bluuebunny/crossref_metadata_2025 huggingface dataset:
Roles and Effects of Human Network of Supporting Experts out of Niigata University to Practical Engineering Education
Authors: Oka Tetsuo , Abe Kazuhisa , Yamauchi Takeshi , Narumi Takatsune , Ishii Nozomu , Nishimura Shin-ya , Sato Takashi , Tanabe Yuji , Sengoku Masakazu
Published: February 2016

The educational supporting human network outside the university we call as “The network of 100 wises” has been constructed by Faculty of Engineering in Niigata University on the process of educational reform activities. We have operated various kinds of practical programs on engineering education which have been assisted by the engineers/scientists in private companies and the societies outside the university. Since the network members possess the various experiences through the processes of their practical R&D activities, the guidance, lectures, and advice by the network members are much beneficial for the university students as well as for the faculties engaged in the engineering education. The network is composed of the engineers/scientists of various generations and industrial areas, mainly based on the personal reliances with the faculties through their research collaborations. It is much advantageous for the university students to obtain the practical engineering skills and the ways of thinking by means of the cooperation with the network.
An Educational Coding Laboratory for Elementary Pre-service Teachers: A Qualitative Approach
Authors: Vaca Cárdenas Leticia Azucena , Tavernise Assunta , Bertacchini Francesca , Gabriele Lorella , Valenti Antonella , Pantano Pietro , Bilotta Eleonora
Published: February 2016

The present study involved 64 pre-service teachers in a first experience of coding with the software Scratch, foreseeing its qualitative evaluation. In particular, the procedure in the laboratorial setting was designed as follows: firstly, subjects attended theoretical lessons on the use of the software, ideated and implemented an educational app. Afterwards, subjects wrote a report on the negative and positive aspects of their laboratorial experience. The analysis of results show that pre-service teachers appreciated the collaborative work, the freedom to code an app following their own interests, and the use of an engaging software. A constant concern regarding teachers’ self-efficacy as future mentors was present. Further quantitative studies are necessary.
Thermal Techniques for the Production of Fe-M Alloys
Authors: Abdel Halim K.S. , Ramadan M. , Shawabkeh A. , Alghamdi A.S.
Published: February 2016

The present manuscript is designed to investigate the possibility of manufacturing iron-metal alloys (Fe-M) via thermal techniques. These techniques are mainly depends on simultaneous reduction-sintering reactions of metal oxides. The reduction of metal oxides is an important property in metallurgical processes. It can be applied to M-Fe-O systems and also is used to develop inter-metallic alloys with specific properties. The produced metallic materials have wide range of applications and are characterized by unique physical and mechanical properties. The composition of the produced alloys is often a key element in optimizing their properties. Iron oxide doped another metal oxide such as nickel oxide is used as starting materials to produce metallic materials containing iron contaminated with nickel metal using thermal techniques. The sintering-reduction reactions of the composite oxide materials are investigated under different operation conditions. The experimental results show that the reduction-sintering thermal techniques are economic and promising routes for the production of different Fe-M alloys. The different factors affecting the rate of reduction such as temperature and ratio of doping materials are investigated. The results obtained are used to demonstrate the kinetics and mechanisms of reduction of metal oxides.
Information Management in Improvement Projects: Qualitative and Linguistic Approaches to Value Stream Design
Authors: Roessler Markus Philipp
Published: February 2016

A wide-spread approach to foster production and logistics related improvements on a system level is value stream mapping (VSM). It is often used as a starting point for implementing lean manufacturing in producing companies. VSM as a modeling approach contains two major phases – one is the analysis, another one the design phase. During these there is always the question of getting accurate information out of the production system to enable a constructive improvement. It can be distinguished between direct data acquisitions (observation, questioning, interviews) and indirect data acquisition (using IT systems) where both quantitative and qualitative data arises. Standard value stream design (VSD) offers no option to combine these data types, instead mostly deterministic values are used for assessing future states; this can lead to an illusion of accuracy. Thus in this paper it is shown how to combine different data types with an appropriate modeling using fuzzy variables in the course of VSD. The whole procedure is applied during a laboratory study to provide internal validity.
Simulations and Experiments on the Force Control of Hydraulic Servo System for Hydraulic Robots
Authors: Kim Hyo Gon , Lee Jong Won , Choi Yong Ho , Park Jeong Woo , Suh Jin Ho
Published: February 2016

Because hydraulic actuator has higher power and force density, it is normally used in heavy load manipulator robots and industrial equipment which require high torque. Also, the hydraulic actuator is applied to underwater robots that need high performance maneuver in underwater operations. The force control has benefits to those kind of robots to ensure compliance with user or environment. However, the hydraulic actuator is difficult to control forces due to the non-linearity characteristic of the hydraulic servo system. In this paper, we propose a force control method with compensation of force derivative and natural velocity feedback. We also describe a method of applying it to the real system. In order to evaluate the effect of the proposed control method, the simulations and experiments were performed.
Modeling and Simulation for One Leg of Quadruped Robot Trajectory
Authors: Shamsudin Hasrul Che , Ayob Mohammad Afif , Wan Zakaria Wan Nurshazwani , Zakaria Mohamad Fauzi
Published: February 2016

In legged robot movement planning, the leg must be carefully design before trajectory analysis can be done. The objective of this paper is to develop a 3 DOF leg which will be used in quadruped robot. In addition, forward kinematic and comparison between real and simulation of the leg is presented. To achieve the objective, SolidWorks 2013 x64 Edition is used to develop the 3D modeling of the leg while SimMechanics with First Generation Format was applied to export the models to Simulink. For the comparison purposes, real model of 3 DOF leg with Arduino Pro Mini 328 - 5V/16MHz as a microcontroller to control the rotation of three servomotors was constructed. With MIT AI2 Companion software, android apps is developed to send signal to rotate each servomotor wirelessly. The zero position of the leg robot has been determined and the maximum rotation range of each servomotor. This is very important in determination of D-H Parameters which allow the resolving of kinematics problems. It is found that specific rotations of each servomotor provide the trajectory pattern of the leg which is compared through Simulink and real model. Nevertheless, there are errors between simulation and real position of the robot leg due to the open loop system.
An Integrated Framework for Product Design and Macro Process Planning Based on ISO 10303 Standard - A Case Study: Integration of Glass Bottle and its Mold Design
Authors: Houshmand Mahmoud , Karami Arya , Ghasemi Reza
Published: February 2016

Nowadays the world of manufacturing and production has been encountered with a constantly changing behavior’s of customers. Moreover in the global market, a company can survive if it has the efficient capabilities for rapid product development.These capabilities are known to be important and they mainly affect on the market penetration and cost reduction. One way to enhance such capabilities is to integrate the essential activities of a manufacturing with the help of information technology. In recent years, the researchers have proposed integration of the computer-aided design (CAD), computer-aided manufacture (CAM) and computer-aided process planning (CAPP) as the main phases of product development lifecycle. These phases play an important role in the manufacturing environment and their integration will result in high-class production with minimum lead time. This paper focuses on the die design and process planning activities to produce the molds seamlessly . It studies the recent works on integration solutions and proposes an integration framework for glass bottle manufacturing companies.The paper considers the integration of the part design, macro process planning and the mold design activities. Moreover, the solution has used the ISO 10303 (STEP standard-International Standard for the Exchange of Product data). The novel aspects of the framework have been discussed through a case study. The case study highlights the integration of glass bottle design, process planning and bottle mold design to show the capabilities of the proposed framework.
Nanofabrication of Polymer Biosensor Structures for Biomedical Applications
Authors: Lai Yeong Lin , Chiu Chi Cheng
Published: February 2016

This paper presents the nanofabrication of polymer biosensor structures for biomedical applications. The polymer biosensor structures were achieved using hot embossing technology. The pressure effects on the replication of patterns during the hot embossing of the polymer biosensor structures were investigated. The fabricated polymer biosensor structures with pillar arrays were applied to immunoassay biochips. The pillar shapes of the polymer biosensor structures provided large surface areas and improved the antibody-antigen interaction of the immunoassay biochips.
Stability and Computer Simulation of Trailed Implement under Different Operating Conditions
Authors: Abu-Hamdeh Nidal H.
Published: February 2016

The mechanics of a trailer system moving up and down sloping ground under different operating conditions was theoretically simulated. A computer program was developed to analyze the system to predict the effect of both the trailer loading weight and the slope angle on the off-road vehicle stability, traction ability, and drawbar loading. The results of this analysis showed that the off-road vehicle becomes unstable when towing a 3750 kg trailer uphill at 28° slope angle. Insufficient traction occurred at slope angles ranging from 15° to 18° corresponding to trailer weight of 3750 to 750 kg. The parallel component of drawbar pull reached a maximum value of (17318) N when the trailer was pushing the off-road vehicle downhill at 30° slope angle. The normal component (normal to the tractive surface) showed similar maximum values for both uphill and downhill motions of the system. The use of computer analysis in this study provided a significant improvement in predicting the effect of different parameters on stability and control of off-road vehicle-trailer combination on sloping ground.Keywords: Stability, Traction, Sloping ground, Drawbar.
Numerical Simulation of the Influence of Laser Power on the Temperature Distribution during Dissimilar Welding of Ti-Al Alloy Plates
Authors: Babalová Eva , Behúlová Mária
Published: February 2016

The paper deals with the design and testing of laser power for laser beam welding of titanium Grade 2 and EN AW 5754 aluminium alloy plates. Transient temperature fields during formation of dissimilar butt joints of Ti-Al alloy plates were investigated by FEM simulation using the program code ANSYS. Moving Gaussian volumetric heat source was applied to model the heat input to the weld. The influence of laser power on the temperature distribution in welded materials and parameters of the weld pool were evaluated. Based on the results of numerical simulation, the suitable laser power was suggested for the real experiments of Ti–Al dissimilar laser welding using the TruDisk 4002 disk laser.
Effect of Axial and Torsional Vibrations on Tapping Performance
Authors: Pawar Swapnil , Patil Sandip , Pawar Pravin , Singh Rajkumar
Published: February 2016

Abrupt breakage of the taps is frequently encountered during tapping threads, especially when tapping on ‘difficult-to-cut’ material like titanium. This work therefore presents an extensive experimentation with the Taguchi approach to investigate maximum torque in tapping on titanium alloys while performing axial and, axial and torsional vibration-assisted tapping (AVAT and ATVAT). The experimentation shows that both AVAT and ATVAT reduce the tapping torqueduring tapping as compared to that of in conventional tapping process. However, ATVAT process had exhibited a higher degree of reduction in torque when compared to AVAT process.
Shear Properties and Modulus of 3D Glass Fibre Reinforced Polyester Thermoformed Composite
Authors: Černý Ivo , Remar Luboš , Černá Marie
Published: February 2016

Shear properties and shear modulus of an advanced 3D multi-layer glass reinforced polyester thermoformed composite material to be used for manufacture of selected car body components were evaluated. The experimental methodology is described in detail and some aspects like effects of extensometer gauge length or minimum material macrostructure length unit on final results are analysed and discussed. Shear modulus values of the material are presented.
Numerical Model of the Static Loading of a Stitched Seam in the Composite Cover of Car Seat
Authors: Kulhavý Petr , Kovalova Natalia , Vosáhlo Josef
Published: February 2016

Fundamental knowledge of the mechanical properties of used materials are the basic preconditions for a successful construction of a final product. For seam as well as the reliability of its strength in some cases we need to know certainty when there will be the malfunction. In this study a spun of polyester thread were sewn on a material used for car seat cover. A single or multiaxial loading either static or dynamic has been used in the field of automotive textiles as well as for conventional materials. There is no standard method of measurement for the determination of dynamic strength of sewn seams and therefore it was necessary to construct a device that may measure the strength of seams under dynamic stress. It was carried out an experimental determination of the tensile strength under a static and shock loading for the textile part itself, then for the thread and also for them all together. A lot of very sophisticated numerical models of the individual materials structures in the world generally exist but considerably less is in this field taken into account the behavior of the whole.The aim of this work is with using the commercial software ANSYS create a contact numerical model that will be able to predict behavior of stitched seams and can be used instead of the classical experiments.
Low Velocity Impact on Fiber Reinforced Geocomposites
Authors: Samal Sneha , Reichmann David , Petrikova Iva , Marvalova Bohdana
Published: February 2016

Low velocity impact strength of the fabric reinforced geocomposite has investigated in this article. Various fabrics such as carbon and E-glass were considered for reinforcement in geopolymer matrix. The primary two parameters such as low velocity, impact damage modes are explained on the E-glass and carbon based fabric geocomposite. The onset mode of damage to failure mode is examined through C-scan analysis. The quality of the composite is observed using c-scan with acoustic vibration mode of sensor before and after impact test. Then the effect of fabric and matrix on the impact behaviour is discussed. Residual strength of the composite is measured to determine post impact behaviour. It has been observed that resistance properties of E-glass reinforced composite is better than carbon fabric reinforced composite.
Strength Determination of Composite Flexible Joint
Authors: Sedláček František , Lašová Václava , Kottner Radek
Published: February 2016

This thesis deals with the design of a joint for composite flexible elements using an integrated connection. For the verification of the selected layout, a wrapping loop was chosen as a simplified member, which was created on a special form designed for these samples. The material used was unidirectional fibreglass and epoxy resin. These samples were then compared using quasi-static tensile and compression tests. The tests were carried out with the Zwick-Roell Z050 machine. The resulting data of the experiment were then compared with the data obtained from numerical simulations using the finite element system Siemens NX 10 and SIMULIA Abaqus 6.13. 3D strength criteria Maximum stress and direct-mode strength criterion LaRC04 were used for evaluation.
Bond Joint Analysis of Thermoplastic Composite Made from Stacked Tailored Blanks
Authors: Šedek Jakub , Hron Robin , Kadlec Martin
Published: February 2016

The interlaminar properties of a bond joint of stacked layers in a carbon fibre-reinforced composite with a thermoplastic matrix were evaluated under static loading. The un-precracked tension specimen with an external reinforcing layer was analysed in detail in the area of a bond joint. A detailed finite element method (FEM) analysis was performed to evaluate the influence of the bond joint shape on the interlaminar cohesive forces, which are simulated using the cohesive zone model (CZM). Simple lap and tapered joints were analysed. Continuum and shell elements were utilized in the FEM analysis, and the delamination results obtained using both solutions were compared to each other; however, no significant influence of the bond joint shape on the delamination onset was observed. The FEM analysis was supported using an experimental test on an un-precracked specimen made from prepreg with a carbon fibre fabric and a polyphenylene sulphide (PPS) matrix.
Influence of Compressed Area on Capacity of Headed Studs Used as Wall/Slab Reinforcement
Authors: Fornůsek Jindřich , Lovichová Romana , Zatloukal Jan , Konvalinka Petr
Published: February 2016

This paper presents results of study of behaviour of headed studs which are used for reinforcing of concrete structures. Numerical simulations of wall/slab joints reinforced by headed studs were carried out to find if there was some increase of wall/slab joint capacity due to the compressive zone in the joint. It was found that there is an increase of capacity of headed studs due to the compressive zone and the coefficient of capacity increase was introduced.
Clay Building Materials and their Properties
Authors: Žabičková Ivana , Otcovská Tereza , Padevět Pavel
Published: February 2016

Unburned clay is a unique building material. It was used for the traditional engineering works for more some 9 thousands years. However, it was almost completely replaced in this role by modern building materials during second half of twentieth century. Because of that, its material characteristics, as its behaviour in the constructions, were never researched very rigorously. In last years, we could see increasing demand for use of this building material. Most of the contemporary unburned clay constructions are made of adobe bricks or pressed-down mud. Brick constructions are made of adobe brick and clay mortar. For both of them it is their mechanical properties, which determine their use in the construction industry. According to our experimental measuring, the tensile strength in bending of common adobe bricks is 2.5 MPa for pressing pressure of 6.6 MPa. The tensile strength in bending in clay mortar made of common clay is 0.45 MPa for pressing pressure of 1.55 MPa.
Creep of the Four Month Old Cement Paste with Content of Fly Ash
Authors: Padevět Pavel , Bittnar Petr
Published: February 2016

The paper presents research in area of the measurement of cement paste creep. The propertiesof four month cement paste mixed with fly ash are presented. The creep and shrinkage are measuredinto the lever mechanism. The basic creep and creep of the saturated cement paste are calculatedfrom data of measurement. Finally, creep of four months old specimens is discussed.
Study of the Mechanical Properties Development of Concrete Containing Fine Recycled Aggregate
Authors: Šefflová Magdaléna , Pavlů Tereza
Published: February 2016

This paper is focused on the mechanical properties development of fine recycled aggregate (FRA) concrete. FRA was obtained from recycling plant in the Czech Republic. There were prepared four concrete mixtures in the laboratory. The first mixture was reference (REF) with fine natural aggregate (FNA). FNA was replaced in concrete mixtures R10, R20 and R30 in varying replacement ratio. The concrete mixtures R10, R20 and R30 contained 10 %, 20 % and 30 % FRA. There were tested properties of concrete. Finally, it is possible to say that the use of the FRA in concrete influences concrete properties. It is necessary to verify of probably an improvement of compressive strength of FRA concrete in future research. However, FRA concrete is possible to be used in the manufacturing of building structures, but it is necessary to test durability and lifespan of FRA concrete.
Influence of Coating on the Poisson's Ratio of Woven Fabrics
Authors: Šimić Penava Diana , Penava Željko , Tkalec Marijana
Published: February 2016

Coated fabrics have complex composite structure whose mechanical properties are considerably improved in relation with the initial basic material. They are obtained by applying a certain number of coatings to raw fabrics. In this paper the practical application of uniaxial testing of coated fabrics for determining its breaking properties and Poisson’s ratio is presented. Due to the anisotropy of woven and coated fabrics, Poisson's ratio changes over the fabric sample stretching. Experimental testing were carried out on two samples of plain weave cotton fabrics. The fabrics were tested before coating, and after one, two and three coatings. Samples are stretched with tensile force in the weft and warp direction, and based on different measured values of fabric stretching, warp and weft Poisson's ratio is calculated. The values of tensile force and relative extension of coated fabrics were measured, and breaking force values, elongation at break, contractions at break.
Study of Fine-Grained Composites Exposed to Sulfuric Acid and Sodium Sulfate
Authors: Vyšvařil Martin , Rovnaníková Markéta
Published: February 2016

The degradation of concrete due to ingress of sulfate ions from the environment plays an important role in the durability of concrete constructions, especially in sewage collection systems where concrete sewer pipes are exposed to sulfates from waste water and from biogenic activity of bacteria. During this process the pH of the surface of concrete sewer pipes is reduced and it may lead to the steel depassivation and results in the corrosion of steel reinforcement. Damage due to sulfate interaction can result in the cracking and softening, with loss of strength of concrete. This paper is focused on the sulfate attack on fine-grained concrete where the effect of one-year contact of 0.5% H2SO4, and 5% Na2SO4 on changes of pH and content of sulfates in 7 types of concrete has been analyzed. It was found that after one year of sulfate attack on concrete, significant growth of content of sulfates is observed in the lowermost layer of the samples. Samples treated by 5% Na2SO4 contain slightly more sulfates in the upper layers than samples treated by sulfuric acid. The reduction in pH of aqueous leaches occurred in all layers of the samples. However, even in the lower layers of the samples, the reduction of pH below 9.5 did not turn up (except for SRS sample), and thus the conditions for the depassivation of reinforcement were not met.
Destructive and Nondestructive Evaluation of Frost Resistance of Cement Pastes with Fly Ash
Authors: Zobal Ondřej , Padevět Pavel , Plachy Tomáš
Published: February 2016

This paper is dedicated to the use of fly ash in cement and concrete. Using fly ash in cement and concrete has ecological and economic benefits. However, it is important to correctly apply the fly ash. If the substitution is close to 50% or more by weight of clinker (HVFAC - High-Volume Fly Ash Concrete), it is necessary to monitor the material and mechanical properties. This paper describes an analysis of a frost resistance of a cement paste with fly ash. The destructive and non-destructive tests were carried out.
An Experimental Analysis of Grandstand Vibrations Caused by Crowd of Spectators during Two Football Matches
Authors: Verner Martin , Polak Michal , Plachy Tomáš
Published: February 2016

A significant dynamic load may be induced by synchronize movement of larger spectators group (like as jumping, bouncing, jouncing, swaying or abruptly rising) on a sport stadium during a sport event. This load could generate discomforting grandstand vibrations and in some extreme cases, the large grandstand vibrations are detectable by spectators even visually. A dynamic experiment is described in the paper which was realized on a steel cantilever grandstand during two football matches in the place where the most active spectators were concentrated. Vertical grandstand accelerations were observed in three points that were located at the ends of three grandstand main beams. The results of the experiment had shown predictably that the most excessive grandstand vibrations were induced by fans in the particular situations when the home team scored a goal and during the fans celebration after the matches especially. In these particular situations, the detected vibrations could be perceived by spectators as uncomfortable.
Use of Open Source DIC Tools for Analysis of Multiple Cracking in Fiber-Reinforced Concrete
Authors: Nežerka Václav , Antoš Jakub , Sajdlová Tereza , Tesárek Pavel
Published: February 2016

Digital image correlation (DIC) became indispensable when monitoring and analyzing adevelopment of displacement or strain fields. The method is capable of capturing strain localization, itis not limited to a relative measurement of discrete points as conventional methods and appears to bemore accurate than measurements by means of extensometers or strain-gauges that often suffer fromimperfect attachment to the measured surface. As open source DIC tools appear, the method becomesfeasible and the development is supported by the growing computational power of modern computers.The presented paper introduces open source 2D DIC tools and simple rules to follow when employingthe method. The presented case study on behavior of fiber reinforced high-performance concretedemonstrates a computational feasibility, accuracy and sensitivity of the method for a relatively lowfinancial cost.
Identification of Glass Alloy Elastic Constants Using Rod Samples
Authors: Vítek Karel
Published: February 2016

The methodology, used for determining the structure material elastic constants, is based on mechanical tests, being mostly tensile ones, applied on partially loaded specimens. There be can glass materials used as different alloy elements, therefore the glass elastic constants can vary considerably. However, using classic glass tensile specimens for tensile tests can be problematic, due to their production and implementation of tensile tests. Experimental methods for identifying the glass Young's modulus of elasticity and Poisson's ratio are based on a comparison of the displacement measurements applied on the glass beam, or curved rod, samples, combined with their displacements calculation.
Optical Investigation of Component Made by FDM Technology
Authors: Jurčišin Miroslav , Blažo Marek , Slota Ján
Published: February 2016

3D printed plastic components are nowadays frequently used parts in all areas of industrial sphere. These components are often made by FDM technology. The main advantage of this technology is quick manufacturing process, price and also possibility of producing complex parts. This paper is aimed to the component made by FDM technology from the view of their strength. Specially designed chair was loaded by different force and the maximum load before destruction was measured. Chair was under inspection of two different optical strain measurement systems working on different principles. System PONTOS working on the principle of digital photogrammetry and system ARAMIS working on the principle of digital image correlation were used. These systems were used in order to investigate and identify weak places of this chair.
Fine needle aspiration biopsy of metastatic malignant mesothelioma with myxoid change and signet ring cells: A case report and review of the literature
Authors: Mishra Manisha M. , Farver Carol F. , Chute Deborah J.
Published: February 2016

Malignant mesothelioma (MM) is a rare neoplasm, which is most commonly encountered in cytology through effusion specimens. Fine needle aspiration biopsy of MM, particularly the epithelioid subtype, can be a source of diagnostic difficulty and may mimic sampling of an adenocarcinoma. This is the first case report to demonstrate abundant extracellular myxoid material and numerous intracellular vacuoles, including signet ring cells, in a fine needle aspirate of metastatic MM. A review of the literature for myxoid change and vacuoles in fine needle aspiration biopsies of MM discloses that vacuoles are found in up to 35% of aspirates of MM, but myxoid change is very rare, reported in <5% of the cases. Cytologists should be aware of this rare morphologic pattern of metastatic epithelioid MM.
Ammonia in the summertime Arctic marine boundary layer: sources, sinks, and implications
Authors: Wentworth Gregory R. , Murphy Jennifer G. , Croft Betty , Martin Randall V. , Pierce Jeffrey R. , Côté Jean-Sébastien , Courchesne Isabelle , Tremblay Jean-Éric , Gagnon Jonathan , Thomas Jennie L. , Sharma Sangeeta , Toom-Sauntry Desiree , Chivulescu Alina , Levasseur Maurice , Abbatt Jonathan P. D.
Published: February 2016

Abstract. Continuous hourly measurements of gas-phase ammonia (NH3(g)) were taken from 13 July to 7 August 2014 on a research cruise throughout Baffin Bay and the eastern Canadian Arctic Archipelago. Concentrations ranged from 30 to 650 ng m−3 (40–870 pptv) with the highest values recorded in Lancaster Sound (74°13′ N, 84°00′ W). Simultaneous measurements of total ammonium ([NHx]), pH and temperature in the ocean and in melt ponds were used to compute the compensation point (χ), which is the ambient NH3(g) concentration at which surface–air fluxes change direction. Ambient NH3(g) was usually several orders of magnitude larger than both χocean and χMP (< 0.4–10 ng m3) indicating these surface pools are net sinks of NH3. Flux calculations estimate average net downward fluxes of 1.4 and 1.1 ng m−2 s−1 for the open ocean and melt ponds, respectively. Sufficient NH3(g) was present to neutralize non-sea-salt sulfate (nss-SO42−) in the boundary layer during most of the study. This finding was corroborated with a historical data set of PM2.5 composition from Alert, Nunavut (82°30′ N, 62°20′ W) wherein the median ratio of NH4+/nss-SO42− equivalents was greater than 0.75 in June, July and August. The GEOS-Chem chemical transport model was employed to examine the impact of NH3(g) emissions from seabird guano on boundary-layer composition and nss-SO42− neutralization. A GEOS-Chem simulation without seabird emissions underestimated boundary layer NH3(g) by several orders of magnitude and yielded highly acidic aerosol. A simulation that included seabird NH3 emissions was in better agreement with observations for both NH3(g) concentrations and nss-SO42− neutralization. This is strong evidence that seabird colonies are significant sources of NH3 in the summertime Arctic, and are ubiquitous enough to impact atmospheric composition across the entire Baffin Bay region. Large wildfires in the Northwest Territories were likely an important source of NH3, but their influence was probably limited to the Central Canadian Arctic. Implications of seabird-derived N-deposition to terrestrial and aquatic ecosystems are also discussed.
Return glider radiosonde for in-situ upper-air research measurements
Authors: Kräuchi Andreas , Philipona Rolf
Published: February 2016

Abstract. Upper-air balloon soundings for weather predictions have been made since the beginning of the 20th century. New radiosonde instruments for in-situ humidity-, radiation- and gas profile measurements in the troposphere and the lower stratosphere, were introduced in recent years for atmospheric research and climate monitoring. Such instruments are often expensive and aimed at being reused on many flights. However, recovering instruments that freely descent with parachutes is time-consuming and sometimes difficult and even dangerous. Here we introduce the Return Glider Radiosonde (RGR), which enables flying and retrieving valuable in-situ upper-air instruments. The RGR is lifted with weather balloons similar to traditional radiosondes to a preset altitude, at which time a release mechanism cuts the tether string, and a built in autopilot flies the glider autonomously back to the launch site or a desired preprogrammed location. Once the RGR reaches the landing coordinates it circles down and releases a parachute 100 m above ground for landing. The motivation for this project was to measure radiation profiles throughout the atmosphere with the same instrument multiple times. The paper describes technical aspects of the return glider radiosonde and the built in radiation instruments, and shows first low and high altitude test flights up to 24 km that are analyzed in terms of flight performance and maximal distances covered. Several successive flights measuring radiation profiles demonstrate the reliability and the operational readiness of the RGR, allowing new ways for atmospheric in-situ research- and monitoring measurements with different built-in sensors and instruments to be utilized.
Organic carbon flux and particulate organic matter composition in Arctic valley glaciers: examples from the Bayelva River and adjacent Kongsfjorden
Authors: Zhu Zhuo-Yi , Wu Ying , Liu Su-Mei , Wenger Fred , Hu Jun , Zhang Jing , Zhang Rui-Feng
Published: February 2016

Abstract. In the face of ongoing global warming and glacier retreat, the composition and flux of organic matter in glacier–fjord systems are key variables for updating the carbon cycle and budget, whereas the role of Arctic valley glaciers seems unimportant when compared with the huge Greenland Ice Sheet. Our field observations of the glacier-fed Bayelva River, Svalbard, and the adjacent Kongsfjorden allowed us to determine the compositions of particulate organic matter from glacier to fjord and also to estimate the flux of organic carbon, both for the river and for Svalbard in general. Particulate organic carbon (POC) and dissolved organic carbon (DOC) in the Bayelva River averaged 56 and 73 µM, respectively, in August, 2012. Amino acids (AAs) and phytoplankton carbon accounted for  ∼ 10 % of the bulk POC in the Bayelva River, while AAs represented > 90 % of particulate nitrogen (PN) in fjord surface water, suggesting the strong in situ assimilation of organic matter. Bacteria accounted for 13 and 19 % of the POC in the Bayelva River and the Kongsfjorden, respectively, while values for PN were much higher (i.e., 36 % in Kongsfjorden). The total discharge from the Bayelva River in 2012 was 29  ×  106 m3. Furthermore, we calculated the annual POC, DOC, and PN fluxes for the river as 20 ± 1.6 tons, 25 ± 5.6 tons, and 4.7 ± 0.75 tons, respectively. Using the POC content and DOC concentration data, we then estimated the annual POC and DOC fluxes for Svalbard glaciers. Although the estimated POC (0.056 ± 0.02  ×  106 tons year−1) and DOC (0.02 ± 0.01  ×  106 tons year−1) fluxes of Svalbard glaciers are small in amount, its discharge-weighted flux of DOC was over twice higher than other pan-Arctic glacier systems, suggesting its important role as a terrestrial DOC source.
Diatoms Si Uptake Capacity Drives Carbon Export In Coastal Upwelling Systems
Authors: Abrantes F. , Cermeño P. , Lopes C. , Romero O. , Matos L. , Van Iperen J. , Rufino M. , Magalhães V.
Published: February 2016

Abstract. Coastal upwelling systems account for approximately half of global ocean primary production and contribute disproportionately to biologically driven carbon sequestration. Diatoms, silica–precipitating microalgae, constitute the dominant phytoplankton in these productive regions, and their abundance and assemblage composition in the sedimentary record is considered one of the best proxies for primary production. The study of the sedimentary diatom abundance (SDA) and total organic carbon content (TOC) in the five most important coastal upwelling systems of the modern ocean (Iberia-Canary, Benguela, Peru-Humboldt, California and Somalia-Oman) reveals a global-scale positive relationship between diatom production and organic carbon burial. The analysis of SDA in conjunction with environmental variables of coastal upwelling systems such as upwelling strength, satellite-derived net primary production and surface water nutrient concentrations shows different relations between SDA and primary production on the regional scale. At the global-scale, SDA appears modulated by the capacity of diatoms to take up silicic acid, which ultimately sets an upper limit to global export production in these ocean regions.
Rates and pathways of CH4 oxidation in ferruginous Lake Matano, Indonesia
Authors: Sturm A. , Fowle D. A. , Jones C. , Leslie K. , Nomosatryo S. , Henny C. , Canfield D. E. , Crowe S. A.
Published: February 2016

Abstract. This study evaluates rates and pathways of methane (CH4) oxidation and uptake using 14C-based tracer experiments throughout the oxic and anoxic waters of ferruginous Lake Matano. Methane oxidation rates in Lake Matano are low compared to other lakes, but are sufficiently high to preclude strong CH4 fluxes to the atmosphere. In addition to aerobic CH4 oxidation, which takes place in Lake Matano's oxic mixolimnion, we also detected CH4 oxidation in Lake Matano's anoxic ferruginous waters. Here, CH4 oxidation proceeds in the apparent absence of oxygen (O2) and instead appears to be coupled to nitrate (NO3−), nitrite (NO2−), iron (Fe), or manganese (Mn) reduction. Throughout the lake, the fraction of CH4 carbon that is assimilated vs. oxidized to carbon dioxide (CO2) is high, indicating extensive CH4 conversion to biomass and underscoring the importance of CH4 as a carbon and energy source in Lake Matano and potentially other ferruginous or low productivity environments.
Contribution of previous year’s leaf N and soil N uptake to current year’s leaf growth in sessile oak
Authors: Bazot Stephane , Fresneau Chantal , Damesin Claire , Barthes Laure
Published: February 2016

Abstract. The origin of the N which contributes to the synthesis of N reserves of in situ forest trees in autumn, and to the growth of new organs the following spring, is currently poorly documented. To characterize the metabolism of various possible N sources (plant N and soil N), six distinct 20 year-old sessile oaks were 15N labelled by spraying 15NH415NO3: (i) on leaves in May, to label the N pool remobilized in the autumn for synthesis of reserves; (ii) on soil in the autumn, to label the N pool taken up from soil; (iii) on soil at the beginning of the following spring, to label the N pool taken up from soil in the spring. The partitioning of 15N in leaves, twigs, phloem, xylem, fine roots, rhizospheric soil and microbial biomass was followed during two growing seasons. Results showed a significant incorporation of 15N in the soil-tree system; more than 30 % of the administered 15N was recovered. Analysis of the partitioning clearly revealed that in autumn, roots’ N reserves were formed from foliage 15N (73 %) and to a lesser extent from soil 15N (27 %). The following spring, 15N used for the synthesis of new leaves came first from 15N stored during the previous autumn, mainly from 15N reserves formed from foliage (95 %). Thereafter, when leaves were fully expanded, 15N uptake from soil during the previous autumn and before budburst contributed to the formation of new leaves (60 %).
A review of multivariate social vulnerability methodologies; a case study of the River Parrett catchment, Somerset
Authors: Willis I. , Fitton J.
Published: February 2016

Abstract. In the field of Disaster Risk Reduction (DRR), there exists a proliferation of research into different ways to measure, represent, and ultimately quantify a population’s differential social vulnerability to natural hazards. Empirical decisions such as the choice of source data, variable selection, and weighting methodology can lead to large differences in the classification and understanding of the 'at risk' population. This study demonstrates how three different quantitative methodologies (based on Cutter et al. (2003), Rygel et al. (2006), and Willis et al. (2010)) applied to the same England and Wales 2011 Census data variables in the geographical setting of the 2013/2014 floods of the Parrett river catchment, UK, lead to notable differences in vulnerability classification. Both the quantification of multivariate census data and resultant spatial patterns of vulnerability are shown to be highly sensitive to the weighting techniques employed in each method. The findings of such research highlight the complexity of quantifying social vulnerability to natural hazards as well as the large uncertainty around communicating such findings to DRR practitioners.
Isotopic exchange on the diurnal scale between near-surface snow and lower atmospheric water vapor at Kohnen station, East Antarctica
Authors: Ritter François , Steen-Larsen Hans Christian , Werner Martin , Masson-Delmotte Valérie , Orsi Anais , Behrens Melanie , Birnbaum Gerit , Freitag Johannes , Risi Camille , Kipfstuhl Sepp
Published: February 2016

Abstract. Quantifying the magnitude of post-depositional processes affecting the isotopic composition of surface snow is essential for a more accurate interpretation of ice core data. To achieve this, high temporal resolution measurements of both lower atmospheric water vapor and surface snow isotopic composition are required. This study presents the first continuous measurements of water vapor isotopes performed in East Antarctica (Kohnen station) from December 2013 to January 2014 using a laser spectrometer. During our monitoring period, the synoptic variability of the water vapor isotopic composition is found to be low compared to the diurnal cycle and we therefore concentrate our study on interaction between the isotopic composition of the vapor and the snow surface on a diurnal timescale. The peak-to-peak amplitude of the snow surface isotopic composition over 24 h reaches 3 ‰ for δD, in phase with the diurnal variations of δD in surface vapor, which itself has an amplitude of 36 ‰. A simple box model treated as a closed system has been developed to study the exchange of water molecules between an air and a snow reservoir. In the vapor, the simulations show too much isotopic depletion compared to the observations. Mixing with other sources (wind advection, free troposphere) has to be included in order to fit the observations. At the snow surface, the simulated isotopic values are close to the observations with a snow reservoir of ∼5 mm depth (range of the snow sample depth). Our analysis suggests that vapor-snow exchanges can no longer be considered insignificant for the isotopic composition of near surface snow in central Antarctica.
Supervillanos muy reales: el uso político del villano en la trilogía de "El Caballero Oscuro" de Christopher Nolan
Authors: Rodriguez de Austria Giménez de Aragón Alfonso M.
Published: February 2016

Es ya casi una tradición que los villanos de celuloide (o digitales) posean una o varias características que nos recuerden a los enemigos políticos reales del país productor de la película, o incluso a los enemigos dentro del propio país según la ideología concreta que sustenta la película. El caso de la trilogía de El caballero oscuro de Christopher Nolan, que aquí analizamos, es representativo de esta tendencia por dos razones. En primer lugar porque llega marcada por la radicalización política llevada a cabo por el gobierno de Estados Unidos tras el atentado del 11 de septiembre de 2001. En segundo lugar porque ofrece una profusa galería de villanos que quedan fuera del círculo de amigos según la nueva doctrina del “o con nosotros o contra nosotros” inaugurada por George Bush para el siglo XXI. Esta galería incluye desde a los propios terroristas que justifican la llamada Guerra contra el Terror (Ra's al Ghul, el Joker), hasta los “radicales de izquierda” (Bane, Talia al Ghul), pasando por los políticos liberales (Harvey Dent), y los corruptos que se aprovechan de la blandura de las leyes para delinquir impunemente (Dr. Crane, el Espantapájaros).
Using Movies in EFL Classrooms: A Study Conducted at the English Language Institute (ELI), King Abdul-Aziz University
Authors: Kabooha Raniah Hassen
Published: February 2016

The present study sought to examine the attitudes of Saudi English as a foreign language (EFL) learners as well as teachers towards the integration of English movies in their classes as a tool to develop students’ language skills. Fifty female intermediate level students studying English in their Preparatory Year Program (PYP) in the English Language Institute (ELI) at King Abdul-Aziz University (KAU), Jeddah, Saudi Arabia, participated in the study. Questionnaires were administered to the students to investigate their perceptions towards the integration of English movies in their classes to develop their language skills. The researcher also conducted semi-structured interviews with both students and teachers to explore their perceptions towards the use of movies in their classes. In addition, teachers were required to write reflective journals regarding the use of movies in their classes. The findings of the study indicate that both students as well as teachers had positive attitudes towards the use of movies in their classes to improve students’ language skills. The study offers pedagogical implications for EFL instructors with respect to the integration of films in their classrooms to improve students’ language learning. Well-selected movie materials could enhance students’ language learning process and increase their motivation to learn the target language.
The Relationship between Learning Effectiveness, Teacher Competence and Teachers Performance Madrasah Tsanawiyah at Serang, Banten, Indonesia
Authors: Rahmatullah Mamat
Published: February 2016

In this study, the problem is limited factors relating to the learning effectiveness and teacher competence in improving the teacher performance. Therefore, this study will try to get explanations from some main issues which include the learning effectiveness issue, and teacher competence to increase teacher performance in Madrasah Tsanawiyah at Serang, Banten, Indonesia. The goal in this research is to get facts about correlation and to see the levels of effectiveness learning and teacher competence as well as the teacher performance in Madrasah Tsanawiyah at Serang, Banten, Indonesia. This research is directed in describing and analyzing the data findings in depth are using the quantitative analysis methods of descriptive and inferential. Collecting data is using the instrument, about the instrument is used as a primary assessment way to collect the information about factors of effectiveness learning, teacher competence, and teacher performance. The samples are 150 Teacher in Madrasah Tsanawiyah at Serang, Banten, Indonesia. The results of this research is there is a relationship between learning effectiveness and teacher performance, there is a relationship between teacher competence and teacher performance, the results of this study can be concluded that increasing teacher performance can be carried out in the presence of learning effectiveness and teacher competence in the Madrasah Tsanawiyah, teachers who have the good performance seen from an process of learning effectiveness as well as the teacher competency.