bluuebunny/crossref_metadata_2025 huggingface dataset:
New Synthesis and Small Angle Neutron Scattering Studies of Polyaniline Nanofibers
Authors: Kavitha B. , Kumar K. Siva
Published: August 2018

Nano structured polyaniline (PANI) is synthesized for the first time by polymerization of aniline in the presence of hydrochloric acid as a catalyst and ammoniumperoxidisulphate as an oxidant by the chemical oxidative polymerization method. The product powder was pelletized with help of hydraulic machine to study the XRD, SEM and SANS. The XRD pattern indicates semi crystalline nature of PANI with interplanar distance 4.210 Å and 3.774 Å respectively. The SEM pictures shows fiber like nature of particles. SANS experiment is used to find different parameters of these crystalline polymer particles. Dynamic light Scattering (DLS) studies are performed to find the sizes of nano structured polyaniline. The length and radius of nano size polyaniline are identified as 617.6 nm and 75.05 nm respectively.
Determination of Mercury (II) Ions by Modified Carbon Paste Electrode Based on Functionalized Nanoporous MCM-48 and Multi-Walled Carbon Nanotubes (MWCNTs)
Authors: Aboufazeli Forouzan , Zhad Hamid Reza Lotfi Zadeh , Amani Vahid , Najafi Ezatollah , Sadeghi Omid , Tavassoli Najmeh
Published: August 2018

A carbon paste electrode for determination of mercury (II) ions in real samples was prepared. The main objective of the present study was to evaluate the concentration of mercury ions in different soil, water, plant, and animal muscle samples by utilizing modified carbon paste electrode. Functionalized nanoporous MCM-48 and multi-walled carbon nanotubes material were used in order to increase the efficiency and selectivity of the electrode for mercury ions determination. The electrode composition material was optimized as graphite powder 57%, Paraffin 22%, modified MCM-48 16% and MWCNTs 5% (W/W). The linear range of the electrode was calculated 5.0×10-8 to 1.0×10-3 mol L-1, and a detection limit was obtained 1.5×10-8 mol L-1. The potential slope was achieved 29.7±1.0 mV, and lifetime for the electrode was investigated about 5 months. The proposed method was applied to a number of natural samples and the amount of mercury was determined.
Electrical and Dielectric Behavior of Nano-bio Ceramic Filler Incorporated Polymer Electrolytes for Rechargeable Lithium Batteries
Authors: Karuppasamy K. , Linda T. , Thanikaikarasan S. , Balakumar S. , Mahalingam T. , Sebastian P.J. , Shajan X. Sahaya
Published: August 2018

A series of nanocomposite solid polymer electrolytes (NCSPE) consisting of PMMA as host polymer, lithium bisoxalatoborate (LiBOB) as doping salt and nano-hydroxy apatite as filler have prepared by membrane hot-press method. To enhance the electrochemical properties and stiffness of polymer electrolyte film, a bioactive ceramic filler nano-hydroxy apatite is incorporated in the polymer matrix. The prepared different weight contents of NCSPE films are subjected to various electrochemical characterizations such as ionic conductivity, electric modulus and dielectric spectroscopy studies. The complexation behavior and structural reorganization in polymer electrolytes are confirmed by means of FT-IR (Fourier-Transform Infra Red Spectroscopy) analysis. The electrical response and relaxation of dipole in polymer electrolytes are investigated by means of electric modulus and dielectric studies. The addition of nano-hydroxy apatite significantly enhances the ionic conductivity and blocking the reorganizing tendency of polymer matrix. The maximum ionic conductivity is found to be in the range of 10-4.8 S/cm for sample containing 10 wt. % nanoceramic filler.
Electrochemical Growth and Characterization of Lead Sulphide Thin Films
Authors: Thanikaikarasan S. , Mahalingam T. , Veeramuthumari S. , Ixtlilco Luis
Published: August 2018

Growth of lead sulphide thin films has been carried out electrochemically on indium doped tin oxide coated conducting glass substrates from an aqueous acidic bath containing Pb(CH3COO)2 and Na2S2O3. X-ray diffraction pattern showed that the deposited films possess cubic structure with most prominent reflection along (200) plane. The dependency of microstructural parameters such as crystallite size, strain and dislocation density with film thickness has been analyzed. Surface morphology and film composition have been analyzed using scanning electron microscopy and energy dispersive analysis by X-rays. Optical absorption analysis showed that the prepared films possess a direct band gap value of 0.37 eV.
Platinum Reduction Study on Pt/C Electro-catalysts for PEMFC
Authors: Hernandez-Pichardo M.L. , Gonzalez-Huerta R. , Angel P. del , Palacios-Gonzalez E. , Tufiño-Velazquez M. , Sánchez-Ochoa J.C.
Published: August 2018

Platinum reduction on Pt/C catalysts was studied on samples prepared by the impregnation method using different Pt precursors and reducing agents such as ethanol, sodium borohydride and ethanol-UV light (photo-assisted reduction), in order to compare the efficiency of the different reducing agents. The influence of the reduction level of the platinum species on the electrochemical behavior of these catalysts has been determined. The catalysts were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and linear and cyclic voltammetry. The results show that the reduction level depends mainly on the platinum precursor. Moreover, it was found that the higher electrochemical activity was found using catalysts reduced with ethanol, whereas by using NaBH4 as the reducing agent, the total reduction of the platinum precursor is very difficult in same synthesis conditions. The analysis of the XPS results shows that samples reduced with ethanol presented the lower PtOx/Pt reduction ratio.
Capacitance Improvement of Carbon Aerogels by the Immobilization of Polyoxometalates Nanoparticles
Authors: Baeza-Rostro D. A. , Cuentas-Gallegos A. K.
Published: August 2018

A hybrid material based on the immobilization of H3PMo12O40 polyoxometalate nanoparticles (POM) was obtained by using an activated carbon aerogel (ACP-100Q2) matrix, and was tested as a potential electrode material for a supercapacitor cell. A chemical activation with KOH was carried out in the carbon aerogel matrix (ACP-100), obtaining a greater BET surface area (334g/cm2) and different electrochemical behavior (ACP-100Q2). Both matrices (ACP-100 and ACP-100Q2) were immersed in a 1.15mM POM solution in order to determine the role of the chemical activation procedure in the immobilization of POM nanoparticles. All materials were characterized by Attenuated Total Reflection (ATR) and nitrogen isotherms. For the electrochemical characterization, the synthesized materials were mixed with 10% of Teflon and 20% conducting carbon in weight ratio. Then, a film was made and a portion was pressed onto a stainless steel grid as current collector. Cyclic voltammetry in 3-electrode cells using a 0.5 M H2SO4 electrolyte was used to determine the electrochemical performance. The chemical activation of the aerogel matrix with KOH was the key factor to immobilize and disperse the POM nanoparticles, which improved the capacitance behavior making this material suitable for its application as supercapacitor electrode material.
Yttrium (III) Selective Electrode Based On Zirconium (IV) Phosphoborate
Authors: Kaushal Sandeep , Singh Pritpal , Mittal Susheel K.
Published: August 2018

Zirconium phosphoborate based heterogeneous membrane electrode has been used as a sensor for yttrium ions in aqueous medium. The electrode shows reproducible and Nernstian behavior for yttrium ions in the oncentration range 10-4M to 10-1M with an RSD of 2%. The electrode does not show any change in response within a pH range of 5-9. The effect of internal solution concentration on the calibration curve was also studied. The electrode performance was also studied in partially non-aqueous medium (5% - 20%) of acetone and ethanol. The system was used successfully as an indicator electrode in potentiometric titration of yttrium ions with EDTA.
Electrochemical Properties of Charge Transfer Complexes of 4,4’-bipyridine with Benzoquinone Derivatives
Authors: Al-Owais A. A. , El-Hallag I. S. , Al-Harbi L. M. , El-Mossalamy E. H. , Qari H. A.
Published: August 2018

The electrochemical characteristics of charge transfer complex of 4,4’-bipyridine with benzoquinone derivative have been investigated using cyclic voltammetry, convolutive voltammetry and digital simulation methods. Cyclic voltammetry experiments were performed at a platinum working electrode. The electrode reaction pathway, the relevant chemical and electrochemical parameters of theinvestigated complex were determined using cyclic voltammetry, convolution - deconvolution transforms. The extracted electrochemical parameters and the nature of the electrode reaction were verified & confirmed via digital simulation method.
Enhanced Hydrogen Generation by LiBH4 Hydrolysis in MOH/water Solutions (MOH: C2H5OH, C4H8O, C4H9OH, CH3COOH) for Micro Proton Exchange Membrane Fuel Cell Application
Authors: Xu Lan , Wang Yu , Zhou Ling tong , Xia Wei , Li Zhu jian , Fan Mei Qiang , Zou Yong Jin
Published: August 2018

LiBH4 has high hydrogen storage capacity, and its high gravimetric hydrogen density reaches 18.36%. However, LiBH4 exhibits poor hydrolysis performance in water because the abrupt ending caused by the agglomeration of its hydrolysis products limits its full utilization [1, 2]. In this paper, four kinds of organics, namely, ethanol, tetrahydrofuran, acetic acid, and butanol (referred to MOH) were added to water, and the effect of MOH species and amount on the hydrolysis performances of LiBH4 was evaluated. Results show that agglomeration can be avoided and that LiBH4 has a controllable hydrogen generation rate and high hydrogen generation amount inMOH/water solutions compared with that in pure water. The order in terms of the hydrolysis performance of LiBH4 in MOH/water solutions is as follows: acetic acid >butanol> tetrahydrofuran >ethanol. From XRD, SEM, and other analyses, the enhancement performance is explained by the diluting and solvent effects. Moreover, the addition of MOH alters the hydrolysis route of LiBH4. MOH acts as not only a carrier for water and LiBH4 but also as a reactant to form intermediate LiBH4·[MOH(H2O)x]y, which slows the hydrolysis kinetics of LiBH4. Hydrolysis conditions were optimized, and high hydrogen amount was achieved correspondingly. The experimental data presents the potential application of LiBH4 as a highly efficiency and stable hydrogen source for fuel cells.
A Conparative Study of Biodiesel Purification with Magnesium Silicate and Water
Authors: Duran E. A. , Tinoco R. , Pérez A. , Berrones R. , Eapen D. , Sebastián P. J.
Published: August 2018

It is not justifiable to use excess of water to purify biodiesel only because it is the "most economical" method. Actually it is one of the problems in the biodiesel production industry an adequate purification method; the most commonly used one is the water washing. Currently, there is considerable interest in the biodiesel purification with other solid materials such as synthetic magnesium silicate, which is an effective absorbent to remove impurities. The two methods discussed here have been tested in similar conditions of temperature, time and concentration of reactants. It was found that it is very important to remove the remaining methanol to avoid saturation of the absorbent. The analysis concluded that residues of glycerol and soap content in the two processes are similar and efficient enough and did not find many differences. The purity requirements and analysis of biodiesel were based on the American standard ASTM D6751.
Rapid Synthesis of Water-soluble NiCl2 Nanorods via Recrystallization for Super Capacitors Applications
Authors: Xing Jia-Chao , Zhu Yan-Li , Jiao Qing-Jie
Published: August 2018

Highly uniform NiCl2 nanorods were synthesized successfully via recrystallization and employed as electrode materials for super capacitors applications. The water-soluble Ni/NiCl2 electrode proves to show typical pseudocapacitive characteristics and delivers a very high specific capacitance of 1182.7 F g-1 at 2 A g-1. The charge storage and conversion process initiates from the chemically combination of Ni2+ and OH-, and maintains a reversible redox reaction of Ni(II) ↔ Ni(III) on the electrode. It opens a new insight into the fabrication of multifarious water-soluble inorganic salts for super capacitors applications using the ionic electro negativity parameter as the theoretical guideline.
Effect of Structural and Electrochemical Properties of Yttrium-doped LiNi0.90Co0.05Al0.05O2 Electrode by Co-precipitation for Lithium Ion-batteries
Authors: Yoo Gi-Won , Tae-Jun Park Tae-Jun , Son Jong-Tae
Published: August 2018

In this study, the LiNi0.90−xCo0.05Al0.05YxO2 (x = 0, 0.025, 0.075) have been synthesized by a co-precipitation and solid-state reaction method. The effect of the Y3+-doping on the structural and electrochemical properties were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and by electrochemical and impedance spectroscopy (EIS). From the results of the XRD pattern changes between before and after the doping, less cation mixing and more ordered hexagonal structure were observed for the LiNi0.875Co0.05Al0.05Y0.025O2 cathode and the cell delivered an initial discharge capacity of 195.8 mAhg-1 and was 10.2 mAhg-1 higher than the pristine cell by yttrium doping effect. High rate capability studies were also performed and showed the capacity retention of 95, 81.7 and 63.8 % at 0.2, 1.0 and 5.0 C-rate, respectively during the cycling. The impedance spectra showed that the charge transfer resistance for the pristine cathode grew significantly, while that for the Y3+-doped cathode decreased during cycling. It was concluded that the capacity fading for LiNi0.90Co0.05Al0.05O2 mainly due to the cation mixing, partially contributed by the impedance growth and by doping the pristine material with Y3+, cation mixing can be efficiently suppressed, which results in the improved rate capability.
Composite Supercapacitor Electrodes by Electrodeposition of MnO2 on MWCNT Felt Directly Grown on Aluminum
Authors: Kavian Reza , Vicenzo Antonello , Bestetti Massimiliano
Published: August 2018

Manganese oxide \ carbon nanotube (CNT) thin film electrodes were fabricated by direct growth of a carbon nanotube layer on aluminum substrate (i.e. a commercially viable material for use as current collector) by chemical vapor deposition, in the presence of an electrochemically deposited thin film nickel catalyst, followed by anodic electrodeposition of MnO2. A proof of concept of this approach is demonstrated showing that the fabrication process, even in its simplest and unsophisticated implementation –notably without any deliberate effort to control the CNT growth arrangement and consequently the composite microstructure– allows the preparation of MnO2/CNT/Al prototype electrodes having almost a three-fold increase in capacitance compared to MnO2/Ni electrodes and, more significantly, comparing favorably with composite electrodes of similar design and fabrication. MnO2/CNT/Al electrodes ensured also improved cyclic stability compared to the reference case of MnO2/Ni electrodes. The proposed scheme is an effective procedure for the fabrication of thin film composite MnO2/CNT/Al electrodes, which may be amenable to significant improvements by tailoring thickness and microstructure of the CNT scaffold and manganese oxide film. Furthermore, a similar process scheme, may be proposed for the fabrication of active electrodes of different scopes with a proper choice of the substrate.
Dye-sensitized Solar Cell (DSSC) Utilizing TiO2 Films Prepared via Microwave Irradiation Technique: Effect of TiO2 Growth Time
Authors: Rahman M.Y.A. , Roza L. , Samsuri S.A.M. , Umar A.A. , Salleh M. M.
Published: August 2018

This paper is concerned with the influence of TiO2 films growth time on the performance parameters of a DSSC. The films were prepared via microwave irradiation technique by varying growth times, 3, 5, 7, 10 and 12 minutes. The XRD results reveal that ana-tase phase exists at (101) and (004) plane with the biggest crystallite size was obtained at the growth time of 3 minutes. The FESEM ima-ges show that morphological shape of nanotablet was obtained at shorter irradiation time. The particle size and thickness were found to increase with growth time. However, the particle density decreases with growth time. The uncoated dye and coated dye samples grown at 10 minutes possesses the highest optical absorption and the broadest absorption window. The DSSC utilizing the TiO2 samples did not show rectification property. It was found that the photovoltaic parameters of the DSSC are greatly influenced by the growth time of TiO2 films. The DSSC utilizing the sample prepared for 10 minutes demonstrated the highest JSC, Voc and η of 2.60 mA cm-2, 0.62 V and 0.86%, respectively due to broadest absorption window, the highest recombination resistance (Rcr) and longest charge carrier lifetime (τ).
Formation Mechanism of Phase Interface for Diffusion Couple of Pb/Sn Layered Composite
Authors: Han Zhaohui , Yu Xiaohua , Zhu Peixian , Zhou Shenggang , Yang Yi
Published: August 2018

This paper prepares the diffusion couple of Pb/Sn layered composite by hot pressing, treat it at different holding times, and investigates the appearance characteristics and forming mechanism of the couple by means of SEM-EDS. The results show that Sn atoms preferentially diffuse into the Pb side under the heating temperature of 503K and the pressure of 0.5MPa. With the increase of the welding time, a eutectic liquid layer is formed on the interface of Pb/Sn and the diffusion-dissolution of Pb and Sn atoms are completed by simulta-neous extension and homogenization. The research also demonstrates the star studded distribution of α-Pb and β-Sn solid solutions.
Strong pronouns in modern spoken French: Cliticization, constructionalization, grammaticalization?
Authors: Detges Ulrich
Published: August 2018

In this article, I show that in spoken French 1smoi, unlike 3slui, has undergone both semantic bleaching and heavy prosodic erosion and has therefore progressed along Lehmann’s parameters of grammaticalization. As will be argued, this person-asymmetry is rooted in the fact thatmoi, unlikelui, is largely used as a discourse-structuring device. Based on a phonetic analysis, I show that the main factor underlying the prosodic weakening of left-detachedmoiis string frequency, i.e., the degree of predictability of the element immediately followingmoi. The erosion ofmoiin spoken French is particularly strong when it is followed by the clitic 1sje; it is even stronger in those cases wheremoiintroduces a stance-verb expression of the typemoi je trouve que… ‘I think that …’. However, despite the massive effects produced by string frequency, the prosodic, distributional and discourse-pragmatic data presented here do not support the view that the prosodically weakened variants ofmoiinstantiate a construction that is distinct from non-cliticmoi.
Laboratory Investigations and Field Implementation of Pervious Concrete Paving Mixtures
Authors: Chandrappa Anush K. , Maurya Rishabh , Biligiri Krishna Prapoorna , Rao J. Srinivasa , Nath Sanjib
Published: August 2018

Pervious concrete (PC) is a sustainable concrete material that is being used as a strategy for reducing stormwater-related runoff and recharging ground water. As part of a smart cities initiative of the Government of India, pervious concrete pavement (PCP) mixtures were studied in the laboratory for different properties and implemented in the field to function as parking lots and walkways. A labor-based methodology was used in the construction of eighteen PC slabs encompassing six different mixtures. The construction practices followed were rational and demonstrated to the field engineers how to carry the technology further. The field-produced mixtures had higher porosity and lower density compared to laboratory mixtures. The infiltration capacities (IC) of field PC slabs were similar to those determined in the laboratory. The single-sized graded mixtures depicted lower IC compared to the mixtures with graded aggregates, which was attributed to thicker cement paste coating in single-sized aggregates, while the mixtures with lower cement-to-aggregate ratio depicted higher IC. The coring procedure resulted in a loss of aggregates that may have provided erroneous values of the in-situ properties, and hence, a methodology is deemed essential to investigate the in-situ characteristics using nondestructive techniques. In the future, the differences in the porosity between field and laboratory mixtures should be accounted for in order to avoid an overestimation of the PC properties and to achieve rational designs of PCP as most of the properties are dependent upon porosity.
Chipaque: un análisis sobre las condiciones de acceso a los espacios educativos en clave de lectura y escritura
Authors: Guevara Aladino Tomás
Published: August 2018

El interés principal de la investigación de la que es fruto este artículo son las prácticas no académicas de lectura y escritura. Se parte del supuesto de que estas prácticas sólo pueden entenderse a la luz del contexto material y simbólico en el que se producen y este artículo es, precisamente, una profundización sobre las condiciones de acceso de la población a los espacios educativos en el municipio de Chipaque (Colombia), donde han tenido lugar estas prácticas no académicas de lectura y escritura. Este artículo propone una estructura narrativa que da cuenta, al hilo de la experiencia del investigador en campo, de la configuración de un problema de investigación pertinente en el contexto específico en el que se ubica. Esta narración pretende enfatizar en las condiciones materiales del municipio y sus espacios educativos, al tiempo que resalta la condición determinada de la investigación social a partir de las mismas condiciones.La metodología de la investigación articulóla observación participante en los espacios educativos, entrevistas semiestructuradas con quienes administran estos espacios y la revisión de documentos institucionales que iluminaron el papel de los espacios educativos en el municipio.Se verá que las condiciones de acceso a los espacios educativos y las prácticas de lectura y escritura que allí se desarrollan están sobre-determinadas por las dinámicas sociales del municipio y por las relaciones entre los ministerios encargados de los espacios educativos.
Rin Rin y Chanchito. La dimensión de sus imágenes. Dos revistas infantiles de ideologías antagónicas publicadas durante la década de los treinta en Colombia
Authors: Peters Rada Victoria Eugenia , Trujillo Acosta Milena
Published: August 2018

Chanchito (1933-1934) y Rin Rin (1935-1939), revistas infantiles de Colombia, difundían el amor por la patria en los corazones de los niños y compartieron el espíritu educativo renovado de las pedagogías de la Escuela Nueva. Aunque no hubo una gran diferencia temporal entre las publicaciones, Chanchito y Rin Rin como dispositivos políticos difundían en sus páginas modelos de ciudadanía disímiles. Chanchito, revista privada para la infancia urbana dirigida por Víctor Caro, creía que la familia vinculada a la iglesia eran las instituciones educativas para formar al futuro ciudadano con valores tradicionales, devotos y obedientes. Rin Rin, como material escolar para las escuelas públicas del Ministerio de Educación, tenía el objetivo de construir un tipo de ciudadano moderno para la democracia mediante una educación mediada por la escuela acorde a los principios políticos del Estado de Alfonso López Pumarejo 1934-1938 y la “Revolución en Marcha”. A través de las imágenes se visibilizaron diferencias sobre el modelo de niño y ciudadano entre las publicaciones. En Chanchito los niños están blanqueados y sus vestimentas recuerdan a los trajes tradicionales europeos; la niña, y futura madre se muestra abnegada. En Rin Rin hay un catálogo multiétnico local, a veces las vestimentas remiten a la realidad regional, a veces a las nuevas modas modernas europeas; las niñas y mujeres son seres libres y letradas. La batalla por configurar el modelo de ciudadano desde ángulos antagónicos fue motivo de enardecidas beligerancias en Colombia durante la década de los treinta.
Análisis multivariado de la evaluación docente estudiantil. Un caso de estudio
Authors: Zambrano Carbonell Alex Johann , Gutierrez Mora Esther
Published: August 2018

La evaluación docente estudiantil es el método más utilizado en las universidades latinoamericanas para evaluar la calidad de la enseñanza impartida por los docentes. Teniendo en cuenta este referente, el presente artículo da cuenta de la forma en que se aplicó un análisis multivariado al cuestionario utilizado por la Universidad Santo Tomás en la sede de Bogotá durante los períodos 2012-2014. Este trabajo contempló un análisis de fiabilidad, un análisis factorial exploratorio y confirmatorio para evaluar la validez, confiabilidad y dimensionalidad del instrumento con el cual son evaluados los docentes. Además, se evaluó la relación entre el desempeño del docente y el rendimiento del estudiante. Se realizó un análisis de clasificación mixta para caracterizar los resultados obtenidos en diferentes niveles (divisiones, facultades y profesores). Finalmente, se construyó un índice de percepción de desempeño para las facultades según los alumnos. Entre los resultados más destacados encontramos que el instrumento propuesto es válido y confiable, sin embargo, hay que ajustar dos ítems. También se observó que la calificación del estudiante hacia el docente no está relacionada con la calificación final del estudiante. En la clasificación de los docentes se encontraron tres grupos de docentes donde se diferencian los profesores con bajo, medio y alto desempeño según los alumnos. Entre los ítems que mejor discriminan a los tres grupos están que ``el docente usa ayudas educativas que potencian el aprendizaje'' y que ``el docente aplica estrategias metodológicas que favorecen el aprendizaje''. Se evidenció que la percepción del desempeño de los docentes por los alumnos es superior al 78\%. Estos resultados permitieron implementar estrategias pedagógicas para mejorar el trabajo docente en la universidad.
CARACTERIZACIÓN DE LA PESCA DEL TIBURÓN MARTILLO SPHYRNA LEWINI , EN LA PARTE EXTERNA DEL GOLFO DE NICOYA, COSTA RICA
Authors: Zanella Ilena , López Andrés , Arauz Rándall
Published: August 2018

En el ámbito nivel mundial, el tiburón martillo (Sphyrna lewini) es una de las especies más afectadas por la sobrepesca y el aleteo. Recientemente se incorporó a la Lista Roja de la UICN como especie en peligro de extinción. El presente estudio pretendió caracterizar la pesca y la distribución de S. lewini en la parte externa del Golfo de Nicoya. Para lograr este propósito, se realizaron muestreos entre marzo del 2006 y mayo del 2007 y se analizaron los tiburones martillo capturados por pescadores artesanales afiliados a la Cooperativa artesanales de Pescadores de Tárcoles (CoopeTárcoles R. L.), que faenan en la parte externa del Golfo de Nicoya. Para cada tiburón, se determinó la longitud total, la zona de pesca donde se capturó y el arte utilizado. En total se analizaron 273 tiburones. Se identificó un área de crianza primaria en el Peñón y se determinó que existe una relación lineal positiva entre la longitud total y la profundidad de la zona de pesca (R2 = 0.4296; p ‹ 0.0001), y la longitud total y la distancia de la zona de pesca de la desembocadura del río Grande de Tárcoles (R2 = 0.4052; p ‹ 0.0001). Los tiburones de menor tamaño (crías) se encontraron en la zona del Peñón, donde las aguas son poco profundas, turbias y productivas, ofreciendo a las crías alimento y protección de los depredadores. Por lo cual, se recomienda proteger esta zona, en particular en marzo, abril y mayo, época de nacimiento de las crías.The scalloped hammerhead shark (Sphyrna lewini) is one of the shark species most impacted by overfishing, and is currently listed by the IUCN Red List as an Endangered.  This research sought to characterize the distribution of S. lewini in the external area of Gulf of Nicoya, central Pacific coast of Costa Rica, based on observations from a coastal artisanal fishery. From March 2006 to May 2007, we analyzed scalloped hammerhead shark landings by members of the Tarcoles Artisanal Fishermen's Cooperative (CoopeTárcoles R. L.), who operate in the outer part of the Gulf of Nicoya. We measured the total length of each shark, recorded the reported location of capture, and the gear used. In total, we recorded data for 273 sharks landed. We determined that total length holds a positive linear relationship with the depth of the fishing area (R2 = 0.4296, *** p <.0001) as well as with the distance from the mouth of the Tárcoles River (R2 = 0.4052, *** p <.0001). The smaller sharks (pups) were caught in a fishing site known as Peñon, slightly north of the mouth of the Tarcoles River, where the waters are shallow, turbid and highly productive, providing food and shelter for the pups.  As pups mature and attain larger sizes, they move towards deeper waters away from the Tarcoles River, out of the Gulf of Nicoya. We identify Peñon as a primary nursery for scalloped hammerhead sharks, and recommend management actions that seek to reduce fishing effort between March and May, when pups are born.
German particle verbs: Compositionality at the syntax-semantics interface
Authors: Bott Stefan , Schulte im Walde Sabine
Published: August 2018

Particle verbs represent a type of multi-word expression composed of a base verb and a particle. The meaning of the particle verb is often, but not always, derived from the meaning of the base verb, sometimes in quite complex ways. In this work, we computationally assess the levels of German particle verb compositionality, with the use of distributional semantic methods. Our results demonstrate that the prediction of particle verb compositionality is possible with statistical significance. Furthermore, we investigate properties of German particle verbs that are relevant for their compositionality: the particular subcategorization behavior of particle verbs and their corresponding base verbs, and the question in how far the verb particles can be attributed meaning by themselves, which they contribute to the particle verb.
Integrating LFG’s binding theory with PCDRT
Authors: Dalrymple Mary , Haug Dag , Lowe John
Published: August 2018

We provide a formal model for the interaction of syntax and pragmatics in the interpretation of anaphoric binding constraints on personal and reflexive pronouns. We assume a dynamic semantics, where e-type expressions introduce discourse referents, and contexts are assignments of individuals to discourse referents. We adopt the Partial Compositional Discourse Representation Theory (PCDRT) of Haug(2014b),which models anaphoric resolution in terms of a pragmatically-established relation between discourse referents. We integrate PCDRT into the constraint-based grammatical framework of Lexical-Functional Grammar (LFG), and show how it is possible to state syntactic constraints on the pragmatic resolution of singular and plural anaphora within this framework.
Educational Disabilities Among Children Born With Neonatal Abstinence Syndrome
Authors: Fill Mary-Margaret A. , Miller Angela M. , Wilkinson Rachel H. , Warren Michael D. , Dunn John R. , Schaffner William , Jones Timothy F.
Published: August 2018

BACKGROUND:

Neonatal abstinence syndrome (NAS) is a postnatal drug withdrawal syndrome that can occur after intrauterine opioid exposure. Adverse neurobehavioral outcomes have been documented in infants with NAS; however, educational outcomes have not been thoroughly examined. We analyzed Tennessee data to understand the need for special educational services among infants who are born with NAS.

METHODS:

By using Tennessee Medicaid and birth certificate data, infants who were born in Tennessee between 2008 and 2011 with a history of NAS were matched (1:3) to infants who were born during the same period without a history of NAS. Groups were matched on the basis of sex, race and/or ethnicity, age, birth region of residence, and Medicaid enrollment status. Data were linked to Tennessee Department of Education special education data during early childhood (3–8 years of age). Conditional multivariable logistic regression was used to assess associations between NAS and selected special education outcomes.

RESULTS:

A total of 1815 children with a history of NAS and 5441 children without NAS were assessed. Children with NAS were significantly more likely to be referred for a disability evaluation (351 of 1815 [19.3%] vs 745 of 5441 [13.7%]; P < .0001), to meet criteria for a disability (284 of 1815 [15.6%] vs 634 of 5441 [11.7%]; P < .0001), and to require classroom therapies or services (278 of 1815 [15.3%] vs 620 of 5441 [11.4%]; P < .0001). These findings were sustained in a multivariable analysis, with multiple models controlling for maternal tobacco use, maternal education status, birth weight, gestational age, and/or NICU admission.

CONCLUSIONS:

Results of this novel analysis linking health and education data revealed that children with a history of NAS were significantly more likely to have a subsequent educational disability.
Stabilization of the Homotopy Groups of the Moduli Spaces of k-Higgs Bundles
Authors: Zúñiga-Rojas Ronald A.
Published: August 2018

El trabajo de Hausel prueba que la estratificación de Bialynicki-Birula del espacio moduli de fibrados de Higgs de rango dos coincide con su estratificación de Shatz. Él usa este hecho para calcular algunos grupos de homotopía del espacio moduli de k-fibrados de Higgs de rango dos. Desafortunadamente, estas dos estratificaciones no coinciden en general. Aquí, el objetivo es presentar una prueba diferente de la estabilización de los grupos de homotopía de Mk(2, d), y generalizarla a Mk(3, d), los espacios moduli de k-fibrados de Higgs de grado d, y rangos dos y tres respectivamente, sobre una superficie de Riemann compacta X, usando los resultados de los trabajos de Hausel y Thaddeus, entre otras herramientas.
SCREENING SALT-TOLERANT PLANTS FOR PHYTOREMEDIATION: EFFECT OF SALINITY ON GROWTH AND MINERAL NUTRIENT COMPOSITION
Authors: Diem Trang Ngo Thuy
Published: August 2018

Scirpus littoralis Schrab and Typha orientalis C. Presl are cultivated in the paddy field and in the shrimp pond in the Mekong Delta of Viet Nam for human food and providing habitat for shrimp, respectively. They are recognized as phytoremediator in brackish shrimp aquaculture wastewater treatment system. However, information on effects of NaCl on plant growth and mineral concentrations of the two species is limited. Therefore, the present study was carried out to identify salt-tolerance between the two species. Six NaCl salinity concentrations (0, 5, 10, 15, 20, 30 ‰) and two plant species were arranged in a completely randomized factorial design with three replications. The plants were supplied full strength Hoagland’s solution as growth condition with an increment of NaCl 5 ‰ weekly for 6 weeks. T. orientalis had 65 % mortality at the high NaCl level of 20-30 ‰ while 100 % S. littoralis plant survived with only young shoots remained green. Fresh weight of T. orientalis at the 0 ‰ was 30.6 g FW/plant higher than those at the 20-30 ‰ (8.3-6.4 g FW/plant, respectively) leading to the same pattern in dry weight. The amount of Na+ accumulated in the shoots of T. orientalis at 30 ‰ (27.4 mg/g) higher than those at 0-5 ‰ (2.76-10.1 mg Na+/g). S. littoralis had a lower Na+ content in the shoots (20.1 mg Na+/g) than that of T. orientalis at 30 ‰. The Cl- concentration in the shoots of T. orientalis at 0 ‰ (19.7 mg Cl-/g) was significantly lower than that at 30 ‰ (83.3 mg Cl-/g) and was ~1.3 times higher than that of S. littoralis at 15-30 ‰.  Between two studied plants, T. orientalis accumulated a higher Na+ and Cl- concentration in the roots and shoots especially at the high levels of NaCl of 15-30 ‰. That indicated S. littoralis are able to withstand salt stress and can be considered the best bio-filter candidate in the integration of constructed wetlands and marine shrimp culture towards sustainable aquaculture in the Mekong delta, Viet Nam.
ENERGY CONSUMPTION AND AIR EMISSION INVENTORY FOR TRANSPORTATION SECTORS OF VIET NAM
Authors: Hue Pham Thi
Published: August 2018

Aiming to clarify the environmental impact caused by transportation activities in sectors of Vietnam, this study uses the Input-Output (IO) model to assess energy consumptions and air emissions from railway, road traffic, waterway, transport service as well as aviation vehicles in 2016. The data is based on the 2012 IO table updated for 2016. All sectors of the original IO table are aggregated into 38 sectors where the transport service sectors are kept intact for the deeper analysis. The energy consumptions of transport activities are determined based on the net contribution rate of fuels to each product/service sector and the calorific value of each fuel type. Then multiplying with the corresponding emission factors of CO2, NOx and SO2, the respective emissions from above sectors are calculated. The results show the contribution of transport activities in total emissions of each product/service sector and compare these numbers among all the sectors. Additionally, the study evidences that among transportation service sectors, the road traffic occupies the highest rate in term of energy consumptions and air emissions as well.
METAL BIOACCUMULATION IN FISHES AND MACRO ZOOPLANKTON IN SOME LAKES IN HA NOI
Authors: Hong Pham Thi
Published: August 2018

Ha Noi lakes are of great ecological interest, but they are suffering from many pollution sources, especially wastewater discharge. Aquatic organisms living, especially Oreochomic mossambicus and Labeo rohita cultured in polluted water for local consumption would pose a threat to human health. The research attempted to understand the metal accumulation in these two fish species and in Macro zooplankton (> 200 µm) living in lakes of Hanoi. Various metals showed different affinity to fish species and their tissues. Metal accumulation factors (BAF) in livers ranged from 4 to 23 is much higher than that in muscles ranged from 0.04 to 2.07. The variation of metal accumulation in fish statistically correlated to the temperature of water. Metal concentration in macrozoo plankton varied during the period of sampling. The results showed the increase in metal accumulation from lower to upper trophic levels in food webs.
WATER MANAGEMENT AND METHANE EMISSION FROM RICE FIELDS IN AN GIANG PROVINCE, VIET NAM
Authors: Thanh Thuy Tran Thi
Published: August 2018

This study was carried out to investigate the effects of irrigated water management to CH4 emission from the paddy fields. It was designed with (1) continuous flooding (CF) and (2) alternate for wetting and drying (AWD) which the water level was controlled + 5 cm and ± 5 cm than the soil surface, respectively at Cho Moi, Chau Thanh, Thoai Son and Tri Ton districts of An Giang province. The soil samples were collected to determine their physico-chemical properties. CH4 was collected weekly during the rice cultivation, and the rice yield was determined at the harvest. The results showed that pH 4.55 – 5.93, EC 105 – 175 µS.cm-1, organic matter 3.21 – 3.94 %, CEC 25.05 – 33.33 cmol.kg-1 of the soil were suitable for rice growth. The average rice yield was about 4.5 - 6.52 ton.ha-1. CH4 emissions of the AWD decreased 59.1 % compared to the CF which was 14.6 mg C-CH4.m-2.h-1. Therefore, the AWD is better than the CF in term of reducing CH4 emissions to the environment.
DESIGN OF WETLAND SYSTEM FOR WASTEWATER QUALITY IMPROVEMENT AT FORMOSA HA TINH STEEL COMPANY
Authors: Anh Nguyen Viet
Published: August 2018

After a marine life disaster in central Viet Nam in 2016 due to poorly treated steel industry wastewater and pipe cleaning solutions, the Formosa Steel Corporation has been improved their wastewater treatment systems. Besides, an effluent polishing and buffer pond – wetland system has to be built. The study team has run the 500 m2 pilot wetland aiming to figure out optimum design parameters such as: balancing requirements of hydraulic conductivity, hydraulic headloss, filtration efficiency and plant growth. The pilot wetland was filled with different kind of lime stone, peanut gravel and sand, running with flow rate 49.5-122.4 m3/h. The pilot test results have provided appropriate design parameters for the 4.3 ha Formosa wetland: Subsurface flow constructed wetland cells CB1, CB2, CB3 placed in series, with maximum horizontal flow rate 122 m3/h, unit hydraulic headloss 22.8cm/100m, followed by free water surface flow wetland cell CB4. The main filtration media selected for wetland cells CB1, 2, 3 was lime stone with diameter 50-100 mm (60 cm depth), where supporting layers for plant vegetation were coarse sand (20cm depth) and peanut gravel of 5-10 mm diameter (10 cm depth). The full scale 10 ha pond-wetland system now is in operation, proving design configurations of the team.
REMOVAL OF FLOUROQUINOLONE ANTIMICROBIALS (CIPROFLOXACIN AND NORFLOXACIN) FROM SHRIMP POND SEDIMENT DURING COMPOSTING
Authors: Kien Nguyen Dac
Published: August 2018

This study aimed to investigate the removal of ciprofloxacin and norfloxacin from shrimp pond sediment during composting process with different antimicrobial concentrations. The results showed that after 40 days of composting, temperature varied from 25 to 55 oC. The highest temperature was on the day 20th. The pH values reduced along with composting time from weak base to neutral. During the composting processes, the removal efficiency of norfloxacin found in the range of 32.5–87.5 % depends on the initial antimicrobials concentrations. For ciprofloxacin, after 20 days of composting, the removal efficiency obtained was around 55 and 45 % and pH was 8.5 and 5.0. Salinity significantly affected ciprofloxacin removal that created remarkably efficiency reduction of ciprofloxacin in salty water as compared to fresh- and brackish water. However, no differences in removal efficiency of norfloxacin were observed between fresh and brackish water. The composted fertilizer was dark brown in color and odorless, contained 15.7-18.8 % C; 2.05 – 2.15 % N; and C/N ratio was 7.5–10.95. This indicated that compost fertilizer was completely decomposed.
HETEROGENEOUS ELECTRO FENTON PROCESS FOR TEXTILE WASTEWATER TREATMENT: APPLICATION OF Fe3O4-Mn3O4 AS A CATALYST
Authors: Phong Nguyen The
Published: August 2018

To produce quality textile products, many stable synthetic dyes are invented. However, textile wastewater discharged into the environment contains a large amount of dyes which are bio-recalcitrants and stable to heat and solar radiation. These toxic contaminants impact negatively the environment for a long time and poison plants, animals, and human. In this study, Heterogeneous Electro Fenton  process with Fe3O4-Mn3O4 as a catalyst was used for textile wastewater treatment. Graphite electrodes were chosen for their stability and good conductivity. Three operating factors greatly affected the removal efficiency are current density, pH and catalyst dosage. Response surface methodology was applied to find empirical mathematical models for these factors, then find an accordant operating condition for treatment which provides high removal efficiency and low operating cost. Investigated ranges scaled in previous studies were: current density (10 – 20 mA/cm2), pH (3 – 5), and catalyst dosage (0.5 – 1.5 g/l). At current density of 17.03 mA/cm2, pH of 3.77, catalyst dosage of 1.17 g/l, the treatment reached its optimum condition, COD and Color removal efficiencies were 93.3 % and 99.2 %, respectively, where COD and Color values in the effluent are 56 mg/l and 16 Pt-Co.
First report of bacterial endophytes from the leaves of Pellaea calomelanos in South Africa
Authors: Mahlangu Siphiwe G. , Serepa-Dlamini Mahloro H.
Published: August 2018

Bacteria have an endosymbiotic association with plants. Previous studies have identified endophytic bacteria and their importance in biocontrol and drug development. However, most medicinal plants identified have not been assayed for bacterial endophytes. In this study, we characterised and identified bacterial endophytes from surface-sterilised leaves of Pellaea calomelanos, a common fern in the Limpopo and Gauteng Provinces, South Africa. Using morphological data and 16S rRNA gene sequencing, we differentiated and identified six putative endophytic bacteria, with Pantoea as the dominant genus; the other two identified bacteria belong to genera Arthrobacter and Bacillus. Data from this study are an addition to the previously less studied phylloplane bacteria. This study is a pilot in cataloguing bacterial endophytes from Pellaea calomelanos.
Significance:

This study provides the first report of six putative bacterial endophytes from Pellaea calomelanos.
Our results will pave the way for exploring the antimicrobial activity of calomelanos bacterial endophytes and whole genome comparisons between plant bacterial endophytes and plant bacterial pathogens.
Emergence of vancomycin-resistant enterococci in South Africa: Implications for public health
Authors: Tatsing Foka Frank E. , Kumar Ajay , Ateba Collins N.
Published: August 2018

South Africa is among the countries with the highest prevalence of debilitating diseases such as HIV/Aids and diabetes. In this context, the emergence of vancomycin-resistant enterococci (VREs) in most South African ecological niches is quite disturbing, taking into consideration the fact that therapeutic options in a case of resistant-enterococci infection would be limited. Agricultural practices coupled with the misuse of antibiotics in intensive animal rearing and in hospital facilities have led to the creation of reservoirs of VREs in the environment. VREs can cause serious health problems by transmitting their resistance genes to susceptible pathogens; they are transmitted to humans by direct or indirect contact and through the food chain. We screened thoroughly the AJOL and the PubMed databases for studies on VRE incidence in South Africa. This review gives insight into the current status of antimicrobial resistance management in South Africa; it explores the different pathways involved in the spread of VREs and proposes possible solutions to tackle the issue of VREs and antimicrobial resistance in South Africa and other parts of the world.
Significance:

The recent detection of vancomycin-resistant enterococci in most South African ecological niches poses a serious threat to public health and is therefore an issue of great concern.
This study not only addresses the causes and patterns of resistance to antimicrobial agents, particularly in South Africa, but also outlines a holistic approach to potential strategies to tackle antimicrobial resistance in South Africa and the world at large.