bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructures and Tensile Characteristics on Direct Recycled Aluminium Chips AA6061/Al Powder by Hot Pressing Method
Authors: Kuddus Suriyanti , Mustapa Mohammad Sukri , Ibrahim Mohd Rasidi , Shamsudin Shazarel , Ab Kadir Muhammad Irfan , Lajis Mohd Amri
Published: November 2017

This research aims to investigate the effect on tensile strength of the recycled chip AA6061 aluminium alloy metal by using powder metallurgy method. Material used is recycled aluminium Chip AA6061 and Al powder. The recycled AA6061 chips mixed together with various compositions of Al powder content were fabricated to form a specimen by hot compaction technique. The compaction using hot pressed at 30 tons with holding time of 60 minutes. The final product was analyzed by tensile test shown the specimen A5 have higher ultimate tensile strength (UTS) 156.404 MPa and yield strength (YS) at 107.399 MPa. Scanning Electron Microscopy (SEM) was conducted to observe the microstructure of fracture surface existing on the tensile specimens.
Binder Jetting of Si3N4 Ceramics with Different Porosity
Authors: Rabinskiy Lev N. , Sitnikov Sergey A. , Pogodin Veniamin A. , Ripetskiy Andrey A. , Solyaev Yury O.
Published: November 2017

This article presents the results of the binder jetting technology application for the silicon nitride ceramics production. A modified version of the Plan-B 3D printer with an epoxy-based binder was used for silicon green bodies preforming. Silicon powder was pre-coated with epoxy resin, and the curing agent was added during 3-D printing of green bodies using a standard cartridge. Curing and removal of organics was carried out during the high-temperature vacuum drying of the printed preforms. Reaction-bonded silicon nitride was obtained by using pressureless sintering. An additional compaction of green bodies is proposed to reduce the porosity of green bodies and sintered ceramics. It is shown that the proposed methods allows to improve the mechanical properties of sintered specimens.
Evaluation of Output Signal Nonlinearity for Semiconductor Strain Gage with ANSYS Software
Authors: Gavryushin Sergey S. , Skvortsov Pavel A.
Published: November 2017

The paper is devoted to the study of the nonlinearity of the output signal of the pressure sensor on the silicon on sapphire structure (SOS). The authors constructed a mathematical model of the strain-gauge and carried out numerical simulation by using the ANSYS 12.1 software. For comparative analysis, the problem was solved both in a geometrically nonlinear and in a geometrically linear formulation. To account for the elastic-plastic properties of the silver solder PSR72, the Prandtl diagram was used. As a result, the maximum stresses and deformations in the sapphire crystal, solder, and titanium membrane under which the design successfully works were determined, and also the nonlinearity of the output signal was estimated in depending of the applied pressure. According to calculations, the nonlinearity of the output signal is 11.3%. The received value is unacceptable for this type of sensor, and requires further tuning, which negatively affects the accuracy of the product and its cost.
Sintering and Mechanical Properties of High-Porosity Ceramics Based on Diatomite
Authors: Skvortsov Arkady A. , Luk'yanov Mikhail N. , Novitsan Yulia V.
Published: November 2017

The study is devoted to the study of the mechanical properties of penodiatomite ceramics. Dynamics of changes in the dynamic moduli of elasticity of highly porous (up to 70%) diatomite ceramics from the annealing time at temperatures of 800-1000 °С has been experimentally studied. The values of the activation energies of the change in the modulus of elasticity (Wa = 0.22-0.24 eV) were measured for high-temperature annealing (800-1000 °С). The change in the phase composition of the samples under the influence of annealing is demonstrated.
Operationalising an effective monitoring and evaluation system for local government: Considerations for best practice
Authors: Kariuki Paul , Reddy Purshottama
Published: November 2017

Background: Post-apartheid South Africa faces major challenges in ensuring that it provides high quality and sustainable services that meet citizens’ expectations. The public wants local government that is not only responsive to their needs but also provides high quality services equitably to all people irrespective of their socioeconomic status. Sadly, basic services delivery has been on a downward spiral, characterised by ongoing community protests in many local municipalities. The article premises that municipalities need effective monitoring and evaluation systems to operate optimally.Objectives: The article sought to show that monitoring and evaluation is a critical development tool that needs to be supported by municipal political and administrative leadership to ensure that it functions optimally by offering citizen-responsive services.Method: The study focused on KwaZulu-Natal province, the second largest province in South Africa, predominantly rural with a significant poverty and underdevelopment. The study utilised a mixed method participatory design, comprising quantitative and qualitative approaches.Results: The study found that monitoring and evaluation capacity is low in the majority of municipalities besides the Metro. The municipalities were inadequately resourced with competent monitoring and evaluation human personnel, thereby stifling their capacity to deliver quality monitoring and evaluation services.Conclusion: The article concluded that effective monitoring and evaluation in local government that is responsive to citizens’ needs is a non-negotiable imperative for government. It recommended that municipalities be adequately resourced with competent monitoring and evaluation human personnel. This is important for strengthening their capacity to deliver efficient monitoring and evaluation services.
Entrepreneurial competencies and financial performance of farmers in South Africa
Authors: Nieuwoudt Simone , Henning Johannes I.F. , Jordaan Henry
Published: November 2017

Aim:The main objective of this study was to explore the relationship between the entrepreneurial competencies of farmers and their financial performance. Setting: The study was conducted in South Africa among farmer clients of a commercial financial organisation.Methods: The financial performance of the farmers was calculated by means of financial ratios which were used to compile a single performance indicator: operating efficiency. The operating efficiency indicator was calculated using a financial-based data envelopment analysis. An entrepreneurial competencies instrument was used to measure the entrepreneurial competencies of the farmers. Ordinary least squares regression was used within the principal component regression framework to explore the relationship between entrepreneurial competencies and financial performance.Results: The results indicate there is a positive relationship between entrepreneurial competencies and financial performance of farmers. Each of the individual competencies also indicated positive correlation between the entrepreneurial competencies and financial performance.Conclusion: An increase in specific entrepreneurial competencies behaviour may increase the operating efficiency of the farm. Educational opportunities exist to educate farmers on the potential benefits of using entrepreneurial behaviour to their advantage (to benefit their operating efficiency). Sectors involved with agriculture, for example agricultural advisors, financial advisors and educational institutes, should emphasise the importance of utilising the competencies of farmers.
Assessment of wood burning versus fossil fuel contribution to
wintertime black carbon and carbon monoxide concentrations in Athens, Greece
Authors: Kalogridis Athina-Cerise , Vratolis Stergios , Liakakou Eleni , Gerasopoulos Evangelos , Mihalopoulos Nikolaos , Eleftheriadis Konstantinos
Published: November 2017

Abstract. The scope of this study was to estimate the contribution of fossil fuel and wood burning combustion to black carbon (BC) and carbon monoxide (CO) during wintertime, in Athens. For that purpose, in-situ measurements of equivalent Black Carbon (eBC) and CO were simultaneously conducted in a suburban and an urban background monitoring site in Athens during three months of winter 2014–2015. For the deconvolution of eBC into eBC emitted from fossil fuel (BCff) and wood burning (BCwb), a method based on the spectral dependency of the absorption of pure black carbon and brown carbon was used. Thereafter, BCwb and BCff estimated fractions were used along with measured CO concentrations in a multiple regression analysis, in order to quantify the contribution of each one of the combustion sources to the ambient CO levels. For an independent evaluation of the results, we additionally estimated the wood-burning and fossil fuel contribution to CO, calculated on the basis of their CO/NOx emission ratios. The results indicate that during wintertime BC and CO are mainly emitted by local sources within the Athens Metropolitan Area (AMA), and are only occasionally affected by long-range transport. Fossil fuel combustion, mainly from road traffic, is found to be the major contributor to both eBC in PM2.5 and CO ambient concentrations in AMA. However, wintertime wood burning makes a significant contribution of about 30 % to the observed eBC and the CO concentrations (on average, 11 % and 16 % of total CO in the two sites, respectively). Both, BC and CO from biomass burning (BCwb and COwb, respectively) present a clear diurnal pattern with highest concentrations during night, supporting the local domestic heating as their main source.
Minimum dissipation of potential energy by groundwater outflow
results in a simple linear catchment reservoir
Authors: Kleidon Axel , Savenije Hubert H. G.
Published: November 2017

Abstract. Streamflow recessions of catchments during periods of no recharge can often be reproduced by a simple, linear reservoir despite the complexity of the catchments. Here we show that such a simple linear behaviour can result from the assumption that groundwater drains from smaller units within the catchment into the stream in such a way that the potential energy of groundwater of the whole catchment is dissipated at the minimum possible rate. To do so, we consider the mass balances of groundwater of two connected sub-catchments that form a hypothetical catchment and consider the depletion of potential energy as groundwater drains into the channel network. We show analytically that the catchment-level depletion of groundwater potential energy has a minimum with respect to a groundwater flux that connects the sub-catchments. The catchment-level minimisation results in equal groundwater levels in the sub-catchments with respect to their channels, which then results in a simple, linear reservoir model for the whole catchment. We then discuss the requirements for such a minimum dissipation state to exist and propose possible mechanisms by which groundwater flow can organise and evolve to such a state. We conclude that the simple, linear response in streamflow recession can be interpreted as the outcome of groundwater flow within the catchment organised to dissipate potential energy at the minimum possible rate. Hence, it would seem that energetic considerations provide an important, additional constraint in the dynamics of water flow networks within catchments that potentially reduces the problem of equifinality in hydrology.
Experimental determination of the flood wave transformation and the sediment resuspension in a small regulated stream in an agricultural catchment
Authors: Zumr David , Dostál Tomáš , Devátý Jan , Valenta Petr , Rosendorf Pavel , Eder Alexander , Strauss Peter
Published: November 2017

Abstract. This paper presents the methodology used for artificial flood experiments conducted in a small artificial, trained (regulated) channel on the Nučice experimental agricultural catchment (0.5 km2), central Czech Republic, and the results of the experiments. The aim was to monitor the transformation of the flood wave and the sediment transport within the channel. Two series of experiments were carried out in contrasting initial conditions: (a) in September, when the stream banks were dry, the baseflow was negligible, and the channel was fully overgrown with vegetation; and (b) in March, when the stream banks were almost water saturated, the baseflow was above the annual average, and there was no vegetation present. Within each campaign, three successive flood waves, each with an approximate volume of 17 m3 and peak flow of ca. 40 L s−1, were pumped into the upper part of the catchment drainage channel. The transformation of the flood wave and the sediment transport regime within an approximately 400 m long channel section were monitored by measuring the discharge, the turbidity, and the electrical conductivity in three profiles along the stream. On the basis of the results, it was concluded that there is a considerable amount of deposited sediment, even in the well-trained and straight channel that can be re-mobilized by small floods. Part of the recorded sediment therefore originates from the particles deposited during previous soil erosion events. The flood waves initiated in dissimilar instream conditions progressed differently – we show that the saturation of the channel banks, the stream vegetation and the actual baseflow had a strong influence on the flood transformation and the sediment regime in the channel. The sediment moves quickly in winter and early spring, but in the later part of the year the channel serves as a sediment trap and the resuspension is slower, if dense vegetation is present.
SATELLITE OBSERVED WATER QUALITY CHANGES IN THE LAURENTIAN GREAT LAKES DUE TO INVASIVE SPECIES, ANTHROPOGENIC FORCING, AND CLIMATE CHANGE
Authors: Shuchman R. A. , Bosse K. R. , Sayers M. J. , Fahnenstiel G. L. , Leshkevich G.
Published: November 2017

Abstract. Long time series of ocean and land color satellite data can be used to measure Laurentian Great Lakes water quality parameters including chlorophyll, suspended minerals, harmful algal blooms (HABs), photic zone and primary productivity on weekly, monthly and annual observational intervals. The observed changes in these water quality parameters over time are a direct result of the introduction of invasive species such as the Dreissena mussels as well as anthropogenic forcing and climate change. Time series of the above mentioned water quality parameters have been generated based on a range of satellite sensors, starting with Landsat in the 1970s and continuing to the present with MODIS and VIIRS. These time series have documented the effect the mussels have had on increased water clarity by decreasing the chlorophyll concentrations. Primary productivity has declined in the lakes due to the decrease in algae. The increased water clarity due to the mussels has also led to an increase in submerged aquatic vegetation. Comparing water quality metrics in Lake Superior to the lower lakes is insightful because Lake Superior is the largest and most northern of the five Great Lakes and to date has not been affected by the invasive mussels and can thus be considered a control. In contrast, Lake Erie, the most southern and shallow of the Laurentian Great Lakes, is heavily influenced by agricultural practices (i.e., nutrient runoff) and climate change, which directly influence the annual extent of HABs in the Western Basin of that lake.
TRACKING FARM MANAGEMENT PRACTICES WITH REMOTE SENSING
Authors: Stals J. P. , Ferreira S.
Published: November 2017

Abstract. Earth observation (EO) data is effective in monitoring agricultural cropping activity over large areas. An example of such an application is the GeoTerraImage crop type classification for the South African Crop Estimates Committee (CEC). The satellite based classification of crop types in South Africa provides a large scale, spatial and historical record of agricultural practices in the main crop growing areas. The results from these classifications provides data for the analysis of trends over time, in order to extract valuable information that can aid decision making in the agricultural sector. Crop cultivation practices change over time as farmers adapt to demand, exchange rate and new technology. Through the use of remote sensing, grain crop types have been identified at field level since 2008, providing a historical data set of cropping activity for the three most important grain producing provinces of Mpumalanga, Freestate and North West province in South Africa. This historical information allows the analysis of farm management practices to identify changes and trends in crop rotation and irrigation practices. Analysis of crop type classification over time highlighted practices such as: frequency of cultivation of the same crop on a field, intensified cultivation on centre pivot irrigated fields with double cropping of a winter grain followed by a summer grain in the same year and increasing cultivation of certain types of crops over time such as soyabeans. All these practices can be analysed in a quantitative spatial and temporal manner through the use of the remote sensing based crop type classifications.
A NEW SAR CLASSIFICATION SCHEME FOR SEDIMENTS ON INTERTIDAL FLATS BASED ON MULTI-FREQUENCY POLARIMETRIC SAR IMAGERY
Authors: Wang W. , Gade M.
Published: November 2017

Abstract. We present a new classification scheme for muddy and sandy sediments on exposed intertidal flats, which is based on synthetic aperture radar (SAR) data, and use ALOS-2 (L-band), Radarsat-2 (C-band) and TerraSAR-X (X-band) fully polarimetric SAR imagery to demonstrate its effectiveness. Four test sites on the German North Sea coast were chosen, which represent typical surface compositions of different sediments, vegetation, and habitats, and of which a large amount of SAR is used for our analyses. Both Freeman-Durden and Cloude-Pottier polarimetric decomposition are utilized, and an additional descriptor called Double-Bounce Eigenvalue Relative Difference (DERD) is introduced into the feature sets instead of the original polarimetric intensity channels. The classification is conducted following Random Forest theory, and the results are verified using ground truth data from field campaigns and an existing classification based on optical imagery. In addition, the use of Kennaugh elements for classification purposes is demonstrated using both fully and dual-polarization multi-frequency and multi-temporal SAR data. Our results show that the proposed classification scheme can be applied for the discrimination of muddy and sandy sediments using L-, C-, and X-band SAR images, while SAR imagery acquired at short wavelengths (C- and X-band) can also be used to detect more detailed features such as bivalve beds on intertidal flats.
IMPLEMENTING THE GROUP ON EARTH OBSERVATIONS DATA MANAGEMENT PRINCIPLES: OBSERVATIONS OF A SCIENTIFIC DATA CENTER
Authors: Downs R. R.
Published: November 2017

Abstract. The Group on Earth Observations (GEO) Data Management Principles (DMP) provide direction for managing geospatial data and related information products and services. Offering opportunities for enabling discovery, accessibility, usability, preservation, and curation, the GEO DMP challenge repositories, such as scientific archives and data centers, to improve practices that foster the use of Earth science data today and in the future. In addition, the Data Management Principles Implementation Guidelines (IG) offer many practical suggestions for implementing the DMP with examples that can inform the consideration of options for improving geospatial data management practices. Implementing such improvements offers value to the users of geospatial data by enabling data providers to support the use of the data products and services that they disseminate. Adopting these improvements also can assist repositories in their efforts to meet the requirements for attaining data repository certification, which offers value for repositories and their stakeholders. This article shows how repositories can improve data management practices for geospatial data by adopting the GEO DMP, with examples drawn from a scientific data center. Current and future opportunities for improving data management practices to attain data repository certification also are described along with practical approaches that repositories can adopt in the short term.
EARTH OBSERVATION ACTIVITIES AND FUTURE PERSPECTIVES IN EGYPT
Authors: El-Magd I. A.
Published: November 2017

Abstract. Egypt was one of the first developing countries in Africa that used earth observation and remote sensing in various applications since 1970s. It has grown up in the last decades to build its own capacity in space science and technology that ended up by launching earth observation satellites. At the same time Egypt continued to develop the capacity in EO applications and contribute to the national development plans. In this domain NARSS, the governmental research institute that lead the EO and space applications has completed many research and development projects in EO applications in mineral resources exploration, coastal and marine resources, air quality, water resources management, food security, etc. This was via operational projects with the stakeholders and users to ensure sustainability and operation of the services. For example, NARSS has developed an operational system to monitor the national crop rice using EO information that capable to provide the actual land planted with rice and predict the yield. The system has enabled to provide recommendations for other plots of land that suitable for rice plantation. In the area of environmental hazards, many projects on the flash floods and the vulnerability to flash flood hazards were developed providing decision makers with vulnerability maps and Atlases on national level. Further details on the EO activities and future plans at NARSS, Egypt will be presented in this paper.
CLOUD-BASED AGRICULTURAL SOLUTION: A CASE STUDY OF NEAR REAL-TIME REGIONAL AGRICULTURAL CROP GROWTH INFORMATION IN SOUTH AFRICA
Authors: Hiestermann J. , Ferreira S. L.
Published: November 2017

Abstract. Recent advances in cloud-based technology has led to the rapid increase of geospatial web-based applications. The combination of GIS and cloud-based solutions is revolutionizing product development in the geospatial industry and is facilitating accessibility to a wider range of users, planners and decision makers. Accessible through an internet browser, web applications are an effective and convenient method to disseminate information in multiple formats, and they provide an interface offering interactive access to geospatial data, real-time integration and data processing, and application specific analysis tools. An example of such a web application is GeoTerraImage’s monthly crop monitoring tool called GeoFarmer. This tool uses climatic data and satellite imagery processed through a complex rule-based algorithms to determine monthly climatic averages and anomalies, and most importantly the field specific crop status (i.e. is the field fallow, or is the crop emerging, or if the field has been harvested). Monthly field verification has formed a part of calibrating the growth classification outputs to further improve the accuracy of its monthly agricultural reporting. The goal of this application is to provide timely data to decision makers to assist them in field-level and regional crop growth monitoring, crop production and management, financial risk assessment and insurance, and food security applications. This web application has the unique advantage of being highly transportable to other regions, since it has been designed so it can easily be adapted to other seasonal growth response patterns, and up-scaled to regional or national coverages for operational use.
SPATIOTEMPORAL VARIATIONS IN THE IMPACTS OF URBAN LAND USE TYPES ON URBAN HEAT ISLAND EFFECTS: THE CASE OF RIYADH, SAUDI ARABIA
Authors: Aina Y. A. , Adam E. M. , Ahmed F.
Published: November 2017

Abstract. Urban heat island (UHI) effect is considered to be one of the key indicators of the impacts of urbanization and the climate changes on the environment. Thus, the growing interest in studying the impacts of urbanization on changes in land surface temperature (LST). The literature on LST indicates the need for more studies on the relationship between changes in LST and land use types, especially in the arid environment. This paper examines the spatial and temporal changes in land surface temperature influenced by land use/land cover types in Riyadh, Saudi Arabia. Multi-temporal Landsat images of the study area, 1985, 1995, 2002 and 2015, were processed to derive land surface temperatures. UHI index was computed for the different land use/land cover types (high-density residential, medium-density residential, low-density residential, industrial, vegetation, and desert) in the study area. The results indicate a trend of rising temperatures in all the land use types in the study area. This is probably due to climate change. The industrial area has the highest temperatures among the land use types. The lowest temperatures are found in the vegetation area as expected. There is a need to implement mitigating measures to reduce the effects of rising temperatures in the study area.
Lichens and lichenicolous fungi of Serranía de Ronda (Málaga-Cádiz), south Spain
Authors: Burgaz Ana Rosa , Atienza Violeta , Chesa María José , Chiva Salvador , Fernández-Salegui Ana Belén , Fontecha Alberto , Gómez-Bolea Antonio , Gutiérrez Blanca , Llop Esteve , López de Silanes María Eugenia , Pérez-Llamazares Alicia , Pino-Bodas Raquel , Prats Sergio , Rodríguez Clara , Trobajo-Pérez Sonia
Published: November 2017

As a result of a field trip organised by the Spanish Lichen Society in Serranía de Ronda, south Spain, a catalogue of 360 taxa is presented (336 lichens, 24 lichenicolous fungi). The list includes three new records for the Iberian Peninsula: Arthonia paretinaria, Micarea myriocarpa and Niesslia keissleri, 51new ones for the Autonomous Andalusian Community, and three and 81 new ones for the province of Cádiz and of Málaga, respectively. After these results, the total updated number of the province of Málaga rises to 556 lichens and lichenicolous fungi. The best represented lichen genus is Cladonia (18) with the most species, unlike Lecanora (15), Pertusaria (12), Physconia (12) and Collema (9). As regard habitat, most lichen species are mainly corticolous (55%), as opposed to saxicolous (24%), terricolous (14%) as the species growing on other lichens as lichenicolous fungi (7%). The percentages of lichen growth forms are mainly foliose (50%) and crustose (31%), while fruticose (7%), crustose squamulose (6%) and dimorphic (6%) are less represented. The lichen wit
Approach to the floristic catalogue of the Dehesa of Somosierra and new records for the Community of Madrid (Spain)
Authors: Lázaro-Lobo Adrián , Rodríguez de Francisco Borja , Palá-Paúl Jesús
Published: November 2017

This study represents an approach to the floristic catalogue of the Dehesa of Somosierra, in the northeast corner of the Community of Madrid. The collection of plant material has been carried out along different expeditions from April 2013 to October 2015. A total of 192 species and subspecies were identified belonging to 135 genera and 47 families. It is also highlighted that two specimens of Betula alba included as two singular trees of the Community of Madrid have been identified as Betula pendula subsp. fontqueri. Besides, it is worth noting that the species Myosotis debilis, Ornithogalum bourgaeanum, and Rubus vagabundus are cited for the first time in the Community of Madrid.
Examining the Relationship between Self-Esteem, Mattering, School Connectedness, and Wellness Among Middle School Students
Authors: Watson Joshua C.
Published: November 2017

With data collected from 254 middle grade (5–8) students enrolled in a rural, southern school district, this study sought to determine the influence of self-esteem, mattering, and school connectedness on students’ overall wellness. Using a two-step hierarchical multiple regression analysis, the author found that school connectedness significantly improved the amount of variance in student wellness accounted for by self-esteem and mattering alone. This article provides implications for future research and suggestions for school counseling practice in light of these results.
Human Capital and Economic Growth in Morocco: Evidence from Bayesian Model Averaging
Authors: Essardi Omar , Razzouk Redouane
Published: November 2017

The paper investigates the relationship between human capital and economic growth in Morocco during the period from 1965 to 2015. In order to test this relationship we estimated a growth function using firstly the Johansen multivariate cointegration test and the Granger causality test. Secondly, we used the method of the Bayesian Model Averaging (BMA) that takes into consideration the uncertainty related to the specification of the model studied. In the theoretical literature, the difficulty of measuring human capital is often stressed. In order to overcome this problem, we use four proxies of human capital: first, we employ the average years of schooling. Second, we use the index of the gap in life expectancy between Morocco and developed countries. Third, we integrate the qualitative aspects of education and health by constructing two composite indicators of human capital using Principal Component Analysis (PCA) method.The main results of regression analysis confirm that in the specification of determinants of GDP per worker the average years of total schooling, the life expectancy index and the indicator of quality of health affect positively and significantly level of GDP per worker. However, in the specification of determinants of the growth of the GDP per worker, we found there is no proxy of human capital that affects significantly the growth of the GDP per worker.In addition, the results of Granger causality test show that only the indicator of quality of health that cause the GDP per worker. As well, these results show that the average years of total schooling and the indicator of quality of education cause the growth of GDP per worker. We suggest that the Moroccan authorities should make additional efforts to raise the level of quality of human capital especially in the health sector and increase the productivity of both public and private investment.
Topical Toxicity of Esenbeckia pumila Extracts on Leaf-Cutting Ants Atta laevigata and Acromyrmex balzani
Authors: Souza Brenda R. , Coelho Gustavo M. , Rocha Ednaldo C. , Jesus Flávio G. , Menezes Antônio C. S. , Araújo Márcio S.
Published: November 2017

The aim of this study was to evaluate the topical toxicity of the Esenbeckia pumila plant extracts on workers of the Atta laevigata and Acromyrmex balzani. Five leaf fractions E. pumila were drawn viz., the hexane, ethanolic, dichloromethane, ethyl acetate and methanolic extracts, as well as the ethanolic fruit extracts. Further, the phytochemical leaf extract exploration was performed, and the secondary compounds detected were as follows: flavonoids, anthraquinones, coumarins, cardioactive heterosides and tannins. The different leaf and fruit extract fractions were first diluted in 70% ethyl alcohol, and different doses were topically applied to the A. laevigata and A. balzani workers. All the fractions extracted exhibited formicidal effects and this effect was greater to A. laevigata rather than to A. balzani. Only a small percentage of the workers succumbed within the first few hours of application of the different extracts in comparison with the workers which died only after a longer exposure time (72 h) implying a delayed effect of E. pumila extracts.
Modeling the Structures and Electronic Properties of Uracil and Thymine in Gas Phase and Water
Authors: Taura Lawan Sani , Ndikilar Chifu Ebenezer , Muhammad Aminu
Published: November 2017

The molecular geometries and electronic properties of Uracil and Thymine are studied at the Restricted Hatree-Fock (RHF) and Density Functional Theory (DFT) levels of theory in gas phase and water. The optimized structures, dipole moments, total energies, charge transfer, quadrupole moments and other electronic properties of the two molecules were computed in gas and water. The two molecules showed higher polarity, stability and band gap in water. The average bond lengths of Thymine are greater than those of Uracil in gas. Thymine has significantly lower bond lengths than Uracil in solution. The average bond lengths of C-C and N-H are respectively the longest and shortest. Thymine molecule has lower total energies compared to Uracil at both levels of theory and in both media. The polarity of both molecules increases in solution. HOMO and LUMO energy values decrease slightly in solution for both molecules at both levels of theory. The Ionization Potential (IP) and Electron Affinity (EA) decreases for both molecules in solution. The chemical potential and electrophilicity of both molecules increase in solution. The chemical hardness of Uracil increases slightly in solution while that of Thymine decreases slightly in solution.
Electrochemical Determination of the Levels of Cadmium, Copper and Lead in Polluted Soil and Plant Samples from Mining Areas in Zamfara State, Nigeria
Authors: Ogunlesi Modupe Mabel , Okiei Wesley , Adio-Adepoju Aderinsola , Oluboyo Michael
Published: November 2017

The concentrations of lead, copper and cadmium in soil and plant samples collected from Abare and Dareta villages in Anka Local Government Area of Zamfara State, Nigeria have been electrochemically determined. The study was carried out because of the high mortality of women and children under five, reported for these areas in June 2010. The cause was ascribed to the lead poisoning which has been related to the mining and processing of gold-containing ores. Linear sweep anodic stripping voltammetry technique was used with the glassy carbon working, Ag/AgCl reference and platinum auxiliary electrodes. Voltammetric peaks for lead, copper and cadmium that were observed at -495 mV, -19.4 mV and -675 mV, respectively, have formed a basis for construction of the corresponding calibration plots. The concentrations (in mg/kg) of lead, copper and cadmium in the soil samples were found in the ranges of 18.99−26,087.70, 2.96−584.60 and 0.00−1354.25, respectively. The concentration values for lead were far above already established USEPA (2002) and WHO (1996) maximum permissible limits for residential areas. The concentrations of lead, copper and cadmium in the food samples ranged between 5.70−79.91, 11.17−41.21 and 0.00−5.74 mg/kg. Several of these values are found well above the FAO/WHO limits of 0.1, 2 and 0.1 mg/kg, respectively. The results indicate that in addition to the lead poisoning, copper and cadmium poisoning may also be responsible for sudden and high mortality in this population.
O JOGO DO DIREITO
Authors: Lopes Péricles Da Cunha
Published: November 2017

O Direito e o jogo apresentam muitas semelhanças em suas estruturas. O ambiente jurídico não só apresenta as características de um jogo, como também, busca a mesma finalidade que esse. São atividades ou ocupações exercidas dentro de certos e determinados limites de tempo e de espaço, segundo regras livremente consentidas, mas absolutamente obrigatórias, dotado de um fim em si mesmo, acompanhado de um sentimento de tensão e de alegria e de uma consciência de ser diferente da ‘vida cotidiana’. A ideia de ganhar está estreitamente relacionada com ambos, e isso significa manifestar sua superioridade num determinado aspecto. A competição judicial está sempre submetida a um sistema de regras restritivas que, independentemente das limitações de tempo e lugar, colocam firme e inequivocamente o julgamento no interior do domínio do jogo ordenado e antitético. Essa sugestão, do direito (processo) como um tipo de jogo, encontra respaldo no conceito de jogo e na própria teoria dos jogos.
Lutar com palavras entre ruínas: narrativa e errância em flores artificiais, de Luiz Ruffato
Authors: Silva Marcela Ferreira
Published: November 2017

A narrativa brasileira contemporânea tem problematizado a relação do sujeito com o espaço de diferentes maneiras, com destaque para a tematização do trânsito nos grandes centros urbanos e as inúmeras viagens realizadas pelas personagens. Esses “não lugares” (AUGÉ, 1994) têm sua relevância garantida por meio da construção de personagens transeuntes, andarilhos, viajantes, turistas, migrantes e imigrantes, que não conseguem se fixar em lugar nenhum, tampouco estabelecer relações de intimidade e pertencimento com os espaços por onde transitam. À luz dessas constatações, discutiremos o entrelaçamento dos temas da errância e da narrativa no romance Flores Artificiais, de Luiz Ruffato, publicado em 2014, visto que, nesse romance, além da referida problematização do sujeito com os espaços, questiona-se, também, as fronteiras da narrativa no contexto da contemporaneidade.
Cruzando fronteiras linguísticas, culturais e geográficas: narrativas diaspóricas na ficção de Julia Alvarez
Authors: Matias-Ferreira, Jr. Tito
Published: November 2017

Este artigo objetiva investigar a maneira em que sujeitos diaspóricos ficcionais negociam o embate entre duas culturas, já que, aparentemente, espelha “a dor daqueles que se encontram divididos entre terras natais e línguas maternas”. As implicações desta negociação na vida do imigrante são questões relevantes na escrita de Julia Alvarez, assim como na de outros escritores contemporâneos. Para tanto, a significância da escrita das reminiscências do âmbito familiar é observada como um meio de apresentar a coletividade da escrita imigrante e, mais importante, como um meio que escritores imigrantes de diferentes lugares usam para possivelmente se sentirem conectados uns com os outros. Do mesmo modo, leva-se também em consideração a questão linguística na construção da identidade imigrante, visto que a língua é um fator chave na negociação que as personagens diaspóricas agenciam para buscar entender onde se posicionam no mundo contemporâneo.
Combatting Consumer Madness
Authors: Henry Wayne , Morehouse Mort , Gardner Susan T. ,   Society for Ethics Across the Curriculum
Published: November 2017

In his 2004 article “Hannah Arendt and Jean Baudrillard: Pedagogy in the Consumer Society,” Trevor Norris bemoans the degree to which contemporary education’s focus can increasingly be described as primarily nurturing “consumers in training.” He goes on to add that the consequences of such “mindless” consumerism is that it “erodes democratic life, reduces education to the reproduction of private accumulation, prevents social resistance from expressing itself as anything other than political apathy, and transforms all human relations into commercial transactions of calculated exchange.” This, then, is the challenge of the age: to articulate the sort of education that might prompt our youngsters to imagine a genuine alternative to this consumer madness—a challenge that the authors of this paper attempt to tackle.
Effect of Blood Collection Tube Type and Time to Processing on the Enumeration and High-Content Characterization of Circulating Tumor Cells Using the High-Definition Single-Cell Assay
Authors: Rodríguez-Lee Mariam , Kolatkar Anand , McCormick Madelyn , Dago Angel D. , Kendall Jude , Carlsson Nils Anders , Bethel Kelly , Greenspan Emily J. , Hwang Shelley E. , Waitman Kathryn R. , Nieva Jorge J. , Hicks James , Kuhn Peter
Published: November 2017

Context.—

As circulating tumor cell (CTC) assays gain clinical relevance, it is essential to address preanalytic variability and to develop standard operating procedures for sample handling in order to successfully implement genomically informed, precision health care.

Objective.—

To evaluate the effects of blood collection tube (BCT) type and time-to-assay (TTA) on the enumeration and high-content characterization of CTCs by using the high-definition single-cell assay (HD-SCA).

Design.—

Blood samples of patients with early- and advanced-stage breast cancer were collected into cell-free DNA (CfDNA), EDTA, acid-citrate-dextrose solution, and heparin BCTs. Time-to-assay was evaluated at 24 and 72 hours, representing the fastest possible and more routine domestic shipping intervals, respectively.

Results.—

We detected the highest CTC levels and the lowest levels of negative events in CfDNA BCT at 24 hours. At 72 hours in this BCT, all CTC subpopulations were decreased with the larger effect observed in high-definition CTCs and cytokeratin-positive cells smaller than white blood cells. Overall cell retention was also optimal in CfDNA BCT at 24 hours. Whole-genome copy number variation profiles were generated from single cells isolated from all BCT types and TTAs. Cells from CfDNA BCT at 24-hour TTA exhibited the least noise.

Conclusions.—

Circulating tumor cells can be identified and characterized under a variety of collection, handling, and processing conditions, but the highest quality can be achieved with optimized conditions. We quantified performance differences of the HD-SCA for specific preanalytic variables that may be used as a guide to develop best practices for implementation into patient care and/or research biorepository processes.
EXTRACTION OF RARE EARTH ELEMENTS FROM SOLID WASTE OF PRODUCTION OF PHOSPHORIC ACID FOLLOWED BY SORPTION ON CATION EXCHANGE RESINS
Authors: Artamonov Aleksandr V. , Smirnova Daria N. , Smirnov Nicolay N. , Ilyin Aleksandr P.
Published: November 2017

The basis of production of extraction phosphoric acid is two simultaneous processes: dissolving phosphate raw material in a mixture of sulfuric and phosphoric (formed in the process) acids and crystallization of calcium sulfate (phosphogypsum). Phosphogypsum is an inevitable large-tonnage and cumbersome waste at sulfuric acid processing of apatite, which is of interest not only as a source of building gypsum, but also as an alternative rare earth raw material does not have a natural activity and containing rare-earth elements as a cerium and yttrium groups. As a raw material for the production of rare earth elements, calcium sulfate of three types has been used: phosphogypsum from a sludge accumulator, calcium phosphate phospho-hemihydrate and calcium sulfate phosphate dihydrate from a carousel filter produced by extraction phosphoric acid at JSC "PhosAgro-Cherepovets". The extraction of rare-earth elements from phosphogypsum from a sludge accumulator by leaching (percolation) with inorganic acids with subsequent sorption on cation-exchange resins is considered. As an adsorbent for extracting REE from leach solutions, cationite "Purolite" S-150 is used. A static exchange capacitance of cation exchanger is found that is the capacity of the resin when equilibrium is reached with a solution of a certain volume and composition. The static capacity of cation exchanger for rare-earth elements is 1.57%, which indicates a good absorbing capacity. Desorption of rare-earth elements from the cation exchanger is carried out with a solution of ammonium nitrate. The optimal solution for leaching was found to be sulfuric acid with a concentration of 5% by weight. The degree of extraction of rare-earth elements from phosphogypsum with sulfuric acid is about 82%.Forcitation:Artamonov A.V., Smirnova D.N., Smirnov N.N., Ilyin A.P. Extraction of rare earth elements from solid waste of production of phosphoric acid followed by sorption on cation exchange resins. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 10. P. 87-93
Transient performance analysis of adaptive multitask network based on correntropy criterion
Authors: Hajiabadi Mojtaba , Khoshbin Hossein , Hodtani Ghosheh Abed
Published: November 2017

In this paper, we investigate the transient performance of the proposed distributed multitask learning algorithm that is developed based on maximum correntropy criterion. In the first stage, we derive the proposed multitask learning algorithm in which the correntropy‐based combination matrix determines which sensors should collaborate together and which sensors should stop the collaboration. In the second stage, according to the variance relation of the error vector, we derive a closed‐form relation that shows the transition of mean‐square‐deviation learning performance. We also find the lower and upper bounds of the step size that ensure the stability of the multitask learning algorithm. The theoretical finding of the transient performance is shown to fit a well match with simulation results.
Modified polyacrylonitrile fiber as a renewable heterogeneous base catalyst for Henry reaction and Gewald reaction in water
Authors: Li Pengyu , Liu Yuanyuan , Wang Lu , Tao Minli , Zhang Wenqin
Published: November 2017

A polyacrylonitrile fiber catalyst with high polar surface micro‐environment (C‐PANF‐Na) was conveniently synthesized and characterized by elemental analysis, Fourier‐transfer infrared spectroscopy, UV–vis spectroscopy, scanning electron microscopy, X‐ray diffraction, and breaking strength test. The catalytic performance of the fiber was tested by Henry reaction and Gewald reaction in water and favorable results were obtained in terms of high yields, mild conditions, extensive applicability, superior catalytic recyclability, and renewability. It also has advantages of easy preparation, high functional degree, good stability in acid and base, high strength, and good flexibility, and so on. In addition, a high solvent selectivity phenomenon was found in this catalytic system and the reason was explained by proposing a high polar micro‐environment effect. Furthermore, the fiber catalyst performed well in scaled‐up experiment and flow chemistry experiment, which shows tremendous potential in industrial catalyst as an ideal material for packed bed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45992.
Electrical conductivity transformation mechanism of GNPs/CB/SR nanocomposite foams
Authors: Liu Caixia , Wu Can , Hao Chao , Liu Ping , Guo Xiaohui , Zhang Yugang , Huang Ying
Published: November 2017

Highly flexible and electrically conductive graphene nanoparticles/carbon black/silicon rubber (GNPs/CB/SR) based nanocomposite foams were formed by using azodicarbonamide (AC) physical foaming technology. The foaming parameters (foaming agent and foaming time) were analyzed to investigate the influence on the electrical properties and microcellular structure. The electrical percolation threshold of GNPs/CB/SR nanocomposite foams approximately decreases from 25% to 30%, as the volume expansion increases through foaming. Nanocomposite foams with conductive fillers of 3–12 wt %, foaming agent of 12–18 wt %, foaming time of about 150–500 s, relative densities of 1.0–0.4 g/cm3 were achieved, providing a scheme to evaluate the transformation of electrical properties with different foaming degree. It is worth noting that the product of AC agent concentration and foaming time reaches a certain value, and the highest electrical conductivity of foamed nanocomposites could be achieved. The nonmonotonicity changing of the electrical conductivity was demonstrated. Combined with the microtopography characterization, the cell growth effect was introduced to illustrate the transformation mechanism of the electrical conductivity. The relationship between the microcellular structure and the electrical conductivity of the foamed nanocomposites was established, which is essential for further optimizations of the foaming materials for the targeted application. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45996.