bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the Long-Term Hydrolytic Behavior of Zwitterionic Polymethacrylates and Polymethacrylamides
Authors: Schönemann Eric , Laschewsky André , Rosenhahn Axel
Published: June 2018

The hydrolytic stability of polymers to be used for coatings in aqueous environments, for example, to confer anti-fouling properties, is crucial. However, long-term exposure studies on such polymers are virtually missing. In this context, we synthesized a set of nine polymers that are typically used for low-fouling coatings, comprising the well-established poly(oligoethylene glycol methylether methacrylate), poly(3-(N-2-methacryloylethyl-N,N-dimethyl) ammoniopropanesulfonate) (“sulfobetaine methacrylate”), and poly(3-(N-3-methacryamidopropyl-N,N-dimethyl)ammoniopropanesulfonate) (“sulfobetaine methacrylamide”) as well as a series of hitherto rarely studied polysulfabetaines, which had been suggested to be particularly hydrolysis-stable. Hydrolysis resistance upon extended storage in aqueous solution is followed by 1H NMR at ambient temperature in various pH regimes. Whereas the monomers suffered slow (in PBS) to very fast hydrolysis (in 1 M NaOH), the polymers, including the polymethacrylates, proved to be highly stable. No degradation of the carboxyl ester or amide was observed after one year in PBS, 1 M HCl, or in sodium carbonate buffer of pH 10. This demonstrates their basic suitability for anti-fouling applications. Poly(sulfobetaine methacrylamide) proved even to be stable for one year in 1 M NaOH without any signs of degradation. The stability is ascribed to a steric shielding effect. The hemisulfate group in the polysulfabetaines, however, was found to be partially labile.
“A Web of Subversive Friends”: New Monasticism in the United States and South Africa
Authors: Schneider Rachel C.
Published: June 2018

This article analyzes new monastic efforts to engage with systemic inequality in the United States and South Africa, arguing for the importance of the concept of friendship to new monastic social justice efforts. Growing in popularity during the 2000s, new monasticism is a term used to describe Christians who are experimenting with forms of community and subject formation that take as their inspiration earlier monastic or other Christian socialist/communitarian movements. Drawing on qualitative research conducted with two South African groups inspired by new monasticism, I show how building relationships with economic and racial others is central to new monastic visions of social change. New monastics emphasize the importance of deep, committed, authentic, relationships—friendships—as the primary means of surmounting race and class divides. Building on the insights of Michael Emerson and Christian Smith in Divided by Faith, I argue that how new monastics conceptualize friendship simultaneously draws on and subverts traditional evangelical approaches to social engagement. Although new monastics are similar to evangelicals in that they attach central importance to interpersonal relationships, new monastics are distinct in that they explicitly connect the value of relationship building to practices of self-transformation and social critique.
Lower Limb Exoskeleton for Rehabilitation with Improved Postural Equilibrium
Authors: Menga Giuseppe , Ghirardi Marco
Published: June 2018

In this work we present a lower limb haptic exoskeleton suitable for patient rehabilitation, specifically in the presence of illness on postural equilibrium. Exoskeletons have been mostly conceived to increase strength, while in this work patient compliance with postural equilibrium enhancement is embedded. This is achieved with two hierarchical feedback loops. The internal one, closing the loop on the joint space of the exoskeleton offers compliance to the patient in the neighborhood of a reference posture. It exploits mechanical admittance control in a position loop, measuring the patient’s Electro Miographical (EMG) signals. The problem is solved using multi variable robust control theory with a two degrees of freedom setting. A second control loop is superimposed on the first one, operating on the Cartesian space so as to guarantee postural equilibrium. It controls the patient’s Center of Gravity (COG) and Zero Moment Point (ZMP) by moving the internal loop reference. Special attention has been devoted to the mechanical multi-chain model of the exoskeleton which exploits Kane’s method using the Autolev symbolic computational environment. The aspects covered are: the switching system between single and double stance, the system’s non-holonomic nature, dependent and independent joint angles, redundancy in the torque controls and balancing weight in double stance. Physical experiments to validate the compliance method based on admittance control have been performed on an elbow joint at first. Then, to further validate the haptic interaction with the patient in a realistic situation, experiments have been conducted on a first exoskeleton prototype, while the overall system has been simulated in a realistic case study.
Daily Retrieval of NDVI and LAI at 3 m Resolution via the Fusion of CubeSat, Landsat, and MODIS Data
Authors: Houborg Rasmus , McCabe Matthew F.
Published: June 2018

Constellations of CubeSats are emerging as a novel observational resource with the potential to overcome the spatiotemporal constraints of conventional single-sensor satellite missions. With a constellation of more than 170 active CubeSats, Planet has realized daily global imaging in the RGB and near-infrared (NIR) at ~3 m resolution. While superior in terms of spatiotemporal resolution, the radiometric quality is not equivalent to that of larger conventional satellites. Variations in orbital configuration and sensor-specific spectral response functions represent an additional limitation. Here, we exploit a Cubesat Enabled Spatio-Temporal Enhancement Method (CESTEM) to optimize the utility and quality of very high-resolution CubeSat imaging. CESTEM represents a multipurpose data-driven scheme for radiometric normalization, phenology reconstruction, and spatiotemporal enhancement of biophysical properties via synergistic use of CubeSat, Landsat 8, and MODIS observations. Phenological reconstruction, based on original CubeSat Normalized Difference Vegetation Index (NDVI) data derived from top of atmosphere or surface reflectances, is shown to be susceptible to large uncertainties. In comparison, a CESTEM-corrected NDVI time series is able to clearly resolve several consecutive multicut alfalfa growing seasons over a six-month period, in addition to providing precise timing of key phenological transitions. CESTEM adopts a random forest machine-learning approach for producing Landsat-consistent leaf area index (LAI) at the CubeSat scale with a relative mean absolute difference on the order of 4–6%. The CubeSat-based LAI estimates highlight the spatial resolution advantage and capability to provide temporally consistent and time-critical insights into within-field vegetation dynamics, the rate of vegetation green-up, and the timing of harvesting events that are otherwise missed by 8- to 16-day Landsat imagery.
Land Cover Change Detection Based on Adaptive Contextual Information Using Bi-Temporal Remote Sensing Images
Authors: Lv Zhiyong , Liu Tongfei , Zhang Penglin , Atli Benediktsson Jón , Chen Yixiang
Published: June 2018

Land cover change detection (LCCD) based on bi-temporal remote sensing images plays an important role in the inventory of land cover change. Due to the benefit of having spatial dependency properties within the image space while using remote sensing images for detecting land cover change, many contextual information-based change detection methods have been proposed in past decades. However, there is still a space for improvement in accuracies and usability of LCCD. In this paper, a LCCD method based on adaptive contextual information is proposed. First, an adaptive region is constructed by gradually detecting the spectral similarity surrounding a central pixel. Second, the Euclidean distance between pairwise extended regions is calculated to measure the change magnitude between the pairwise central pixels of bi-temporal images. All the bi-temporal images are scanned pixel by pixel so the change magnitude image (CMI) can be generated. Then, the Otsu or a manual threshold is employed to acquire the binary change detection map (BCDM). The detection accuracies of the proposed approach are investigated by three land cover change cases with Landsat bi-temporal remote sensing images and aerial images with very high spatial resolution (0.5 m/pixel). In comparison to several widely used change detection methods, the proposed approach can produce a land cover change inventory map with a competitive accuracy.
Automatic Measurement of Water Height in the As Conchas (Spain) Reservoir Using Sentinel 2 and Aerial LiDAR Data
Authors: González-Jorge Higinio , González-deSantos Luis Miguel , Martínez-Sánchez Joaquin , Sánchez-Rodríguez Ana , Lorenzo Henrique
Published: June 2018

A methodology for the measurement of height in water reservoirs is developed. It is based on Sentinel 2 imagery and aerial LiDAR data. The methodology is automatized using Matlab software and focused on image processing techniques (equalization, binarization, and edge detection) combined with LiDAR data processing (near neighbour search and height averaging). It is applied in a region of interest selected by the user characterized by a water–land interface. Results are validated in the As Conchas water reservoir (Spain) using an in situ sensing system provided by the Hydrographic Miño-Sil Confederation. The duration of the experiment was one year. The Sentinel 2 bands B2, B3, B4, and B8 were tested during this study. The best results for water height evaluation were obtained for band B8 (842 nm) with an error of 0.20 m and a standard deviation of 0.17 m. The time resolution of the technique depends on the Sentinel 2 revisit time. The time resolution and height accuracy could be improved using complementary satellite systems.
Soil Moisture Monitoring in a Temperate Peatland Using Multi-Sensor Remote Sensing and Linear Mixed Effects
Authors: Millard Koreen , Thompson Dan K. , Parisien Marc-André , Richardson Murray
Published: June 2018

The purpose of this research was to use empirical models to monitor temporal dynamics of soil moisture in a peatland using remotely sensed imagery, and to determine the predictive accuracy of the approach on dates outside the time series through statistically independent validation. A time series of seven Moderate Resolution Imaging Spectroradiometer (MODIS) and Synthetic Aperture Radar (SAR) images were collected along with concurrent field measurements of soil moisture over one growing season, and soil moisture retrieval was tested using Linear Mixed Effects models (LMEs). A single-date airborne Light Detection and Ranging (LiDAR) survey was incorporated into the analysis, along with temporally varying environmental covariates (Drought Code, Time Since Last Rain, Day of Year). LMEs allowed repeated measures to be accounted for at individual sampling sites, as well as soil moisture differences associated with peatland classes. Covariates provided a large amount of explanatory power in models; however, SAR imagery contributed to only a moderate improvement in soil moisture predictions (marginal R2 = 0.07; conditional R2 = 0.7, independently validated R2 = 0.36). The use of LMEs allows for a more accurate characterization of soil moisture as a function of specific measurement sites, peatland classes and measurement dates on model strength and predictive power. For intensively monitored peatlands, SAR data is best analyzed in conjunction with peatland Class (e.g., derived from an ecosystem classification map) to estimate the spatial distribution of surface soil moisture, provided there is a ground-based monitoring network with a sufficiently fine spatial and temporal resolution to fit the LME models.
Seasonal and Decadal Groundwater Changes in African Sedimentary Aquifers Estimated Using GRACE Products and LSMs
Authors: Bonsor H. , Shamsudduha M. , Marchant B. , MacDonald A. , Taylor R.
Published: June 2018

Increased groundwater abstraction is important to the economic development of Africa and to achieving many of the Sustainable Development Goals. However, there is little information on long-term or seasonal groundwater trends due to a lack of in situ monitoring. Here, we used GRACE data from three products (the Centre for Space Research land solution (CSR), the Jet Propulsion Laboratory’s Global Mascon solution (JPL-MSCN), and the Centre National D’etudes Spatiales / Groupe de Recherches de Géodésie Spatiale solution (GRGS)), to examine terrestrial water storage (TWS) changes in 12 African sedimentary aquifers, to examine relationships between TWS and rainfall , and estimate groundwater storage (GWS) changes using four Land Surface Models (LSMs) (Community Land Model (CLM2.0), the Variable Infiltration Capacity model (VIC), the Mosaic model (MOSAIC) and the Noah model (NOAH)). We find that there are no substantial continuous long-term decreasing trends in groundwater storage from 2002 to 2016 in any of the African basins, however, consistent rising groundwater trends amounting to ~1 km3/year and 1.5 km3/year are identified in the Iullemmeden and Senegal basins, respectively, and longer term variations in ΔTWS in several basins associated with rainfall patterns. Discrete seasonal ΔTWS responses of ±1–5 cm/year are indicated by GRACE for each of the basins, with the exception of the Congo, North Kalahari, and Senegal basins, which display larger seasonal ΔTWS equivalent to approx. ±11–20 cm/year. The different seasonal responses in ΔTWS provide useful information about groundwater, including the identification of 5 to 9 month accumulation periods of rainfall in many semi-arid and arid basins as well as differences in ΔTWS responses between Sahelian and southern African aquifers to similar rainfall, likely reflecting differences in landcover. Seasonal ΔGWS estimated by combining GRACE ΔTWS with LSM outputs compare inconsistently to available in situ measurements of groundwater recharge from different basins, highlighting the need to further develop the representation of the recharge process in LSMs and the need for more in situ observations from piezometry.
Hyperspectral Image Compression Using Vector Quantization, PCA and JPEG2000
Authors: Báscones Daniel , González Carlos , Mozos Daniel
Published: June 2018

Compression of hyperspectral imagery increases the efficiency of image storage and transmission. It is especially useful to alleviate congestion in the downlinks of planes and satellites, where these images are usually taken from. A novel compression algorithm is presented here. It first spectrally decorrelates the image using Vector Quantization and Principal Component Analysis (PCA), and then applies JPEG2000 to the Principal Components (PCs) exploiting spatial correlations for compression. We take advantage of the fact that dimensionality reduction preserves more information in the first components, allocating more depth to the first PCs. We optimize the selection of parameters by maximizing the distortion-ratio performance across the test images. An increase of 1 to 3 dB in Signal Noise Ratio (SNR) for the same compression ratio is found over just using PCA + JPEG2000, while also speeding up compression and decompression by more than 10%. A formula is proposed which determines the configuration of the algorithm, obtaining results that range from heavily compressed-low SNR images to low compressed-near lossless ones.
Scalable Parcel-Based Crop Identification Scheme Using Sentinel-2 Data Time-Series for the Monitoring of the Common Agricultural Policy
Authors: Sitokonstantinou Vasileios , Papoutsis Ioannis , Kontoes Charalampos , Lafarga Arnal Alberto , Armesto Andrés Ana Pilar , Garraza Zurbano José Angel
Published: June 2018

This work investigates a Sentinel-2 based crop identification methodology for the monitoring of the Common Agricultural Policy’s (CAP) Cross Compliance (CC) and Greening obligations. In this regard, we implemented and evaluated a parcel-based supervised classification scheme to produce accurate crop type mapping in a smallholder agricultural zone in Navarra, Spain. The scheme makes use of supervised classifiers Support Vector Machines (SVMs) and Random Forest (RF) to discriminate among the various crop types, based on a large variable space of Sentinel-2 imagery and Vegetation Index (VI) time-series. The classifiers are separately applied at three different levels of crop nomenclature hierarchy, comparing their performance with respect to accuracy and execution time. SVM provides optimal performance and proves significantly superior to RF for the lowest level of the nomenclature, resulting in 0.87 Cohen’s kappa coefficient. Experiments were carried out to assess the importance of input variables, where top contributors are the Near Infrared (NIR), vegetation red-edge, and Short-Wave Infrared (SWIR) multispectral bands, and the Normalized Difference Vegetation (NDVI) and Plant Senescence Reflectance (PSRI) indices, sensed during advanced crop phenology stages. The scheme is finally applied to a Lansat-8 OLI based equivalent variable space, offering 0.70 Cohen’s kappa coefficient for the SVM classification, highlighting the superior performance of Sentinel-2 for this type of application. This is credited to Sentinel-2’s spatial, spectral, and temporal characteristics.
New Energy Efficient Multi-Hop Routing Techniques for Wireless Sensor Networks: Static and Dynamic Techniques
Authors: Alnawafa Emad , Marghescu Ion
Published: June 2018

The performance of Wireless Sensor Networks (WSNs) faces a number of challenges. Of these challenges, energy consumption is considered a hot research area. Most WSN energy is used in transmitting the data from the sensor nodes either among each other or to a Base Station (BS). For this reason, many routing protocols have been developed to facilitate the data dissemination in the WSNs. One of these protocols, Low Energy Adaptive Clustering Hierarchy (LEACH) has provided a distinctive hierarchical approach that efficiently forwards the nodes data to the BS, but it suffers from increased energy consumption and a significant decline in the network performance in the case of large-scale networks. This paper aims to present a new approach for splitting the whole sensor network into several levels. Thus, every node will be acting accordingly on its position and status. Further, two techniques, a static one and a dynamic one, have been developed to route the data between the levels. The simulation results demonstrated that the proposed techniques prolong the lifespan, improve the stability and raise the throughput of the network compared with the LEACH, the Improved MHT-LEACH (IMHT-LEACH), and the Enhancing DMHT-LEACH (EDMHT-LEACH) protocols.
Reproducible Molecularly Imprinted Piezoelectric Sensor for Accurate and Sensitive Detection of Ractopamine in Swine and Feed Products
Authors: Pan Mingfei , Li Rui , Xu Leling , Yang Jingying , Cui Xiaoyuan , Wang Shuo
Published: June 2018

This paper describes the development of a reproducible molecularly imprinted piezoelectric sensor for the accurate and sensitive detection of ractopamine (RAC) in swine and feed products. The synthesized molecularly imprinted polymer (MIP) was directly immobilized on the surface of a quartz crystal microbalance (QCM) Au chip as the recognition element. The experimental parameters in the fabrication, measurement and regeneration process were evaluated in detail to produce an MIP-based piezoelectric sensor with high sensing capability. The developed piezoelectric sensor was verified to perform favorably in the RAC analysis of swine and feed products, with acceptable accuracy (recovery: 75.9–93.3%), precision [relative standard deviation (n = 3): 2.3–6.4%], and sensitivity [limit of detection: 0.46 ng g−1 (swine) and 0.38 ng g−1 (feed)]. This portable MIP-based chip for the piezoelectric sensing of RAC could be reused for at least 30 cycles and easily stored for a long time. These results demonstrated that the developed MIP-based piezoelectric sensor presents an accurate, sensitive and cost-effective method for the quantitative detection of RAC in complex samples. This research offers a promising strategy for the development of novel effective devices used for use in food safety analysis.
Ultrasensitive Electrochemical Detection of Clostridium perfringens DNA Based Morphology-Dependent DNA Adsorption Properties of CeO2 Nanorods in Dairy Products
Authors: Qian Xingcan , Qu Qing , Li Lei , Ran Xin , Zuo Limei , Huang Rui , Wang Qiang
Published: June 2018

Foodborne pathogens such as Clostridium perfringens can cause diverse illnesses and seriously threaten to human health, yet far less attention has been given to detecting these pathogenic bacteria. Herein, two morphologies of nanoceria were synthesized via adjusting the concentration of NaOH, and CeO2 nanorod has been utilized as sensing material to achieve sensitive and selective detection of C. perfringens DNA sequence due to its strong adsorption ability towards DNA compared to nanoparticle. The DNA probe was tightly immobilized on CeO2/chitosan modified electrode surface via metal coordination, and the DNA surface density was 2.51 × 10−10 mol/cm2. Under optimal experimental conditions, the electrochemical impedance biosensor displays favorable selectivity toward target DNA in comparison with base-mismatched and non-complementary DNA. The dynamic linear range of the proposed biosensor for detecting oligonucleotide sequence of Clostridium perfringens was from 1.0 × 10−14 to 1.0 × 10−7 mol/L. The detection limit was 7.06 × 10−15 mol/L. In comparison, differential pulse voltammetry (DPV) method quantified the target DNA with a detection limit of 1.95 × 10−15 mol/L. Moreover, the DNA biosensor could detect C. perfringens extracted DNA in dairy products and provided a potential application in food quality control.
Application of Crack Identification Techniques for an Aging Concrete Bridge Inspection Using an Unmanned Aerial Vehicle
Authors: Kim In-Ho , Jeon Haemin , Baek Seung-Chan , Hong Won-Hwa , Jung Hyung-Jo
Published: June 2018

Bridge inspection using unmanned aerial vehicles (UAV) with high performance vision sensors has received considerable attention due to its safety and reliability. As bridges become obsolete, the number of bridges that need to be inspected increases, and they require much maintenance cost. Therefore, a bridge inspection method based on UAV with vision sensors is proposed as one of the promising strategies to maintain bridges. In this paper, a crack identification method by using a commercial UAV with a high resolution vision sensor is investigated in an aging concrete bridge. First, a point cloud-based background model is generated in the preliminary flight. Then, cracks on the structural surface are detected with the deep learning algorithm, and their thickness and length are calculated. In the deep learning method, region with convolutional neural networks (R-CNN)-based transfer learning is applied. As a result, a new network for the 384 collected crack images of 256 × 256 pixel resolution is generated from the pre-trained network. A field test is conducted to verify the proposed approach, and the experimental results proved that the UAV-based bridge inspection is effective at identifying and quantifying the cracks on the structures.
The Governmentality of Rural Household Waste Management Practices in Ala Ajagbusi, Nigeria
Authors: Abdulwakeel Saheed Adebayo , Bartholdson Orjan
Published: June 2018

There is a gap in the literature linking waste management practices to social theory. This paper attempts to bridge this gap through a study of waste management practices in Ala Ajagbusi village, Nigeria. The study explores how members of households in Ala Ajagbusi handle waste. The relevant themes of the empirical findings are categorized and linked to a social theory, Michel Foucault’s governmentality. The aim was to investigate how members of the households handle and make sense of their waste management practices. This research adopts a qualitative approach and is inspired by phenomenology. These are the bedrocks upon which the data collection methods are chosen and the interview questions are informed accordingly. The results show that villagers collectively, every week in a rotational manner, sweep their households, dispose of, and burn waste in public spaces. Villagers walk some miles from their households before they can empty their waste receptacles. Sometimes waste management behaviours are adjusted to seasonal variations. The findings also show that the villagers have no engagement with the state and local government concerning waste management. The results are linked to social theory to understand the waste management behaviours of villagers in Ala Ajagbusi.
Incorporating Power Transmission Bottlenecks into Aggregated Energy System Models
Authors: Cao Karl-Kiên , Metzdorf Johannes , Birbalta Sinan
Published: June 2018

Energy scenario analyses are able to provide insights into the future and possible strategies for coping with challenges such as the integration of renewable energy sources. The models used for analyzing and developing future energy systems must be simplified, e.g., due to computational constraints. Therefore, grid-related effects and regional differences are often ignored. We tackle this issue by presenting a new methodology for aggregating spatially highly resolved transmission grid information for energy system models. In particular, such approaches are required in studies that evaluate the demand for spatially balancing power generation and consumption in future energy systems. Electricity transmission between regions is crucial, especially for scenarios that rely on high shares of renewable energy sources. The presented methodology estimates transmission line congestions by evaluating the nodal price differences and then applies a spectral clustering on these particular link attributes. The objective of the proposed approach is to derive aggregated model instances that preserve information regarding electricity transmission bottlenecks. The resulting models are evaluated against observables such as the annual amount of redispatched power generation. For a selection of defined performance indicators, we find a significantly higher accuracy compared to the commonly used, spatially aggregated models applied in the field of energy scenario analysis.
Operating Point Adaptation for NVH-Optimization of Induction Machines
Authors: Bischof Wolfgang , Draeger Florian , Hennen Martin , Kennel Ralph
Published: June 2018

Inverter-fed drive systems are mostly optimized to operate at the best efficiency, neglecting the possibility of acoustic optimization. The chosen operating point can lead to undesired harmonics involving vibrations and noises of the electrical drive. In order to optimize the system with respect to acoustics, the given operating point for best efficiency is left and a noise, vibration and harshness (NVH)-optimized operating point is chosen. This paper shows the influence of the operating point on NVH, describes an NVH-optimized control and draws a comparison between simulation and measurement.
Food Tourism and the Use of Authenticity in Thailand
Authors: Lunchaprasith Thanya , Macleod Donald
Published: June 2018

This article explores the concept of authenticity as it relates to its use by hosts at tourist destinations, the relationship between food and tourism, especially food produced and sold by market traders, and the various uses of authenticity by traders and tourists. It specifically
aims to further our understanding of the use of authenticity in Thailand by stakeholders in a synergistic process, thereby filling a gap in research. Mixed research methods were used (interviews, questionnaires, and observation of the markets) with fieldwork totaling 6 months in Central Thailand.
Eight different markets were chosen providing qualitative material leading to a sample of emic material on attitudes and approaches to authenticity, its construction, and utilization. It was found that authenticity, as it relates to traditional food markets, has been constructed by stakeholders.
Authenticity may differ through the products, according to the personal experiences and motivations of the agents involved. Additionally, the tourists' experiences and expectations impact on the final product in an evolving process. It is recommended that traditional food may be further promoted
in traditional markets by stimulating visitors' engagement in food culture. The article argues that authenticity, in its sociocultural constructivist context, is a relativistic phenomenon, which may be seen as existing in a continuum where there are degrees of authenticity.
Unconfirmed Near-Earth Objects
Authors: Vereš Peter , Payne Matthew J. , Holman Matthew J. , Farnocchia Davide , Williams Gareth V. , Keys Sonia , Boardman Ian
Published: June 2018

We studied the Near-Earth Asteroid (NEA) candidates posted on the Minor Planet Center’s Near-Earth Object Confirmation Page (NEOCP) between years 2013 and 2016. Out of more than 17000 NEA candidates, while the majority became either new discoveries or were associated with previously known objects, about 11% were unable to be followed-up or confirmed. We further demonstrate that of the unconfirmed candidates, 926 ± 50 are likely to be NEAs, representing 18% of discovered NEAs in that period. Only 11% (∼93) of the unconfirmed NEA candidates were large (having absolute magnitude H < 22). To identify the reasons why these NEAs were not recovered, we analyzed those from the most prolific asteroid surveys: Pan-STARRS, the Catalina Sky Survey, the Dark Energy Survey, and the Space Surveillance Telescope. We examined the influence of plane-of-sky positions and rates of motion, brightnesses, submission delays, and computed absolute magnitudes, as well as correlations with the phase of the moon and seasonal effects. We find that delayed submission of newly discovered NEA candidate to the NEOCP drove a large fraction of the unconfirmed NEA candidates. A high rate of motion was another significant contributing factor. We suggest that prompt submission of suspected NEA discoveries and rapid response to fast-moving targets and targets with fast growing ephemeris uncertainty would allow better coordination among dedicated follow-up observers, decrease the number of unconfirmed NEA candidates, and increase the discovery rate of NEAs.
Ultra-dense Broad-line Region Scale Outflow in Highly Reddened Quasar SDSS J145057.28+530007.6
Authors: Zhang Shaohua , Zhou Hongyan , Shi Xiheng , Pan Xiang , Ji Tuo , Jiang Peng
Published: June 2018

We report the discovery of highly reddening and hydrogen Balmer and metastable helium broad absorption lines in the quasar SDSS J145057.28+530007.6, based on the optical and near-infrared spectra taken from the SDSS-III/BOSS and the TripleSpec observations. The nuclear continuum, Balmer decrement, and absorption-line depth analyses suggest that (1) the accretion disk is completely obscured and the covering factor of the broad-line region (BLR) is only 0.39 ± 0.03, (2) the power-law continuum is reddened by the SMC extinction law of E(B – V) =0.72 ± 0.01 mag and the dusty materials are mainly associated with Ca ii H and K rather than the Balmer and He i* absorption-line system, (3) the unsaturated Balmer (Hβ, Hγ, and Hδ) and He i* λ3889 absorption lines have the same two-Gaussian profiles as the shifts of −931 ± 33 and −499 ± 39 km s−1 and the widths of 121 ± 28 and 196 ± 37 km s−1, respectively. Constrained mutually by the Balmer, He i* absorption lines and undetected Fe ii* λ5169 in the photoionization simulations, the physical properties of the outflow gases are derived as follows: ionization parameter 10−1.4 ≲ U ≲ 10−0.8, density 108.2±0.4 ≲ n
H ≲ 109.0±0.4 cm−3, and column density 1022.0±0.2 ≲ N
H ≲ 1022.2–22.3 cm−2. We propose that the ultra-dense outflow gases appear in the vicinity of the surface of the BLR or are located at most 3.12 pc away from the engine. That probably implies that the outflow originates from the BLR, and this kind of ultra-dense BLR scale outflow gases can effectively test the physical properties of the outer gases of the BLR.
Constraints for the Progenitor Masses of Historic Core-collapse Supernovae
Authors: Williams Benjamin F. , Hillis Tristan J. , Murphy Jeremiah W. , Gilbert Karoline , Dalcanton Julianne J. , Dolphin Andrew E.
Published: June 2018

We age-date the stellar populations associated with 12 historic nearby core-collapse supernovae (CCSNe) and two supernova impostors; from these ages, we infer their initial masses and associated uncertainties. To do this, we have obtained new Hubble Space Telescope imaging covering these CCSNe. Using these images, we measure resolved stellar photometry for the stars surrounding the locations of the SNe. We then fit the color–magnitude distributions of this photometry with stellar evolution models to determine the ages of any young existing populations present. From these age distributions, we infer the most likely progenitor masses for all of the SNe in our sample. We find ages between 4 and 50 Myr, corresponding to masses from 7.5 to 59 solar masses. There were no SNe that lacked a local young population. Our sample contains four SNe Ib/c; their masses have a wide range of values, suggesting that the progenitors of stripped-envelope SNe are binary systems. Both impostors have masses constrained to be ≲7.5 solar masses. In cases with precursor imaging measurements, we find that age-dating and precursor imaging give consistent progenitor masses. This consistency implies that, although the uncertainties for each technique are significantly different, the results of both are reliable to the measured uncertainties. We combine these new measurements with those from our previous work and find that the distribution of 25 core-collapse SNe progenitor masses is consistent with a standard Salpeter power-law mass function, no upper mass cutoff, and an assumed minimum mass for core-collapse of 7.5 M
⊙. The distribution is consistent with a minimum mass <9.5 M
⊙.
The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. XV. The Dynamical Clock: Reading Cluster Dynamical Evolution from the Segregation Level of Blue Straggler Stars
Authors: Ferraro F. R. , Lanzoni B. , Raso S. , Nardiello D. , Dalessandro E. , Vesperini E. , Piotto G. , Pallanca C. , Beccari G. , Bellini A. , Libralato M. , Anderson J. , Aparicio A. , Bedin L. R. , Cassisi S. , Milone A. P. , Ortolani S. , Renzini A. , Salaris M. , van der Marel R. P.
Published: June 2018

The parameter A
+, defined as the area enclosed between the cumulative radial distribution of blue straggler stars (BSSs) and that of a reference population, is a powerful indicator of the level of BSS central segregation. As part of the Hubble Space Telescope UV Legacy Survey of Galactic globular clusters (GCs), here we present the BSS population and the determination of A
+ in 27 GCs observed out to about one half-mass radius. In combination with 21 additional clusters discussed in a previous paper, this provides us with a global sample of 48 systems (corresponding to ∼32% of the Milky Way GC population), for which we find a strong correlation between A
+ and the ratio of cluster age to the current central relaxation time. Tight relations have also been found with the core radius and the central luminosity density, which are expected to change with the long-term cluster dynamical evolution. An interesting relation is emerging between A
+ and the ratio of the BSS velocity dispersion relative to that of main sequence turn-off stars, which measures the degree of energy equipartition experienced by BSSs in the cluster. These results provide further confirmation that BSSs are invaluable probes of GC internal dynamics and that A
+ is a powerful dynamical clock.
Density Fluctuations in a Polar Coronal Hole
Authors: Hahn Michael , D’Huys Elke , Savin Daniel Wolf
Published: June 2018

We have measured the root-mean-square (rms) amplitude of intensity fluctuations, ΔI, in plume and interplume regions of a polar coronal hole. These intensity fluctuations correspond to density fluctuations. Using data from the Sun Watcher using the Active Pixel System detector and Image Processing on the Project for Onboard Autonomy
(Proba2), our results extend up to a height of about 1.35 R
⊙. One advantage of the rms analysis is that it does not rely on a detailed evaluation of the power spectrum, which is limited by noise levels to low heights in the corona. The rms approach can be performed up to larger heights where the noise level is greater, provided that the noise itself can be quantified. At low heights, both the absolute ΔI, and the amplitude relative to the mean intensity, ΔI/I, decrease with height. However, starting at about 1.2 R
⊙, ΔI/I increases, reaching 20%–40% by 1.35 R
⊙. This corresponds to density fluctuations of Δn
e/n
e ≈ 10%–20%. The increasing relative amplitude implies that the density fluctuations are generated in the corona itself. One possibility is that the density fluctuations are generated by an instability of Alfvén waves. This generation mechanism is consistent with some theoretical models and with observations of Alfvén wave amplitudes in coronal holes. Although we find that the energy of the observed density fluctuations is small, these fluctuations are likely to play an important indirect role in coronal heating by promoting the reflection of Alfvén waves and driving turbulence.
Probing Self-interacting Dark Matter with Disk Galaxies in Cluster Environments
Authors: Secco Lucas F. , Farah Amanda , Jain Bhuvnesh , Adhikari Susmita , Banerjee Arka , Dalal Neal
Published: June 2018

Self-interacting dark matter (SIDM) has long been proposed as a solution to small-scale problems posed by standard cold dark matter. We use numerical simulations to study the effect of dark matter interactions on the morphology of disk galaxies falling into galaxy clusters. The effective drag force on dark matter leads to offsets of the stellar disk with respect to the surrounding halo, causing distortions in the disk. For anisotropic scattering cross sections of 0.5 and

, we show that potentially observable warps, asymmetries, and thickening of the disk occur in simulations. We discuss observational tests of SIDM with galaxy surveys and more realistic simulations needed to obtain detailed predictions.
ELUCID. V. Lighting Dark Matter Halos with Galaxies
Authors: Yang Xiaohu , Zhang Youcai , Wang Huiyuan , Liu Chengze , Lu Tianhuan , Li Shijie , Shi Feng , Jing Y. P. , Mo H. J. , Bosch Frank C. van den , Kang Xi , Cui Weiguang , Guo Hong , Li Guoliang , Lim S. H. , Lu Yi , Luo Wentao , Wei Chengliang , Yang Lei
Published: June 2018

In a recent study, using the distribution of galaxies in the north galactic pole of the SDSS DR7 region enclosed in a 500

box, we carried out our ELUCID simulation (ELUCID III). Here, we light the dark matter halos and subhalos in the reconstructed region in the simulation with galaxies in the SDSS observations using a novel neighborhood abundance matching method. Before we make use of the galaxy–subhalo connections established in the ELUCID simulation to evaluate galaxy formation models, we set out to explore the reliability of such a link. For this purpose, we focus on the following few aspects of galaxies: (1) the central–subhalo luminosity and mass relations, (2) the satellite fraction of galaxies, (3) the conditional luminosity function (CLF) and conditional stellar mass function (CSMF) of galaxies, and (4) the cross-correlation functions between galaxies and dark matter particles, most of which are measured separately for all, red, and blue galaxy populations. We find that our neighborhood abundance matching method accurately reproduces the central–subhalo relations, satellite fraction, and the CLFs, CSMFs, and biases of galaxies. These features ensure that galaxy–subhalo connections thus established will be very useful in constraining galaxy formation processes. We provide some suggestions for the three levels of using the galaxy–subhalo pairs for galaxy formation constraints. The galaxy–subhalo links and the subhalo merger trees in the SDSS DR7 region extracted from our ELUCID simulation are available upon request.
On the UV/Optical Variation in NGC 5548: New Evidence Against the Reprocessing Diagram
Authors: Zhu 朱飞 Fei-Fan 凡 , Wang 王俊 Jun-Xian 贤 , Cai 蔡振 Zhen-Yi 翼 , Sun 孙玉 Yu-Han 涵 , Sun 孙谋 Mou-Yuan 远 , Zhang 张继 Ji-Xian 贤
Published: June 2018

The reprocessing scenario is widely adopted in literature to explain the observed tight inter-band correlation and short lags in the UV/optical variations of active galactic nuclei (AGNs). In this work we look into the color variability of the famous Seyfert galaxy NGC 5548 with high-quality Swift multi-band UV/optical light curves. We find the color variation of NGC 5548 is clearly timescale-dependent, in a way that it is more prominent on shorter timescales. This is similar to that previously detected in quasar samples, but for the first time in an individual AGN. We show that while a reprocessing model with strict assumptions on the driving source and the disk size can apparently match the observed light curves and inter-band lags, it fails to reproduce the observed timescale dependency in the color variation. Such discrepancy raises a severe challenge to, and can hardly be reconciled under the widely accepted reprocessing diagram. It also demonstrates that the timescale dependency of the color variation is uniquely powerful in probing the physics behind AGN UV/optical variations.
Implantação do gerenciamento da rotina em uma fábrica de ração para aves
Authors: De genaro Chiroli Daiane Maria , Pugler Marina Muniz , Callefi Mario Henrique Bueno Moreira , Dzulinski Ana Caroline
Published: June 2018

A elevada competitividade nas organizações faz com que seja necessário um maior controle e acompanhamento dos processos produtivos buscando a melhoria contínua dos seus resultados. A partir disto, este artigo apresenta um estudo que objetivou a implementação do gerenciamento da rotina do trabalho do dia-a-dia, isto é, o acompanhamento e análise dos resultados de forma sistemática. Com a utilização da metodologia PDCA é possível aumentar a produtividade de uma organização, sendo assim, com vistas ao atendimento do objetivo proposto analisou-se uma empresa produtora de ração para aves de maneira quali-quantitativa, onde foram quantificados os problemas utilizando ferramentas da qualidade, para posteriormente elaborar um plano de melhoria na área de estocagem (aquisição de silos de expedição), área de produção (compra de máquina peletizadora) e padronização (elaboração de padrões e checklists) de maneira a alcançar a meta de produção de 76,81 ton/h. Uma das principais dificuldades encontradas refere-se a padronização das ações visto que a cultura da empresa não tinha como atividade rotineira a padronização e proliferação de ações de melhoria.
Avaliação das variações espaciais e temporais no Rio São Lourenço em área urbana e a correlação com eventos extremos
Authors: Zanchin Mayara , Leandro Diuliana , Quadro Maurizio Silveira , Nadaleti Willian Cezar
Published: June 2018

No Brasil, a preocupação com os impactos dos desastres naturais sobre a sociedade tem aumentando significativamente nos últimos anos. O propósito do trabalho é realizar uma análise temporal das margens do arroio São Lourenço do Sul, através de imagens obtidas por sensoriamento remoto, e propor soluções para a região ligadas a contenção dos eventos extremos de inundação. Com as imagens de estudo foi possível observar que houve retirada da mata ciliar no entorno do corpo hídrico – possibilitando carreamento de sedimentos para o seu interior – além de ocupações irregulares nas margens. Estes pontos chave evidenciam o aumento de ocorrência de eventos como inundações ou enxurradas nas regiões. Propõem-se construção de bacias de detenção, dragagem do arroio e recuperação da área no entorno do arroio. Estas medidas devem estar relacionadas a fiscalização ambiental e programas de educação ambiental.
Fragilidade potencial e emergente na bacia do rio Peruaçu, região norte de Minas Gerais
Authors: Nogueira Martins Rodrigo , Ferreira Colares Ana Paula , Luns Hatum de Almeida Samira , Antonio Zanella Marco , Mendes Nery César Vinícius
Published: June 2018

O presente trabalho teve como objetivo mapear a fragilidade potencial e emergente na Bacia do Rio Peruaçu, com base na metodologia proposta por Ross (1994). A Bacia do Rio Peruaçu está localizada na Região Norte de Minas Gerais, cobrindo uma área de 1.552,3 km². A partir da sobreposição de mapas de diferentes atributos, tais como, declividade, erosividade da chuva, tipo de solo e uso e cobertura do solo, foi possível mapear a fragilidade ambiental. A fragilidade foi classificada em cinco diferentes níveis: muito fraca, fraca, média, forte e muito forte. Como resultado, para a fragilidade potencial predominou a classe de alta fragilidade com 56,88% (882,9 km²) da área. Enquanto que, na análise da fragilidade emergente, observou-se a predominância das classes de Alta e média fragilidade, com 37,22% (577,71 km²) e 36,83% (571,73 km²), respectivamente. Os resultados obtidos evidenciam a necessidade de recuperação das áreas degradadas e a implantação de técnicas de conservação do solo nas áreas de maior fragilidade.
A relação entre governo eletrônico e cidade digital: o caso do município de São José dos Pinhais
Authors: Silva Marcus Vinicius Gonçalves da , From Danieli Aparecida , Conte Fábio Luiz
Published: June 2018

Em evidência desde a década de 1990, o conceito de governo eletrônico e suas relações com as denominadas cidades digitais ganhou destaque a partir da universalização do acesso à internet e às tecnologias da informação e comunicação. O objetivo deste artigo é explorar conceitos e comparar os serviços públicos oferecidos eletronicamente em dois municípios brasileiros localizados no Estado do Paraná. Metodologicamente, o estudo tem abordagem exploratória, bibliográfica e qualitativa no quesito conceitual, seguido de um estudo de caso comparativo. Os resultados apontam que em ambos os municípios há a coexistência de elos conceituais e práticos de governo eletrônico e que a participação digital se materializa desde o desenvolvimento das políticas públicas até o monitoramento de ações e resultados por meio do acesso às informações e transparência dos atos públicos.
Prática de reciclagem em um centro municipal de educação infantil do município de São José dos Pinhais, Paraná
Authors: Santos Beatriz Letícia Camargo dos , Silva Brenda Alexandra da , Cordeiro Camila , Anjos Caroline Aparecida dos , Dêa Naiara Cassiane , Setnarsky Renata Pinheiro da Silva , Bonassina Ana Lucia Berno , Catapan Dariane Cristina
Published: June 2018

A prática de reciclagem é um conjunto de técnicas de reaproveitamento de materiais descartados; reintroduzindo-os no ciclo produtivo. O objetivo do presente artigo foi propor a ampliação do projeto, encontrado no Centro Municipal de Educação Infantil (CMEI) e oportunizar um melhor entendimento do CMEI em relação à importância da reciclagem. Para isso, foram utilizados os seguintes métodos de pesquisa: pesquisa bibliográfica, pesquisa descritiva, estudo de campo e questionário. Como principais resultados, observou-se através de coleta de dados que as professoras do CMEI acreditam ser possível a ampliação do projeto de reciclagem. A partir disso, desenvolveu-se uma proposta de ampliação do projeto encontrado na instituição, que incluía folder explicativo, em dois tamanhos para que fossem entregues aos alunos e distribuídos pelo CMEI. Para incentivar as práticas de reciclagem dentro da escola, fez-se necessário a confecção de lixeiras de acordo com a legislação vigente. Essa proposta se dividiu em 5 etapas, que são: a conscientização dos colaboradores da escola, conscientização das professoras para a formação continuada, abordagem do tema reciclagem com os alunos, abordagem do tema com os pais dos alunos e a entrega dos materiais e das lixeiras. Concluiu-se que para que as práticas de reciclagem cheguem em casa, elas precisam começar em algum lugar. A escola pode e precisa plantar a ideia de um mundo melhor através das práticas de separação do lixo, pois daqui alguns anos as crianças que estão na escola hoje serão responsáveis por cuidar do nosso planeta.