bluuebunny/crossref_metadata_2025 huggingface dataset:
Devices and Equipment for Mixing Granular Materials in Industry
Authors: Krolczyk Jolanta B. , Legutko Stanisław
Published: November 2015

Very large variety of constructions are among granular materials mixers. This is a result of different needs from industry. The paper presents the mixers available in industrial practice. Analysis of mixers construction has been performed and their applications have been specify.
Manufacturing Precision on the Numeric Simulation of Spur Gear with Asymmetric Teeth
Authors: Banica Mihai , Ravai-Nagy Sándor
Published: November 2015

This paper approach the study of the dynamic behaviour of a real gear with asymmetric teeth which will replace the current gear with symmetrical teeth. Research approach is founded on two questions: How does the error of the flank's tooth form influence the dynamic behaviour of a gear? How is the dynamic behaviour influenced by the configuration of a gear with asymmetric teeth compared with a gear with symmetric teeth, with comparable accuracy?
Numerical Simulations of Heat Treatment Processes
Authors: Kik Tomasz , Slovacek Marek , Moravec Jaromir , Vanek Mojmir
Published: November 2015

Welding and heat treatment are a modern, high efficient production technologies. During last few years requirements for quality of the welded joints have been constantly increasing in all production areas. Unfortunately, this approach increases the cost of production due to demand of intense experimental or prototype work prior the use of technology to make a final product. Preliminary experiments have to take into account proper chose of welding technology, materials, welding parameters, clamping and final optimization the welding conditions. All of these activities can be supported or even replaced by numerical simulations based on finite elements method. Tremendous advance in field of numerical simulation, facilitates very high correlation of simulation and experimental results bringing this new approach to common use. This paper highlight to usefulness of numerical simulation in heat treatment of bulk materials in various production stages. It was shown that it is possible to predict formation of metallurgical phases, hardness distribution, strains and stresses during and after quenching process. Simulations of different heating conditions and cooling media makes it possible to simulate processes such as heating, quenching, carburizing and nitriding.
Accurate NC Program Generation Based on New Model Editing Process
Authors: Armasoiu Giorgiana Elena
Published: November 2015

This paper emphasizes the benefits of part-model editing process that does not depend on hystory-based modelling system. The use of synchronous technology in mechanical engineering applications allows the NC programmer to efficiently generate the NC program regardless the source of 3D model. The programming and machining process can be more efficient if the intuitive geometric changes on 3D model are allowed. Synchronous technology makes possible NC programmer’s intervention over 3D model geometry, without breaking the rules defined in CAD. Synchronous technology works with both, native and non-native models and it is available in NX and Solid Edge. With synchronous technology, the changes are performed with or without regard to the history of the model.
Application of Programs of the CAD/CAE Class for Creating the Virtual Laboratory Stand
Authors: Buchacz Andrzej , Baier Andrzej , Herbuś Krzysztof , Majzner Michał , Ociepka Piotr
Published: November 2015

The article presents the stages of creating a virtual laboratory stand for performing the cycle of tests of the system response to dynamic excitation. To create the virtual laboratory stand was used the PLM Siemens NX 8.5 software. It was shown the method of realization the dynamic analysis in the Motion Simulation module, which result was the characteristic (form) of the system excitation. Then, on the virtual laboratory stand, was conducted the analysis of vibration of the investigated system realized in the Advanced Simulation module. For calculations was used the “Response Simulation” solver, which allows analyzing the system responses to dynamic excitations. Next the results were compared with vibrations measurements made on the real laboratory stand. This lets to verify and adjust the created FEM model.
Computer Aided Design of Centrifugal Fan Impeller Using CATIA Software
Authors: Zahariea Dănuţ
Published: November 2015

In this paper, the 3D model of the centrifugal fan impeller will be obtained using CAD software (CATIA). The blade will be obtained with 4 design methods: constant blade width and variable blade angle; hyperbolic blade width and variable blade angle; hyperbolic blade width and constant blade angle; linear blade width and variable blade angle. A comparative analysis of the weight of the blade, as well as of the weight of the rotor composed by cascade of blades, front and rear shrouds will be presented. Two materials have been used for all the elements of the centrifugal fan impeller: steel and aluminium. For computational purposes the MATLAB programming language will be used. The centrifugal fan blade will be designed as untwisted geometry with =2 reference curves (one on the rear shroud and the other one on the front shroud) with different numbers of reference points ={5, 10, 20, 30, 40, 50}. After running the MATLAB script file, the coordinates of reference points of the blade will be obtained for all 4 blade design methods. The transfer of the reference points coordinates from MATLAB workspace to CATIA has been performed using the automatic surface generation method, via an EXCEL macro file. This is the recommended method especially for a big number of reference points.
Dimensional Validation of a 3D Digitization System
Authors: Santos Francisco , Sanchez Elena , Lopez Roberto , Martin Oscar , Negoescu Florin , San-Juan Manuel
Published: November 2015

A three-dimensional measurement system has been set up. The digital models have been obtained using a webcam and structured light. After this, a software for measuring the digital geometries has been applied. In order to validate the digital models, the workpiece has been measured in a Laboratory of Metrology by means of a Coordinate Measuring Machine. While digital models can be obtained from multiple scan system configurations, not all of them get the same degree of accuracy. After analyzing the results, it can be determined the best condition for obtaining the digital model so that discrepancies between measurements and corresponding digital model of the workpiece are minimized. Also, it has been estimated a value of measurement uncertainty for each of the models studied.
FEM Simulation of the Effects of Mining on the Strength of a Structure
Authors: Becker-Daugherty Lothar
Published: November 2015

Influence on the environment has caused and still causes today the destruction of terrain and buildings. It further analyzes the main forms of land and the effects of surface destruction. The state of tension and deformations of the massif is affected by underground mining. On the 23rd of February of 2008, in Saarland, a vibration of 93.54 mm/s, which corresponds to a value of 4.0 on the Richter scale, was measured. Numerous resistance structures have suffered as a result of strong subsidence damage. Size and expansion of compact according to the characteristics of the mine is studied. Less well known are the effects of mining compaction on the behavior of a resistance structure. This study attempts to answer this question. The research method is the numerical simulation using the finite element method combined with in situ measurements of damage. Framework was charged as the usual load of a building norm. The corner to a 300 mm compacted statically indeterminate structure produces additional stresses and strains. Research results are comparisons between load cases with and without compaction and the calculated mechanical stress with rupture stress. As a result of the rupture is measured experimentally effective crack opening.
Implementing some Evolutionary Computing Methods for Determining the Optimal Parameters in the Turning Process
Authors: Florea Adrian , Cofaru Nicolae
Published: November 2015

In this paper, we comparatively present two heuristics search methods – Simulated Annealing and Weighted Sum Genetic Algorithm, in order to find optimal cutting parameters in turning operation. We consider five different constraints aiming to achieve minimum total cost of machining. We developed a customizable software application in Microsoft Visual Studio with C# source code, flexible and extensible that implements the optimization methods. The experiments are based on real data gathered from S.C. “Compa” S.A Sibiu, a company that manufactures automotive components and targets improving of product quality and reducing cost and production time. The obtained results show that, although the Weighted Sum Genetic Algorithm does not guarantee the optimality of finals solution despite of a high probability to be, it is superior to that provided by Simulated Annealing.
Lagrange's Equations versus Bond Graph Modeling Methodology by an Example of a Mechanical System
Authors: Ibănescu Radu , Ungureanu Cătălin
Published: November 2015

The bond graph modeling method was discovered by Henry Painter in 1959 and has quickly become a wide spread method all over the modeling engineering world. The method is based on the analysis of power circulation in systems and has some indisputable advantages over other modeling methods, based in principle on mathematical aspects. The paper proposes a comparison between the bond graph method and Lagrange's equations method, by applying both methods to model a mechanical system. The bond graph model is a graphical model. There are three possibilities to exploit the bond-graph diagram. The first one consists in deducing a system of differential or algebraic-differential equations from the diagram. The second one consists in obtaining the block diagram model from the bond graph diagram, without additionally writing any equations, followed by the block diagram implementation in the appropriate software, which permits to perform simulations at once. The third one consists in implementing the bond graph diagram directly in the appropriate software, where simulations can immediately run. The advantages and the disadvantages of the methods are emphasized, but the decision about the most appropriate method is up to the modeler.
Considerations Regarding Some Surface State Parameters Characterized by a more Restricted Use
Authors: Urzică Ionuţ , Râznic Ciprian , Apostol Mihai , Pavăl Corina Mihaela , Boca Mihai , Rîpanu Marius
Published: November 2015

Frequently, on the drawings of mechanical parts, only indications concerning the surface roughness parameter Ra and, relatively rarely, the surface roughness parameter Rz are included. However, the study of the machined surface roughness highlights the necessity to use yet other surface roughness parameters, in order to have a clearer image on the state of the machined surface. Some other surface roughness parameters possible to be used and presenting importance, without the parameters Ra and Rz, were highlighted. One took into consideration the possibility of measuring parameters Rsk and Rmr by means of the available surface roughness testers. Experimental researches of turning by applying the method of full factorial experiment were developed. As input factors in turning process, the cutting speed, the feed rate and the tool nose radius were used. The experimental results were mathematically processed, being determined empirical mathematical models that highlight the influence of certain input factors of turning process on the values of some surface roughness parameters characterized by a more restricted use
Optimization Design of a 500 kN Workover Rig Mast after Computer Simulated Overload Test
Authors: Stanciu Lavinia Silvia , Popa Ioan
Published: November 2015

The 500 kN mast, which is part of a workover rig used for interventions and overhauling works for oil and gas wells, is a spatial multiple indeterminate structure made of many bars, with rigid nodes. The aim of this paper is to determine, through computer simulation of overload test, the state of stress and displacements for the existing construction and to find an improved solution. The overload test is experimentally realized on specialized stands and involves the mast’s loading with the maximum hook load multiplied by a safety factor of 1.4 and, in addition, with the dead weight, the hoisting system weight, and with the corresponding forces due to the draw works drum socket and the blind end. Since this is a prototype construction made of structural steel rectangular pipes and profiles as L, I, U-shaped cross section, such an analysis is necessary to ensure the mast’s and rig’s safety during functioning.
Impact Properties of Parts Manufactured from Fiberglass and Kevlar Composite Panels
Authors: Croitoru Emilian Ionut , Oancea Gheorghe
Published: November 2015

This paper presents a method of finite element modelling used to study the effect of laminates orientation and thickness on impact properties of a composite sandwich panel made of glass and kevlar fibers in an epoxy resin matrix. In this research, the composite sandwich panel consists of a fuselage skin panel from an aircraft having two configurations: (0/90/0/90/core/90/0/90/0) and (0/90/45/-45/core/-45/45/90/0). This panel is loaded with one uniform distributed abuse loading case and the stress variation within the composite panel for each configuration is determined.
Stress State Evaluation in Biaxially Loaded Cruciform Specimens
Authors: Andrusca Liviu , Goanta Viorel , Barsanescu Paul Doru , Savin Adriana , Comanici Ana Maria
Published: November 2015

Testing cruciform specimens under static biaxial loading conditions is the method with the best results used to determine the mechanical behavior of materials. A static stress with nonlinear material analysis was applied for only one-eighth of the specimen geometry, due to symmetry conditions, to evaluate stress state from different cruciform specimens subjected to equi-biaxial tension. For the majority of isotropic materials with ductile behavior, such as metals, the most suitable yield criterion used to predict failure is von Mises.
A Graphical Expression for the Method of Substitutive Circles Family Applied for Profiling Side Mill Designed to Generate Sealing Worms of Cycloid Pumps
Authors: Teodor Virgil , Baroiu Nicuşor , Berbinschi Silviu , Oancea Nicolae
Published: November 2015

This paper approach the issue of side mill profiling, for generation of helical surfaces – the sealing worms from the construction of the helical pumps with cycloid worms. The issue of side mill profiling is based on the complementary theorem of the “substitutive circles family”. This method will be applied as so as for profiling the crossing section of the worm, in order to generate the helical flute and for profiling the revolution surface that constitutes the primary peripheral surface of the side mill. They are discussed some aspects related to singular points onto profiles and problems related to discontinuities onto the tool’s profile. For a certain case, are presented profiles determined in numerical form, which may serve for design of templates for side mill check and, obviously, for design of relieving tools.
Semaphorin 7A Promotes Chemokine-Driven Dendritic Cell Migration
Authors: van Rijn Anoek , Paulis Leonie , te Riet Joost , Vasaturo Angela , Reinieren-Beeren Inge , van der Schaaf Alie , Kuipers Arthur J. , Schulte Luuk P. , Jongbloets Bart C. , Pasterkamp R. Jeroen , Figdor Carl G. , van Spriel Annemiek B. , Buschow Sonja I.
Published: November 2015

Dendritic cell (DC) migration is essential for efficient host defense against pathogens and cancer, as well as for the efficacy of DC-based immunotherapies. However, the molecules that induce the migratory phenotype of DCs are poorly defined. Based on a large-scale proteome analysis of maturing DCs, we identified the GPI-anchored protein semaphorin 7A (Sema7A) as being highly expressed on activated primary myeloid and plasmacytoid DCs in human and mouse. We demonstrate that Sema7A deficiency results in impaired chemokine CCL21-driven DC migration in vivo. Impaired formation of actin-based protrusions, resulting in slower three-dimensional migration, was identified as the mechanism underlying the DC migration defect. Furthermore, we show, by atomic force microscopy, that Sema7A decreases adhesion strength to extracellular matrix while increasing the connectivity of adhesion receptors to the actin cytoskeleton. This study demonstrates that Sema7A controls the assembly of actin-based protrusions that drive DC migration in response to CCL21.
Selective CD28 Antagonist Blunts Memory Immune Responses and Promotes Long-Term Control of Skin Inflammation in Nonhuman Primates
Authors: Poirier Nicolas , Chevalier Melanie , Mary Caroline , Hervouet Jeremy , Minault David , Baker Paul , Ville Simon , Le Bas-Bernardet Stephanie , Dilek Nahzli , Belarif Lyssia , Cassagnau Elisabeth , Scobie Linda , Blancho Gilles , Vanhove Bernard
Published: November 2015

Novel therapies that specifically target activation and expansion of pathogenic immune cell subsets responsible for autoimmune attacks are needed to confer long-term remission. Pathogenic cells in autoimmunity include memory T lymphocytes that are long-lived and present rapid recall effector functions with reduced activation requirements. Whereas the CD28 costimulation pathway predominantly controls priming of naive T cells and hence generation of adaptive memory cells, the roles of CD28 costimulation on established memory T lymphocytes and the recall of memory responses remain controversial. In contrast to CD80/86 antagonists (CTLA4-Ig), selective CD28 antagonists blunt T cell costimulation while sparing CTLA-4 and PD-L1–dependent coinhibitory signals. Using a new selective CD28 antagonist, we showed that Ag-specific reactivation of human memory T lymphocytes was prevented. Selective CD28 blockade controlled both cellular and humoral memory recall in nonhuman primates and induced long-term Ag-specific unresponsiveness in a memory T cell–mediated inflammatory skin model. No modification of memory T lymphocytes subsets or numbers was observed in the periphery, and importantly no significant reactivation of quiescent viruses was noticed. These findings indicate that pathogenic memory T cell responses are controlled by both CD28 and CTLA-4/PD-L1 cosignals in vivo and that selectively targeting CD28 would help to promote remission of autoimmune diseases and control chronic inflammation.
Prevalence of and factors influencing postnatal depression in a rural community in South Africa
Authors: Stellenberg Ethelwynn L. , Abrahams Johanna M.
Published: November 2015

Background: Knowledge about postnatal depression (PND) and associated risk factors whichin fluence the development of PND is vital for early detection, intervention and prevention.Setting: The study was conducted in primary health care clinics (PHC) in the Witzenberg subdistrict, a rural community in South Africa.Objectives: Objectives of this study were to determine the prevalence of PND and to identify the contributing risk factors associated with PND.Methods: A descriptive cross sectional research design with a quantitative approach was applied. The target population was mothers, 18 years and older. A convenience sampling method was used to select a sample of 159 (10%) from a population of 1605 live births. Th eEdinburgh Postnatal Depression Scale (EPDS) and Beck Depression Inventory (BDI), two validated self-rating questionnaires, including a questionnaire based on demographical, psychosocial and obstetrical data, were applied. The data was analysed using various statistical tests to determine statistical associations between variables using a 95% confidence interval.Results: PND was a serious health problem with 50.3% of the mothers who suffered from PND. A BDI analysis showed that of the participants who had PND, 28.8% was severe, 48.8% moderate and 22.5% mild. Factors influencing the development of PND included most participants (63.5%) were unmarried, 61.3% were unemployed and the majority (53.8%) had a history of a psychiatric illness. Significant associations between PND and unplanned and unwelcome babies (p < 0.01); partner relationship (p < 0.01); were identified.Conclusion: Prevention, early detection, appropriate referral and treatment of PND are critical in managing maternal, child and family well-being.
Eigenvarieties for Cuspforms Over PEL
Type Shimura Varieties With Dense Ordinary Locus
Authors: Brasca Riccardo
Published: November 2015

Let p > 2 be a prime and let X be a compactified PEL Shimura variety of type (A) or (C) such that p is an unramified prime for the PEL datum and such that the ordinary locus is dense in the reduction of X. Using the geometric approach of Andreatta, Iovita, Pilloni, and Stevens, we define the notion of families of overconvergent locally analytic p-adic modular forms of Iwahoric level for X. We show that the systemof eigenvalues of any finite slope cuspidal eigenformof Iwahoric level can be deformed to a family of systems of eigenvalues living over an open subset of the weight
space. To prove these results, we actually construct eigenvarieties of the expected dimension that parameterize finite slope systems of eigenvalues appearing in the space of families of cuspidal forms.
Burden of Norovirus and Rotavirus in Children After Rotavirus Vaccine Introduction, Cochabamba, Bolivia
Authors: McAtee Casey L. , Webman Rachel , Gilman Robert H. , Mejia Carolina , Bern Caryn , Apaza Sonia , Espetia Susan , Pajuelo Mónica , Saito Mayuko , Challappa Roxanna , Soria Richard , Ribera Jose P. , Lozano Daniel , Torrico Faustino
Published: November 2015

The effectiveness of rotavirus vaccine in the field may set the stage for a changing landscape of diarrheal illness affecting children worldwide. Norovirus and rotavirus are the two major viral enteropathogens of childhood. This study describes the prevalence of norovirus and rotavirus 2 years after widespread rotavirus vaccination in Cochabamba, Bolivia. Stool samples from hospitalized children with acute gastroenteritis (AGE) and outpatients aged 5–24 months without AGE were recruited from an urban hospital serving Bolivia's third largest city. Both viruses were genotyped, and norovirus GII.4 was further sequenced. Norovirus was found much more frequently than rotavirus. Norovirus was detected in 69/201 (34.3%) of specimens from children with AGE and 13/71 (18.3%) of those without diarrhea. Rotavirus was detected in 38/201 (18.9%) of diarrheal specimens and 3/71 (4.2%) of non-diarrheal specimens. Norovirus GII was identified in 97.8% of norovirus-positive samples; GII.4 was the most common genotype (71.4% of typed specimens). Rotavirus G3P[8] was the most prevalent rotavirus genotype (44.0% of typed specimens) and G2P[4] was second most prevalent (16.0% of typed specimens). This community is likely part of a trend toward norovirus predominance over rotavirus in children after widespread vaccination against rotavirus.
Serologic Evidence of the Geographic Distribution of Bacterial Zoonotic Agents in Kenya, 2007
Authors: Omballa Victor O. , Musyoka Raymond N. , Vittor Amy Y. , Wamburu Kabura B. , Wachira Cyrus M. , Waiboci Lilian W. , Abudo Mamo U. , Juma Bonventure W. , Kim Andrea A. , Montgomery Joel M. , Breiman Robert F. , Fields Barry S.
Published: November 2015

Diseases of zoonotic origin contribute to the burden of febrile illnesses in developing countries. We evaluated serologic evidence of exposure to Bacillus anthracis, Brucella spp., spotted fever group rickettsioses (SFGR), and typhus group rickettsioses (TGR) from samples of persons aged 15–64 years collected during a nationwide human immunodeficiency virus (HIV) serosurvey conducted in 2007 in Kenya. The seropositivity observed for pathogens was B. anthracis 11.3%, Brucella spp. 3.0%, SFGR 23.3%, and TGR 0.6%. On univariate analysis, seropositivity for each pathogen was significantly associated with the following risk factors: B. anthracis with province of residence; Brucella spp. with sex, education level, and wealth; SFGR with age, education level, wealth, and province of residence; and TGR with province of residence. On multivariate analysis, seropositivity remained significantly associated with wealth and province for B. anthracis; with sex and age for Brucella spp; and with sex, education level, and province of residence for SFGR whereas TGR had no significance. High IgG seropositivity to these zoonotic pathogens (especially, B. anthracis and SFGR) suggests substantial exposure. These pathogens should be considered in the differential diagnosis of febrile illness in Kenya.
Stereo-photometric techniques for scanning micrometer scale
Authors: Cachero Rocio , Abello Carlota
Published: November 2015

This paper describes a new methodology based on the combination of photogrammetric and stereo-photometric techniques that allows creating virtual replicas reproducing the relief in micrometric scale, with a geometric resolution until 7 microns. The finest details of the texture obtained by photogrammetric methods are translated to the relief of the mesh to provide quality 3D printing by additive manufacturing methods. These results open new possibilities for virtual and physical reproduction of archeological items that need a great accuracy and geometric resolution.
Characteristics and typology of sheep herding systems in the suburban area of Ouagadougou (Burkina Faso)
Authors: Tindano K. , Moula N. , Traoré A. , Leroy P. , Antoine-Moussiaux N.
Published: November 2015

Abstract. Strong increase in demand for animal products could benefit local producers in developing countries. This development opportunity particularly concerns suburban livestock. In Burkina Faso, the suburban area of Ouagadougou is a place for the setting up of an increasing number of breeders. Due to its importance in religious traditions, spurring its consumption in whole West Africa, mutton is a major part of this suburban production. In order to characterize sheep farming in the suburban zone of Ouagadougou, in terms of motives, practices, and economic performance, and to better understand the dynamic at play in the sheep sector, a survey has been conducted among 80 sheep farmers around Ouagadougou. The results show that suburban sheep keeping is a highly dual sector. Nearly half (42.5 %) of farms may be described as traditional livestock, while 50 % are evolving towards intensification. These two groups essentially differ in terms of animal genetic and feeding management, farm infrastructure, and farmer education level. Economically, the whole sample tends to indicate a lack of profitability of the activity in terms of monetary income. Several factors contributing to this situation are pinpointed, namely feed and animal health constraints, flock and production management, and the market conditions.
The origins of ice crystals measured in mixed-phase clouds at the high-alpine site Jungfraujoch
Authors: Lloyd G. , Choularton T. W. , Bower K. N. , Gallagher M. W. , Connolly P. J. , Flynn M. , Farrington R. , Crosier J. , Schlenczek O. , Fugal J. , Henneberger J.
Published: November 2015

Abstract. During the winter of 2013 and 2014 measurements of cloud microphysical properties over a 5-week period at the high-alpine site Jungfraujoch, Switzerland, were carried out as part of the Cloud Aerosol Characterisation Experiments (CLACE) and the Ice Nucleation Process Investigation and Quantification project (INUPIAQ). Measurements of aerosol properties at a second, lower site, Schilthorn, Switzerland, were used as input for a primary ice nucleation scheme to predict ice nuclei concentrations at Jungfraujoch. Frequent, rapid transitions in the ice and liquid properties of the clouds at Jungfraujoch were identified that led to large fluctuations in ice mass fractions over temporal scales of seconds to hours. During the measurement period we observed high concentrations of ice particles that exceeded 1000 L−1 at temperatures around −15 °C, verified by multiple instruments. These concentrations could not be explained using the usual primary ice nucleation schemes, which predicted ice nucleus concentrations several orders of magnitude smaller than the peak ice crystal number concentrations. Secondary ice production through the Hallett–Mossop process as a possible explanation was ruled out, as the cloud was rarely within the active temperature range for this process. It is shown that other mechanisms of secondary ice particle production cannot explain the highest ice particle concentrations. We describe four possible mechanisms that could lead to high cloud ice concentrations generated from the snow-covered surfaces surrounding the measurement site. Of these we show that hoar frost crystals generated at the cloud enveloped snow surface could be the most important source of cloud ice concentrations. Blowing snow was also observed to make significant contributions at higher wind speeds when ice crystal concentrations were < 100 L−1.
Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review
Authors: Zhang L. , Wang S. X. , Wu Q. R. , Wang F. Y. , Lin C.-J. , Zhang L. M. , Hui M. L. , Hao J. M.
Published: November 2015

Abstract. Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, municipal solid waste incinerators, and biomass burning. Mercury in coal, ores and other raw materials is released to flue gases in the form of Hg0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 °C to below 300 °C in flue gases leaving boilers, kilns or furnaces promotes homogeneous and heterogeneous oxidation of gaseous elemental mercury (Hg0) to gaseous divalent mercury (Hg2+), with a portion of Hg2+ adsorbed onto fly ash to form particulate-bound mercury (Hgp). Halogen is the primary oxidizer for Hg0 in flue gases, and active components (e.g.,TiO2, Fe2O3, etc.) on fly ash promote heterogeneous oxidation and adsorption processes. In addition to mercury removal, mercury transformation also occurs when passing through air pollution control devices (APCDs), affecting the mercury speciation in flue gases. In coal-fired power plants, selective catalytic reduction (SCR) system promotes mercury oxidation by 34–85 %, electrostatic precipitator (ESP) and fabric filter (FF) remove over 99 % of Hgp, and wet flue gas desulfurization system (WFGD) captures 60–95 % of Hg2+. In non-ferrous metal smelters, most Hg0 is converted to Hg2+ and removed in acid plants (APs). For cement clinker production, mercury cycling and operational conditions promote heterogeneous mercury oxidation and adsorption. The mercury speciation profiles in flue gases emitted to the atmosphere are determined by transformation mechanisms and mercury removal efficiencies by various APCDs. For all the sectors reviewed in this study, Hgp accounts for less than 5 % in flue gases. In China, mercury emission has a higher fraction (66–82 % of total mercury) in flue gases from coal combustion, in contrast to a greater Hg2+ fraction (29–90 %) from non-ferrous metal smelting, cement and iron/steel production. The higher Hg2+ fractions shown here than previous estimates may imply stronger local environmental impacts than previously thought, caused by mercury emissions in East Asia. Future research should focus on determining mercury speciation in flue gases from iron and steel plants, waste incineration and biomass burning, and on elucidating the mechanisms of mercury oxidation and adsorption in flue gases.
Atmospheric speciated mercury concentrations on an island between China and Korea: sources and transport pathways
Authors: Lee G.-S. , Kim P.-R. , Han Y.-J. , Holsen T. M. , Seo Y.-S. , Yi S.-M.
Published: November 2015

Abstract. As a global pollutant, mercury (Hg) is of particular concern in East Asia where anthropogenic emissions are the largest. In this study, speciated Hg concentrations were measured in the western most island in Korea, located between China and the Korean mainland to identify the importance of local, regional and distant Hg sources. Various tools including correlations with other pollutants, conditional probability function, and back-trajectory based analysis consistently indicated that Korean sources were important for gaseous oxidized mercury (GOM) whereas, for total gaseous mercury (TGM) and particulate bound mercury (PBM), long-range and regional transport were also important. A trajectory cluster based approach considering both Hg concentration and the fraction of time each cluster was impacting the site was developed to quantify the effect of Korean sources and out-of-Korean source. This analysis suggests that Korean sources contributed approximately 55 % of the GOM and PBM while there were approximately equal contributions from Korean and out-of-Korean sources for the TGM measured at the site. The ratio of GOM / PBM decreased when the site was impacted by long-range transport, suggesting that this ratio may be a useful tool for identifying the relative significance of local sources vs. long-range transport. The secondary formation of PBM through gas-particle partitioning with GOM was found to be important at low temperatures and high relative humidity.
Effect of varying experimental conditions on the viscosity of α-pinene derived secondary organic material
Authors: Grayson J. W. , Zhang Y. , Mutzel A. , Renbaum-Wolff L. , Böge O. , Kamal S. , Herrmann H. , Martin S. T. , Bertram A. K.
Published: November 2015

Abstract. To predict the role of secondary organic material (SOM) particles in climate, visibility, and health, information on the viscosity of particles containing SOM is required. In this study we investigate the viscosity of SOM particles as a function of relative humidity and SOM particle mass concentration during SOM synthesis. The SOM was generated via the ozonolysis of α-pinene at < 5 % relative humidity (RH). Experiments were carried out using the poke-and-flow technique, which measures the experimental flow time (τexp, flow) of SOM after poking the material with a needle. In the first set of experiments, we show that τexp, flow increased by a factor of 3600 as the RH increased from < 0.5 to 50 % RH, for SOM with a production mass concentration of 121 μg m−3. Based on simulations, the viscosities of the particles were between 6 × 105 and 5 × 107 Pa s at < 0.5 % RH and between 3 × 102 and 9 × 103 Pa s at 50 % RH. In the second set of experiments we show that under dry conditions τexp, flow decreased by a factor of 45 as the production mass concentration increased from 121 to 14 000 μg m−3. From simulations of the poke-and-flow experiments, the viscosity of SOM with a production mass concentration of 14 000 μg m−3 was determined to be between 4 × 104 and 1.5 × 106 Pa s compared to between 6 × 105 and 5 × 107 Pa s for SOM with a production mass concentration of 121 μg m−3. The results can be rationalised by a dependence of the chemical composition of SOM on production conditions. These results emphasise the shifting characteristics of SOM, not just with RH and precursor type, but also with the production conditions, and suggest that production mass concentration and the RH at which the viscosity was determined should be considered both when comparing laboratory results and when extrapolating these results to the atmosphere.
Impact of cloud horizontal inhomogeneity and directional sampling on the retrieval of cloud droplet size by the POLDER instrument
Authors: Shang H. , Chen L. , Bréon F. M. , Letu H. , Li S. , Wang Z. , Su L.
Published: November 2015

Abstract. The principles of cloud droplet size retrieval via Polarization and Directionality of the Earth's Reflectance (POLDER) requires that clouds be horizontally homogeneous. The retrieval is performed by combining all measurements from an area of 150 km × 150 km to compensate for POLDER's insufficient directional sampling. Using POLDER-like data simulated with the RT3 model, we investigate the impact of cloud horizontal inhomogeneity and directional sampling on the retrieval and analyze which spatial resolution is potentially accessible from the measurements. Case studies show that the sub-grid-scale variability in droplet effective radius (CDR) can significantly reduce valid retrievals and introduce small biases to the CDR (~ 1.5 μm) and effective variance (EV) estimates. Nevertheless, the sub-grid-scale variations in EV and cloud optical thickness (COT) only influence the EV retrievals and not the CDR estimate. In the directional sampling cases studied, the retrieval using limited observations is accurate and is largely free of random noise. Several improvements have been made to the original POLDER droplet size retrieval. For example, measurements in the primary rainbow region (137–145°) are used to ensure retrievals of large droplet (> 15 μm) and to reduce the uncertainties caused by cloud heterogeneity. We apply the improved method using the POLDER global L1B data from June 2008, and the new CDR results are compared with the operational CDRs. The comparison shows that the operational CDRs tend to be underestimated for large droplets because the cloudbow oscillations in the scattering angle region of 145–165° are weak for cloud fields with CDR > 15 μm. Finally, a sub-grid-scale retrieval case demonstrates that a higher resolution, e.g., 42 km × 42 km, can be used when inverting cloud droplet size distribution parameters from POLDER measurements.
Evaluation of three lidar scanning strategies for turbulence measurements
Authors: Newman J. F. , Klein P. M. , Wharton S. , Sathe A. , Bonin T. A. , Chilson P. B. , Muschinski A.
Published: November 2015

Abstract. Several errors occur when a traditional Doppler-beam swinging (DBS) or velocity–azimuth display (VAD) strategy is used to measure turbulence with a lidar. To mitigate some of these errors, a scanning strategy was recently developed which employs six beam positions to independently estimate the u, v, and w velocity variances and covariances. In order to assess the ability of these different scanning techniques to measure turbulence, a Halo scanning lidar, WindCube v2 pulsed lidar and ZephIR continuous wave lidar were deployed at field sites in Oklahoma and Colorado with collocated sonic anemometers. Results indicate that the six-beam strategy mitigates some of the errors caused by VAD and DBS scans, but the strategy is strongly affected by errors in the variance measured at the different beam positions. The ZephIR and WindCube lidars overestimated horizontal variance values by over 60 % under unstable conditions as a result of variance contamination, where additional variance components contaminate the true value of the variance. A correction method was developed for the WindCube lidar that uses variance calculated from the vertical beam position to reduce variance contamination in the u and v variance components. The correction method reduced WindCube variance estimates by over 20 % at both the Oklahoma and Colorado sites under unstable conditions, when variance contamination is largest. This correction method can be easily applied to other lidars that contain a vertical beam position and is a promising method for accurately estimating turbulence with commercially available lidars.
Controls on dissolved organic matter (DOM) degradation in a headwater stream: the influence of photochemical and hydrological conditions in determining light-limitation or substrate-limitation of photo-degradation
Authors: Cory R. M. , Harrold K. H. , Neilson B.T. , Kling G. W.
Published: November 2015

Abstract. We investigated how absorption of sunlight by chromophoric dissolved organic matter (CDOM) controls the degradation and export of DOM from Imnavait Creek, a beaded stream in the Alaskan Arctic. We measured concentrations of dissolved organic carbon (DOC), as well as concentrations and characteristics of CDOM and fluorescent dissolved organic matter (FDOM), during ice-free periods of 2011–2012 in the pools of Imnavait Creek and in soil waters draining to the creek. Spatial and temporal patterns in CDOM and FDOM in Imnavait Creek were analyzed in conjunction with measures of DOM degradation by sunlight and bacteria and assessments of hydrologic residence times and in situ UV exposure. CDOM was the dominant light attenuating constituent in the UV and visible portion of the solar spectrum, with high attenuation coefficients ranging from 86 ± 12 m−1 at 305 nm to 3 ± 1 m−1 in the photosynthetically active region (PAR). High rates of light absorption and thus light attenuation by CDOM contributed to thermal stratification in the majority of pools in Imnavait Creek under low-flow conditions. In turn, thermal stratification increased the residence time of water and DOM, and resulted in a separation of water masses distinguished by contrasting UV exposure (i.e., UV attenuation by CDOM with depth resulted in bottom waters receiving less UV than surface waters). When the pools in Imnavait Creek were stratified, DOM in the pool bottom water closely resembled soil water DOM in character, while the concentration and character of DOM in surface water was reproduced by experimental photo-degradation of bottom water. These results, in combination with water column rates of DOM degradation by sunlight and bacteria, suggest that photo-degradation is the dominant process controlling DOM fate and export in Imnavait Creek. A conceptual model is presented showing how CDOM amount and lability interact with incident UV light and water residence time to determine whether photo-degradation is "light-limited" or "substrate-limited". We suggest that degradation of DOM in CDOM-rich streams or ponds similar to Imnavait is typically light-limited under most flow conditions. Thus, export of DOM from this stream will be less under conditions that increase the light available for DOM photo-degradation (i.e., low flows, sunny days).
CHLOROHYDRINATION OF NR LATEX BY USING SODIUM HYPOCHLORITE FOR FUEL-RESISTANT MATERIALS
Authors: Chanroj T. , Paoprasert P.
Published: November 2015

NR is hydrophobic and cannot be used to store, transfer, or make contact with hydrocarbon compounds. We report a simple method to increase the hydrophilicity of NR: a chlorohydrination reaction of NR latex by using sodium hypochlorite is described. It was found that only chlorohydrinated NR was obtained and side products were unnoticeable. The effects of sodium hypochlorite concentration, hydrochloric acid concentration, surfactant concentration, and reaction time on chlorohydrin content in NR were investigated. The swelling resistance of chlorohydrinated NR with 11% chlorohydrin content in diesel and gasohol fuels was improved nearly 3-fold and 4-fold, respectively, compared to that of the unmodified NR. The thermal and mechanical properties of the chlorohydrinated NR were characterized and found to be similar to those of pristine NR, indicating that the chlorohydrinated NR can be an excellent substitute for NR. This method has merits such as low cost of raw materials, easier and greener production processes than traditional methods, and scaling-up possibilities for the fabrication of chlorohydrinated NR for a variety of applications.
Strong insertion of a $\gamma-$ continuous function
Authors: Mirmiran Majid , Naderi Binesh
Published: November 2015

Necessary and sufficient conditions in terms of lower cut sets are given for the strong insertion of a $\gamma-$continuous function between two comparable real-valued functions.In this paper, is given a sufficient condition for the weak $\gamma-$insertion property. Also for a  space with the weak $\gamma-$insertion property, we give necessary and sufficient conditions for the space to have the strong $\gamma-$insertion property. Several insertion theorems are obtained as corollaries of these results.
Coefficient estimate of p-valent Bazilevic functions with a bounded positive real part
Authors: Babu O. S. , Selvaraj C. , Logu S. , Murugusundaramoorthy Gangadharan
Published: November 2015

By considering a $p-$valent Bazilevi\v{c} function in the open unit disk$\triangle$ which maps $\triangle$ onto the strip domain $w$ with$p\alpha < \Re\, w < p \beta,$ we estimate bounds of coefficients and solve Fekete-Szeg\"{o} problem forfunctions in this class.\\
A fourth order method for finding a simple root of univariate function
Authors: Sbibih D. , Serghini Abdelhafid , Tijini A. , Zidna A.
Published: November 2015

In this paper, we describe an iterative method for approximating asimple zero $z$ of a real defined function. This method is aessentially based on the idea to extend Newton's method to be theinverse quadratic interpolation. We prove that for a sufficientlysmooth function $f$ in a neighborhood of $z$ the order of theconvergence is quartic. Using Mathematica with its high precisioncompatibility, we present some numerical examples to confirm thetheoretical results and to compare our method with the others givenin the literature.
Epiconvergence method to a nonlinear value boundary problem with L^1 data
Authors: Messaho Jamal
Published: November 2015

The aim of this work is to study the existence of solutions of a value boundary problem with L^1 data with truncation and epicon-vergence method.
El profesor ingenuo
Authors: Martínez Reyes Nelson Rubén
Published: November 2015

En el presente artículo el autor explora la dimensión de la ingenuidad como una condición adscrita al profesor que, en mayor o menor medida, configura no solo su visión sobre educación y los procesos formativos sino también configura y condiciona su práctica educativa. Se destaca en el artículo como el profesor ingenuo, que es una mujer u hombre crédulo, confiado, acrítico, no es capaz de dilucidar las intenciones, las consecuencias, las incoherencias y contradicciones que plantea la educación ni de discernir el entramado socio-político-económico-cultural que subyace su práctica educativa, la escuela y el currículo porque dichas acciones suceden en forma oculta y disfrazada. Dicho análisis se hace desde la pedagogía crítica.Diá-logos 14, 5-18.
Educación intercultural en la carrera de Informática Empresarial de la Sede de Occidente de la Universidad de Costa Rica: una observación in situ
Authors: Salas Araya Yorley
Published: November 2015

Este artículo es el resultado de la investigación realizada en la Universidad de Costa Rica, Sede de Occidente y Recinto de Tacares en el II-2013 y se refiere a si es posible hablar de Educación Intercultural en la carrera de Informática Empresarial, específicamente en los dos primeros años de carrera, que es, precisamente donde ocurre más fuertemente los procesos de ajuste a la vida universitaria y donde también se presentan los índices más altos de deserción estudiantil. La metodología de trabajo se enmarca en el paradigma socio crítico y emplea la observación participante como método, principal de recolección de información. El análisis de la información evidencia que la carrera de informática empresarial presenta, en general, procesos pedagógicos incluyentes, sin embargo requiere, como opción académica, repensar estrategias que le permitan solventar algunas deficiencias observadas y avanzar hacia una verdadera educación intercultural.Diá-logos 14, 41-54.
The Application of Distributional Henstock-Kurzweil Integral on Third-order Three-Point Nonlinear Boundary-Value Problems
Authors: Zhou Dakai , Ye Guoju , Liu Wei , Liang Bing
Published: November 2015

We consider a type of form such as $u'''=-f$ with three-point
nonlinear boundary-value problems (NBVPs). We verified the existence
of solutions of the (NBVPs) when $f$ is distributional
Henstock-Kurzweil integral but not Henstock-Kurzweil integral.We use
the distribution derivative and fixed point theorem to deal with the
problem. The results obtained generalize the known results. For
this reason, it is conducive to the further study of NBVPS.