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In the last decade, IPv6 over Low power Wireless Personal Area Networks, also known as 6LoWPAN, has well evolved as a primary contender for short range wireless communication and holds the promise of an Internet of Things, which is completely based on the Internet Protocol. In the meantime, various 6LoWPAN implementations are available, be it open source or commercial. One of these implementations, which was developed by the authors' team, was tested on an Automated Physical Testbed for Wireless Systems at the Laboratory Embedded Systems and Communication Electronics of Offenburg University of Applied Sciences, which allows the flexible setup and full control of arbitrary topologies. It also supports time-varying topologies and thus helps to measure performance of the RPL implementation. The results of the measurements show a very good stability and short-term and long-term performance also under dynamic conditions. In addition, it can be proven that the performance predictions from other papers are consistent with real-life implementations.
A benchmark analysis of Long Range (LoRaTM) Communication at 2.45 Ghz for safety applications
(2014)
Air traffic is by nature crossing borders and organizations. The supporting infrastructure represents a federative distributed system of independent Air Traffic Service Units, typically each with its own proprietary system architecture. Interaction between the centers is taking place over dedicated protocols, often organized as a mesh of 1:1 bilateral data exchanges.
This contribution gives an overview of the ongoing efforts to standardize this data exchange. At the core is a data-centric view, using a shared virtual Flight Object as the IT counterpart of a real flight. It permits a uniform way to access and update a flight’s static and dynamic attributes. A middleware is presented that implements this abstraction and maps it onto a physical level, employing DDS (Data Distribution Service) technology for the 1:N dissemination of flight data.
Signal detection and bandwidth estimation, also known as channel segmentation or information channel estimation, is a perpetual topic in communication systems. In the field of radio monitoring this issue is extremely challenging, since unforeseeable effects like fading occur accidentally. In addition, most radio monitoring devices normally scan a wide frequency range of several hundred MHz and have to detect a multitude of different signals, varying in signal power, bandwidth and spectral shape. Since narrowband sensing techniques cannot be directly applied, most radio monitoring devices use Nyquist wideband sensing to discover the huge frequency range. In practice, sensing is normally conducted by an FFT sweep spectrum analyzer that delivers the power spectral density (PSD) values to the radio monitoring system. The channel segmentation is the initial step of a comprehensive signal analysis in a radio monitoring system based on the PSD values. In this paper, a novel approach for channel segmentation is presented that is based on a quantization and a histogram evaluation of the measured PSD. It will be shown that only the combination of both evaluations will lead to an successful automatic channel segmentation. The performance of the proposed algorithm is shown in a real radio monitoring szenario.
A new RFID/NFC (ISO 15693 standard) based inductively powered passive SoC (System on chip) for biomedical applications is presented here. The proposed SOC consists of an integrated 32 bit microcontroller, RFID/NFC frontend, sensor interface circuit, analog to digital converter and some peripherals such as timer, SPI interface and memory devices. An energy harvesting unit supplies the power required for the entire system for complete passive operation. The complete chip is realized on CMOS 0.18 μm technology with a chip area of 1.5 mm × 3.0 mm.
Various rapid prototyping methods have been available for the production of physical architectural models for a few years. This paper highlights in particular the advantages of 3D printing and Fused Layer Modeling for the production of detailed architectural models. In addition, the current challenges for the creation and transfer of CAAD-data are explained. Furthermore, new methods are being developed in order to improve both the technical and economic boundary conditions for the application of 3DP und FLM. This makes the production of models with very detailed interior rooms possible. The internal details are made visible by dividing the complex overall model into individual models connected by means of an innovative plug-in system. In addition, three case studies are shown in which the developed methods are applied in order to implement detailed architectural models. Finally manufacturing time and costs of the architectural models in the three case studies are compared.
Recently a P-matrix and COM formalism was presented, which predicts third order intermodulation (IMD3) and triple beat with good accuracy and needs only a single nonlinearity constant. This formalism describes frequency dependence correctly. In this work the dependence of this nonlinearity constant on metalization ratio is investigated for aluminum metalization on LiTaO 3 (YXl)/42°. By comparison to test devices the nonlinearity constant is shown to be largely independent of metalization ratio. The nonlinear effect, however, strongly depends on metalization ratio, which is well described by the model. The linearity of a duplexer is optimized by reduction of metalization ratio and redesign of Tx branch topology.
This paper investigates the maximum torque capability and torque ripple reduction using the asymmetric stator teeth for interior permanence magnet (IPM) synchronous machines. Traditional electric machines have the identical width for all stator teeth and the winding function is fixed. Using different widths for different stator teeth changes the winding function, therefore, the torque ripple components. The mathematical modeling of interior permanent magnet (IPM) synchronous machine torque ripple and finite element analysis simulation results for the characteristic properties of electric machines are presented. Compared with a similar rating IPM machine, certain combinations of the teeth widths can reduce the torque ripple by 80% with less than 4% average torque decline.
Transcatheter aortiv valve implantation is a new safe strategy treatment for patients with symptomatic severe aortic stenosis and high operative risk. The aim of the study was to compare the pre-and post- muiscatheter aortiv valve implantation procedures to determine the atrioventricuktr conduction time as a potential predictor of permanent pacemaker therapy requirement after transcatheter aortiv valve implantation. The transcatheter aortiv valve implantation patients were divided into groups without pacemaker and with dual or single chamber pacemEtker with diffent atrioventrieular conduction time disturbance before and after transcatheter aortiv valve implantation. In heart failure, patients without permanent pacemaker therapy after transcatheter aortiv valve implantation, atrioventricular conduction time was prolonged after transcatheter aortiv valve implantation. In patients with permanent dual chamber pacemaker therapy after transcatheter aortiv valve implantation, atrioventricular conduction time was normalised with dual chaniber atrioventrieuku pacing mode. Atrioventricular conduction time may be a useful parameter to evaluate the risk of post-procedural atrioventricular conduction block and permanent pacemaker therapy in transcatheter north, valve implantation patients.
Automated RF Emulator for a Highly Scalable IEEE802.11p Communication and Localization Subsystem
(2014)
The IEEE802.11p standard describes a protocol for car-to-X and mainly for car-to-car-communication. In the research project Ko-TAG, which is part of the research initiative Ko-FAS, cooperative sensor technology is developed for the support of highly autonomous driving. The Ko-TAG subsystem improves the real-time characteristics of IEEE802.11p needed for precise time of flight real-time localization while still fitting into the regulatory schemes. A secondary radar principle based on communication signals enables localization of objects with simultaneous data transmission. The Ko-TAG subsystem mainly concentrates on the support of traffic safety applications in intra-urban scenarios. This paper details on the development of a fully automated RF emulator used to test the Ko-TAG subsystem.
The RF emulator includes the physical networking nodes, but models the RF environment using RF-waveguides. The RF emulator allows the controlling of path loss and connectivity between any of the nodes with the help of RF attenuators and programmable RF switches, while it is shielded against its surrounding RF environment in the lab. Therefore it is an inexpensive alternative to an RF absorber chamber, which often is not available or exceeds the project’s budget.
Details about the system definition can be found in earlier papers. Test results are shown in the last part of the paper.
Several cloud schedulers have been proposed in the literature with different optimization goals such as reducing power consumption, reducing the overall operational costs or decreasing response times. A less common goal is to enhance the system security by applying specific scheduling decisions. The security risk of covert channels is known for quite some time, but is now back in the focus of research because of the multitenant nature of cloud computing and the co-residency of several per-tenant virtual machines on the same physical machine. Especially several cache covert channels have been identified that aim to bypass a cloud infrastructure's sandboxing mechanism. For instance, cache covert channels like the one proposed by Xu et. al. use the idealistic scenario with two alternately running colluding processes in different VMs accessing the cache to transfer bits by measuring cache access time. Therefore, in this paper we present a cascaded cloud scheduler coined C 3 -Sched aiming at mitigating the threat of a leakage of customers data via cache covert channels by preventing processes to access cache lines alternately. At the same time we aim at maintaining the cloud performance and minimizing the global scheduling overhead.
This book constitutes the proceedings of the 6th International Workshop on Communication Technologies for Vehicles, Nets4Cars/Nets4Trains/Nets4Aircraft 2014, held in Offenburg, Germany in May 2014. The 10 papers presented in this volume were carefully reviewed and selected from 15 submissions. The book also contains 4 invited papers. The contributions are organized in topical sections named: automotive issues, car-to-car, aviation issues, in-car, and infrastructures.
Energy management in distribution grids is one of the key challenges that needs to be overcome to increase the share of fluctuating renewable energies. Current control systems for energy management mainly demonstrate centralized- or decentralized-hierarchical control structures. Very few systems manifest a fully decentralized multiagent-based control structure. Multiagent-based control systems promise to be an advantageous approach for the future distributed energy supply system because no central control entity is necessary, which eases parameterization in case of grid topology changes, and the agents are more stable against failures and changes of control topologies. Research is necessary to prove these benefits. In this study, we introduce a design of a multiagent-based voltage control system for low-voltage grids. In detail we introduce cooperative decision-making processes and software solutions that allow the agents to perceive and control their environment, the agent-discovery and localization in different types of communication networks, agent-to-agent communication, and the integration of the multiagent system in existing grid-control infrastructures. Furthermore, the study proposes how different existing technologies can be combined into an applicable multiagent-based voltage control system: the Java/OSGi-based OpenMUC framework allows a generic field–device interaction; peer-to-peer discovery and session establishment functionalities are combined with the agent communication defined by the Foundation for Intelligent Physical Agents (FIPA). The ripple control-signal technology is applied as a fallback communication between the agent and a central grid-control center.
Efficient, secure and reliable communication is a major precondition for powerful applications in smart metering and smart grid. This especially holds true for the so called primary communication in the Local Metrological Network (LMN) between meter and data collector, as the LMN comes with the most stringent requirements with regard to cost, range, as well as bandwidth and energy efficiency. Until today, LMN field tests are operated all over the world. In these installations, however, energy autarkic systems play a marginal role. This contribution describes the results of the framework 7 (FP 7) WiMBex project (“Remote wireless water meter reading solution based on the EN 13757 standard, providing high autonomy, interoperability and range”). In this project an energy autarkic water meter was developed and tested, which follows the specification of the Wireless M-Bus protocol (EN 13757). The complete system development covers the PCB with the RF transceiver and the microcontroller, the energy converter and storage, and the software with the protocol. This contribution especially concentrates on the design, the development and the verification of the routing protocol. The routing protocol is based on the Q mode of EN13757-5 (Wireless M-Bus) and was extended by an additional energy state related parameter. This extension is orthogonal to the existing protocol and considers both the charge level and the charge characteristics (rate of occurrences, intensity). The software was implemented in NesC under the operating system TinyOS. The system was verified in an automated test bed and in field tests in UK and Ireland.
The invention relates to a device for metalising substrates. In particular, the invention relates to the field of contact elements used to electroplate solar cells within the context of a wet-chemical continuous treatment system. A wet-chemical treatment system according to the invention, for electrochemically coating flat substrates (1) with coating material, has a tank for accommodating an electrolyte, transporting means, by means of which the flat substrates (1) can be transported through the electrolyte horizontally, and at least one contact element (2), which comprises a shaft (4) having an axis of rotation (5) and a cylindrical circumferential surface suitable for rolling on the substrate (1), wherein the circumferential surface comprises at least one electrically insulating segment (3B) and at least one electrically conductive segment (3A), which can be connected to a current source (6) in such a way that the polarity can be reversed, wherein the axis of rotation (5) of the contact element (2) is positioned above the surface of the electrolyte, and wherein the contact element (2) is designed as a consumable electrode.
Introduction: Despite lots of developments in the last years, radiofrequency ablation of rhythm diseases is a safe but still complex procedure that requires special experience and expertise of the physicians and biomedical engineers. Thus, there is a need of special trainings to become familiar with the different equipment and to explain several effects that can be observed during clinical routine.
Methods: The Offenburg University of Applied Sciences offers a biomedical engineering study path specialized in the fields of cardiology, electrophysiology and cardiac electronic implants. It`s Peter Osypka Institute for Pacing and Ablation provides teaching following the slogan “Learning by watching, touching and adjusting”. It conducts lots of trainings for students as well as young physicians interested in electrophysiology and radiofrequency ablation.
Results: In-vitro trainings will be provided using the Osypka HAT 200 and HAT300s, Stockert EPshuttle and SmartAblate system as well as the Boston EPT-1000XP and Maestro 3000 and the Radionics RFG-3E cardiac radio frequency ablation generators. All of them require different handling as well as special accessories like catheter connection cables or boxes and back plates. The participants will be trained in the setup of temperature, power and cut-off impedance dependent on different ablation catheters. Furthermore troubleshooting in hard- and software is part of the program. Performing procedures in pork or animal protein and using physiological saline solution to simulate the blood flow, they can study the influence of contact force and impedance on lesion geometry etc. and to avoid adverse effects like “plops”. Lots of catheter types are available: 4mm tip, 8mm standard and gold tip, open and closed irrigated tip ablation catheters of different companies. The experiments will be completed by measuring the lesion size dependent on the used catheter type and ablation settings.
Conclusion: In-vitro training in radiofrequency ablation is a challenge for biomedical engineering students and young physicians.
Active safety systems for advanced driver assistance systems act within a complex, dynamic traffic environment featuring various sensor systems which detect the vehicles’ surroundings and interior. This paper describes the recent progress towards a performance evaluation of car-to-car communication (C2C) for active safety systems - in particular for crash constellation prediction. The methodology introduced in this work is designed to evaluate the impact of different sensors on the accuracy of a crash constellation prediction algorithm. The benefit of C2C communication (viewed as a virtual sensor) within a sensor data fusion architecture for pre-crash collision prediction is explored. Therefore, a simulation environment for accident scenarios analysis reproducing real-world sensor behaviour, is designed and implemented. Performance evaluation results show that C2C increases confidence in the estimated position of the oncoming vehicle. With C2C enhancement the given accuracy in time-to-collision (TTC) estimation is achievable about 110 ms earlier for moderate velocities at TTC range of [0.5s..0.2s]. The uncertainty in the vehicle position prediction at the time of collision can be reduced about half by integrating C2C communication into the sensor data fusion.
This paper presents the competence-, business- and research-orientated education approach Fit4PracSis (= Fit for Practice and Sciences). Fit4PracSis is designed for freshman students in interdisciplinary engineering degree programs. It is an education concept, which is establishing a relationship to the future profession and scientific work during the introductory study phase. The freshman students will be early trained in important skills, which are necessary for the successful achievement of the final degree and the future business and research activities.
Meeting the requirements of smart grids local, decentralized subnets will offer additional potentials to stabilize and compensate the utility grid mainly on the low voltage level. In a quite complex configuration these decentralized energy systems are combined power, heat and cooling power distributions. According to the regional and local availability of renewable energy sources advanced energy management concepts should consider climatic conditions as well as the state of the interacting utility grid and consumption profiles. The approach uses demonstrational setups to develop a forecast based energy management for trigeneration subnets by taking into account the running conditions of local electrical and thermal energy conversion units. This should lead to the best coverage of the demand and supporting/stabilizing the utility grid at the same time. For the first of three demonstrational projects the priorities of the subnet are given with the maximization of the CHP operation to substitute a major part of the heating and cooling power delivered by electric heaters or compression chillers.
A former remote area power supply was converted to a smart cogeneration subnet with combined heat and power to develop and validate a forecast based energy management at the University of Applied Sciences in Offenburg/Germany. Locally processed weather forecasts and forecasted demand profiles are integrated to allow a precise reaction to changes of fluctuating power sources, changes in scheduled demand profiles and to improve the energy efficiency of the supply. The management of the electrical and thermal storages is influenced by the forecasted energy contributions and the forecasted demand. Further approaches should improve the accuracy of forecasting algorithms and integrate parameter models gained of a detailed monitoring to realize predictive controllers.
Formal Description of Inductive Air Interfaces Using Thévenin's Theorem and Numerical Analysis
(2014)
With the development of new integrated circuits to interface radio frequency identification protocols, inductive air interfaces have become more and more important. Near field communication is not only able to communicate, but also possible to transfer power wirelessly and to build up passive devices for logistical and medical applications. In this way, the power management on the transponder becomes more and more relevant. A designer has to optimize power consumption as well as energy harvesting from the magnetic field. This paper discusses a model with simple equations to improve transponder antenna matching. Furthermore, a new numerical analysis technique is presented to calculate the coupling factors, inductions, and magnetic fields of multiantenna systems.
Although short range wireless communication explicitly targets local and very regional applications, range continues to be an extremely important issue. The range directly depends on the so called link budget, which can be increased by the choice of modulation and coding schemes. Especially, the recent transceiver generation comes with extensive and flexible support for Software Defined Radio (SDR). The SX127x family from Semtech Corp. is a member of this device class and promises significant benefits for range, robust performance, and battery lifetime compared to competing technologies. This contribution gives a short overview into the technologies to support Long Range (LoRa ™), describes the outdoor setup at the Laboratory Embedded Systems and Communication Electronics of Offenburg University of Applied Sciences, shows detailed measurement results and discusses the strengths and weaknesses of this technology.
Logging information is more precious as it contains the execution of a system; it is produced by millions of events from simple application logins to random system errors. Most of the security related problems in the cloud ecosystem like intruder attacks, data loss, and denial of service, etc. could be avoided if Cloud Service Provider (CSP) or Cloud User (CU) analyses the logging information. In this paper we introduced few challenges, which are place of monitoring, security, and ownership of the logging information between CSP and CU.
Also we proposed a logging architecture to analyze the behaviour of the cloud ecosystem, to avoid data breaches and other security related issues at the CSP space. So that we believe our proposed architecture can provide maximum trust between CU and CSP.
We present a two dimensional (2D) planar chromatographic separation of estrogenic active compounds on RP-18 (Merck, 1.05559) and silica gel (Merck, 1.05721) phase. A mixture of 13 substances was separated using a solvent mix consisting of methanol–acetonitrile–water (2 + 2 + 1, v/v/v) on RP-18 phase in the first direction and cyclohexane–butylacetate–methanol (8 + 6 + 1, v/v/v) in the second direction on silica gel plate. Both developments were carried out over a distance of 70 mm. We used the grafted method to combine both plates in a 2D-separation. This 2D-separation method can be used to quantify 17α-ethinylestradiol (EE2) in an effect-directed analysis using the yeast strain Saccharomyces cerevisiae BJ3505. The test strain (according to McDonnell) contains the estrogen receptor. Its activation by estrogen active compounds is measured by inducting the reporter gene lacZ that encodes the enzyme ß-galactosidase. This enzyme activity is determined on plate by using the fluorescent substrate MUG (4-methylumbelliferyl ß-D-galactopyranoside).
Since direct current high energy shock fulguration was initially performed in the mid 1980s, ablation of cardiac arrhythmias has come to widespread use. Today the most frequently used energy source for catheter ablation is radio frequency (RF). It was the German engineer Peter Osypka who made available the HAT 100 as the first simple commercial RF ablator.
Nevertheless, in the first years of ablation, physicians were effectively working in the dark. Until today with an increasing understanding of arrhythmia mechanisms, both at the atrial and ventricular levels, this curative technology has made tremendous progress. Now, due to crucial improvement of RF ablation generators, temperature and contact force sensor catheters in combination with non-flouroscopic electroanatomical mapping technologies, computerized temperature and impedance controlled radiofrequency catheter ablation can be used to cure all types of arrhythmias including atrial and ventricular fibrillation. For the latter, cooled ablation by saline solution irrigated catheters has been developed to a widely used standard method. This procedure resulting in pulmonary vein isolation requires transseptal puncture and is technically demanding. Nevertheless, it has shown to be more effective than antiarrhythmic drug therapy.
While earliest RF ablations were performed with non-steerable catheters, today are used steerable sensor catheters without or with external and internal cooling and tips of 4mm or 8mm length. Further innovations like integration of mapping and cardiac imaging give exact information of the number of pulmonary veins and branching patterns and help to correlate electrical signals with anatomical structures.
The magnetic navigation significantly improved the success rates and safety of catheter ablation. Thus, in most cases RF catheter ablation has developed in the treatment of supraventricular arrhythmias from an alternative approach to drug therapy into the first therapeutic choice providing low complication rates.
In future, robotic navigation will further simplify procedures and reduce radiation exposure of this curative approach.
Hybrid SPECT/US
(2014)
Impedance of the Surface Double Layer of LSCF/CGO Composite Cathodes: An Elementary Kinetic Model
(2014)
This thesis deals with the implementation of character controls and combat system of the Action Adventure 'Scout 3D'. The game development was realized with the game engine Unity 3D. In the first part, the architecture of a typical game engine is explained. The single components are describes step by step. Then, five well-known game engines are compared and evaluated. In the next chapter, a short overview about design and architecture patterns is worked out. The features of Unity, that are used for the implementation, and Unity's animation system 'Mecanim, are described finally. The second part includes the requirement definitions for the game 'Scout COD' which define player input, different conditions that allow or disallow several activities and the behaviour of enemies. With the help of patterns the architecture of the game is designed. Then, the implementation is explained by means of code snippets.
Non-responder rate in cardiac resynchronization therapy (CRT) could be partly decreased by individualized parameter optimization excluding adverse hemodynamic timing. In heart failure patients with sinus rhythm, an atrial kick enables the completion of atrial contraction and may significantly enhance the ventricular filling. Compared to that, exclusion of atrial kick is a sign of suboptimal atrioventricular timing. However, the recognition of atrial kick by echocardiography will be negatively affected in patients requiring a very short or long AV delays.
Integration of BACNET OPC UA-Devices Using a JAVA OPC UA SDK Server with BACNET Open Source Library
(2014)
Data is ever increasing in the computing world. Due to advancement of cloud technology the dynamics of volumes of data and its capacity has increased within a short period of time and will keep increasing further. Providing transparency, privacy, and security to the cloud users is becoming more and more challenging along with the volume of data and use of cloud services. We propose a new approach to address the above mentioned challenge by recording the user events in the cloud ecosystem into log files and applying MAR principle namely 1) Monitoring 2) Analyzing and 3) Reporting.
The characteristic features and applications of linear and nonlinear guided elastic waves propagating along surfaces (2D) and wedges (1D) are discussed. Laser-based excitation, detection, or contact-free analysis of these guided waves with pump–probe methods are reviewed. Determination of material parameters by broadband surface acoustic waves (SAWs) and other applications in nondestructive evaluation (NDE) are considered. The realization of nonlinear SAWs in the form of solitary waves and as shock waves, used for the determination of the fracture strength, is described. The unique properties of dispersion-free wedge waves (WWs) propagating along homogeneous wedges and of dispersive wedge waves observed in the presence of wedge modifications such as tip truncation or coatings are outlined. Theoretical and experimental results on nonlinear wedge waves in isotropic and anisotropic solids are presented.
In anisotropic media, the existence of leaky surface acoustic waves is a well-known phenomenon. Very recently, their analogs at the apex of an elastic silicon wedge have been found in experiments using laser-ultrasonics. In addition to a wedge-wave (WW) pulse with low speed, a pseudo-wedge wave (p-WW) pulse was found with a velocity higher than the velocity of shear bulk waves, propagating in the same direction. With a probe-beam-deflection technique, the propagation of the WW pulses was monitored on one of the faces of the wedge at variable distance from the apex. In this way, their depth structure and the leakage of the p-WW could be visualized directly. Calculations were carried out using a method based on a representation of the displacement field in Laguerre functions. This method has been validated by calculating the surface density of states in anisotropic media and comparing the results with those obtained from the surface Green's tensor. The approach has then been extended to the continuum of acoustic modes in infinite wedges with fixed wave-vector along the apex. These calculations confirmed the measured speeds of the WW and p-WW pulses.
Nowadays, it is assumed of many applications, companies and parts of the society to be always available online. However, according to [Times, Oct, 31 2011], 73% of the world population do not use the internet and thus aren't “online” at all. The most common reasons for not being “online” are expensive personal computer equipment and high costs for data connections, especially in developing countries that comprise most of the world’s population (e.g. parts of Africa, Asia, Central and South America). However it seems that these countries are leap-frogging the “PC and landline” age and moving directly to the “mobile” age. Decreasing prices for smart phones with internet connectivity and PC-like operating systems make it more affordable for these parts of the world population to join the “always-online” community. Storing learning content in a way accessible to everyone, including mobile and smart phones, seems therefore to be beneficial. This way, learning content can be accessed by personal computers as well as by mobile and smart phones and thus be accessible for a big range of devices and users. A new trend in the Internet technologies is to go to “the cloud”. This paper discusses the changes, challenges and risks of storing learning content in the “cloud”. The experiences were gathered during the evaluation of the necessary changes in order to make our solutions and systems “cloud-ready”.
This paper reports on the evolution of cracks in the cylinder heads of a large V8 Diesel engine during cyclic engine tests. The observations are compared with the predictions of a lifetime model for combined thermo-mechanical (TMF) and high cycle fatigue (HCF) loading, which is based on a fracture mechanics analysis of microcrack growth in viscoplastic solids and assumes that the crack advance per cycle is proportional to the cyclic crack tip opening displacement. Since the material of the cylinder heads, the cast iron EN-GJV450, exhibits the typical features of cast iron, namely pressure dependence of the yield stress, dilatancy and tension-compression asymmetry, the Gurson model is applied and combined with the viscoplastic Chaboche model. This constitutive model together with the lifetime model is implemented into a finite element code as a user defined material routine. Published model parameters for the considered cast iron are used to carry out the simulation of the engine test. This simulation comprises a CFD analysis to determine the heat transfer coefficients, a thermal analysis of the load cycle and the mechanical analysis. The thermal analysis reproduces the temperatures at various measuring points sufficiently accurately. Finally, the mechanical analysis predicts the location and orientation of the cracks in the valve bridges correctly in all cases. However, the lifetime predictions are rather conservative compared to the tests (by a factor of 1 to 5 in lifetime). This is discussed and explained by the fact that the cracks were detected in the tests only when they had already spread over a substantial fraction of the valve bridge width. To describe this situation a long-crack analysis would be necessary, which is not yet included in the applied lifetime model.
The paper is addressing the needs of the universities regarding qualification of students as future R&D specialists in efficient techniques for successfully running innovation process. It briefly describes the program of a novel one-semester-course of 150 hours in new product development and inventive problem solving with TRIZ methodology, offered for the master students at the Beuth University of Applied Sciences in Berlin. The paper outlines multi-source educational approach, which includes a new product development project (about 50% of the complete course), theory, practical work, self-learning with the software tools for computer-aided innovation, and demonstrates examples of the students work. The research part analyses the learning experience, identifies the factors that impact the innovation and problem solving performance of the students, and underlines the main difficulties faced by the students in the course. It describes a method for measurement of education efficiency and compares the results with educational experience in the industry. The presented results can help universities to establish the education in new product development or to improve its performance.
Lithium–sulfur (Li/S) cells are promising candidates for a next generation of safe and cost-effective high energy density batteries for mobile and stationary applications. At present, most Li/S cells still suffer from relatively poor cyclability, capacity loss under moderate current densities and self-discharge. Furthermore, the underlying chemical mechanisms of the general discharge/charge behavior as well as Li/S-specific phenomena like the polysulfide shuttle are not yet fully understood. Here we present a thermodynamically consistent, fully reversible continuum model of a Li/S cell with simplified four-step electrochemistry, including a simple description of the polysulfide shuttle effect. The model is parameterized using experimental discharge curves obtained from literature and reproduces behavior at various current densities with fairly high accuracy. While being instructively simple, the presented model can still reproduce distinct macroscopic Li/S-cell features caused by the shuttle effect, e.g., seemingly infinite charging at low charge current densities, and suboptimal coulombic efficiency. The irreversible transport of active material from the cathode to the anode results in a voltage drop and capacity loss during cycling, which can also be observed experimentally.
The invention relates to the field of transporting flat substrates such as silicon substrates. In particular, the invention relates to particularly protective and continuous transport of such substrates. The method according to the invention is used to transport a vertically aligned flat substrate (1) comprising two flat sides in a transport direction inside a transport channel (2) that is at least partially filled with a liquid medium (F), wherein said liquid medium (F) flows against at least one of the flat sides of the substrate (1) and has a supporting component, which lifts the sum of the weight and buoyancy force of the substrate (1), and an advancing component, which is directed in the transport direction, so that the substrate (1) is supported and transported without mechanical aids. The device according to the invention comprises a transport channel (2) for accommodating a liquid medium (F) and a substrate (1) to be guided in vertical alignment within said medium (F), wherein the transport channel (2) has inflow openings (5) in the walls (3, 4).
We tested the MOF framework Cu-BTC for natural gas (NG) storage. Adsorption isotherms of C1–C4 alkanes were simulated applying the Grand Canonical ensemble and the Monte Carlo algorithm in a classical molecular mechanics approach. Experimental monocomponent isotherm of the alkanes was used to validate the force field. We performed multicomponent adsorptions calculations for three different quaternary mixtures of C1–C4 alkanes, matching typical NG streams composition, and predicted theoretical storage capacities, efficiency and accumulation of the NG within that composition. Despite being one of the frameworks with greatest storage capacity of methane, we found that Cu-BTC presented great sensitivity to the variation of the heavier alkanes in NG composition. When we increase the percentage of butane from 0.1% to 0.7% in the mixture, the mass of components retained in the discharge pressure (1 bar) increases from 35 to 60%. We also perform siting and interaction energy investigations and compare the NG storage performance of the Cu-BTC with that of activated carbons. To our knowledge, this is the first study regarding the efficiency of the NG storage in Cu-BTC.
Monitoring of the molecular structure of lubricant oil using a FT-Raman spectrometer prototype
(2014)
The determination of the physical state of the lubricant materials in complex mechanical systems is highly critical from different points of view: operative, economical, environmental, etc. Furthermore, there are several parameters that a lubricant oil must meet for a proper performance inside a machine. The monitoring of these lubricants can represent a serious issue depending on the analytical approach applied. The molecular change of aging lubricant oils have been analyzed using an all-standard-components and self-designed FT-Raman spectrometer. This analytical tool allows the direct and clean study of the vibrational changes in the molecular structure of the oils without having direct contact with the samples and without extracting the sample from the machine in operation. The FT-Raman spectrometer prototype used in the analysis of the oil samples consist of a Michelson interferometer and a self-designed photon counter cooled down on a Peltier element arrangement. The light coupling has been accomplished by using a conventional 62.5/125μm multi-mode fiber coupler. The FT-Raman arrangement has been able to extract high resolution and frequency precise Raman spectra, comparable to those obtained with commercial FT-Raman systems, from the lubricant oil samples analyzed. The spectral information has helped to determine certain molecular changes in the initial phases of wearing of the oil samples. The proposed instrument prototype has no additional complex hardware components or costly software modules. The mechanical and thermal irregularities influencing the FT-Raman spectrometer have been removed mathematically by accurately evaluating the optical path difference of the Michelson interferometer. This has been achieved by producing an additional interference pattern signal with a λ= 632.8 nm helium-neon laser, which differs from the conventional zero-crossing sampling (also known as Connes advantage) commonly used by FT-devices. It enables the FT-Raman system to perform reliable and clean spectral measurements from the analyzed oil samples.
In addition to traditional methods in product development, the increasing availability of additive manufacturing AM technologies offer new opportunities in product development processes today. This contribution explores several ways in which AM can productively be used in education. New to this approach is amongst others that the students assemble and install the 3D-printers themselves. In two case studies is demonstrated how students in design education are able to autonomously research and realize technical possibilities and limitations of AM technologies, as well as economic constraints.
In addition to traditional methods in product development, the increasing availability of two new technologies, namely additive manufacturing AM (e.g. 3D-printing) and reverse engineering RE by means of 3D-scanning, offer new opportunities in product development processes today. However, to date only very few approaches exist those include these new technologies systematically in the education of students in the field of product development. This paper explores several ways in which AM and RE can productively be used in education. New to this approach is, on the one hand, that the students assemble and install the 3Dprinters themselves, and on the other hand, that they are introduced to an approach that combines 3D-scanning followed by 3D-printing. In different case studies is demonstrated that students in design education are able to autonomously research and realize technical possibilities and limitations of these technologies, as well as economic parameters and constraints.
Non-fluoroscopic Imaging with MRT/CT Image Integration - Catheter Positioning with Double Precision
(2014)
Introduction: When antiarrhythmic drug therapy has failed, different approaches of pulmonary vein isolation are considered a reasonable option in the treatment of atrial fibrillation. It will be performed predominantly by radiofrequency catheter ablation. As the individual anatomy of left atrium and the pulmonary veins differs considerably, accurate visualization of these structures is essential during catheter positioning. Using non-fluoroscopic electroanatomic mapping system with image integration, electroanatomic mapping can be combined with highly detailed anatomical MRT or CT information on complex left atrial structures. This may facilitate catheter navigation during ablation for atrial fibrillation.
Methods: The CARTO XP electroanatomic system was used in a project during biomedical engineering study to practice image integration of anonymized real patients that underwent pulmonary vein isolation by CARTO XP and a MRT/CT procedure. Using the image integration software, MRT or CT images were imported into the CARTO XP system. The next process was segmentation of the acquired images. It involves dividing the images into different regions in order to select the structures of interest. In clinical routine, this segmentation has to be performed before catheter ablation. Then, the segmented images were aligned with the reconstructed electroanatomic maps. This consists of several steps, including selection of the left atrium, scaling of the reconstructed geometry, fusion of the structures using landmarks, and optimization of the integration by adjusting the reconstructed geometry of the left atrium.
Results: In the 3 months lasting period of the project, image integration was trained in 13 patients undergoing catheter ablation for atrial fibrillation. Within this period, time consumption for the process decreased from about 90 minutes at the beginning to about 35 minutes at the end for one patient.
Conclusion: Image integration into non-fluoroscopic electroanatomic map is a sophisticated tool in cardiac radiofrequency catheter ablation. Intensive training is necessary to control the procedure.
This work describes a camera-based method for the calibration of optical See-Through Glasses (STGs). A new calibration technique is introduced for calibrating every single display pixel of the STGs in order to overcome the disadvantages of a parametric model. A non-parametric model compared to the parametric one has the advantage that it can also map arbitrary distortions. The new generation of STGs using waveguide-based displays [5] will have higher arbitrary distortions due to the characteristics of their optics. First tests show better accuracies than in previous works. By using cameras which are placed behind the displays of the STGs, no error prone user interaction is necessary. It is shown that a high accuracy tracking device is not necessary for a good calibration. A camera mounted rigidly on the STGs is used to find the relations between the system components. Furthermore, this work elaborates on the necessity of a second subsequent calibration step which adapts the STGs to a specific user. First tests prove the theory that this subsequent step is necessary.
On the possibility to use leaky feeders for positioning in chirp spread spectrum technologies
(2014)
Real Time Localization Systems using electromagnetic waves have significantly evolved during the last years. They also might be used in industrial and in mining environments. Here, topologies might include tunnels, where it might be difficult to ensure the field coverage. Leaky feeder cables are a common solution in case of normal radio communication. In this paper, we study the possibilities to use leaky feeders also for Time-of-Flight based real time localization in such linear topologies, like tunnels, but possibly also for 2D-localization. Theoretical analysis is verified with real-life measurements, which were performed using Chirp Spread Spectrum Technologies.
Cardiac resynchronization therapy with atrioventricular and interventricular pacing delay optimized biventricular pacing is an established therapy for heart failure patients with sinus rhythm and reduced left ventricular ejection fraction. The aim of the study was to evaluate atrioventricular and interventricular pacing delay optimization in cardiac resynchroniza-tion therapy by transthoracic impedance cardiography in biventricular pacing with different left ventricular electrode po-sition. In biventricular pacing heart failure patients with lateral, posterolateral and anterolateral left ventricular electrode position, the mean optimal atrioventricular sening delay was 108.6 ± 20.3 ms and the mean optimal interventricular pac-ing delay -12.3 ± 25.9 ms. Transthoracic impedance cardiography may be a useful technique to optimize atrioventricular and interventricular pacing delay in biventricular pacing with different left ventricular electrode position.
Packed beds serve as thermal energy storages (TES) and heat exchangers (HEX) in different technological applications. In this paper, a general heterogeneous model of heat transfer in packed beds is developed. It is implemented by lumped element formulation in object-oriented modeling language Modelica and is successful validated with data sets taken from two different experiments reported in literature.
The main advantages of the introduced model are the general, theory-based approach and the lumped element formulation in Modelica. The first point mentioned above should allow to simulate a packed bed TES/HEX without the necessity applying measured data for model calibration or to apply specific heat transfer correlations with restricted application. The second point establishes the possibility to integrate the TES/HEX model within plant models of larger scale without increasing the simulation time drastically.
PET and SPECT in Neurology
(2014)
PET and SPECT in Neurology highlights the combined expertise of renowned authors whose dedication to the investigation of neurological disorders through nuclear medicine technology has achieved international recognition. Classical neurodegenerative disorders are discussed as well as cerebrovascular disorders, brain tumors, epilepsy, head trauma, coma, sleeping disorders, and inflammatory and infectious diseases of the CNS. The latest results in nuclear brain imaging are detailed. Most chapters are written jointly by a clinical neurologist and a nuclear medicine specialist to ensure a multidisciplinary approach. This state-of-the-art compendium will be valuable to anybody in the field of neuroscience, from the neurologist and the radiologist/nuclear medicine specialist to the interested general practitioner and geriatrician. It is the second volume of a trilogy on PET and SPECT imaging in the neurosciences, the other volumes covering PET and SPECT in psychiatry and in neurobiological systems.
PET and SPECT in Psychiatry
(2014)
PET and SPECT in Psychiatry showcases the combined expertise of renowned authors whose dedication to the investigation of psychiatric disease through nuclear medicine technology has achieved international recognition. The classical psychiatric disorders as well as other subjects – such as suicide, sleep, eating disorders, and autism – are discussed and the latest results in functional neuroimaging are detailed. Most chapters are written jointly by a clinical psychiatrist and a nuclear medicine expert to ensure a multidisciplinary approach. This state of the art compendium will be valuable to all who have an interest in the field of neuroscience, from the psychiatrist and the radiologist/nuclear medicine specialist to the interested general practitioner and cognitive psychologist. It is the first volume of a trilogy on PET and SPECT imaging in the neurosciences; other volumes will focus on PET and SPECT in neurology and PET and SPECT of neurobiological systems.
PET and SPECT of Neurobiological Systems combines the expertise of renowned authors whose dedication to the development of novel probes and techniques for the investigation of neurobiological systems has achieved international recognition. Various aspects of neurotransmission in the brain are discussed, such as visualization and quantification of (more than 20 different) neuroreceptors, neuroinflammatory markers, transporters, and enzymes as well as neurotransmitter synthesis, β-amyloid deposition, cerebral blood flow, and the metabolic rate of glucose. The latest results in probe development are also detailed.
Most chapters are written jointly by radiochemists and nuclear medicine specialists to ensure a multidisciplinary approach. This state of the art compendium will be valuable to anyone in the field of clinical or preclinical neuroscience, from the radiochemist and radiologist/nuclear medicine specialist to the interested neurobiologist and general practitioner. It is the second volume of a trilogy on PET and SPECT imaging in the neurosciences. Other volumes focus on PET and SPECT in psychiatry and PET and SPECT in neurology".
Photonics meet digital art
(2014)
The paper focuses on the work of an interdisciplinary project between photonics and digital art. The result is a poster collection dedicated to the International Year of Light 2015. In addition, an internet platform was created that presents the project. It can be accessed at http://www.magic-of-light.org/iyl2015/index.htm. From the idea to the final realization, milestones with tasks and steps will be presented in the paper. As an interdisciplinary project, students from technological degree programs were involved as well as art program students. The 2015 Anniversaries: Alhazen (1015), De Caus (1615), Fresnel (1815), Maxwell (1865), Einstein (1905), Penzias Wilson, Kao (1965) and their milestone contributions in optics and photonics will be highlighted.
Pressure dynamics in metal-oxygen (metal-air) batteries: a case study on sodium superoxide cells
(2014)
Electrochemical reactions in metal–oxygen batteries come along with the consumption or release of gaseous oxygen. We present a novel methodology for investigating electrode reactions and transport phenomena in metal–oxygen batteries by measuring the pressure dynamics in an enclosed gas reservoir above the oxygen electrode. The methodology is exemplified by a room-temperature sodium–oxygen battery forming sodium superoxide (NaO2) in an electrolyte of diethylene glycol dimethyl ether (diglyme) and sodium trifluoromethanesulfonate (NaOSO2CF3, NaOTf). The experiments are supported by microkinetic simulations with a one-dimensional multiphysics continuum model. During galvanostatic cycling over 30 cycles, a constant oxygen consumption/release rate is observed upon discharge/charge. The number of transferred electrons per oxygen molecule is calculated to 1.01 ± 0.02 and 1.03 ± 0.02 for discharge and charge, respectively, confirming the nature of the oxygen reaction product as superoxide O2–. The same ratio is observed in cyclic voltammetry experiments with low scan rate (<1 mV/s). However, at higher scan rates, the ratio increases as a result of oxygen transport limitations in the electrolyte. We introduce electrochemical pressure impedance spectroscopy (EPIS) for simultaneously analyzing current, voltage, and pressure of electrochemical cells. Pressure recording significantly increases the sensitivity of impedance toward oxygen transport properties of the porous electrode systems. In addition, we report experimental data on the diffusion coefficient and solubility of oxygen in electrolyte solutions as important parameters for the microkinetic models.
Aqueous lithium–oxygen batteries are promising candidates for electric energy storage. In this paper we present and discuss a multiphase continuum model of an aqueous lithium–oxygen single cell including reactions and transport in a porous gas diffusion electrode (GDE). The model is parameterized using in-house half-cell experiments and available literature data on aqueous electrolytes. We validate our transport model with cyclic voltammetry and electrochemical impedance spectroscopy measurements over a wide range of temperatures (25, 40, 55 °C) and electrolyte concentrations (0.1–2 M). We observe very good agreement between simulations and measurements during oxygen reduction conditions. A sensitivity analysis of the validated model demonstrates the influence of the porous structure on GDE performance and gives directions for the future development of electrodes.
Todays‘ traffic support environments are distributed by nature. In many cases the monitoring, control and guidance of traffic is effected by a federation of coordinating centers, often managed by different organizations, using differing local IT technology and system architecture. Despite the federative character of such systems, maintenance of a consistent overall traffic state is indispensable for a safe operation. This project develops a new type of middleware supporting federative systems
in the domain of Air Traffic Control (ATC), using OMG‘s DDS (Data Distribution Service) standard as contributor.
Introduction: Radiofrequency ablation allows successful treatment of most supraventricular reentrant and focal tachycardias and an increasing number of ventricular tachycardias. Different catheter tips are used. While AV nodal reentrant tachycardias require catheters with a tip of 4mm length, an 8 mm tip electrodes will be used for atrial flutter. A pulmonary vein isolation will be performed using 4 mm irrigated tip electrodes to achieve larger and deeper lesions. The need of a tubing set and pump for saline transfusion is a disadvantage of this technique. Gold tip electrodes can alternatively be used to produce increases in lesion size. Aim of this study was to compare RF ablation catheters of exactly the same geometry with either platin-iridum or gold tip.
Methods: Gold provides an almost four-fold thermal conductivity compared with platinum-iridium. The Cerablate G flutter (Osypka AG, Rheinfelden-Herten) is a newly designed radiofrequency ablation catheter with an 8 mm gold tip. Its power delivery was compared with the Cerablate flutter of same geometry but platin-iridium tip. Therefore, in-vitro RF ablations were performed using pork meat in a 0.9% saline solution at 37°C temperature. A pulsed volume flow was generated using a pump to simulate the blood flow. Temperature controlled ablations of 60 seconds using 45, 55 and 65°C and a maximum of 70W RF power were performed.
Results: Using the Osypka HAT300smart ablator, cumulative power of 167, 474 and 672W was delivered with gold tip against 121, 227 and 310 W with platin-iridium tip. By the Stockert SmartAblate G4 ablator, 202, 546 and 1075W was delivered with gold tip against 117, 246 and 394W with platin-iridium using 45, 55 and 65°C temperature.
Conclusion: During in-vitro investigations, the gold tip electrodes allowed a in power delivery increase of 117 up to 173%. Thus, gold tips can be used to increase lesion depth and diameter without cooling equipment.
In this work a set of nonlinear coupled COM equations at interacting frequencies is derived on the basis of nonlinear electro-elasticity. The formalism is presented with the aim of describing intermodulation distortion of third-order (IMD3) and triple beat. The resulting COM equations are translated to the P-matrix formalism, where care is taken to obtain the correct frequency dependence. The scheme depends on two frequency-independent constants for an effective third-order nonlinearity. One of these two constants is negligibly small in the systems considered here. The P-matrix approach is applied to single filters and duplexers on LiTaO 3 (YXl)/42° operating in different frequency ranges. Both IMD3 and triple beat show good agreement with measurement.
A wide range catalyst screening with noble metal and oxide catalysts for a metal–air battery with an aqueous alkaline electrolyte was carried out. Suitable catalysts reduce overpotentials during the charge and discharge process, and therefore improve the round-trip efficiency of the battery. In this case, the electrodes will be used as optimized cathodes for a future lithium–air battery with an aqueous alkaline electrolyte. Oxide catalysts were synthesized via atmospheric plasma spraying. The screening showed that IrO2, RuO2, La0.6Ca0.4Co3, Mn3O4, and Co3O4 are promising bi-functional catalysts. Considering the high price for the noble metal catalysts further investigations of the oxide catalysts were carried out to analyze their electrochemical behavior at varied temperatures, molarities, and in case of La1−x Ca x CoO3 a varying calcium content. Additionally all catalysts were tested in a longterm test to proof cyclability at varied molarities. Further investigations showed that Co3O4 seems to be the most promising bi-functional catalyst of the tested oxide catalysts. Furthermore, it was shown that a calcium content of x = 0.4 in LCCO has the best performance.
Mice and rats make up 95% of all animals used in medical research and drug discovery and development. Monitoring of physiological functions such as ECG, blood pressure, and body temperature over the entire period of an experiment is often required. Restraining of the animals in order to obtain this data can cause great inconvenience. The use of telemetric systems solves this problem and provides more reliable results. However, these devices are mostly equipped with batteries, which limit the time of operation or they use passive power supplies, which affects the operating range. The semi-passive telemetric implant being presented is based on RFID technology and overcomes these obstacles. The device is inductively powered using the magnetic field of a common RFID reader device underneath the cage, but is also able to operate for several hours autonomously. Being independent from the battery capacity, it is possible to use the implant over a long period of time or to re-use the device several times in different animals, thus avoiding the disadvantages of existing systems and reducing the costs of purchase and refurbishment.
WirelessHART protocol was specifically designed for real-time communication in the wireless sensor networks domain for industrial process automation requirements. Whereas the major purpose of WirelessHART is the read-out of sensors with moderate real-time requirements, an increasing demand for integration of actuator applications can be observed. Therefore, it must be verified that the WirelessHART protocol gives sufficient support to real-time industry requirements. As a result, the delay of especially burst and command messages from actuator and sensor nodes to the gateway and vice versa must be analyzed. In this paper, we implemented a WirelessHART network scenario in WirelessHART simulator in NS-2 [8], simulated and analyzed its time characteristics under ideal and noisy conditions. We evaluated the performance of the implementation in order to verify whether the requirements of industrial process and control can be met. This implementation offers an early alternative to expensive test beds for WirelessHART in real-time actuator applications.
Private households constitute a considerable share of Europe's electricity consumption. The current electricity distribution system treats them as effectively passive individual units. In the future, however, users of the electricity grid will be involved more actively in the grid operation and can become part of intelligent networked collaborations. They can then contribute the demand and supply flexibility that they dispose of and, as a result, help to better integrate renewable energy in-feed into the distribution grids.
Smoothie: a solution for device and content independent applications including 3D imaging as content
(2014)
Network landscape of recent time contains many different network technologies, a wide range of end-devices with a large scale of capabilities and power, and an immense quantity of information represented in different data formats. Research on 3D imaging, virtual reality and holographic techniques will result in new user interfaces (UI) for mobile devices and will increase their diversity and variety. A lot of effort is being made in order to establish open, scalable and seamless integration of various technologies and content presentation for different devices including those that are mobile, considering the individual situation of the end user. Till today the research is going on in different parts of the world but the task is not completed yet. The goal of this research work is to find a way to solve the above stated problems by investigating system architectures to provide unconstrained, continuous and personalized access to the content and interactive applications everywhere and at anytime with different devices. As a Solution of the problem considered, a new architecture named “Smoothie” is proposed.
The improvements in the hardware and software of communication devices have allowed running Virtual Reality (VR) and Augmented Reality (AR) applications on those. Nowadays, it is possible to overlay synthetic information on real images, or even to play 3D on-line games on smart phones or some other mobile devices. Hence the use of 3D data for business and specially for education purposes is ubiquitous. Due to always available at hand and always ready to use properties of mobile phones, those are considered as most potential communication devices. The total numbers of mobile phone users are increasing all over the world every day and that makes mobile phones the most suitable device to reach a huge number of end clients either for education or for business purposes. There are different standards, protocols and specifications to establish the communication among different communication devices but there is no initiative taken so far to make it sure that the send data through this communication process will be understood and used by the destination device. Since all the devices are not able to deal with all kind of 3D data formats and it is also not realistic to have different version of the same data to make it compatible with the destination device, it is necessary to have a prevalent solution. The proposed architecture in this paper describes a device and purpose independent 3D data visibility any time anywhere to the right person in suitable format. There is no solution without limitation. The architecture is implemented in a prototype to make an experimental validation of the architecture which also shows the difference between theory and practice.
The process of establishing an industry standard for TRIZ has been initiated: VDI Guideline 4521 will cover TRIZ. Work is going on on the first part of the standard which will define and explain basic TRIZ vocabulary and notions. A first draft of a list of terms has been compiled by V. Souchkov and is currently being discussed at MATRIZ. The standardization committee consists of TRIZ specialists of various degrees together with TRIZ users from industry. It is working in close connection with MATRIZ. In parallel, translations for the elements of TRIZ terminology into several languages are being sought. According to schedule, work on the first part of the standard may be finished by July 2014 and may go into print by the end of the year.
Pure component sorption isotherms of n-butane, isobutane, 1-butene and isobutene on the metal–organic framework (MOF) 3∞[Cu4(μ4-O)(μ2-OH)2(Me2trz-pba)4] at various temperatures between 283 K and 343 K and pressures up to 300 kPa are presented. The isotherms show a stepwise pore filling which is typical for structurally flexible materials with broad adsorption–desorption hysteresis loops. Gate opening pressures in their endemic characteristic depend on the used hydrocarbon gases. From all investigated gases only the isotherms of 1-butene present a second step at a relative pressure above p/p0 = 0.55. As a consequence, only 1-butene can fully open the framework resulting in a pore volume of 0.54 cm3 g−1. This result is in good agreement with the value of 0.59 cm3 g−1 calculated based on single crystal structure data. The isosteric heat of adsorption was calculated from the experimental isotherms for all C4-isomers. At low loadings the isosteric heat is in a narrow region between 41 and 49 kJ mol−1. Moreover, in situ XRD measurements at different relative hydrocarbon pressures were performed at 298 K for the C4-isomers. The differences in the pressure-depending powder diffraction patterns indicate phase transitions as a result of adsorption. Similar diffraction patterns were observed for all C4-hydrocarbons, except 1-butene, where the second step at higher relative pressure (p/p0 > 0.55) is accompanied by an additional phase transition. This powder pattern resembles that of the as-synthesized MOF material containing solvent molecules in the pore system. The resulting structural changes of the material during guest and pressure induced external stimuli are evidenced by the new coupled XRD adsorption equipment.
A laser-operated, angle-tunable transducer was employed to excite selectively elastic waves guided along the apex of a solid wedge. The propagation of wedge waves at anisotropic monocrystalline silicon edges with different symmetry properties was studied by optical detection. The reduced symmetry in crystals, as compared to isotropic media, causes a number of new features, such as the existence of supersonic leaky wedge waves, tilted spatial pulse profiles, and other peculiarities of their localization. Experimental and theoretical results are presented for three different types of symmetry configurations: the wedge symmetric about its midplane, the wedge symmetric about the plane normal to its apex line, and the wedge symmetric about one of its faces. The experiments include accurate measurements of the phase velocity and the wave field distribution, providing information on localization and coupling of wedge waves with other waves. Theoretically, the wedge waves were treated by the Laguerre function method, extended to modes that are not localized at the tip of the wedge. This approach allowed an accurate description of the observed localized and leaky wedge waves in anisotropic wedges.
This paper presents the elements and the results from the European research project inCASA (Integrated Network for Completely Assisted Senior Citizen’s Autonomy), which designed and implemented a seamless integration of heterogeneous systems and network protocols for regionally distributed telecare and telehealth applications. The integration includes a multitude of physical interface, the transcoding of data models using embedded middleware, and a backend system with open interfaces. The implementation was verified in field tests in five European countries.
Both German and French Air-Source Heat Pump (ASHP) markets have been enjoying an overall upwards trend for many years but, nevertheless, they remain merely slightly penetrated. In terms of market players and their share, the French market is aptly diversified, whereas the German one, being utterly dominated by one single manufacturer, is badly in need of some diversification. At the same time Korean ASHP manufacturers are targeting the French but not German ASHP market. The main purpose of the paper is to find out likely reasons for their one-sided engagement, primarily those associated with the ASHP technology and its system-related aspects.
G.R.E.C is a adventure game, set in an dystopien industrial world, where you are a scavenger for hire. Explore the village of Vankhart Valley and grab everything valuable you can get your hands on.
Your trusty old jump boots will help you avoiding the nasty and deadly spores that changed the world of G.R.E.C forever.
The services sector is also called “tertiary sector” and has become increasingly important in the last few decades. The process of this occurring structural change is characterized by a significant increase in employment in the services sector. On the other hand, the former economic importance in traditional areas, such as agriculture and forestry, as well as manufacturing, is declining.
To have an overview it is important to look and to analyse the different research studies.
The Internet of Things (IoT), ubiquitous computing and ubiquitous connectivity, Cyber Physical Systems (CPS), ambient intelligence, Machine-to-Machine communication (M2M) or Car-to-Car (C2C)-communication, smart metering, smart grid, telematics, telecare, telehealth – there are many buzzwords around current developments related to the Internet.
This contribution gives an overview on such IoT-applications, as they are already used today to improve the availability of information, increase efficiency, push system limits and extend the value chain. At a closer look, the economic and technical development can be separated into different phases. It is interesting that we are currently at the threshold to a new phase, with decentralized and cooperative communication and control nodes as cornerstones. Thus, embedded systems and their connectivity are in the middle of the scene.
This recent development is described along with some example projects from the author’s team which are used in industrial automation, energy supply and distribution (home automation and smart metering), traffic engineering (cooperative driver assistance systems), and in telehealth and telecare.
This paper describes the new Sweaty humanoid adult size robot trying to qualify for the RoboCup 2014 adult size humanoid competition. The robot is built from scratch to eventually allow it to run. One characteristic is that to prevent the motors from overheating, water evaporation is used for cooling. The robot is literally sweating which has given it its name. Another characteristic is, that the motors are not directly connected to the frame but by means of beams. This allows a variable transmission ratio depending on the angle.
Temperature regulation is an important component for modern high performance single -core and multi-core processors. Especially high operating frequencies and architectures with an increasing number of monolithically integrated transistors result in a high power dissipation and - since processor chips convert the consumed electrical energy into thermal energy - in high operating temperatures. High operating temperatures of processors can have drastic consequences regarding chip reliability, processor performance, and leakage currents. External components like fans or heat spreaders can help to reduce the processor temperature - with the disadvantage of additional costs and reduced reliability. Therefore, software based algorithms for dynamic temperature management are an attractive alternative and well known as Dynamic Thermal Management (DTM). However, the existing approaches for DTM are not taking into account the requirements of real-time embedded computing, which is the objective in the given project. The first steps are the profiling and the thermal modeling of the system, which is reported in this paper for a Freescale i. MX6Q quad-core microprocessor. An analytical model is developed and verified by an extensive set of measurement runs.
HiSiMo cast irons are frequently used as material for high temperature components in engines as e.g. exhaust manifolds and turbo chargers. These components must withstand severe cyclic mechanical and thermal loads throughout their service life. The combination of thermal transients with mechanical load cycles results in a complex evolution of damage, leading to thermomechanical fatigue (TMF) of the material and, after a certain number of loading cycles, to failure of the component. In this paper (Part I), the low-cycle fatigue (LCF) and TMF properties of HiSiMo are investigated in uniaxial tests and the damage mechanisms are addressed. On the basis of the experimental results a fatigue life model is developed which is based on elastic, plastic and creep fracture mechanics results of short cracks, so that time and temperature dependent effects on damage are taken into account. The model can be used to estimate the fatigue life of components by means of finite-element calculations (Part II of the paper).
HiSiMo cast irons are frequently used as material for high temperature components in engines as e.g. exhaust manifolds and turbo chargers. These components must withstand severe cyclic mechanical and thermal loads throughout their life cycle. The combination of thermal transients with mechanical load cycles results in a complex evolution of damage, leading to thermomechanical fatigue (TMF) of the material and, after a certain number of loading cycles, to failure of the component. In Part I of the paper, a fracture mechanics model for TMF life prediction was developed based on results of uniaxial tests. In this paper (Part II), the model is formulated for three-dimensional stress states, so that it can be applied in a post-processing step of a finite-element analysis. To obtain reliable stresses and (time dependent plastic) strains in the finite-element calculation, a time and temperature dependent plasticity model is applied which takes non-linear kinematic hardening into account. The material properties of the model are identified from the results of the uniaxial test. The plasticity model and the TMF life model are applied to assess the lifetime of an exhaust manifold.