar evolution models today.
Studies of Turbulence Dissipation in the Taurus Molecular Cloud with Core Velocity Dispersion
Authors: Qian Lei , Li Di , Gao Yang , Xu Haitao , Pan Zhichen
Published: September 2018

Turbulence dissipation is an important process affecting the energy balance in molecular clouds, the birth place of stars. Previously, the rate of turbulence dissipation is often estimated with semi-analytic formulae from simulation. Recently, we developed a data analysis technique called core velocity dispersion, which, for the first time, provides direct measurements of the turbulence dissipation rate in Taurus, a star-forming cloud. The thus measured dissipation rate of

is similar to those from dimensional analysis, and is also consistent with the previous energy injection rate based on molecular outflows and bubbles.
The Formation of Extremely Diffuse Galaxy Cores by Merging Supermassive Black Holes
Authors: Rantala Antti , Johansson Peter H. , Naab Thorsten , Thomas Jens , Frigo Matteo
Published: September 2018

Given its velocity dispersion, the early-type galaxy NGC 1600 has an unusually massive (M
• = 1.7 × 1010
M
⊙) central supermassive black hole (SMBH) surrounded by a large core (r
b = 0.7 kpc) with a tangentially biased stellar distribution. We present high-resolution equal-mass merger simulations including SMBHs to study the formation of such systems. The structural parameters of the progenitor ellipticals were chosen to produce merger remnants resembling NGC 1600. We test initial stellar density slopes of ρ ∝ r
−1 and ρ ∝ r
−3/2 and vary the initial SMBH masses from 8.5 × 108 to 8.5 × 109
M
⊙. With increasing SMBH mass, the merger remnants show a systematic decrease in central surface brightness, an increasing core size, and an increasingly tangentially biased central velocity anisotropy. Two-dimensional kinematic maps reveal decoupled, rotating core regions for the most massive SMBHs. The stellar cores form rapidly as the SMBHs become bound, while the velocity anisotropy develops more slowly after the SMBH binaries become hard. The simulated merger remnants follow distinct relations between the core radius and the sphere of influence, and the SMBH mass, similar to observed systems. We find a systematic change in the relations as a function of the progenitor density slope and present a simple scouring model reproducing this behavior. Finally, we find the best agreement with NGC 1600 using SMBH masses totaling the observed value of M
• = 1.7 × 1010
M
⊙. In general, density slopes of ρ ∝ r
−3/2 for the progenitor galaxies are strongly favored for the equal-mass merger scenario.
An Updated Catalog of 4680 Northern Eclipsing Binaries with Algol-type Light-curve Morphology in the Catalina Sky Surveys
Authors: Papageorgiou Athanasios , Catelan Márcio , Christopoulou Panagiota-Eleftheria , Drake Andrew J. , Djorgovski S. G.
Published: September 2018

We present an updated catalog of 4680 northern eclipsing binaries (EBs) with Algol-type light-curve (LC) morphology (i.e., with well-defined beginnings and ends of primary and secondary eclipses), using data from the Catalina Sky Surveys. Our work includes revised period determinations, phenomenological parameters of the LCs, and system morphology classifications based on machine-learning techniques. While most of the new periods are in excellent agreement with those provided in the original Catalina catalogs, improved values are now available for ∼10% of the stars. A total of 3456 EBs were classified as detached and 449 were classified as semi-detached, while 145 could not be classified unambiguously into either subtype. The majority of the SD systems seem to be comprised of short-period Algols. By applying color criteria, we searched for K- and M-type dwarfs in these data, and present a subsample of 609 EB candidates for further investigation. We report 119 EBs (2.5% of the total sample) that show maximum quadrature light variations over long timescales, with periods bracketing the range 4.5–18 years and a fractional luminosity variance range of 0.04–0.13. We discuss possible causes for this, making use of models of variable starspot activity in our interpretation of the results.
Internacionalistas entre la revolución y el fascismo: la Unión General de Trabajadores en el mundo (1919-1936)
Authors: Aroca Mohedano Manuela
Published: September 2018

El artículo analiza la política exterior que desarrolló UGT de España, en el marco del internacionalismo obrero, durante el periodo de entreguerras. Se ha consultado documentación del Instituto de Historia Social de Ámsterdam, documentación de las Fundaciones Francisco Largo Caballero y Pablo Iglesias, así como abundante documentación de hemeroteca. Metodológicamente, se basa en la comparación entre los documentos de las Internacionales y los que elaboró la central sindical española, referidos a cuestiones exteriores. Entre 1919 y el estallido de la guerra civil española, se estabiliza el mundo internacional obrero, al que los ugetistas españoles se incorporaron en la creencia de que el internacionalismo sería eficaz para solucionar grandes problemas. Los acontecimientos fueron demostrando la impotencia de las organizaciones obreras a la hora de enfrentarse a los grandes desafíos de las décadas de los años veinte y treinta. UGT acudió al internacionalismo para justificar la estrategia reformista que el sindicato había adoptado en el interior. Durante el bienio negro, contribuyó a radicalizar la posición de líderes y militantes. El artículo pretende demostrar que la política exterior fue, en todo este tiempo, muy influyente en la línea estratégica que adoptó el sindicato en el interior de España.
Patentes sobre fotografía en España (1839-1939). Análisis documental: contenidos y solicitantes
Authors: Sánchez-Vigil Juan Miguel , Olivera-Zaldua María , Marcos-Recio Juan Carlos
Published: September 2018

Desde la presentación oficial de la fotografía en la Academia de Ciencias de París en el año 1839, la invención de procedimientos, aplicaciones, aparatos y materiales fue constante. La documentación histórica sobre el tema se conserva en la Oficina Española de Patentes y Marcas (OEPM) desde el 27 de marzo de 1826 hasta la actualidad. Es objeto de este artículo el análisis documental de las patentes sobre fotografía concedidas durante un siglo, entre 1839 y 1939, periodo comprendido entre el invento del daguerrotipo y el final de la Guerra Civil de 1936-1939. La metodología específica se basa en la recuperación de la información desde las bases de datos de la OEPM, que comprenden documentación entre 1826 y 1966. A partir de 85 términos de búsqueda han resultado 973 patentes en el periodo estudiado, de las que se han extraído 221 conceptos clasificados en cinco categorías generales1: Aplicación, Material, Procedimientos, Color y Tecnología. Se han recopilado además los nombres de los solicitantes (1.130) y las fechas de registro de las solicitudes, que se presentan en anexo.
Perceptions of Diversity, Inclusion, and Belongingness at an HBCU
Authors: Hiatt Matthew A. , Mc Letchie Alison , Bagasra Anisah B. , Laufersweiler-Dwyer Deborah L. , Mackinem Mitchell
Published: September 2018

Most studies about inclusion of traditional minority groups and women on university campuses have been conducted at Predominantly White Institutions with student populations. This chapter focuses on the experiences, perceptions, and implications of diversity, belongingness, and inclusion of faculty at Historically Black Colleges and Universities (HBCUs). Data collected from students, staff, and faculty highlight the diversity and positive climate at HBCUs but indicate that there are important differences in how particular groups perceive inclusion. This chapter offers suggestions on how faculty and HBCUs can celebrate diversity and yet acknowledge, discuss, and act against the negative experiences that shape feelings of inclusion. The authors emphasize the role of HBCUs in standing for and leading discussions on diversity, equity, and inclusion.
Global Wannacrypt Ransomware Attack
Authors: Assay Benjamin Enahoro
Published: September 2018

Cyber-attacks have become a global phenomenon that organizations, government agencies, and business entities have to contend with as cyber criminals frequently target their operations. One such cyber-attack is the Wannacrypt ransomware that was unleashed on the global community in early May 2017 with a resultant devastating effect. The attack, described as the largest in the history of the internet, disrupted major organizations and affected over 200,000 computers in 150 countries. It is against this backdrop that this chapter examines the issues and trends in the Wannacrypt ransomware attack and recommends ways to avert future occurrences.
Challenges for Promotion of Heritage Tourism
Authors: Seraphim Joanna , Haq Farooq
Published: September 2018

This chapter appreciates the growing significance of heritage tourism, even in a place well-known as a fun-based modern destination. This study is based on an exploratory research which used qualitative research to study issues related to the promotion of heritage tourism in the United Arab Emirates. The purpose of this chapter was to identify challenges faced by the public and private tourism organizers for heritage tourism in the country. This original research employed the Delphi techniques and interviewed renowned heritage and cultural experts. Critical realism ontology was applied to analyze the qualitative data where themes emerged as the key challenges. Five themes emerged from the research that could be replicated to study heritage tourism challenges in other countries. A subsequent study to identify and assess solutions and strategies for these challenges is the suggested future study for this chapter.