bluuebunny/crossref_metadata_2025 huggingface dataset:
Joining of Aluminum Matrix Composites and Stainless Steel by Arc Brazing
Authors: Elßner Michael , Weis Sebastian , Wagner Guntram
Published: July 2015

To enlarge the field of application of aluminum matrix composites (AMC) suitable joining technologies are necessary. Especially dissimilar joints like between AMC and stainless steel are of interest. In this work the arc brazing of this material combination is investigated. A new filler based on the ternary system Al-Ag-Cu is used. The results of wetting tests of the base filler and adapted variants are described and discussed. Wetting angles and microstructure of the interfaces are regarded.
Metal/FRP Connection Module – A Powder Metallurgical Approach
Authors: Hutsch Thomas , Lang Anna , Schubert Thomas , Schiebel Patrick , Christ Mirko , Weißgärber Thomas , Kieback Bernd , Herrmann Axel S.
Published: July 2015

The Development of Fiber Reinforced Plastics (FRP) offers a great opportunity for applications in automobile industry, aeronautics and consumer goods to achieve light weight structures. However, the connection technology between FRP and mainly metallic based structures is the key to use the full potential of the FRP. Out of this motivation recent developments address this aspect.Using the powder metallurgical approach to generate a metal/ FRP connection module by spark plasma sintering a great variety is possible by integration of different metal and/ or fiber components. In this work aluminum and stainless steel was chosen for the upper and lower metallic side. The fibers integrated into the metal were glass, basalt and carbon fiber in one layer, two layer and mixed layer configuration. To connect the sintered module to greater CF weaves an infiltration process with a room temperature curing resin was used in a modified vacuum infusion (MVI) setup. In not optimized configuration the shear test after infiltration indicated an initial value for module shear strength above 20 MPa which can be enhanced in future developments by optimized armor between the upper and lower metal side and the number of integrated fiber layers of the connection module. A model is predicted to calculate the module shear strength in sintered state by multiplication of the armor area with the shear strength of the armor material. First experiments additionally show the possibility to weld the connection module directly to metallic structures.
Process-Integrated Manufacturing and Embedding of Novel Piezoelectric Sensor Modules into Glass Fibre-Reinforced Polyurethane Composite Structures
Authors: Geller Sirko , Gude Maik
Published: July 2015

Due to an increasing use of composite materials in various applications and related open questions concerning structural health monitoring and damage detection, the realisation of function integrating lightweight structures with sensory properties is subject of numerous research activities. Main objective is the transfer of already in laboratory and prototype scale established methods for the integration of sensory elements on serial applications. Here, combining the previously separated processing steps sensor manufacturing, component manufacturing and sensor integration can help to make a significant step forwards. Therefore, as part of the activities in the Collaborative Research Centre/Transregio (CRC/TR) 39, a highly productive spray coat method based on the long fibre injection (LFI) process is developed, which allows the process-integrated manufacturing and embedding of novel piezoelectric sensor modules into fibre-reinforced polyurethane composite structures.Based on studies on the technological implementation of the newly developed process, theoretical and experimental studies for contacting and polarisation of the novel sensor elements are presented. In addition, the characterisation of the adhesion properties of thermoplastic films on the used fibre-reinforced polyurethane composites is part of the presented research to evaluate the possibility of integrating thermoplastic-compatible piezo modules for actuator applications.
Highly-Sensitive Humidity Sensors for Condition Monitoring of Hybrid Laminates
Authors: Seider Thomas , Martin Joerg , Boeddicker Alexander , Rühling Julia , Wett Daniel , Nestler Daisy , Wagner Guntram , Huebler Arved Carl , Otto Thomas , Gessner Thomas
Published: July 2015

In recent years fibre-reinforced polymers (FRPs) gained importance in a wider field of application due to such favourable properties as low mass and tailorable mechanical strength. However, water penetrating into the lightweight material can lead to a loss of shear strength and finally to a collapse of the whole mechanical structure. Consequently, the integration of humidity sensors into compound materials is able to promote the reliability via online condition monitoring. An innovative concept is the use of ceramics-polymer-composites, which are well suited for the integration into lightweight structures during inline production. Composite and polyimide based humidity sensors have been manufactured by flexographic printing and spin-coating processes. A 5-fold increase in sensor’s capacity related to a humidity change from 10 to 80 % r.h. manifests the outstanding sensitivity of manufactured composite sensors. In addition, FRP-integrated polyimide sensors showed a significant response to water penetration, whereby the capability of condition monitoring could be confirmed.
Integration Methods of Sensors in FRP Components
Authors: Christof Hans , Müller Lena , Küppers Simon , Hofmann Paul , Giebel Elisabeth , Frick Sabine , Gabler Markus , Gresser Götz T.
Published: July 2015

Structural health monitoring is an important research topic in the field of fiber reinforced plastics (FRP). An effective way to detect defects or overloads in these FRP has still not been found. One way to monitor the actual state of FRP components is via integrated sensors. Integrating current standard sensors negatively affects the flux of force. Therefore investigations about integration methods of sensors in FRP components have been made. The integration of an optical fiber sensor into FRP profiles via a pultrusion process was investigated. It could be shown that the pultrusion process is suitable method for the integration of fiber optic sensors for strain measurements. Another investigated sensor principle was the integration of piezoelectric polyvinylidene fluoride (PVDF) fibers via a vacuum assisted process. The PVDF fibers were integrated into 3-point bending specimen and the piezoelectric effect was tested with and without polarization. The investigation showed that it is possible to measure the piezoelectric effect of PVDF fibers integrated into a 3-point bending test specimen. It could also be shown that carbon fibers can be used as textile electrodes for the measurement of the generated charge on the PVDF surface.
Nanostructured Coatings for Tooling Applications
Authors: Köpf Arno , Keckes Jozef , Todt Juraj , Pitonak Reinhard , Weissenbacher Ronald
Published: July 2015

In this contribution the authors will present a short summit of the state of the art in the field of nanostructured coatings and will then emphasise on the most recent developments concerning the possible changes in the coating architecture of CVD AlTiN, which can be achieved by changing some of the process parameters
Diamond Coatings on Carbon Based Substrates
Authors: Haubner Roland , Lessiak Mario
Published: July 2015

Diamond deposition on carbon substrates is difficult, because atomic hydrogen needed for the diamond growth, attacks the graphitic and amorphous carbon of the substrate. To reduce the etching effect, the duration till diamond layer formation should be short.By controlling the diamond deposition conditions, boron addition and seeding with diamond prior to the deposition, the formation of diamond coatings is possible.Diamond coated carbon substrates are of high interest for electrochemical applications because they show electrical conductivity and are chemically inert in a wide range. Boron doped diamond shows high overvoltage for hydrogen and oxygen and allows electrochemical reactions in water without decomposing it. Diamond was deposited on glassy carbon and electro-graphite.
Al-Mn Thermally Sprayed Coatings as Replacement of Cd-Based Coatings
Authors: Förg Andrea , Wolf Gerhard , Dotzler Klaus , Libralesso Laure , Masset Patrick J.
Published: July 2015

Cadmium coatings are used in aerospace and offshore industries for parts in corrosive environments. Since cadmium is a highly toxic heavy metal, it is subject to strong restrictions. Alternatives include Al-based alloys. The present work describes preliminary results for Cd substitution by using Al-Mn with 25 at.-% Mn deposited on 42CrMo4 steel by atmospheric plasma spraying (APS). The prepared alloy powder for the APS process was characterized by laser granulometry, SEM/EDX, and STA. A fraction with particle sizes ranging from 20 µm to 45 µm was used for the thermal spraying process. The APS coating and an Al reference sample were characterized by image analysis, Vickers hardness, and Standard Salt Spray (SSP) testing. The Al-Mn coating exhibits a significantly higher hardness in comparison to pure Al. In both cases, red iron corrosion did not appear during SSP testing. The Al coating was partially covered by a thick oxide film, whereas Al-Mn showed only moderate oxidation but lower adhesion to the substrate
Oxidation and Decomposition of Ti2AlN MAX Phase Coating Deposited on Nickel-Based Super Alloy IN718
Authors: Garkas Wagdi , Fröhlich Maik , Weltmann Klaus Dieter , Leyens Christoph
Published: July 2015

In this work, the oxidation behavior of Ti2AlN coating deposited on nickel super alloy IN718 was investigated. The coating was obtained by DC-magnetron sputtering at 540°C and subsequent vacuum annealing at 800°C for 1h. The coating morphology as well as the chemical composition were analyzed using SEM, EDS and XRD, respectively. The XRD results revealed that the coating mainly composed of Ti2AlN MAX phase. Cycling oxidation was performed at 700 °C and 800 °C in air. The XRD and SEM results proved the interaction between substrate and coating and the formation of the quaternary Ti3NiAl2N phase during oxidation at the interface. Due to the Ni diffusion towards the surface, the Ti3NiAl2N phase grew continuously and the Ti2AlN phase decomposed gradually resulting in a coating failure. The results indicate that the oxidation behavior of the coating is essentially controlled by the interdiffusion of Ni from substrate into the coating.
Anodic Oxidation of AMCs: Influence of Process Parameters on Coating Formation
Authors: Morgenstern Roy , Nickel Daniela , Dietrich Dagmar , Scharf Ingolf , Lampke Thomas
Published: July 2015

Aluminium matrix composites (AMCs) consisting of high-strength, age-hardenable aluminium alloys and homogeneously dispersed hard particles open up new possibilities in designing light-weight material based security related structures. The susceptibility of the matrix alloy to selective corrosion can be reduced significantly by anodic oxidation. A powder-metallurgical processed alloy AlCu4MgMn with hard particles and a commercial wrought alloy for reference were used for the investigations.In order to control the microstructure of anodic aluminium oxide (AAO) formed on AMCs, it is necessary to understand the formation mechanism and the influencing parameters. Therefore in a first run, the anodizing behaviour of matrix alloy was separated from the behaviour of hard particles. The AAO coatings show small growth rates on the matrix and the reference alloy accompanied by a complex pore structure which differs from the ordered vertical pore structure on pure aluminium. Depending on the type and the size as well as the anodizing parameters, the particles are either incorporated into the AAO coating unchanged or partly resp. completely oxidized. The AAO microstructure changes significantly in dependence of the anodizing parameters. It is shown that a technically relevant coating thickness can be achieved on AMCs by choosing appropriate process parameters.
Coupling of Mold Flow Simulations with Two-Scale Structural Mechanical Simulations for Long Fiber Reinforced Thermoplastics
Authors: Buck Fabian , Brylka Barthel , Müller Viktor , Müller Timo , Hrymak Andrew N. , Henning Frank , Böhlke Thomas
Published: July 2015

The entire simulation process for long fiber reinforced thermoplastics is examined to determine the effective mechanical properties which are influenced by the microstructural fiber orientation state. Therefore, flow and fiber orientation simulations are conducted and the obtained fiber orientation tensors are used in two-scale structural simulations. The fiber orientation distributions as well as the mechanical properties are compared with micro-computed tomography data and results from threepoint bending tests performed by dynamical mechanical analysis (DMA), respectively. The validated results show that prediction of the essential mechanical properties is possible with the applied combinated methods and that the knowledge of the fiber orientation and its gradients is of crucial importance for the entire simulation process.
Surface Structuring of Sheet Moulding Compounds (SMC) for Process Reliable Coatings
Authors: Petzold Carina , Lucia Martin , Groß Stefan , Müller Anett , Schneider Jörg , Stoll Andrea
Published: July 2015

This study investigates how roughness and coatability of sheet moulding compound (SMC) components can be improved by modifying the surface morphology of the compression tool. A modular tool was developed that allowed to mould SMC work pieces simultaneously with different tool surfaces. In this study, mainly the tool roughness was modified using various surface treatments. Three different SMC formulations were applied to mould 2D components using the modular system. It was found that the demoulding was affected by both the tool morphology and the SMC formulations. Contamination of the tool by SMC material could be reduced by chrome-plating. The morphology of the tool was transferred to the SMC work piece if the structures were larger than 5 µm. The adhesion strength of a coating system differed for the three SMC formulations. While two of them showed generally good coatability, the coating adhesion on the third formulation decreased with increasing roughness of the tool used for moulding.
Preparing of Heatable, CNT-Functionalized Polymer Membranes for Application in Textile Composites
Authors: Trommer Kristin , Morgenstern Bernd , Petzold Carina
Published: July 2015

The electrically induced heating of textile composite materials is already applied in the clothing and outdoor use. However, making thin, flexible and washable heating layers remains a challenge. Based on various polymers thin electrically heatable polymer sheets were developed using multi-walled carbon nanotubes as electrically conductive fillers in silicone, polyurethane as well as polyvinylchloride. To prepare the membranes a knife coating process was applied. The viscosity of the polymer masses, the particle alignment, the percolation as well as the electrically and heating properties of the membranes were investigated.
Continuous Winding Technology for Specific Closed Structural Components
Authors: Wallasch Rainer , Tirschmann Ramon
Published: July 2015

Since energy resources are limited, there is a strong need for efficient technologies, which are suitable for large scale production. Therefore, an innovative Continuous Orbital Winding Technology was developed within the Federal Cluster of Excellence EXC 1075 “MERGE Technologies for Multifunctional Lightweight Structures” at TU Chemnitz. This continuous orbital winding (COW) technology is aiming for mass-production-suited processing of special semi-finished fiber reinforced thermoplastic materials. The new process chain and modular concept allows the implementation of other technologies and special applications, e.g. sensor integration. The COW process is a combination of thermoplastic tape winding and automated thermoplastic tape laying technology.The technological aim is to produce structural components with variable closed cross sections having rotationally symmetric and asymmetric sections. In addition, the machine concept is specifically designed to realize flexible layer constructions. The experimental part geometry was determined and it is intended to carry out pilot studies in order to validate the functionality.The key challenge is the desired processing speed for mass production. Therefore, an exemplary cross-section contour has been derived and used for the realization of the demonstrative concept. In this special concept the number of discontinuous moved assembly units was reduced. Furthermore, the appropriate and effective drive system was dimensioned by using inverse kinematics.For the fundamental experiments unidirectional fiber reinforced thermoplastic tapes are used. These investigations imply the level of consolidation in critical areas. The achievable maximum processing speed is of prime importance. These results will be used for further optimizations and specifications.
Experimental and Numerical Analyses of the Lightweight Potential for Hybrid Thin-Walled Members
Authors: Denk Josef , Diel Sergej , Huber Otto
Published: July 2015

Within this study, the lightweight potential of thin-walled closed hat members, partially supported by hollow cores, consisting of glass foam granulate and a two component epoxy resin, is investigated. Nonlinear finite element analyses are applied to simulate the behavior under quasi-static three-point bending and to find out the lightweight potential. The simulations are validated by experiments on thin-walled side members of the chassis of a recreational vehicle with and without supporting cores. The results show a significant potential for weight reduction by using supporting cores. Related to the weight (Fmax/Fg), experiments have shown that the collapse load is 38 % larger in comparison to thin-walled members without supporting cores.
X-Ray Refraction Techniques for Fast, High-Resolution Microstructure Characterization and Non-Destructive Testing of Lightweight Composites
Authors: Müller Bernd R. , Léonard Fabien , Lange Axel , Kupsch Andreas , Bruno Giovanni
Published: July 2015

X-ray refraction is based on optical deflection of X-rays, similar to the well-known small angle X-ray scattering, but hundreds of times more intense, thus enabling shorter measurement time. We show that X-ray refraction techniques are suitable for the detection of pores, cracks, and in general defects. Indeed, the deflected X-ray intensity is directly proportional to the internal specific surface (i.e., surface per unit volume) of the objects. Although single defects cannot be imaged, the presence of populations of those defects can be detected even if the defects have sizes in the nanometer range.We present several applications of X-ray refraction techniques to composite materials:- To visualize macro and microcracks in Ti-SiC metal matrix composites (MMC);- To correlate fatigue damage (fibre de-bonding) of carbon fibre reinforced plastics (CFRP) to X-ray refraction intensity;- To quantify the impact damage by spatially resolved single fibre de-bonding fraction as a function of impact energy in CFRP laminates.An example of classic high-resolution computer tomography of an impact-damaged CFRP will also be presented, as a benchmark to the present state-of-the-art imaging capabilities. It will be shown that while (absorption) tomography can well visualize and quantify delamination, X-ray refraction techniques directly yield (spatially resolved) quantitative information about fibre de-bonding, inaccessible to absorption tomography.
Identification of Bearing Defects in Hybrid Thrust Ball Bearings by Vibration Analysis
Authors: Ziebell Arne , Schöppl Oskar , Haubner Roland , Konegger Thomas
Published: July 2015

Hybrid ball bearings, consisting of metallic washers in combination with ceramic bearing balls, feature a variety of significant advantages in comparison to standard steel bearings, including mechanical properties and reduced friction during operation. Key aspects for a successful operation are a prevention of defects of both balls and washers, as well as the knowledge of critical and optimal operation parameters. This relevant information can be obtained through test rig trials, where vibration analysis has found to be a versatile and efficient tool for the characterization of the operational status. In this contribution, hybrid thrust ball bearings with Si3N4 balls are investigated. After an introduction of defined damages in different parts of the bearing, test rig trials were conducted, and the vibration behavior during operation was compared to new, unused bearings. The characteristic vibrational frequencies, obtained through a variety of software-based filter and analysis algorithms, were correlated with materialographic investigations of failed bearings. The proposed method was shown to yield valuable information about damage morphologies and, subsequently, about the status of the bearing during operation.
Composite-Composite Joining with through the Thickness Reinforcements for Enhanced Damage Tolerance
Authors: Stelzer Steffen , Ucsnik Stephan , Pinter Gerald
Published: July 2015

A novel composite-composite joining technology based on metal pins oriented in through thickness direction of the composites is presented. A defined pin geometry, which is capable of establishing a through-thickness form-fit connection between composites and the metal reinforcement, is created on thin metal sheets in an automated pin production process. Based on numerical simulations of the fracture of unreinforced single lap shear (SLS) composite specimens, optimum locations for the pin reinforcement were found. Tests on reinforced SLS specimens proved that an enhanced damage tolerance can be achieved by the use of cold metal transfer welded pins (CMT pins) as through-the-thickness reinforcement of the joint area. This paper investigates the mechanisms responsible for the load transfer and failure of such through-the-thickness reinforced composite-composite joints during monotonic loading.
 Failure Analysis of High-Strength Fiber Ropes
Authors: Schmieder Annett , Heinze Thorsten , Michael Markus
Published: July 2015

Until the present days, in discontinuous conveyor systems, e.g. cranes and elevators, steel wire ropes and steel chains are the exclusively used tension members. Nevertheless, these tension members are exhibiting essential disadvantages, e.g. high dead weight, low bending flexure and high susceptibility to corrosion. For fulfilling the steadily increasing requirements especially in running ropes, alternative tension members have to be developed and approved concerning their series-production readiness by utilization of new technologies and new materials. High-strength fiber ropes are demonstrating promising mechanical properties, regarding tensile strength, vibration behavior and bending fatigue life. Still, the application of such high-strength fiber ropes is limited, due to unavailable systematic investigations and insufficient guidelines for dimensioning and processes for determination of discard criteria. With the help of new technologies and procedures, e.g. multi-zone cyclic bend-over-sheave (CBOS) test machinery and computer-assisted tomography, new knowledge concerning the wear behavior of fiber ropes is to be gained and new discard criteria are to be developed.
Micro Test Specimens for Compound Engineering with Minimum Material Needs
Authors: Doerffel Christoph , Jüttner Gábor , Dietze Roland
Published: July 2015

The use of micro test specimens is a good way to characterize micro injection molding processes and the resulting material properties. The material properties of microparts may differ from standard injection molding parts, due to an overrepresentation of the surface layers with high fiber orientation and divergent morphology. In order to characterize the distribution and agglomeration of fibers and particles for the manufacturing of micro injection molding parts of functionalized polymer compounds, it is essential to manufacture the test specimens and the part using the same process. The distribution and size of these particles e.g. Carbon-Nano-Tubes (CNT) or piezo ceramic particles is dependent on the polymer plastication process during injection molding. Therefore the use of micro test specimens is a requirement for precise material selection and engineering.Due to the minimum material needs, micro test specimens are also useful for the comparison of the material properties of new polymers and compounds, which were produced in amounts of 20 g to 100 g. Another application is the testing of highly elastic and ductile materials with strains over 100%. By using micro test specimens it is possible to test high strains with low elongations in a short time.A new innovative micro test specimen has been developed at the Technische Universität Chemnitz in cooperation with the Kunststoff-Zentrum in Leipzig, that is especially designed for the testing and dimensioning of plastic microparts with weights less than 0.1 g. The main feature of the new specimen and testing process is the combined positive and force-fitted locking, which enables a precise positioning of the micro specimen and an even application of the clamping force. In order to achieve reproducible clamping, testing and handling of the sample, the clamping and testing process are spatially separated. The shape of the test specimen enables a parameter optimization for the micro injection molding process.
Stiffness and Strength Based Models for the Fatigue-Life Prediction of Continuously Fiber Reinforced Composites
Authors: Brunbauer Julia , Pinter Gerald
Published: July 2015

The fatigue-life prediction of continuously fiber reinforced carbon/epoxy composites is of importance in order to support or partially replace the extensive amount of mechanical testing necessary for safe structural applications. However, the factors influencing the damage behaviour and the degradation of mechanical properties under real applications are numerous. To be able to predict fatigue-life of composites in an application-oriented way in the future, two novel approaches towards fatigue-life predictions have been studied by the authors in the last years. In this work, the promising approaches based on fatigue stiffness and fatigue strength and their potentials are introduced briefly.
New Approaches in Nondestructive Characterisation of Defects in Metal - CFRP Hybrids
Authors: Schwarz Michael , Summa Jannik , Quirin Steven , Herrmann Hans Georg
Published: July 2015

In this paper a new metal - CFRP (Carbon Fibre Reinforced Polymer) hybrid concept is introduced. The new aspect of this hybrid is a thermoplastic polymer component inserted between the metal and CFRP structure to reduce the gap of the different stiffnesses in each structure. To characterise defects in the hybrid, both destructive and nondestructive testing (NDT) approaches are shown. Especially the interface between the metal structure and the thermoplastic polymer component as well as the interface between the thermoplastic polymer component and the CFRP structure, where is most-likely the starting point for cracks, are investigated. An additional probability of detection (POD) approach enables to connect fracture mechanics with crack values of NDT. In consequence it is possible to achieve the assessment of defect-caused damage progress, so called effects of defects.
3D-FIB Characterization of Wear in WC-Co Coated Composites
Authors: García José , Carvalho Miranda Thais , Pinto Haroldo Cavalcanti , Soldera Flavio , Mücklich Frank
Published: July 2015

In this work 3D visualization of wear in milling inserts has been investigated by Focused Ion Beam tomography. It has been observed that the morphology of the cracks differs in the z-axis direction, allowing particular characteristics of the microstructure and wear evolution to be visible. Two types of cracks develop: principal and lateral cracks. The formation of lateral cracks is strongly influenced by the degradation of the binder phase in the regions surrounding the principal crack. The lateral cracks and the deflection of the main cracks present a particular semi-elliptical geometry, which correlates with the stress field originated during the input of a cycling load in a fatigue condition.
What is the correct staging and treatment strategy for locally advanced prostate cancer extending to the bladder?
Authors: Yüksel Özgür Haki , Verit Ayhan , Ürkmez Ahmet
Published: July 2015

In locally advanced prostate cancer with bladder invasion, frequently encountered problems such as bleeding, urinary retention, hydronephrosis, and pain create distress for the patients. Therefore patients’ quality of life is disrupted and duration of hospitalization is prolonged. Relevant literature about accurate staging and treatment of locally advanced prostate cancer with bladder invasion was investigated. Locally advanced prostate cancer can present as a large-volume aggressive tumor extending beyond boundaries of prostate gland, and involving neighboring structures which can be involved as recurrence(s) following initial local therapy. Survival times of these patients can range between 5 and 8 years. Their common characteristics are adverse and severe local symptoms unfavorably affecting quality of life Control of local symptoms and their effective palliation are independent clinical targets influencing survival outcomes of these patients. The treatment outcomes of locally advanced prostate cancer into the bladder are currently debatable. Although in the current TNM classification, it is defined in T4a, we think that this may be categorized as a subgroup of T3 and thus encourage surgeons for the indication of radical surgeries (radical prostatectomy, radical cystoprostatectomy) in selected patient populations after discussing issues concerning consequences of the treatment alternatives, and expectations with the patients. Cystoprostatectomy followed by immediate androgen deprivation therapy may be a feasible option for selected patients with previously untreated prostate cancer involving the bladder neck because of excellent local control and long term survival.
Different presentation types of primary Brucella epididimo-orchitis
Authors: Aydemir Huseyin , Budak Gokcen , Budak Salih , Celik Orcun , Yalbuzdag Okan , Keles Ibrahim
Published: July 2015

Brucellosis is a zoonotic disease that involved genitourinary system in 2-20% and most commonly cause single sided epididymo-orchitis. In our country Brucella is an endemic disease and causes serious and different diagnosis of acute scrotum and epididy-moorchitis. In this paper six cases of epididymo-orchitis cases which were resistant to classical treatment were discussed according to clinical and laboratory findings. We describe different types of presentation of Brucella epididymoorchitis with diagnosis and treatment modalities.
Giant renal artery aneurysm: A case report
Authors: Cindolo Luca , Ingrosso Manuela , De Francesco Piergustavo , Castellan Pietro , Berardinelli Francesco , Fiore Franco , Schips Luigi
Published: July 2015

A case of a 12 cm giant renal artery aneurysm (RAA) in an 59-year-old woman is reported. The patient was referred to our hospital for flank pain and spot hematuria. Ultrasonography (US) revealed some wide lacunar areas in her right kidney and a thin cortex. Three-dimensional computed tomography (3D-CT) revealed a giant right renal arteriovenous malformation (AVM). AngioCT scan showed a pervious right renal artery. The cavities of the right kidney were dilated and the parenchyma was markedly reduced. Two months later the patient underwent an open resection of the aneurysm and a right nephrectomy. She had an uneventful recovery and a healthy status (last follow-up: 9 month). In this particular case, a safe approach is the transabdominal approach since the aneurysm was very large, friable, and located on the right side. This report confirms the opportunity of a planned nephrectomy once there is adequate renal reserve in the opposite kidney using a midline approach.
Extraintestinal gastrointestinal stromal tumor of undetermined origin: Is the mass resection a wrong approach? A case report and review of the literature
Authors: Yüksel Özgür Haki , Akan Serkan , Yildirim Çaglar , Ürkmez Ahmet , Verit Ayhan
Published: July 2015

Gastrointestinal stromal tumor (GIST) was first defined by Mazur et al. in 1983. GIST is evaluated among tumoral lesions that can be acquired or congenital. Those not associated with gastrointestinal system are termed as extragastrointestinal stromal tumor (EGIST). EGISTs can develop on intraperitoneal spaces as omentum, mesenterium and gallbladder and they can occur on retroperitoneum, extraperitoneal (prostate) and intrapelvic organs. Herein, we present a case with EGIST in a 65-year-old male patient located in intrapelvic and retroprostatic area which had no connection with gastrointestinal system as assessed by radiological methods and we discuss its treatment. We reviewed the literature and observed that ours is the first case report on a patient in which the mass was only extirpated rather than performing radical surgery. He is still at the 2. year of his follow-up period without any disease recurrence.
A new entropy model for RNA: part IV, The Minimum Free Energy (mFE) and the thermodynamically most-probable folding pathway (TMPFP)
Authors: Dawson Wayne , Kawai Gota
Published: July 2015

Here we discuss four important questions (1) how can we be sure that the thermodynamically most-probable folding-pathway yields the minimum free energy for secondary structure using the dynamic programming algorithm (DPA) approach, (2) what are its limitations, (3) how can we extend the DPA to find the minimum free energy with pseudoknots, and finally (4) what limitations can we expect to find in a DPA approach for pseudoknots. It is our supposition that some structures cannot be fit uniquely by the DPA, but may exist in real biology situations when disordered regions in the biomolecule are necessary. These regions would be identifiable by using suboptimal structure analysis. This grants us some qualitative tools to identify truly random RNA sequences, because such are likely to have greater degeneracy in their thermodynamically most-probable folding-pathway.
‘De God van de vrede’ in het Nieuwe Testament
Authors: Van Houwelingen Rob
Published: July 2015

‘The God of peace’ in the New Testament. Why does the New Testament use the expression ‘the God of peace’ and what is the meaning of this phrase? In the Old Testament, the God of Israel is often connected with peace, but he is never called ‘the God of peace’. Not until the Hellenistic period is this expression sporadically found in Judaism (once in the Testaments of the Twelve Patriarchs and once in Philo). As for the biblical Umwelt, the gods of the ancient Near East were not very peace-loving, and in the perception of Greco-Roman culture the god of war, Arès/Mars, as one of the twelve Olympians was much more prominent than Eirènè/Pax. However, the expression ‘the God of peace’ is found several times in the Corpus Paulinum and once in the letter to the Hebrews. This article investigates all New Testament texts that have this formula, suggesting that the apostle Paul could be responsible for the wording. In conclusion, Paul states that the God of Israel desires to establish a definitive peace in his creation through the crucifixion and resurrection of Jesus Christ and by finally defeating all powers of evil. This apostolic message further indicates that Christians are supposed to be bearers of peace, promoting a peaceful atmosphere in their environment and in the world.
The renouncement of possessions according to Matthew 19:16–30
Authors: Nel Marius J.
Published: July 2015

This article focuses on the renouncement of possessions in Matthew 19:16–30 in terms of three related questions. Firstly, it asks if the renouncement of possessions was, according to Matthew, a general requirement for following Jesus or for membership of the Matthean community. Secondly, it investigates if this requirement did not lead to a distinction within the Matthean community between those who adhered to a stricter ethic of Jesus and those who did not (i.e. between religious virtuosi and non-virtuosi)? Finally it enquiries as to what would have compelled followers of Jesus or members of the latter Matthean community to comply with it? The article concludes that at least some of the followers of Jesus are depicted by Matthew as having renounced their possessions as a sign of their unconditional commitment to him. The Matthean community could thus have been a two-tiered community comprised of virtuosi who had renounced all their possessions, as was demanded of the rich young man, and those who had not. The renouncement of their possessions could have been part of their initiation into the Matthean community and have been motivated by the promise of an incomparable eschatological reward. It further appears that while not all who were considered to be followers of Jesus had surrendered their possessions, all would share in God’s eschatological reward if they provided hospitality to those who did.
’n Studie van die Bybel as God se mosaïekwerk
Authors: Snyman A.H.
Published: July 2015

No abstract available.
The joy of seeing Christ: A thematic study of joy in the Gospel of John
Authors: Jordaan Gert J.C.
Published: July 2015

An investigation of the recurring references to joy in the fourth Gospel brings to light that joy is developed in the Gospel as a distinct theme. This theme is developed in typical Johannine style within a spiral-like pattern, with its climax in the joy of seeing Jesus as the risen Lord. Furthermore, starting with Abraham in the Old Testament and climaxing in Jesus’ appearance after his resurrection, joy in the fourth Gospel is evolved within the broad theological framework of God’s covenant and his kingdom.Blydskap om Christus te sien: ’n Tematiese studie van blydskap in die Johannes-Evangelie.’n Ondersoek na die herhaalde verwysings na blydskap in die vierde Evangelie bring aan die lig dat blydskap in hierdie Evangelie tot ’n selfstandige tema uitgebou word. Die tema is volgens die tipiese spiraalpatroon van Johannes se gedagtegang gerangskik, met sy klimaks in die blydskap daarvan om Jesus as die opgestane Here te sien. Binne hierdie patroon word die blydskaptema vanaf Abraham in die Ou Testament tot by Jesus se verskyning ná sy opstanding openbaringshistories ontvou en binne die breë raamwerk van die verbond en die koninkryk van God ontwikkel.
Comparing grazing and resting electivity of beef cattle for BC bunchgrass communities using GPS collars
Authors: Thompson D. J. , Wheatley B. J. , Church J. S. , Newman R. , Walker J.
Published: July 2015

Thompson, D., Wheatley, B. J., Church, J. S., Newman, R. and Walker, J. 2015. Comparing grazing and resting electivity of beef cattle for BC bunchgrass communities using GPS collars. Can. J. Anim. Sci. 95: 499–507. Grasslands in the interior of British Columbia often contain a mosaic of plant communities that provide variable habitat for free-ranging cattle. Global positioning system (GPS) collars have been used to study natural habitat use by cattle on a coarse scale (such as riparian, grassland and forested habitats), but not on a fine scale (such as choice among grassland plant communities). Cows equipped with GPS collars were tracked during the spring grazing period for 4 yr. Six grassland pastures were used as replicates. The activity (grazing or resting) of cattle at GPS locations was classified using a distance travelled algorithm. A detailed plant community map of five plant community types was constructed, and cow relative use within the plant communities was determined. Electivity, which scales for differences in community area, was used to compare the use of plant communities. While grazing, electivity for the Kentucky bluegrass community (mean +0.3) was greater than for the bluebunch wheatgrass community (mean −0.2). While resting, these differences were more pronounced. GPS collars can be used to estimate fine-scale choices among grassland communities.
N2 fixation ability of different dry bean genotypes
Authors: Farid Mehdi , Navabi Alireza
Published: July 2015

Farid, M. and Navabi, A. 2015. N2 fixation ability of different dry bean genotypes. Can. J. Plant Sci. 95: 1243–1257. Common bean (Phaseolous vulgaris L.) is generally known as a weak N2 fixer compared with other legumes. The availability of genetic variation for N2 fixation potential of common bean supports the idea that symbiotic nitrogen fixation (SNF) in common bean can be improved through breeding. To assess the potential N2 fixation of selected common bean genotypes, 12 bean varieties including three Andean and nine Middle American were screened for SNF ability and related traits in controlled environments and field trials in Ontario, Canada. A non-nodulating mutant, R99, was used as the reference plant to estimate nitrogen derived from the atmosphere (Ndfa) through the natural 15N abundance method. Significant variation was found among the bean genotypes for Ndfa and its related traits. Environmental and genotype by environmental effects significantly influenced Ndfa and its related traits. The three Andean bean genotypes were superior to Middle American genotypes for nodulation ability, while the Middle American genotypes were generally stronger nitrogen fixers in optimum soil moisture conditions. In general, nitrogen fixation was found to be significantly associated with seed yield and carbon isotope discrimination, an indicator of water use efficiency.
How Applicable is the Idea of Deep Ecology in the African Context?
Authors: Mangena F
Published: July 2015

In this paper, I outlined and discussed the idea of deep ecology as defended by Arne Næss (1973) as well as Bill Devall and George Sessions (1985). I especially looked at how deep ecology has responded to the dominant view in ecological ethics, especially its attendant theory – anthropocentrism or homo-centrism or simply the reason-based account – which I outlined and explained in the first section of this paper. In the final analysis, I looked at the feasibility (or lack thereof) of applying deep ecology in Sub-Saharan African ecological contexts focusing particularly on the Shona ecological matrix of Zimbabwe. My intention was to answer the question: How applicable is the idea of deep ecology in the African context? Having reviewed Zimbabwean literature, I came to the conclusion that the Shona enviro nment had a different form of deep ecology that was not only anchored on spirituality but that it also interpreted cosmology and ecology from a communitarian viewpoint.Keywords: Deep ecology, the dominant view, anthropocentrism, spirituality, the human world, the non-human world
African Philosophy and the Search for an African Philosopher: The Demise of a Conflictual Discourse
Authors: Oyedola DA
Published: July 2015

There are contending reasons why the rationale, qualification and justification for becoming an African philosopher are still facing the problem of ontology. One reason, as Didier Kaphagawani posits, is premised on the challenges by anthropology and colonialism (1986, 86). Given Oruka, Makinde, Oladipo, Oke, and Hallen’s perception of these challenges, they concede that these challenges gave birth to the postcolonial search for a distinct African identity. On the one hand, D. A. Masolo’s submission that because “Africa cannot be re -subjectivised; hence, an identity which is peculiarly African is impossible” (1997, 283-285) downplays the concession of Kaphagawani, Oruka, et al. Moreover, there tend s to be agreement among certain philosophers who have devoted their time promoting Africana philosophy and culture-oriented discourse in Africa like Outlaw, Cabral, Fanon, Makinde, Oladipo, Oke, Hallen, Horton, etc., that “the  Western discourse on Africa and the response to such discourse” (MASOLO 1994, 1) led many African philosophers like Nazombe, Okpewho, Tempels, Nkrumah, Nyerere, Senghor, Cesaire, Awolowo, Mandela, etc., to react using socio-political and academic means to establish a distinct African philosophical paradigm which craves for the re-subjectivisation of Africa. By implication, the response to the Western discourse on Africa, as Outlaw, et al, opine, lend credence to (a) the rationale for the qualification and justification to be an African philosopher; (b) the existence of African philosophy, and (c) the modality of doing philosophy in Africa. Nevertheless, the problem with Outlaw, et al, o n one hand, and D. A. Masolo, on the other, is the failure to recognize that any philosopher need not be of African descent or blood before he can make a meaningful contribution to address the problems facing the development of Africa in all spheres of lif e. This is possible in as much as there is an adequate understanding of the subject under discussion or what it means to do African philosophy. It is this failure or weakness that we shall explore in this essay.Keywords: Africa, African Paradigm, African Philosophy, African Philosopher,Identity
Evapotranspiración del cultivo de arroz bajo riego por aspersión
Authors: Martínez Cob Antonio , Pérez Coveta Olga
Published: July 2015

La evapotranspiración del arroz (ETarroz) bajo riego por aspersión se determinó mediante el método de la renovación de la superficie aplicado a distintas alturas de medida en el valle medio del Ebro (Zaragoza) en 2001 y 2003. Los valores semihorarios de flujo de calor latente (LE) determinados en las diferentes alturas fueron significativamente diferentes entre sí (a = 0.95). Estas diferencias no fueron sistemáticas; a escala diaria, se produjeron con una incertidumbre similar a la de otros métodos micrometeorológicos (alrededor del 10 %). Los valores diarios de ETarroz fueron relativamente altos debido al riego frecuente que necesita este cultivo. En 2003, más caluroso, fueron algo mayores que en 2001, con valores estacionales de 799 mm en 2001 y 812 mm en 2003. La fase inicial del cultivo fue muy larga (50-60 días), mientras que las fases de crecimiento, máximo desarrollo y final fueron de unos 20, 50 y 20-30 días, respectivamente. Los valores de coeficiente de cultivo (Kc) en la fase inicial fueron aproximadamente de 0.90, con oscilaciones importantes causadas por los frecuentes precipitaciones y riegos. Durante la fase de máximo desarrollo, los valores de Kc fluctuaron entre 1.10 y 1.15; durante la fase final, los valores se aproximaron a 0.90. Aún deben resolverse diversos problemas agronómicos para este cultivo y sistema de riego. Por ello, estos valores de ETarroz y Kc deben considerarse con precaución. Son convenientes campañas posteriores de medidas para confirmar o mejorar estos resultados.
Selección de bombas en redes de riego a presión
Authors: Planells P. , Carrión Pedro , Ortega José Fernando , Moreno M. A. , Tarjuelo Martín-Benito José María
Published: July 2015

Dada la aplicación cada vez más extendida de las redes colectivas de riego a la demanda, se presenta una herramienta de utilización general como ayuda a la toma de decisiones para el dimensionamiento y regulación de las estaciones de bombeo. Se trata de una aportación novedosa que trata de dar soluciones a un problema todavía sin resolver sobre el mejor equilibrio entre coste total (inversión y operación) y garantía de suministro. Para la selección del tipo y número de bombas de velocidad fija y variable se presenta un procedimiento fácil de implementar (Excel, Visual Basic), que proporciona la solución de menor coste total utilizando equipos existentes en el mercado. Los resultados indican que, es muy importante seleccionar correctamente el tipo de bomba que mejor seadapta a las necesidades de la demanda de la red, y que la solución de mínimo coste total es con una o dos bombas de velocidad variable y el resto de velocidad fija.