bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecosystem Services Mapping Uncertainty Assessment: A Case Study in the Fitzroy Basin Mining Region
Authors: Wang Zhenyu , Lechner Alex , Baumgartl Thomas
Published: January 2018

Ecosystem services mapping is becoming increasingly popular through the use of various readily available mapping tools, however, uncertainties in assessment outputs are commonly ignored. Uncertainties from different sources have the potential to lower the accuracy of mapping outputs and reduce their reliability for decision-making. Using a case study in an Australian mining region, this paper assessed the impact of uncertainties on the modelling of the hydrological ecosystem service, water provision. Three types of uncertainty were modelled using multiple uncertainty scenarios: (1) spatial data sources; (2) modelling scales (temporal and spatial) and (3) parameterization and model selection. We found that the mapping scales can induce significant changes to the spatial pattern of outputs and annual totals of water provision. In addition, differences in parameterization using differing sources from the literature also led to obvious differences in base flow. However, the impact of each uncertainty associated with differences in spatial data sources were not so great. The results of this study demonstrate the importance of uncertainty assessment and highlight that any conclusions drawn from ecosystem services mapping, such as the impacts of mining, are likely to also be a property of the uncertainty in ecosystem services mapping methods.
Considering a Threshold Energy in Reactive Transport Modeling of Microbially Mediated Redox Reactions in an Arsenic-Affected Aquifer
Authors: Rotiroti Marco , Jakobsen Rasmus , Fumagalli Letizia , Bonomi Tullia
Published: January 2018

The reductive dissolution of Fe-oxide driven by organic matter oxidation is the primary mechanism accepted for As mobilization in several alluvial aquifers. These processes are often mediated by microorganisms that require a minimum Gibbs energy available to conduct the reaction in order to sustain their life functions. Implementing this threshold energy in reactive transport modeling is rarely used in the existing literature. This work presents a 1D reactive transport modeling of As mobilization by the reductive dissolution of Fe-oxide and subsequent immobilization by co-precipitation in iron sulfides considering a threshold energy for the following terminal electron accepting processes: (a) Fe-oxide reduction, (b) sulfate reduction, and (c) methanogenesis. The model is then extended by implementing a threshold energy on both reaction directions for the redox reaction pairs Fe(III) reduction/Fe(II) oxidation and methanogenesis/methane oxidation. The optimal threshold energy fitted in 4.50, 3.76, and 1.60 kJ/mol e− for sulfate reduction, Fe(III) reduction/Fe(II) oxidation, and methanogenesis/methane oxidation, respectively. The use of models implementing bidirectional threshold energy is needed when a redox reaction pair can be transported between domains with different redox potentials. This may often occur in 2D or 3D simulations.
Evolution des karsts océaniens (Karsts, bauxites et phosphates)
Authors: Bourrouilh-Le Jan F
Published: January 2018

Les phénomènes karstiques sont un des traits dominants des îles hautes carbonatées de l'Océan Pacifique. Ils sont la clé qui permet la compréhension de l'évolution géologique, de la diagenèse et de l'intérêt économique actuel de ces plates-formes. Les variations eustatiques du niveau de la mer ont été très nombreuses depuis 25 millions d'années et se sont additionnées ou retranchées aux mouvements d'émersion ou de submersion. Chaque île présente donc une histoire complexe, accompagnée de dolomitisation, de calcrètes, de sols bauxitiques, d'encoches marines fossiles, de réseaux karstiques ennoyés ou remplis de phosphates économiquement exploitables. L'étude systématique de ces plates-formes a permis de dresser une évolution de la karsto-genèse en fonction de l'évolution de la lithosphère et de présenter un nouveau modèle de la phosphatoge-nèse lié à des retombées volcaniques, à des sols phosphato-bauxi-tiques et à des lacs méromictiques anoxiques.
Korea Microlensing Telescope Network Microlensing Events from 2015: Event-finding Algorithm, Vetting, and Photometry
Authors: Kim D.-J. , Kim H.-W. , Hwang K.-H. , Albrow M. D. , Chung S.-J. , Gould A. , Han C. , Jung Y. K. , Ryu Y.-H. , Shin I.-G. , Yee J. C. , Zhu W. , Cha S.-M. , Kim S.-L. , Lee C.-U. , Lee D.-J. , Lee Y. , Park B.-G. , Pogge R. W. ,   (The KMTNet Collaboration)
Published: January 2018

We present microlensing events in the 2015 Korea Microlensing Telescope Network (KMTNet) data and our procedure for identifying these events. In particular, candidates were detected with a novel “completed-event” microlensing event-finder algorithm. The algorithm works by making linear fits to a

grid of point-lens microlensing models. This approach is rendered computationally efficient by restricting u
0 to just two values (0 and 1), which we show is quite adequate. The implementation presented here is specifically tailored to the commission-year character of the 2015 data, but the algorithm is quite general and has already been applied to a completely different (non-KMTNet) data set. We outline expected improvements for 2016 and future KMTNet data. The light curves of the 660 “clear microlensing” and 182 “possible microlensing” events that were found in 2015 are presented along with our policy for their public release.
Observational Signatures of Mass-loading in Jets Launched by Rotating Black Holes
Authors: Riordan Michael O’ , Pe’er Asaf , McKinney Jonathan C.
Published: January 2018

It is widely believed that relativistic jets in X-ray binaries (XRBs) and active-galactic nuclei are powered by the rotational energy of black holes. This idea is supported by general-relativistic magnetohydrodynamic (GRMHD) simulations of accreting black holes, which demonstrate efficient energy extraction via the Blandford–Znajek mechanism. However, due to uncertainties in the physics of mass loading, and the failure of GRMHD numerical schemes in the highly magnetized funnel region, the matter content of the jet remains poorly constrained. We investigate the observational signatures of mass loading in the funnel by performing general-relativistic radiative transfer calculations on a range of 3D GRMHD simulations of accreting black holes. We find significant observational differences between cases in which the funnel is empty and cases where the funnel is filled with plasma, particularly in the optical and X-ray bands. In the context of Sgr A*, current spectral data constrains the jet filling only if the black hole is rapidly rotating with a ≳ 0.9. In this case, the limits on the infrared flux disfavor a strong contribution from material in the funnel. We comment on the implications of our models for interpreting future Event Horizon Telescope observations. We also scale our models to stellar-mass black holes, and discuss their applicability to the low-luminosity state in XRBs.
Dynamics of SiO Masers around VX Sgr
Authors: Su J. B. , Shen Z.-Q. , Chen X. , Jiang D. R.
Published: January 2018

We performed Very Long Baseline Array (VLBA) observations of SiO masers (

) toward VX Sgr from 2006 July to 2008 August. With the application of a phase reference technique, the accurate relative positions of maser spots at the two transitions can be acquired. The relative positions enable us to obtain more matched masers in the same coordinate frame to better study the dynamics of the maser shell. We adopt two different methods to investigate the global motions of the maser shell, which is found to expand in a decelerated manner. At the beginning of this process, the decelerative force can be interpreted as a force dominated by the gravitational attraction of the star. However, in the later epochs, the deceleration has a smaller magnitude, suggesting that an outward force is combating the stellar gravity. In addition, we construct a model of a rotating and expanding maser shell. The consistency of the model and observations at the first two epochs suggests approximate Keplerian rotation of the shell with a period of 46.9 years. However, other explanations, such as an axisymmetric outflow, are also possible. We also find two matched maser spots with double-peak spectra moving at a velocity of 6.8 km s−1. The special spectra provide direct observational evidence that the motion of a maser spot reflects the real gas stream, rather than changes in physical conditions. Finally, the distance to VX Sgr is calculated to be 1.10 ± 0.11 kpc using a statistical parallax method. This value is within the range reported in the literature.
Reconnection Fluxes in Eruptive and Confined Flares and Implications for Superflares on the Sun
Authors: Tschernitz Johannes , Veronig Astrid M. , Thalmann Julia K. , Hinterreiter Jürgen , Pötzi Werner
Published: January 2018

We study the energy release process of a set of 51 flares (32 confined, 19 eruptive) ranging from
GOES
class B3 to X17. We use Hα filtergrams from Kanzelhöhe Observatory together with Solar Dynamics Observatory HMI and Solar and Heliospheric Observatory MDI magnetograms to derive magnetic reconnection fluxes and rates. The flare reconnection flux is strongly correlated with the peak of the
GOES
1–8 Å soft X-ray flux (c = 0.92, in log–log space) for both confined and eruptive flares. Confined flares of a certain
GOES
class exhibit smaller ribbon areas but larger magnetic flux densities in the flare ribbons (by a factor of 2). In the largest events, up to ≈50% of the magnetic flux of the active region (AR) causing the flare is involved in the flare magnetic reconnection. These findings allow us to extrapolate toward the largest solar flares possible. A complex solar AR hosting a magnetic flux of 2 × 1023 Mx, which is in line with the largest AR fluxes directly measured, is capable of producing an X80 flare, which corresponds to a bolometric energy of about 7 × 1032 erg. Using a magnetic flux estimate of 6 × 1023 Mx for the largest solar AR observed, we find that flares of
GOES
class ≈X500 could be produced (E
bol ≈ 3 × 1033 erg). These estimates suggest that the present day’s Sun is capable of producing flares and related space weather events that may be more than an order of magnitude stronger than have been observed to date.
A Dependence of the Tidal Disruption Event Rate on Global Stellar Surface Mass Density and Stellar Velocity Dispersion
Authors: Graur Or , French K. Decker , Zahid H. Jabran , Guillochon James , Mandel Kaisey S. , Auchettl Katie , Zabludoff Ann I.
Published: January 2018

The rate of tidal disruption events (TDEs),

, is predicted to depend on stellar conditions near the super-massive black hole (SMBH), which are on difficult-to-measure sub-parsec scales. We test whether

depends on kpc-scale global galaxy properties, which are observable. We concentrate on stellar surface mass density,

, and velocity dispersion,

, which correlate with the stellar density and velocity dispersion of the stars around the SMBH. We consider 35 TDE candidates, with and without known X-ray emission. The hosts range from star-forming to quiescent to quiescent with strong Balmer absorption lines. The last (often with post-starburst spectra) are overrepresented in our sample by a factor of

or

, depending on the strength of the Hδ absorption line. For a subsample of hosts with homogeneous measurements,

–

, higher on average than for a volume-weighted control sample of Sloan Digital Sky Survey galaxies with similar redshifts and stellar masses. This is because (1) most of the TDE hosts here are quiescent galaxies, which tend to have higher

than the star-forming galaxies that dominate the control, and (2) the star-forming hosts have higher average

than the star-forming control. There is also a weak suggestion that TDE hosts have lower

than for the quiescent control. Assuming that

, and applying a statistical model to the TDE hosts and control sample, we estimate

and

. This is broadly consistent with

being tied to the dynamical relaxation of stars surrounding the SMBH.
Desenvolvimento e análise sensorial de esfirra integral com e sem farinha de aveia
Authors: Vagula Julianna Matias , Castro Juliana Cristina , Veronezi Milena , Zuanazzi Jovana Garbelini , Pascoli Isabela Carolini , Madrona Grasiele Scaramal
Published: January 2018

O objetivo foi testar duas formulações de esfirra integral, uma com adição de aveia e outra sem adição de aveia, ambas com recheio de proteína texturizada de soja, além de realizar a pesquisa de mercado, identificar a porção recomendada, o valor calórico, o índice de aceitação e a análise sensorial. A análise sensorial foi realizada com 117 provadores não treinados, os atributos avaliados foram aroma, sabor, textura, aparência global e intenção de compra. O índice de aceitação para as duas formulações de esfirras foi maior que 70%, sendo que não foi observada a rejeição dos produtos avaliados. A composição centesimal demonstrou esfirras com bom aporte protéico e de fibra alimentar. Estudos sobre esfirras integrais são escassos, e este estudo demonstrou a oportunidade da junção de ingredientes com alegação funcional, os quais apresentam tanto aplicabilidade na fabricação dos produtos quanto benefício aos consumidores.
Deterioração fúngica em indústria de queijo tipo tropical
Authors: Jahn Raquel Carine , Garcia Marcelo Valle , Copetti Marina Venturini
Published: January 2018

A elaboração de queijos constitui uma importante atividade na indústria de laticínios, necessitando uma série de operações desde a obtenção do leite até o último dia de maturação do produto e expedição para o mercado. Devido às características intrínsecas, este produto também é capaz de proporcionar um meio adequado para a proliferação de micro-organismos patógenos e deteriorantes oriundos da matéria-prima ou inseridos durante as etapas de processamento. O desenvolvimento microbiano, sobretudo fúngico, nas diferentes etapas da produção pode provocar deterioração e descarte do produto. Este trabalho objetivou investigar a ocorrência da deterioração fúngica em uma indústria de queijo tipo tropical. Foram analisadas amostras de produtos deteriorados, matérias-primas e produto em diferentes etapas de produção, utensílios e ar dos ambientes de processamento através de técnicas micológicas rotineiras, além do produto deteriorado. Detectou-se a presença de fungos filamentosos em 70% das amostras de matérias-primas e produtos analisados, com predominância dos gêneros Penicillium spp. e Cladosporium sp. Nas análises feitas do ambiente do processamento da fábrica foi observada uma elevada contagem fúngica, com elevada recuperação dos gêneros Penicillium, Fusarium, Cladosporium e Aspergillus. Nas amostras de queijo deteriorado foi isolado apenas Penicillium commune. Esta espécie também estava presente no ar, nos utensílios e no queijo nas diferentes fases de produção. Considerando que P. commune não estava presente nas matérias-primas, conclui-se que o ambiente de fabricação teve papel crucial para a contaminação do produto. O fato desta espécie ser capaz de se desenvolver em temperaturas de refrigeração pode ter colaborado para a deterioração dos queijos.
Elaboração de chips de yacon pelo processo de desidratação osmótica e secagem
Authors: Rabelo Nadja Maria , Silva Larissa Morais Ribeiro da , Canuto Kildere Marques , Vieira Janaina Maria Martins
Published: January 2018

O yacon está sendo considerado um alimento funcional em decorrência dos estudos sobre sua função prebiótica e redução dos níveis de açúcar no sangue. O crescente aumento da busca no mercado por produtos que apresentem benefícios comprovados à saúde, além de qualidade nutricional e sensorial faz com que as pesquisas nesse setor se desenvolvam. Considerando que a vida útil do yacon é muito reduzida em condições ambientes, métodos de desidratação têm sido empregados a fim de estendê-la.  Com isso, o objetivo desse estudo foi a elaboração de chips de yacon através do processo de desidratação osmótica e secagem. Foram elaboradas três formulações, sendo uma submetida apenas a secagem em estufa e as outras submetidas a desidratação osmótica com glicerol ou sucralose, ambas seguidas de secagem em estufa. As soluções para a desidratação osmótica apresentaram concentração de 20%, numa proporção de uma parte de yacon para cinco partes de solução. Foi realizada análise sensorial (escala hedônica para cor, aroma, aparência, sabor e textura) e teste de intenção de compra, que mostraram ser possível a obtenção de um produto com boas características sensoriais, apesar da diferença significativa entre as 3 formulações. De acordo com os resultados, a formulação 3 foi a que apresentou as melhores características sensoriais.
A Linguistic Analysis of Health Literacy Demands of Chronic Kidney Disease Patient Education Materials
Authors: Morony Suzanne , Webster Angela C. , Buchbinder Rachelle , Kirkendall Suzanne , McCaffery Kirsten J. , Clerehan Rosemary
Published: January 2018

Background:

Instruments to assess the quality and comprehensibility of printed patient education materials may lack proper consideration of how readers derive meaning from text. The Evaluative Linguistic Framework (ELF) considers how factors that influence readers' expectations about health care texts also affect their ability to understand them. The ELF has demonstrated value in improving the quality of patient materials about medication, consent, and self-reported questionnaires, but has not yet been used to evaluate a corpus of patient education materials about chronic disease self-management.

Objective:

This study sought to apply the ELF to examine specific elements of printed self-management patient education materials for chronic kidney disease (CKD) not captured by other tools.

Methods:

From a previously published systematic review, we identified 14 patient education materials (eight self-management, six diet and nutrition) for people with CKD. We used the ELF to identify the different ways the text could be structured, its intended purpose, the relationship established between reader and writer, presence of signposting, its complexity and technicality of language, and factual content.

Key Results:

Our analysis identified nine possible structural units, of which “introducing the problem” and “instructing the reader to self-manage” were common to all materials. However, there was no consistency or common sequence to these units of text. The intended readership and aims of the author(s) were not always clear; many materials made assumptions about what the reader knew, the language was often complex and dense, and the meta-discourse was sometimes distracting.

Conclusions:

Our analysis suggests CKD document developers can benefit from a theoretically grounded linguistic tool that focuses on the intended audience and their specific needs. The ELF identified structural units of text, aligned with rhetorical elements that can be uniformly applied for developing self-management education materials for CKD, and provided checks for language complexity. Further work can determine its usefulness for other (e.g., electronic) formats and other chronic diseases.

[
HLRP: Health Literacy Research and Practice
. 2018;2(1):e1–e14.]

Plain Language Summary:

Helping patients make meaning from information about their condition is a key goal of health care organizations. We analyzed chronic kidney disease patient education materials on self-management using the Evaluative Linguistic Framework. The purpose and intended audience were frequently unclear. We identified nine structural units of text that may assist information providers to plan and structure content.
La contribución de la música de George Fenton al cine de Ken Loach
Authors: López Hernández Sofía
Published: January 2018

Ken Loach es un realizador británico de gran relevancia. Desde mediados de los 60 ha dirigido numerosas películas para cine y televisión. Y aunque sobre su modo de rodar se ha escrito mucho, hay muy poco sobre su el sentido de su música de cine. Para conocer este aspecto es indispensable hablar de George Fenton, que desde 1994 es su compositor habitual.
Esta investigación surge del interés por descubrir qué características musicales aporta Fenton al cine de Loach.
Constraint-based Student Modelling in Probability Story Problems with Scaffolding Techniques
Authors: Khodeir Nabila , Wanas Nayer , Elazhary Hanan
Published: January 2018

Constraint-based student modelling (CBM) is an important technique employed in intelligent tutoring systems to model student knowledge to provide relevant assistance. This paper introduces the Math Story Problem Tutor (MAST), a Web-based intelligent tutoring system for probability story problems, which is able to generate problems of different contexts, types and difficulty levels for self-paced learning. Constraints in MAST are specified at a low-level of granularity to allow fine-grained diagnosis of the student error. Furthermore, MAST extends CBM to address errors due to misunderstanding of the narrative story. It can locate and highlight keywords that may have been overlooked or misunderstood leading to an error. This is achieved by utilizing the role of sentences and keywords that are defined through the Natural Language Generation (NLG) methods deployed in the story problem generation. MAST also integrates CBM with scaffolding questions and feedback to provide various forms of help and guidance to the student. This allows the student to discover and correct any errors in his/her solution. MAST has been preliminary evaluated empirically and the results show the potential effectiveness in tutoring students with a decrease in the percentage of violated constraints along the learning curve. Additionally, there is a significant improvement in the results of the post–test exam in comparison to the pre-test exam of the students using MAST in comparison to those relying on the textbook
Recent Developments in Game-Based Virtual Reality Educational Laboratories Using the Microsoft Kinect
Authors: Zhang Mingshao , Zhang Zhou , Chang Yizhe , Aziz El-Sayed , Esche Sven , Chassapis Constantin
Published: January 2018

Virtual Reality (VR) is a well-known concept and has been proven to be beneficial in various areas. However, several disadvantages inherent in VR prevent its broad deployment in the educational arena. These limitations include non-realistic representation, lack of customizability and flexibility, financial feasibility, physical and psychological discomforts of the users, simulator sickness, etc. In this paper, an innovative method that uses the Microsoft Kinect as an essential component for developing game-based VR educational laboratories is presented. This technique addresses three different aspects. First, it represents an efficient method for creating the VE using the Kinect as a measuring tool. Second, the Kinect is employed as a substitute DAQ system for acquiring range data and tracking the motion of objects of interest. At last, the Kinect serves as a novel human-computer interface for tracking the users’ entire body motion and recognizing their voices. Using the method described here, three major aspects of educational VR development can be accomplished with an inexpensive and commercially available Kinect.
Failure of Service Exposed Heat Resistant Cast Steel Tube
Authors: Aichaoui Meriem , Hadji Ali
Published: January 2018

A heat resistant cast steel tube from an ammonia plant made of modified HP40 steel that failed after seven years of service was investigated for damage mechanism. The assessment of material degradation was carried out using optical microscopy, scanning electron microscopy (SEM) in combination with energy dispersive spectroscopy (EDS) analysis and mechanical tests. The main cause of failure appears to be overheating and localized corrosion along the network of intergranular carbides. Failed portion of the tube showed that the interdendritic eutectic carbides had coarsened, secondary carbides were precipitate and strongly coaresned within the austenitic regions. Witch decrease the mechanical strength and ductility of the service exposed tube compared with the as cast tube. Presence of unacceptable impurities like chlorine in the internal working gas destroy the protective oxide layer leading to penetration of corroding elements and degradation of service life of the tube.
Lead Time Reduction through Execution of Lean Tool for Productivity Enhancement in Small Scale Industries
Authors: Saravanan V. , Nallusamy S. , Balaji K.
Published: January 2018

In the current dynamic global market place, especially among small and medium scale manufacturing industries the competition is show rigorous for a profitable survival. To be competent the industries have to necessarily work in an efficient way by updating and implementing new techniques. These day’s manufacturers may have to introduce and prove the success of the products not only faster but also to deliver it to the end users at the right time. The aim of this study has been to present a lean approach in the manufacturing system of injection moulding facility by reducing the change over time. In this research a lean tool of Single Minute Exchange of Die (SMED) has proved to be an effective tool for eliminating waste of time. In SMED the time taken for mould or die exchange should be less than 10 minutes. This improves the productivity by reducing the down time of a machine. The main objective has been to reduce the change over time from the current setup time of 39.94 minutes to less than 10 minutes. After implementing the SMED, the total change over time was reduced by about 67.72% which indirectly reduced production losses and increased the productivity.
The Stress Triaxiality Effect under Large Plastic Deformation of a Polybutylene Terephthalate (PBT)
Authors: Zaim Abdel Nour , Bouchouicha Benattou , Meddah Hadj Miloud , Ould Chikh El Bahri
Published: January 2018

In this work, we focus on a new generation of polymer named Polybutylene terephthalate (PBT). In order to analyse and determine true behaviour of this polymer, a special experimental method was used. Hence, the true stress/strain responses are investigated under a large plastic deformation in different stress triaxiality frameworks with a particular attention on the volumetric strain evolution, with their decomposition to an elastic volumetric strain, plastic volumetric strain and the pure shear. Moreover, the effect of stress triaxiality on the plastic instability and the fracture strain is also examined. With the plastic instability analysis, it was found that plastic strain hardening increases gradually with the triaxiality. Finally, in order to evaluate the damage of this polymer, a theoretical damage formula is proposed.
Sales and Operations Planning (S&OP) Concepts and Models under Constraints: Literature Review
Authors: Nabil LAHLOUA , El Barkany Abdellah , El Khalfi Ahmed
Published: January 2018

Globalization has had a significant impact on company’s management, particularly in the supply chain (lead time, investment in production capacity and technology, organization & management ...). The sales and operations planning (S&OP) include all the processes that link the strategic objectives of the enterprise with the production plan. The impact of the S&OP on operational performance was consistently and significantly demonstrated in the operational aspects of production ; quality (conformity of production, product quality and reliability), delivery (the delivery agility, reliability of supply, manufacturing deadlines, lead times), stocks (reduction of inventory levels, inventory optimization) and flexibility (flexible volume and mix). Our objective in this paper is to present, in the first part, a literature overview of the sales and operations planning, and various research and models developed. In the second part, we will emphasize the transversal aspect of our research that involves both operational issues, tactical and strategic in a context subject to different constraints.
Evaluation of Moisture and Ageing Effects on Calcium Carbonite Nanoparticles Modified Asphalt Mixtures
Authors: Ali Shaban Ismael Albrka , Abdulwahid Riyadh , Eidan Muhamed Laith , Md Yusoff Nur Izzi
Published: January 2018

Flexible pavements deteriorate and crack with time due to the frequent traffic load imposed upon it. Many studies have been done to predict the effects of frequent traffic load and environmental conditions on pavements in the effort to find the best pavement design which resist deterioration and ensure longer pavement service time. This study investigates the effect of mixing asphalt with varying percentages of nano calcium carbonate (CaCO3), namely 0, 2, 4, and 6 %. The mixtures were designed based on the Superpave mix design criteria. Investigation was done using several tests, namely resilient modulus, indirect tensile strength, moisture susceptibility, and dynamic modulus tests. Samples were subjected to aging to determine their resilient modulus. The results of the investigation show that resilient modulus and indirect tensile strength increased when higher percentages of nanoparticles were added to asphalt mixture, with improvement of 138 and 48.18% respectively. Modified binders showed up to 17% improvement in moisture susceptibility comparison to base asphalt mixture, while the result of dynamic modulus test showed that the stiffness of modified asphalt increased 76.69%. The investigation also found that adding 6% CaCO3 nanoparticles to asphalt produced modified asphalt with the best performance. In addition, the results show that the modified asphalt with CaCO3 is suitable for hot and humid regions (tropical countries) in the field of highways construction, as the modifier was able to mitigate the influences of high-temperature rutting and moisture damage.
Study of Microstructure and Mechanical Properties of Sintered Fe-Cu Alloys
Authors: Baroura Lazhar , Boukhobza Abdelyamine , Derardja Akila , Fedaoui Kamel
Published: January 2018

In the present work, Fe-Cu based alloys with different compositions have been obtained by using Powder metallurgy (PM). These alloys were created with the purpose of increasing mechanical properties of the parts. Nevertheless, little have been published, once this is a matter of industrial interest. In this work, samples of Fe100-x Cux (x=0.40, 0.55, 0.70, 0.85 and 1) alloys were processed by cold pressing at 10 MPa, followed by sintering at 1250 C°. Structures formed during sintering were studied by EDS. Microstructural aspects were observed by MEB. Densification and microhardness tests were also performed.
Modelling of Grewia mollis Stem Bark Gum Extraction Yield Using Neuro-Fuzzy Technique
Authors: Oke Emmanuel Olusola , Adeyi Oladayo , Adeyi Abiola John , Adekunle Kayode Feyisetan
Published: January 2018

In this paper, Adaptive Neuro-Fuzzy Inference System (ANFIS) was used to model and predict Grewia Polysaccharide Gum (GPG) extraction yield from Grewia mollis (GM) powder/water system. The data for modelling the process behaviour consisted of four inputs (process temperature, GM powder/water ratio, process time and pH) and GPG yield as the output. The gbell Membership Function (MF) was used for the fuzzification of input variables and hybrid algorithm was chosen for the learning method of input–output data of the process. Simulation study was conducted on the developed ANFIS architecture at different MFs and epoch numbers to establish minimum error and maximum correlation coefficient (R) of the model. From the results obtained, ANFIS can be used as a reliable tool for modelling and prediction of GPG powder/water extraction process behaviour. The R between the experimental and predicted values was found to be high (> 0.96) and the mean percentage error was less than 2%, showing the great efficiency and reliability of the developed model.
Voltage Unbalance Mitigation and Voltage Profile Enhancement in Secondary Distribution System Using Dynamic Voltage Restorer
Authors: Ogunboyo Patrick Taiwo , Tiako Remy , Davidson Innocent
Published: January 2018

This study addresses the effective mitigation of power quality disturbance such as unbalanced voltage, voltage fluctuation, voltage variation of secondary distribution network using dynamic voltage restorer (DVR). To make distribution system operate at its best performance and minimum loss, DVR is employed. The proposed system is designed using MATLAB/Simulink in Sim Power System tool box. Considering, nevertheless, that standard acceptable performance implies correct voltage profile, minimum loss, no phase shift for voltage and current, absence of overloading of transformers and electrical wires, and acceptable frequency deviation. The new setup of DVR has been put forward using dq0 controller and proportional integral (PI) controller method to improve voltage profile, correct unbalance voltage and enhance power quality problems in secondary distribution network. The simulation results attest to the ability of the proposed DVR configuration in mitigating the power quality problems in secondary distribution network.
Alkaline Aluminosilicate Binder for Gluing Wood Board Materials
Authors: Kryvenko Pavlo V. , Petropavlovsky Оleg , Vozniuk Grigorii
Published: January 2018

Organic adhesive – bonded wood board materials like particleboards, plywood and others are widely used in construction, furniture, car- making, etc. However, all materials made with organic adhesives release non-reacted toxic substances, in particular formaldehyde and phenol, which produce negative effects on human health during production and use. Current trend in wood processing industry is to replace organic binders used as adhesives by inorganic ones. One of such solutions to improve indoor air quality is to replace organic adhesives by inorganic ones and the use of the alkaline aluminosilicate binders of the system R2O-Al2O3-SiO2-H2O is a highly advantageous solution and no need of preliminary treatment of wood. Among disadvantages are the low elasticity. Among disadvantages of these binders restricting their use as adhesives are low elastic properties (high modulus of elasticity, stiffness) of the resulted wood-based products. The paper covers the results of modification of the alkaline aluminosilicate binders to improve properties using specially chosen organic additives – modifiers
Preliminary Study of the Use of a Secondary Lead Smelting Slag as an Addition to Portland Cement
Authors: Torres Agredo Janneth , Gallego Restrepo Sergio , Álvarez Hincapié Fernando , Giraldo Alzate Daniela
Published: January 2018

In this work, the preliminary study about the use of secondary lead smelting slag (SLSS) as an addition to Portland cement is presented. SLSS is a waste from a Colombian secondary lead smelter. The chemical, physical and mineralogical characteristics of the raw materials were evaluated by X-ray fluorescence, particle size and X-ray diffraction. To assess the SLSS pozzolanic activity, the ASTM C618 standards were used. Additionally, cement pastes added with SLSS as Portland cement replacement in proportions of 0, 5, 10, 20 and 30% were prepared, to study the hydration process at 7, 14 and 28 of curing times. To determine the hydration products the technique of X-ray diffraction was used. Furthermore, the environmental test TCLP (Toxicity Characteristic Leaching Procedure) was performed in pastes with 28 days of curing time. Results showed that SLSS reported an index of pozzolanic activity of 87%, this value meets the standard (greater than 75%). The hydration process showed that since early curing time the waste presented a good reactivity. TCLP results satisfied the environmental standards. The outcomes showed that this waste could be used as a partial replacement of Portland cement.
Crack Initiation of Alkali-Activated Slag Based Composites with Graphite Filler
Authors: Šimonová Hana , Topolář Libor , Rovnaník Pavel , Schmid Pavel , Keršner Zbyněk
Published: January 2018

The alkali-activated slag is an alternative building material to ordinary Portland cement based materials. This type of material is effective in reducing CO2 emissions and energy consumption. Addition of graphite powder increases its electric conductivity, hence, introducing new functionality to building materials such as self-sensing and self-heating properties. In this study, the effect of graphite filler on the crack initiation of alkali-activated slag composite is investigated. The graphite powder was added in the amount of 5, 10 and 15% with respect to the slag mass. Beam specimens with an initial stress concentrator were tested in three-point bending at the age of 28 days. The load versus crack mouth crack opening displacement (F–CMOD) diagrams were recorded during the fracture tests and subsequently evaluated using the Double-K fracture model. This model allows the quantification of two different levels of crack propagation: initiation, which corresponds to the beginning of stable crack growth, and the level of unstable crack propagation. The course of fracture tests was also monitored by acoustic emission (AE) method.
Shrinkage of Fine-Grained Composites Based on Alkali-Activated Slag
Authors: Kucharczyková Barbara , Bílek Jr. Vlastimil , Kocáb Dalibor , Karel Ondřej
Published: January 2018

The paper deals with the experimental determination of shrinkage development of the composites based on the alkali-activated slag (AAS). The main aim of the experimental investigation was to verify the effect of the addition of shrinkage-reducing admixture (SRA) on the overall process of shrinkage properties during AAS composites ageing.
Effect of Curing Temperature on Mechanical and Fracture Parameters of Alkali-Activated Brick Powder Based Composite
Authors: Šimonová Hana , Keršner Zbyněk , Schmid Pavel , Rovnaníková Pavla
Published: January 2018

The paper describes alkali-activation of the brick body with potassium water glass having the silicate modulus of 1.0. The 28-days compressive strengths, elasticity modulus, effective fracture toughness, effective toughness, and specific fracture energy of the specimens stored at 20, 40 and 60 °C are evaluated. The storage temperature of specimens and the content of the alkaline solution have a significant influence on all mechanical fracture properties of the studied materials.
Phononic Band Gaps in Al2O3/Epoxy Composite
Authors: Miranda Jr. Edson Jansen Pedrosa , dos Santos J.M.C.
Published: January 2018

In this study, we have investigated the band structure of elastic waves propagating in a phononic crystal, consisting of an epoxy matrix reinforced by Al2O3 inclusions in a square and hexagonal lattices. We also studied the influence of the inclusion geometry cross section – circular, hollow circular, square and rotated square with a 45° angle of rotation with respect to the x, y axes. The plane wave expansion (PWE) method is used to solve the wave equation considering the wave propagation in the xy plane (longitudinal-transverse vibration, XY mode, and transverse vibration, Z mode). The complete band gaps between the XY and Z modes are observed to circular, square and rotated square cross section inclusion and the best performance is for rotated square cross section inclusion in a square lattice. We suggest that the Al2O3/epoxy composite is feasible for vibrations management.
Interlocking Concrete Paving Blocks Produced with Foundry Sand Waste
Authors: Santos C.C. , dalla Valentina Luiz Oliveira Veriano , Cuzinsky F.C. , Witsmiszyn L.C.
Published: January 2018

Industrialized products demand huge quantities of raw material, and generate enormous volumes of residue. This fact has caused an imbalance in the environment, such as the soil, the water tables, ecosystems and public health. The foundry industry, known for being one of the biggest users of raw material, is among the major pollutants. Concomitantly, the civil construction sector is notorious for its huge consumption of natural resources, but in contrast, it has the potential to aggregate residues from other industries, resulting in added- value products. Recycling is one of the alternatives found when trying to lessen the environmental impacts created by industrial waste, transforming residue into useful products for society. The goal of this research is to analyze the use of spent foundry sand (SFS) and foundry exhausted dust (ED) in the making of interlocking concrete paving blocks. These blocks have been made with foundry sand waste as aggregate and this element has been substituted partially by 0, 5, 10, 15 and 20% with exhausted dust. The blocks were technically analyzed for their compressive strength, measurement of dimension and water absorption. The results obtained concerning compressive strength were below the standard specification, whereas the dimensions and water absorption testing were in accordance with the Brazilian National Standards Organization NBR 9781 [1].
Experimental Statistics Applied to Porous Ceramics Processing
Authors: de Oliveira Déborah Caroline , Mendes Patrícia Neves , Godinho Lucas Marcello , Maestrelli Sylma Carvalho , Storion Ana Gabriela
Published: January 2018

Statistical techniques are particularly useful in the engineering, objecting the optimization of fabrication processes. This paper had the purpose of evaluating if the variables such as mechanical resistance, linear shrinkage, apparent porosity, density and water absorption are influenced by the amount of peat added to refractory clay, to ensure the porosity on the production of porous ceramics used as ceramic filters. In order to treat the data it was used the technique of variance analysis, with the regression analysis and the Scott-Knott test. According to the variance analysis, there were some differences between the treatments for all properties analyzed and, by the regression analysis, optimum peat levels were found for all properties analyzed, for some properties these levels were considered inadequate for being superior to the limit stablished.
Preparation and Physical Chemistry Characterization of New Nanostructured Oxides Catalysts by Spray Pyrolysis Method for the Biodiesel Production
Authors: Lanfredi Silvania , Djurado Elisabeth , Nobre Marcos A.L.
Published: January 2018

In this work were synthesized new catalysts of stoichiometries Sr0.8K0.2TiCu0.10O3, Sr0.7K0.3TiCu0.15O3 and Sr0.5K0.5TiCu0.25O3 by spray pyrolysis method. The synthesis conditions were optimized to obtain single phase powder of titanates of double perovskite structure, with an ultrasound vibration frequency of 1.3 MHz at 700 °C under air flow. The average crystallite size of the powders, determined by the Scherrer equation and using the Jade Plus 8 software, was at around 9 nm. The powder morphology was analyzed by scanning electron microscopy (SEM). The Sr0.5K0.5TiCu0.25O3 system showed particles with smooth surfaces, spherical and with smaller agglomerates than Sr0.8K0.2TiCu0.10O3, Sr0.7K0.3TiCu0.15O3 systems. This phenomenon suggests that the stoichiometry changes the aspect of the particle surface, which may influence in the catalytic activity. Thus, particles without roughening and smaller size can act as promising catalysts.
Characterisation of Refractory Ceramic Pressed Body Containing Industrial Waste
Authors: Frade S.B. , Gomes G. , Correia Sivaldo L. , Segadaes A.M.
Published: January 2018

This study investigates the use of an industrial refractory brick waste in the refractory based silica and alumina ceramic body. From the characterization of the waste, a mixture containing a clay, silica, alumina and waste was processed via wet route and sintered at 1400 °C. The specimens were evaluated in dry (density) and after sintering (linear shrinkage, density and modulus of rupture).Microstructural characterization by scanning electron microscopy (secondary electron) revealed a microstructure unevenly and a presence of big porous which shows also small amounts of vitreous phase, which can be related to sintering process not fully finished. The results for the linear shrinkage (about 6 %) and modulus of rupture at three points (about 63 MPa) showed that the mixture containing the refractory brick waste and the processing conditions were satisfactory for obtaining a suitable refractory material for the manufacture of bricks for melting furnaces.
A rare case of odynophagia
Authors: Moolla Yusuf , Naidoo Lavanya
Published: January 2018

A rare aetiology of isolated tonsillar mass lesions causing odynophagia was demonstrated in a young immunocompromised woman.
Symptomatic neurocutaneous melanosis with unusual benign course: A case report and review
Authors: Ayyash Baker , Fathalla Waseem
Published: January 2018

Neurocutaneous melanosis (NCM) is a rare, congenital, noninherited neurocutaneous syndrome characterized by the presence of “multiple or large congenital nevi” with central nervous system melanocytic deposits. Majority of cases are asymptomatic. Symptomatic cases present with hydrocephalus and signs and symptoms of increased intracranial pressure. The latter is associated with poor prognosis. We herein report an asymptomatic patient with giant congenital melanocytic nevi. He had a screening magnetic resonance imaging study at the age of 2 months that showed T1 hyperintensities in the region of amygdala of both temporal lobes. He was asymptomatic until the age of 4 years when he presented with seizure activity. A diagnosis of NCM was made. He was discharged on emergency antiepileptic medication. On regular follow-up, he remained seizure free for 1 year after the first episode of seizure. Unlike other cases reported in literature, this, to the best of our knowledge, is the first report of nonprogressive symptomatic NCM.
Assessment of the Agreement between Cerebral Hemodynamic Indices Quantified Using Dynamic Susceptibility Contrast and Dynamic Contrast-enhanced Perfusion Magnetic Resonance Imagings
Authors: Zakariaee Seyed Salman , Oghabian Mohammad Ali , Firouznia Kavous , Sharifi Guive , Arbabi Farshid , Samiei Farhad
Published: January 2018

Background:

Brain tumor is one of the most common tumors. A successful treatment might be achieved with an early identification. Pathological investigation as the gold standard method for tumor identification has some limitations. Noninvasive assessment of tumor specifications may be possible using perfusion-weighted magnetic resonance imaging (MRI). Cerebral blood volume (CBV) and cerebral blood flow (CBF) could be calculated based on dynamic contrast-enhanced MRI (DCE-MRI) in addition to dynamic susceptibility contrast MRI (DSC-MRI) modality. Each category of the cerebral hemodynamic and permeability indices revealed the specific tumor characteristics and their collection could help for better identification of the tumor. Some mathematical methods were developed to determine both cerebral hemodynamic and permeability indices based on a single-dose DCE perfusion MRI. There are only a few studies available on the comparison of DSC- and DCE-derived cerebral hemodynamic indices such as CBF and CBV.

Aim:

The objective of the study was to validate first-pass perfusion parameters derived from T1-based DCE method in comparison to the routine T2*-based DSC protocol.

Materials and Methods:

Twenty-nine patients with brain tumor underwent DCE- and DSC-MRIs to evaluate the agreement between DSC- and DCE-derived cerebral hemodynamic parameters. Agreement between DSC- and DCE-derived cerebral hemodynamic indices was determined using the statistical method described by Bland and Altman. The reliability between DSC- and DCE-derived cerebral hemodynamic indices was measured using the intraclass correlation analysis.

Results:

The achieved magnitudes for DCE-derived CBV (gray matter [GM]: 5.01 ± 1.40 mL/100 g vs. white matter [WM]: 1.84 ± 0.74 mL/100 g) and DCE-derived CBF (GM: 60.53 ± 12.70 mL/100 g/min vs. WM: 32.00 ± 6.00 mL/100 g/min) were in good agreement with other studies. The intraclass correlation coefficients showed that the cerebral hemodynamic indices could accurately be estimated based on the DCE-MRI using a single-compartment model (>0.87), and DCE-derived cerebral hemodynamic indices are significantly similar to the magnitudes achieved based on the DSC-MRI (P < 0.001). Furthermore, an acceptable agreement was observed between DSC- and DCE-derived cerebral hemodynamic indices.

Conclusion:

Based on the measurement of the cerebral hemodynamic and blood–brain barrier permeability using DCE-MRI, a more comprehensive collection of the physiological parameters cloud be achieved for tumor evaluations.