bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalytic Performance of Co3O4 on Different Activated Carbon Supports in the Benzyl Alcohol Oxidation
Authors: Cordoba Misael , Miranda Cristian , Lederhos Cecilia , Coloma-Pascual Fernando , Ardila Alba , Fuentes Gustavo , Pouilloux Yannick , Ramírez Alfonso
Published: December 2017

Co3O4 particles were supported on a series of activated carbons (G60, CNR, RX3, and RB3). Incipient wetness method was used to prepare these catalysts. The effect of the structural and surface properties of the carbonaceous supports during oxidation of benzyl alcohol was evaluated. The synthetized catalysts were characterized via IR, TEM, TGA/MS, XRD, TPR, AAS, XPS, and N2 adsorption/desorption isotherm techniques. Co3O4/G60 and Co3O4/RX3 catalysts have high activity and selectivity on the oxidation reaction reaching conversions above 90% after 6 h, without the presence of promoters. Catalytic performances show that differences in chemistry of support surface play an important role in activity and suggest that the presence of different ratios of species of cobalt and oxygenated groups on surface in Co3O4/G60 and Co3O4/RX3 catalysts, offered a larger effect synergic between both active phase and support increasing their catalytic activity when compared to the other tested catalysts.
Cryptographically Secure Multiparty Computation and Distributed Auctions Using Homomorphic Encryption
Authors: Kulshrestha Anunay , Rampuria Akshay , Denton Matthew , Sreenivas Ashwin
Published: December 2017

We introduce a robust framework that allows for cryptographically secure multiparty computations, such as distributed private value auctions. The security is guaranteed by two-sided authentication of all network connections, homomorphically encrypted bids, and the publication of zero-knowledge proofs of every computation. This also allows a non-participant verifier to verify the result of any such computation using only the information broadcasted on the network by each individual bidder. Building on previous work on such systems, we design and implement an extensible framework that puts the described ideas to practice. Apart from the actual implementation of the framework, our biggest contribution is the level of protection we are able to guarantee from attacks described in previous work. In order to provide guidance to users of the library, we analyze the use of zero knowledge proofs in ensuring the correct behavior of each node in a computation. We also describe the usage of the library to perform a private-value distributed auction, as well as the other challenges in implementing the protocol, such as auction registration and certificate distribution. Finally, we provide performance statistics on our implementation of the auction.
Phononic Crystal Made of Multilayered Ridges on a Substrate for Rayleigh Waves Manipulation
Authors: Oudich Mourad , Djafari-Rouhani Bahram , Bonello Bernard , Pennec Yan , Sarry Frédéric
Published: December 2017

We present a phononic crystal to achieve efficient manipulation of surface acoustic waves (SAW). The structure is made of finite phononic micro-ridges arranged periodically in a substrate surface. Each ridge is constructed by staking silicon and tungsten layers so that it behaves as one-dimensional phononic crystal which exhibits band gaps for elastic waves. The band gap allows the existence of resonance modes where the elastic energy is either confined within units in the free end of the ridge or the ones in contact with the substrate. We show that SAW interaction with localized modes in the free surface of the ridge gives rise to sharp attenuation in the SAW transmission, while the modes confined within the ridge/substrate interface cause broad band attenuations of SAW. Furthermore, we demonstrate that the coupling between the two kinds of modes within the band gap gives high SAW transmission amplitude in the form of Fano-like peaks with high quality factor. The structure could provide an interesting solution for accurate SAW control for sensing applications, for instance.
Narrative Inquiry on the Teaching of STEM to Blind High School Students
Authors: Villanueva Idalis , Di Stefano Marialuisa
Published: December 2017

This study aimed to elevate the experiences and voices of teachers who led the STEM informal education program summer series: National Federation of the Blind Engineering Quotient (NFB EQ). Through its integration with science, technology, engineering, and math (STEM), NFB EQ opened opportunities from 2013–2016 in Baltimore, Maryland, for 60 blind students (Grades 9–12) to learn about engineering. The purpose of this narrative inquiry study was to understand how teachers foster interest towards STEM among blind students. The participants were two sighted teachers, one blind teacher, one sighted teacher–researcher, and one sighted researcher participant. We collected data in the form of field notes, semi-structured interviews, personal narratives, collective narratives, a focus group discussion, and teaching artifacts. We engaged in conversation analysis and used MAXQDA 12 software for data analysis. Guided by the principles of community of practices and universal design for learning, our results identified the importance of teacher awareness and positionalities in guiding blind students’ inclusion and identity in the STEM classroom. Findings also suggest teachers are in a unique position to allow or prevent inclusive opportunities from occurring in their classrooms.
Optimal Design of a Multi-Carrier Microgrid (MCMG) Considering Net Zero Emission
Authors: Amir Vahid , Jadid Shahram , Ehsan Mehdi
Published: December 2017

In this paper, a two-stage optimum planning and design method for a multi-carrier microgrid (MCMG) is presented in the targeted operation period considering energy purchasing and the component’s maintenance costs. An MCMG is most likely owned by a community or small group of public and private sectors comprising loads and distributed energy resources (DERs) with the ability of self-supply to regulate the flows of various energies to local consumers. The operation cost is undoubtedly reduced by selecting the proper components. In the proposed model, the investment and operation and maintenance costs of MCMG are simultaneously carried out in order to choose the right component and its size in the given period. Moreover, in this innovative model, net zero emission (NZE) is regarded as an environmental constraint. The genetic algorithm of MATLAB and the mixed-integer nonlinear programming (MINLP) technique of GAMS (general algebraic modeling system) software are used to solve the optimization problem. Illustrative examples show the efficiency of the proposed model.
Rare Earth Borohydrides—Crystal Structures and Thermal Properties
Authors: Frommen Christoph , Sørby Magnus H. , Heere Michael , Humphries Terry D. , Olsen Jørn E. , Hauback Bjørn C.
Published: December 2017

Rare earth (RE) borohydrides have received considerable attention during the past ten years as possible hydrogen storage materials due to their relatively high gravimetric hydrogen density. This review illustrates the rich chemistry, structural diversity and thermal properties of borohydrides containing RE elements. In addition, it highlights the decomposition and rehydrogenation properties of composites containing RE-borohydrides, light-weight metal borohydrides such as LiBH4 and additives such as LiH.
Modeling and Predicting Carbon and Water Fluxes Using Data-Driven Techniques in a Forest Ecosystem
Authors: Dou Xianming , Yang Yongguo
Published: December 2017

Accurate estimation of carbon and water fluxes of forest ecosystems is of particular importance for addressing the problems originating from global environmental change, and providing helpful information about carbon and water content for analyzing and diagnosing past and future climate change. The main focus of the current work was to investigate the feasibility of four comparatively new methods, including generalized regression neural network, group method of data handling (GMDH), extreme learning machine and adaptive neuro-fuzzy inference system (ANFIS), for elucidating the carbon and water fluxes in a forest ecosystem. A comparison was made between these models and two widely used data-driven models, artificial neural network (ANN) and support vector machine (SVM). All the models were evaluated based on the following statistical indices: coefficient of determination, Nash-Sutcliffe efficiency, root mean square error and mean absolute error. Results indicated that the data-driven models are capable of accounting for most variance in each flux with the limited meteorological variables. The ANN model provided the best estimates for gross primary productivity (GPP) and net ecosystem exchange (NEE), while the ANFIS model achieved the best for ecosystem respiration (R), indicating that no single model was consistently superior to others for the carbon flux prediction. In addition, the GMDH model consistently produced somewhat worse results for all the carbon flux and evapotranspiration (ET) estimations. On the whole, among the carbon and water fluxes, all the models produced similar highly satisfactory accuracy for GPP, R and ET fluxes, and did a reasonable job of reproducing the eddy covariance NEE. Based on these findings, it was concluded that these advanced models are promising alternatives to ANN and SVM for estimating the terrestrial carbon and water fluxes.
Modeling of Heat Distribution in Porous Aluminum Using Fractional Differential Equation
Authors: Brociek Rafał , Słota Damian , Król Mariusz , Matula Grzegorz , Kwaśny Waldemar
Published: December 2017

The authors present a model of heat conduction using the Caputo fractional derivative with respect to time. The presented model was used to reconstruct the thermal conductivity coefficient, heat transfer coefficient, initial condition and order of fractional derivative in the fractional heat conduction inverse problem. Additional information for the inverse problem was the temperature measurements obtained from porous aluminum. In this paper, the authors used a finite difference method to solve direct problems and the Real Ant Colony Optimization algorithm to find a minimum of certain functional (solve the inverse problem). Finally, the authors present the temperature values computed from the model and compare them with the measured data from real objects.
Cosmological Effects of Quantum Vacuum Condensates
Authors: Capolupo Antonio
Published: December 2017

In quantum field theory, many phenomena are characterized by a condensed structure of their vacua. Such a structure is responsible of a non trivial vacuum energy. Here we analyze disparate systems and we show that the thermal vacuum state for hot plasmas, the vacuum for boson field in curved space and the vacuum for mixed neutrinos have the state equation of dark matter, w = 0 , and values of the energy density which are in agreement with the one estimated for dark matter. Moreover, we show that the vacuum of axions mixed with photons has the state equation of the cosmological constant w = − 1 and a value of the energy density compatible with the one of dark energy.
Bell Inequality and Its Application to Cosmology
Authors: Kanno Sugumi , Soda Jiro
Published: December 2017

One of the cornerstones of inflationary cosmology is that primordial density fluctuations have a quantum mechanical origin. However, most physicists consider that such quantum mechanical effects disappear in CMB data due to decoherence. In this conference report, we show that the violation of Bell inequalities in an initial state of our universe increases exponentially with the number of modes to measure in inflation. This indicates that some evidence that our universe has a quantum mechanical origin may survive in CMB data, even if quantum entanglement decays exponentially afterward due to decoherence.
Mainstreaming Multi-Risk Approaches into Policy
Authors: Scolobig Anna , Komendantova Nadejda , Mignan Arnaud
Published: December 2017

Multi-risk environments are characterized by domino effects that often amplify the overall risk. Those include chains of hazardous events and increasing vulnerability, among other types of correlations within the risk process. The recently developed methods for multi-hazard and risk assessment integrate interactions between different risks by using harmonized procedures based on common metrics. While the products of these assessments, such as multi-hazard and -risk indexes, maps, cascade scenarios, or warning systems provide innovative and effective information, they also pose specific challenges to policy makers and practitioners due to their novel cross-disciplinary aspects. In this paper we discuss the institutional barriers to the adoption of multi-risk approaches, summarizing the results of the fieldwork conducted in Italy and Guadeloupe and of workshops with disaster risk reduction practitioners from eleven European countries. Results show the need for a clear identification of responsibilities for the implementation of multi-risk approaches, as institutional frameworks for risk reduction remain to this day primarily single-risk centered. Authorities are rarely officially responsible for the management of domino effects between e.g., tsunamis and industrial accidents, earthquake and landslides, floods and electricity network failures. Other barriers for the implementation of multi-risk approaches include the limited measures to reduce exposure at the household level, inadequate financial capacities at the local level and limited public-private partnerships, especially in case of interactions between natural and industrial risks. Adapting the scale of institutions to that of multi-risk environments remains a major challenge to better mainstream multi-risk approaches into policy. To address it, we propose a multi-risk governance framework, which includes the phases of observation, social and institutional context analysis, generation of multi-risk knowledge and stakeholder engagement processes. Yet, more research is needed in order to test the framework and to identify the hallmark characteristics of effective multi-risk governance.
Heavy Metal Contamination and Health Risk Assessment in the Vicinity of a Tailing Pond in Guangdong, China
Authors: Liang Yaya , Yi Xiaoyun , Dang Zhi , Wang Qin , Luo Houmei , Tang Jie
Published: December 2017

The purpose of this study was to assess heavy metal contamination and health risks for residents in the vicinity of a tailing pond in Guangdong, southern China. Water, soil, rice, and vegetable samples were collected from the area in the vicinity of the tailing pond. Results showed that surface water was just polluted by Ni and As, while groundwater was not contaminated by heavy metals. The concentrations of Pb, Zn, Cu, Cd, Ni, and As in the paddy soil exceeded the standard values but not those of Cr. In vegetable soils, the concentration of heavy metals was above the standard values except for Ni and As. Soil heavy metal concentrations generally decreased with increasing distance from the polluting source. Leafy vegetables were contaminated by Pb, Cr, Cd, and Ni, while the non-leafy vegetables were contaminated only by Cr. There was a significant difference in heavy metal concentrations between leafy vegetables and non-leafy vegetables. Almost all the rice was polluted by heavy metals. Diet was the most significant contributor to non-carcinogenic risk, which was significantly higher than the safe level of 1. The total cancer risk was also beyond the safe range (10−6–10−4). Results revealed that there is a risk of potential health problems to residents in the vicinity of the tailing pond.
Guided Image Filtering-Based Pan-Sharpening Method: A Case Study of GaoFen-2 Imagery
Authors: Zheng Yalan , Dai Qinling , Tu Zhigang , Wang Leiguang
Published: December 2017

GaoFen-2 (GF-2) is a civilian optical satellite self-developed by China equipped with both multispectral and panchromatic sensors, and is the first satellite in China with a resolution below 1 m. Because the pan-sharpening methods on GF-2 imagery have not been a focus of previous works, we propose a novel pan-sharpening method based on guided image filtering and compare the performance to state-of-the-art methods on GF-2 images. Guided image filtering was introduced to decompose and transfer the details and structures from the original panchromatic and multispectral bands. Thereafter, an adaptive model that considers the local spectral relationship was designed to properly inject spatial information back into the original spectral bands. Four pairs of GF-2 images acquired from urban, water body, cropland, and forest areas were selected for the experiments. Both quantitative and visual inspections were used for the assessment. The experimental results demonstrated that for GF-2 imagery acquired over different scenes, the proposed approach consistently achieves high spectral fidelity and enhances spatial details, thereby benefitting the potential classification procedures.
Protective Effects of ω-3 PUFA in Anthracycline-Induced Cardiotoxicity: A Critical Review
Authors: Serini Simona , Ottes Vasconcelos Renata , Nascimento Gomes Renata , Calviello Gabriella
Published: December 2017

It has been demonstrated that ω-3 polyunsaturated fatty acids (ω-3 PUFA) may exert a beneficial role as adjuvants in the prevention and treatment of many disorders, including cardiovascular diseases and cancer. Particularly, several in vitro and in vivo preclinical studies have shown the antitumor activity of ω-3 PUFA in different kinds of cancers, and several human studies have shown that ω-3 PUFA are able to decrease the risk of a series of cardiovascular diseases. Several mechanisms have been proposed to explain their pleiotropic beneficial effects. ω-3 PUFA have also been shown to prevent harmful side-effects (including cardiotoxicity and heart failure) induced by conventional and innovative anti-cancer drugs in both animals and patients. The available literature regarding the possible protective effects of ω-3 PUFA against anthracycline-induced cardiotoxicity, as well as the mechanisms involved, will be critically discussed herein. The study will analyze the critical role of different levels of ω-3 PUFA intake in determining the results of the combinatory studies with anthracyclines. Suggestions for future research will also be considered.
The Relevance of Criminal Courts in the Global South
Authors: Ciocchini Pablo Leandro
Published: December 2017

The literature on comparative law has a long and robust tradition, but studies comparing courts and judicial systems are scarce. Comparative studies in the Global South, following Shapiro’s institutional approach, have aimed to measure the involvement of courts in politics by assessing the power of the judiciary in society, the level of judicial independence, and their role in the context of the judicialization of politics. The focus was on the high courts, including either Constitutional or Supreme Courts. Criminal courts have not received similar attention despite the influence of their everyday decisions on people’s lives and their perception of the judicial system. This article argues that developing a comparative approach for criminal courts in the Global South is needed to help understand the role they play in the development of the rule of law and democratic life. This comparative study helps understand the impact of judicial reform programmes in the Global South. These reforms, inspired by a neoliberal paradigm, have focused on improving the efficiency of the courts. The reforms have promoted managerial techniques detrimental to the standards of due process. Any assessment of the impact of the reforms on the courts in the Global South should start by recognising the widely differing settings under which they operate. This context is characterised by serious economic constraints, such as a lack of material and human resources, and a democratic deficit legacy from the past authoritarian regimes, including widespread police abuse and corruption. Given this context, the role of the courts in ensuring due process and the legality of police procedures is crucial. The impact of the judicial reforms promoting managerial rationality in recent decades must be analysed. To examine the role courts are playing in criminal matters, two cases were explored where courts have undergone extensive judicial reforms, Argentina and the Philippines.
An Exploration of Big Data Practices in Retail Sector
Authors: Aktas Emel , Meng Yuwei
Published: December 2017

Connected devices, sensors, and mobile apps make the retail sector a relevant testbed for big data tools and applications. We investigate how big data is, and can be used in retail operations. Based on our state-of-the-art literature review, we identify four themes for big data applications in retail logistics: availability, assortment, pricing, and layout planning. Our semi-structured interviews with retailers and academics suggest that historical sales data and loyalty schemes can be used to obtain customer insights for operational planning, but granular sales data can also benefit availability and assortment decisions. External data such as competitors’ prices and weather conditions can be used for demand forecasting and pricing. However, the path to exploiting big data is not a bed of roses. Challenges include shortages of people with the right set of skills, the lack of support from suppliers, issues in IT integration, managerial concerns including information sharing and process integration, and physical capability of the supply chain to respond to real-time changes captured by big data. We propose a data maturity profile for retail businesses and highlight future research directions.
Solving the Lane–Emden Equation within a Reproducing Kernel Method and Group Preserving Scheme
Authors: Hashemi Mir Sajjad , Akgül Ali , Inc Mustafa , Mustafa Idrees Sedeeq , Baleanu Dumitru
Published: December 2017

We apply the reproducing kernel method and group preserving scheme for investigating the Lane–Emden equation. The reproducing kernel method is implemented by the useful reproducing kernel functions and the numerical approximations are given. These approximations demonstrate the preciseness of the investigated techniques.
In Situ Observations of Blistering of a Metal Irradiated with 2-MeV Protons
Authors: Badrutdinov Alexander , Bykov Timophey , Gromilov Sergey , Higashi Yasuo , Kasatov Dmitrii , Kolesnikov Iaroslav , Koshkarev Alexey , Makarov Alexandr , Miyazawa Takuya , Shchudlo Ivan , Sokolova Evgeniia , Sugawara Hirotaka , Taskaev Sergey
Published: December 2017

A vacuum-insulated tandem accelerator was used to observe in situ blistering during 2-MeV proton irradiation of metallic samples to a fluence of up to 6.7 × 1020 cm−2. Samples consisting of copper of different purity, tantalum and tantalum-copper compounds were placed on the proton beam path and forced to cool. The surface state of the samples was observed using a charge-coupled device camera with a remote microscope. Thermistors, a pyrometer and an infrared camera were applied to measure the temperature of the samples during irradiation. After irradiation, the samples were analyzed on an X-ray diffractometer, laser and electron microscopes. The present study describes the experiment, presents the results obtained and notes their relevance and significance in the development of a lithium target for an accelerator-based neutron source, for use in boron neutron capture therapy of cancer.
Enhanced Methods to Estimate the Efficiency of Magnetic Nanoparticles in Imaging
Authors: Hirt Ann , Kumari Monika , Heinke David , Kraupner Alexander
Published: December 2017

Magnetic resonance imaging (MRI) and magnetic particle imaging (MPI) are powerful methods in the early diagnosis of diseases. Both imaging techniques utilize magnetic nanoparticles that have high magnetic susceptibility, strong saturation magnetization, and no coercivity. FeraSpinTM R and its fractionated products have been studied for their imaging performances; however, a detailed magnetic characterization in their immobilized state is still lacking. This is particularly important for applications in MPI that require fixation of magnetic nanoparticles with the target cells or tissues. We examine the magnetic properties of immobilized FeraSpinTM R, its size fractions, and Resovist®, and use the findings to demonstrate which magnetic properties best predict performance. All samples show some degree of oxidation to hematite, and magnetic interaction between the particles, which impact negatively on image performance of the materials. MRI and MPI performance show a linear dependency on the slope of the magnetization curve, i.e., initial susceptibility, and average blocking temperature. The best performance of particles in immobilized state for MPI is found for particle sizes close to the boundary between superparamagnetic (SP) and magnetically ordered, in which only Néel relaxation is important. Initial susceptibility and bifurcation temperature are the best indicators to predict MRI and MPI performance.
The Effect of Different Coupling Agents on Nano-ZnO Materials Obtained via the Sol–Gel Process
Authors: Purcar Violeta , Şomoghi Raluca , Niţu Sabina , Nicolae Cristian-Andi , Alexandrescu Elvira , Gîfu Ioana , Gabor Augusta , Stroescu Hermine , Ianchiş Raluca , Căprărescu Simona , Cinteză Ludmila
Published: December 2017

Hybrid nanomaterials based on zinc oxide were synthesized via the sol–gel method, using different silane coupling agents: (3-glycidyloxypropyl)trimethoxysilane (GPTMS), phenyltriethoxysilane (PhTES), octyltriethoxysilane (OTES), and octadecyltriethoxysilane (ODTES). Morphological properties and the silane precursor type effect on the particle size were investigated using dynamic light scattering (DLS), environmental scanning electron microscopy (ESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The bonding characteristics of modified ZnO materials were investigated using Fourier transform infrared spectroscopy (FTIR). The final solutions were deposited on metallic substrate (aluminum) in order to realize coatings with various wettability and roughness. The morphological studies, obtained by ESEM and TEM analysis, showed that the sizes of the ZnO nanoparticles are changed as function of silane precursor used in synthesis. The thermal stability of modified ZnO materials showed that the degradation of the alkyl groups takes place in the 300–500 °C range. Water wettability study revealed a contact angle of 142 ± 5° for the surface covered with ZnO material modified with ODTES and showed that the water contact angle increases as the alkyl chain from the silica precursor increases. These modified ZnO materials, therefore, can be easily incorporated in coatings for various applications such as anti-corrosion and anti-icing.
Synthesis of Formate Esters and Formamides Using an Au/TiO2-Catalyzed Aerobic Oxidative Coupling of Paraformaldehyde
Authors: Metaxas Ioannis , Vasilikogiannaki Eleni , Stratakis Manolis
Published: December 2017

A simple method for the synthesis of formate esters and formamides is presented based on the Au/TiO2-catalyzed aerobic oxidative coupling between alcohols or amines and formaldehyde. The suitable form of formaldehyde is paraformaldehyde, as cyclic trimeric 1,3,5-trioxane is inactive. The reaction proceeds via the formation of an intermediate hemiacetal or hemiaminal, respectively, followed by the Au nanoparticle-catalyzed aerobic oxidation of the intermediate. Typically, the oxidative coupling between formaldehyde (2 equiv) and amines occurs quantitatively at room temperature within 4 h, and there is no need to add a base as in analogous coupling reactions. The oxidative coupling between formaldehyde (typically 3 equiv) and alcohols is unprecedented and occurs more slowly, yet in good to excellent yields and selectivity. Minor side-products (2–12%) from the acetalization of formaldehyde by the alcohol are also formed. The catalyst is recyclable and can be reused after a simple filtration in five consecutive runs with a small loss of activity.
Silver Nanoparticles in the Lung: Toxic Effects and Focal Accumulation of Silver in Remote Organs
Authors: Wiemann Martin , Vennemann Antje , Blaske Franziska , Sperling Michael , Karst Uwe
Published: December 2017

The distribution of silver (Ag) into remote organs secondary to the application of Ag nanoparticles (Ag-NP) to the lung is still incompletely understood and was investigated in the rat with imaging methods. Dose-finding experiments were carried out with 50 nm- or 200 nm-sized polyvinyl pyrrolidine (PVP)-coated Ag-NP using alveolar macrophages in vitro and female rats, which received Ag-NP via intratracheal instillation. In the main study, we administered 37.5–300 µg per rat lung of the more toxic Ag50-PVP and assessed the broncho-alveolar lavage fluid (BALF) for inflammatory cells, total protein and fibronectin after three and 21 days. In parallel, lung tissue was analysed for DNA double-strand breaks and altered cell proliferation. While 75–150 µg Ag50-PVP per rat lung caused a reversible inflammation, 300 µg led to DNA damage, accelerated cell proliferation and progressively increasing numbers of neutrophilic granulocytes. Ag accumulation was significant in homogenates of liver and other peripheral organs upon lung dose of ≥75 µg. Quantitative laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) combined with enhanced dark field microscopy and autometallography revealed focal accumulations of Ag and/or Ag-NP in sections of peripheral organs: mediastinal lymph nodes contained Ag-NP especially in peripheral macrophages and Ag in argyrophilic fibres. In the kidney, Ag had accumulated within proximal tubuli, while renal filter structures contained no Ag. Discrete localizations were also observed in immune cells of liver and spleen. Overall, the study shows that concentrations of Ag-NP, which elicit a transient inflammation in the rat lung, lead to focal accumulations of Ag in peripheral organs, and this might pose a risk to particular cell populations in remote sites.
An Insight into the Flammability of Some Bio-Based Polyesters
Authors: Dumazert Loïc , Sonnier Rodolphe
Published: December 2017

The heat release capacity of polymers can be generally predicted using a method based on the additivity of group contributions (the Van Krevelen approach). Nevertheless, there are some exceptions, evidencing that this approach is insufficient and must be completed. In this study, the kinetic triplet accounting for the description of pyrolysis is identified for 11 polymers. Activation energy and the frequency factor are calculated using Kissinger’s method. Reaction models are chosen among the Avrami–Erofeev functions. The high flammability of poly(3-hydroxybutyrate) and the underestimation of its heat release capacity using the Van Krevelen approach are explained from these parameters. The results highlight the possibility of improving the model, using additional but easily accessible data.
Dry Reforming of Methane Using a Nickel Membrane Reactor
Authors: Leimert Jonas , Karl Jürgen , Dillig Marius
Published: December 2017

Dry reforming is a very interesting process for synthesis gas generation from CH 4 and CO 2 but suffers from low hydrogen yields due to the reverse water–gas shift reaction (WGS). For this reason, membranes are often used for hydrogen separation, which in turn leads to coke formation at the process temperatures suitable for the membranes. To avoid these problems, this work shows the possibility of using nickel self-supported membranes for hydrogen separation at a temperature of 800 ∘ C. The higher temperature effectively suppresses coke formation. The paper features the analysis of the dry reforming reaction in a nickel membrane reactor without additional catalyst. The measurement campaign targeted coke formation and conversion of the methane feedstock. The nickel approximately 50% without hydrogen separation. The hydrogen removal led to an increase in methane conversion to 60–90%.
Barriers and Motivations for Construction Waste Reduction Practices in Costa Rica
Authors: Abarca-Guerrero Lilliana , Maas Ger , Van Twillert Hijmen
Published: December 2017

Low- and middle-income countries lag behind in research that is related to the construction industry and the waste problems that the sector is facing. Literature shows that waste reduction and recycling have received a continuous interest from researchers, but mainly from developed countries. Few reports from low- and middle-income countries are concerned about the reuse of masonry, concrete, and mortar in clay based building ceramics or recycling construction waste, but mostly in relation to concrete aggregates. Furthermore, few authors have described the major barriers and motivations for construction waste reduction. The objective of this paper is to report the findings on a research performed in Costa Rica with the objective to determine the barriers and motivations that the construction sector is facing to improve the management of the construction materials. The study is based on data collected in two phases. During the first phase, a survey was sent via e-mail to 419 main contractors registered at the School Federation of Engineers and Architects (CFIA). The second phase consisted of a focus group discussion with 49 professionals from the construction industry to analyse and validate the findings from the survey. Descriptive statistic methods helped to draw the conclusions. The result of the research is a comprehensive list of observed barriers and motivations for waste reduction practices in the construction sector. These are not only applicable to Costa Rica, but can be used as a guide for similar studies in other low- and middle-income countries.
Pre-Launch JPSS-2 VIIRS Response versus Scan Angle Characterization
Authors: McIntire Jeff , Moyer David , Chang Tiejun , Oudrari Hassan , Xiong Xiaoxiong
Published: December 2017

On-orbit whisk-broom sensors have scanning mirror assemblies, whose reflectance variations with scan angle must be characterized prior to launch. One such instrument is the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Joint Polar Satellite System 2 (JPSS-2) platform. The scanning optics inside VIIRS includes a four mirror rotating telescope assembly (RTA) and a half angle mirror (HAM), rotating at half the speed of the RTA, which de-rotates the light before it enters the aft-optics assembly. The angle of incidence (AOI) on the HAM varies with scan angle; all of the other optical components in VIIRS have a fixed AOI with scan angle. In general, the reflectance of the HAM will vary with AOI. This parameter is difficult to quantify once in orbit and therefore must be characterized pre-launch. Ground measurements were performed in the summer of 2016 to determine the relative reflectance change of the instrument with scan angle, referred to as the response versus scan angle (RVS). This work will describe the RVS testing performed and the results obtained, including an atmospheric water vapor correction and an uncertainty analysis. Results indicate that the reflectance variation with scan angle is small for spectral bands between 0.4 μ m and 4 μ m (less than 2% over the full range of AOI); in contrast, the reflectance variation is between 3% and 10% for the spectral bands in the 8 μ m to 12 μ m range. Uncertainties are below 0.05% in the reflective solar spectral region and below 0.26% in the thermal emissive spectral region. Comparisons to previous VIIRS builds (on the SNPP and JPSS-1 satellites) show comparable performance.
Research on the Parallelization of the DBSCAN Clustering Algorithm for Spatial Data Mining Based on the Spark Platform
Authors: Huang Fang , Zhu Qiang , Zhou Ji , Tao Jian , Zhou Xiaocheng , Jin Du , Tan Xicheng , Wang Lizhe
Published: December 2017

Density-based spatial clustering of applications with noise (DBSCAN) is a density-based clustering algorithm that has the characteristics of being able to discover clusters of any shape, effectively distinguishing noise points and naturally supporting spatial databases. DBSCAN has been widely used in the field of spatial data mining. This paper studies the parallelization design and realization of the DBSCAN algorithm based on the Spark platform, and solves the following problems that arise when computing macro data: the requirement of a great deal of calculation using the single-node algorithm; the low level of resource-utilization with the multi-node algorithm; the large time consumption; and the lack of instantaneity. The experimental results indicate that the proposed parallel algorithm design is able to achieve more stable speedup at an increased involved spatial data scale.
In Vivo Non-Destructive Monitoring of Capsicum Annuum Seed Growth with Diverse NaCl Concentrations Using Optical Detection Technique
Authors: Ravichandran Naresh Kumar , Wijesinghe Ruchire Eranga , Shirazi Muhammad Faizan , Kim Jeehyun , Jung Hee-Young , Jeon Mansik , Lee Seung-Yeol
Published: December 2017

We demonstrate that optical coherence tomography (OCT) is a plausible optical tool for in vivo detection of plant seeds and its morphological changes during growth. To investigate the direct impact of salt stress on seed germination, the experiment was conducted using Capsicum annuum seeds that were treated with different molar concentrations of NaCl. To determine the optimal concentration for the seed growth, the seeds were monitored for nine consecutive days. In vivo two-dimensional OCT images of the treated seeds were obtained and compared with the images of seeds that were grown using sterile distilled water. The obtained results confirm the feasibility of using OCT for the proposed application. Normalized depth profile analysis was utilized to support the conclusions.
Consistently Sampled Correlation Filters with Space Anisotropic Regularization for Visual Tracking
Authors: Shi Guokai , Xu Tingfa , Guo Jie , Luo Jiqiang , Li Yuankun
Published: December 2017

Most existing correlation filter-based tracking algorithms, which use fixed patches and cyclic shifts as training and detection measures, assume that the training samples are reliable and ignore the inconsistencies between training samples and detection samples. We propose to construct and study a consistently sampled correlation filter with space anisotropic regularization (CSSAR) to solve these two problems simultaneously. Our approach constructs a spatiotemporally consistent sample strategy to alleviate the redundancies in training samples caused by the cyclical shifts, eliminate the inconsistencies between training samples and detection samples, and introduce space anisotropic regularization to constrain the correlation filter for alleviating drift caused by occlusion. Moreover, an optimization strategy based on the Gauss-Seidel method was developed for obtaining robust and efficient online learning. Both qualitative and quantitative evaluations demonstrate that our tracker outperforms state-of-the-art trackers in object tracking benchmarks (OTBs).
One-step chemical vapor deposition synthesis and supercapacitor performance of nitrogen-doped porous carbon–carbon nanotube hybrids
Authors: Lobiak Egor V , Bulusheva Lyubov G , Fedorovskaya Ekaterina O , Shubin Yury V , Plyusnin Pavel E , Lonchambon Pierre , Senkovskiy Boris V , Ismagilov Zinfer R , Flahaut Emmanuel , Okotrub Alexander V
Published: December 2017

Novel nitrogen-doped carbon hybrid materials consisting of multiwalled nanotubes and porous graphitic layers have been produced by chemical vapor deposition over magnesium-oxide-supported metal catalysts. CNx nanotubes were grown on Co/Mo, Ni/Mo, or Fe/Mo alloy nanoparticles, and MgO grains served as a template for the porous carbon. The simultaneous formation of morphologically different carbon structures was due to the slow activation of catalysts for the nanotube growth in a carbon-containing gas environment. An analysis of the obtained products by means of transmission electron microscopy, thermogravimetry and X-ray photoelectron spectroscopy methods revealed that the catalyst's composition influences the nanotube/porous carbon ratio and concentration of incorporated nitrogen. The hybrid materials were tested as electrodes in a 1M H2SO4 electrolyte and the best performance was found for a nitrogen-enriched material produced using the Fe/Mo catalyst. From the electrochemical impedance spectroscopy data, it was concluded that the nitrogen doping reduces the resistance at the carbon surface/electrolyte interface and the nanotubes permeating the porous carbon provide fast charge transport in the cell.
Recent progress in the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres
Authors: Drouin Myriam , Paquin Jean-François
Published: December 2017

Monofluoroalkenes are fluorinated motifs that can be used to replace amide bonds. In order to be incorporated into peptides, it is normally necessary to first synthesize a dipeptide where the amide bond has been replaced with a monofluoroalkene. In that context, this review will present the racemic and enantioselective synthesis of monofluoroalkene-based dipeptide isosteres described since 2007. Some applications of those compounds will also be presented.
The Asymmetric Bow Shock/Pulsar Wind Nebula of PSR J2124–3358
Authors: Romani Roger W. , Slane Patrick , Green Andrew W.
Published: December 2017

We describe new measurements of the remarkable Hα/UV/X-ray bow shock and pulsar wind nebula (PWN) of the isolated millisecond pulsar (MSP) PSR J2124−3358. Chandra X-ray Observatory imaging shows a one-sided jet structure with a softer equatorial outflow. KOALA integral field unit spectroscopy shows that non-radiative emission dominates the bow shock and that the Hα nebula is asymmetric about the pulsar velocity with an elongation into the plane of the sky. We extend analytic models of the contact discontinuity to accommodate such shapes and compare these to the data. Using Hubble Space Telescope UV detections of the pulsar and bow shock, radio timing distance, proper motion measurements, and the CXO-detected projected spin axis, we model the 3D PWN momentum flux distribution. The integrated momentum flux depends on the ionization of the ambient ISM, but for an expected ambient warm neutral medium, we infer

. This implies

, depending on the equation of state, which in turn suggests that the MSP gained significant mass during recycling and then lost its companion. However, this conclusion is at present tentative, since lower ionization allows

lower masses, and uncertainty in the parallax allows up to 50% error.
ALMA Reveals Transition of Polarization Pattern with Wavelength in HL Tau’s Disk
Authors: Stephens Ian W. , Yang Haifeng , Li Zhi-Yun , Looney Leslie W. , Kataoka Akimasa , Kwon Woojin , Fernández-López Manuel , Hull Charles L. H. , Hughes Meredith , Segura-Cox Dominique , Mundy Lee , Crutcher Richard , Rao Ramprasad
Published: December 2017

The mechanism for producing polarized emission from protostellar disks at (sub)millimeter wavelengths is currently uncertain. Classically, polarization is expected from non-spherical grains aligned with the magnetic field. Recently, two alternatives have been suggested. One polarization mechanism is caused by self-scattering from dust grains of sizes comparable with the wavelength, while the other mechanism is due to grains aligned with their short axes along the direction of radiation anisotropy. The latter has recently been shown as a likely mechanism for causing the dust polarization detected in HL Tau at 3.1 mm. In this paper, we present ALMA polarization observations of HL Tau for two more wavelengths: 870 μm and 1.3 mm. The morphology at 870 μm matches the expectation for self-scattering, while that at 1.3 mm shows a mix between self-scattering and grains aligned with the radiation anisotropy. The observations cast doubt on the ability of (sub)millimeter continuum polarization to probe disk magnetic fields for at least HL Tau. By showing two distinct polarization morphologies at 870 μm and 3.1 mm and a transition between the two at 1.3 mm, this paper provides definitive evidence that the dominant (sub)millimeter polarization mechanism transitions with wavelength. In addition, if the polarization at 870 μm is due to scattering, the lack of polarization asymmetry along the minor axis of the inclined disk implies that the large grains responsible for the scattering have already settled into a geometrically thin layer, and the presence of asymmetry along the major axis indicates that the HL Tau disk is not completely axisymmetric.
Nova Ophiuchus 2017 as a Probe of 13C Nucleosynthesis and Carbon Monoxide Formation and Destruction in Classical Novae
Authors: Joshi Vishal , Banerjee D. P. K. , Srivastava Mudit
Published: December 2017

We present a series of near-infrared spectra of Nova Ophiuchus 2017 in the K band that record the evolution of the first overtone CO emission in unprecedented detail. Starting from 11.7 days after maximum, when CO is first detected at great strength, the spectra track the CO emission to +25.6 days by which time it is found to have rapidly declined in strength by almost a factor of ∼35. The cause for the rapid destruction of CO is examined in the framework of different mechanisms for CO destruction, namely, an increase in photoionizating flux, chemical pathways of destruction, or destruction by energetic nonthermal particles created in shocks. From LTE modeling of the CO emission, the 12C/13C ratio is determined to be 1.6 ± 0.3. This is consistent with the expected value of this parameter from nucleosynthesis theory for a nova eruption occuring on a low mass (

) carbon–oxygen core white dwarf. The present 12C/13C estimate constitutes one of the most secure estimates of this ratio in a classical nova.
A química em espaços de educação não formal: uma análise dos museus de ciências da região sul do Brasil
Authors: Colere Frohlich Fernanda Carolina , Da Silva Camila Silveira
Published: December 2017

O trabalho analisa as exposições de Química em museus de ciências da região Sul do Brasil, identificando os conceitos químicos contemplados e seus modos de mediação. A pesquisa se caracteriza como qualitativa do tipo documental, realizando um levantamento dos museus de ciência da região Sul do País, a partir do Guia de Centros e Museus de Ciências do Brasil (ABCMC, 2015) e do site de cada instituição selecionada. Como metodologia de análise utilizou-se a Análise de Conteúdo na perspectiva de Bardin (1977). Observamos uma baixa quantidade de locais que abordam a Química, e a relação dos conhecimentos químicos com os visitantes é observada em experimentos, que priorizam, na maioria dos locais, o espetáculo. A mediação é basicamente humana, nos espaços que foi possível obter essa informação. Com base na investigação nos sites das instituições, encontramos algumas limitações nos dados registrados.
As visões distorcidas da natureza da ciência sob o olhar da história e filosofia da ciência: uma análise nos anais dos ENEQ e ENEBIO de 2012 e 2014
Authors: Costa Franciellen Rodrigues da Silva , Zanin Ana Paula de Souza , Oliveira Thais Andressa Lopes de , Andrade Mariana Aparecida Bologna Soares de
Published: December 2017

Neste artigo buscou-se analisar as propostas e abordagens das visões distorcidas da Natureza da Ciência apresentadas em trabalhos sobre História e Filosofia da Ciência (HFC) publicados nas antepenúltimas e penúltimas edições de dois dos principais eventos nacionais de Ensino de Química e Ensino de Biologia. Procurou-se investigar quais foram as principais visões distorcidas identificadas nos trabalhos analisados, assim como, quantificar aqueles que apresentam tais discussões. Este trabalho configura-se como uma pesquisa documental que utilizou como fonte de dados os trabalhos publicados no XVI e XVII Encontro Nacional de Ensino de Química (ENEQ) e no IV e V Encontro Nacional de Ensino de Biologia (ENEBIO), nos anos de 2012 e 2014. Os resultados apontaram que entre as linhas temáticas que abordam a História e Filosofia da Ciência, há vários trabalhos que apresentam discussões sobre as visões distorcidas da Natureza da Ciência e do trabalho científico.