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Design Concept (design + concept)
Selected AbstractsA DESIGN CONCEPT OF AUTONOMOUS CONTROLLER FOR IMPROVING SEISMIC PROOF CAPABILITY OF SEMI-ACTIVE CONTROL DEVICEEXPERIMENTAL TECHNIQUES, Issue 4 2010M.-H. Shih First page of article [source] Fabrication of Direct Fiber-Reinforced Posts: A Structural Design ConceptJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 4 2001DOUGLAS A. TERRY DDS ABSTRACT As the clinician continues the quest for optimal functional and esthetic success of a tooth-restorative complex, the current selection of restorative materials and techniques may prove overwhelming. Although no single system provides the ideal restorative solution for every clinical circumstance, understanding of general design criteria and the components for the various post and core systems available allow the clinician to appropriately select the method and materials compatible with the existing tooth structure and desired result. This article provides a discussion of the various post and core systems, the methods and materials inherent in these systems, and general design principles. Using that basic information and clinical experience, the authors offer an alternative procedure for the rehabilitation of the intraradicular anatomy of the post-endodontic channel with a direct composite resin,the fiber-reinforced post and core system. CLINICAL SIGNIFICANCE Using improved restorative materials that simulate the physical properties and other characteristics of natural teeth in combination with the proper design principles, the clinician can develop a tooth-restorative complex with optimal functional and esthetic results. [source] ChemInform Abstract: A Design Concept of Long-Wavelength Fluorescent Analogues of Rhodamine Dyes: Replacement of Oxygen with Silicon Atom.CHEMINFORM, Issue 33 2008Meiyan Fu Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] A pedagogical Web service-based interactive learning environment for a digital filter design course: An evolutionary approachCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 3 2010Wen-Hsiung Wu Abstract The course of digital filter design in electronic/electrical engineering involves complicated mathematical equations and dynamic waveform variations. It is a consensus among educators that using simulation tools assist in improving students' learning experiences. Previous studies on system simulation seemed to lack an appropriate approach to design such a course. Few emphasized the design of an interactive learning environment by using an evolutionary approach. This study integrated the design concept of an evolutionary approach and Web service-based technology into a simulation system entitled Pedagogical Web Service-Based Interactive Learning Environment (PEWSILE) was introduced. The PEWSILE system contained two interactive learning environments,a simple system and an advanced system. It offered a total of six pedagogical Web services. The simple interactive learning environment included text/color-based services, and text/color/diagram-based services. The advanced interactive learning environment included batch-based, interval change-based, comparison-based, and scroll bar-based services. The study also assessed the students' performance in six pedagogical Web services covering interaction and overall use, usefulness, and intention to use through a questionnaire survey and subsequent interviews. Three significant findings were reported. For example, in the advanced interactive learning environment, the designs of interval change-based and comparison-based services make it easier to observe differences in the outcome of parameter change, while batch-based services lacks the element of waveform comparison. In sum, the findings in this study provide helpful implications in designing engineering educational software. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 423,433, 2010; View this article online at wileyonlinelibrary.com; DOI 10.1002/cae.20163 [source] Seismic performance evaluation of steel arch bridges against major earthquakes.EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 14 2004Part 2: simplified verification procedure Abstract The performance-based philosophy has been accepted as a more reasonable design concept for engineering structures. For this purpose, capacity evaluation and demand prediction procedures for civil engineering structures under earthquake excitations are of great significance. This work presents a displacement-based seismic performance verification procedure including capacity and seismic demand predictions for steel arch bridges and investigates its applicability. Pushover analyses is employed as a basis in this method to investigate the structure's behaviors. A failure criterion for steel members accounting for the effect of local buckling is involved and an equivalent single-degree-of-freedom (ESDOF) system with a simplified bilinear hysteretic model formulated using pushover analyses results is introduced to estimate the displacement capacity and maximum demand of steel arch bridges under major earthquakes. To check the accuracy of the proposed method, seismic capacities and demands from multi-degree-of-freedom (MDOF) time-history analyses with Level-II design earthquake record inputs modeling major earthquakes are used as benchmarks for comparison. By a case study, it is clarified that the proposed prediction procedure can give accurate estimations of displacement capacities and demands of the steel arch bridge in the transverse direction, while insufficient for the longitudinal direction, which confirms the conclusion drawn in other structure types about the applicability of pushover analyses. Copyright © 2004 John Wiley & Sons, Ltd. [source] Broadband wireless access based on VSF-OFCDM and VSCRF-CDMA and its experimentsEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 3 2004Hiroyuki Atarashi This paper presents broadband packet wireless access schemes based on variable spreading factor (VSF)-orthogonal frequency and code division multiplexing (OFCDM) in the downlink and variable spreading and chip repetition factors (VSCRF)-CDMA in the uplink for the systems beyond IMT-2000. In our design concept for wireless access in both links, radio parameters such as the spreading factor (SF) are optimally controlled so that the system capacity is maximized according to the cell configuration, channel load and radio channel conditions, based on the tradeoff between efficient suppression of other-cell interference and the capacity increase in the target cell by exploiting orthogonality in the time and frequency domains. We demonstrate that the peak throughput of greater than 100,Mbps and 20,Mbps is achieved by the implemented base station and mobile station transceivers using the 100-MHz and 40-MHz bandwidths in the downlink and uplink respectively. Moreover, the simulation results show the possibility of the peak throughput of approximately 1,Gbps for short-range area applications using the 100-MHz bandwidth OFCDM downlink by applying four-branch multiple input multiple output (MIMO) multiplexing with 16,QAM data modulation and punctured turbo coding. Copyright © 2004 AEI [source] Empirical design of computer support and staffing in concurrent engineeringHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 2 2006Joe W. Meredith Manufacturing environments are characterized by underlying operational approaches and assumptions. One such assumption is that concurrent engineering (CE) is superior to traditional sequential processing. A laboratory experiment was conducted using 180 engineering and building construction students as subjects. The engineering methodology variable was sequential and concurrent engineering. There were large teams, consisting of six students, and small teams, consisting of three students. The computer support variable was using and not using groupware. Each team was given a set of requirements to design a transportation system that moved a payload from one point to another. Each team was asked to (a) develop a design concept, (b) develop a detail design in the form of engineering drawings, (c) manufacture the system based on their design products (e.g., drawings and specifications) using toy plastic LEGOS, and (d) test the system to determine if it met the design requirements. There was no significant difference in performance between concurrent engineering groups and sequential engineering processes. Small groups significantly outperformed large groups in all conditions. Computer support did not significantly improve the performance of large or small groups. Participants in the experiment were equally satisfied with all conditions. An external survey strongly endorsed the superiority of CE as compared to sequential engineering. Results are discussed in terms of why practitioners believe in the effectiveness of CE, yet an empirical test failed to demonstrate better performance. © 2006 Wiley Periodicals, Inc. Hum Factors Man 16: 177,193, 2006. [source] The effect of retainer thickness on posterior resin-banded prostheses: a finite element studyJOURNAL OF ORAL REHABILITATION, Issue 11 2004T.-S. Lin summary, According to its design concept, a resin-bonded prosthesis, compared with the conventional fixed partial denture, is a weak and unstable structure. Therefore, a resin-bonded prosthesis induces a higher failure rate, especially in the posterior region. Recently, adhesion agents have been profoundly improved. However, the design guidelines of posterior resin-bonded prostheses (RBP) have seldom been evaluated from a biomechanical perspective. The objective of this study was to investigate the biomechanical effects of the retainer thickness on posterior RBP using the finite element method. A solid model of a posterior mandibular resin-bonded prosthesis, which employed the second molar and second premolar as the abutment teeth, was constructed and meshed with various retainer thickness (ranging from 0·2 to 1·0 mm). Horizontal and vertical loadings of 200 N were applied respectively at the central fossa of the pontic to examine the stress level at the interface between the retainer and abutment teeth. All exterior nodes in the root, below the cementoenamel junction were fixed as the boundary condition. The results showed that horizontal loading would induce higher interfacial stresses than the vertical loading which indicated that the horizontal component of the occlusal force plays a more important role in evaluating the debonding phenomenon. Further, the peak interfacial stresses increased as the retainer thickness decreased and, based on the fitted relation between retainer thickness and interfacial stresses, a 0·4 mm retainer thickness was suggested as the minimum required to prevent severe interfacial stresses increasing. [source] Development of a differential pumping system for soft X-ray beamlines for windowless experiments under normal atmospheric conditionsJOURNAL OF SYNCHROTRON RADIATION, Issue 2 2010Y. Tamenori A novel design for a differential pumping system has been investigated. This system allows windowless experiments in a soft X-ray beamline under normal atmospheric conditions. The new design consists of an aperture-based four-stage differential pumping system, based on a simple model calculation. A prototype system with a total length of 600,mm was constructed to confirm the validity of the design concept. Relatively short conductance-limiting components allow easy installation and alignment of the system on a synchrotron beamline. The fabricated system was installed on a beamline to test the transmission of soft X-rays through atmospheric helium. [source] Harmonic suppressed and size-reduced bandstop and bandpass filtersMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2009Majeed A. S. Alkanhal Abstract New bandstop/bandpass microstrip structures with harmonic suppression are presented in this article. By replacing the series quarter-wavelength connecting lines of conventional open-stub bandpass/bandstop filters with the equivalent ,-shaped line section, compact open-stub bandstop/bandpass filters with second harmonic suppression are achieved. Transmission-line theory is used to derive the design equations of the equivalent ,-shaped lines. Simulation and experiments have also been done to validate the proposed design concept. When compared with the conventional open-stub Bandpass/Bandstop filters, the second harmonic is suppressed and size reduction is achieved in both the Bandstop/bandpass structures. Moreover, results confirm that the proposed shaped bandpass filter achieves a further third harmonic rejection. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2109,2114, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24580 [source] A second-order dual-band bandpass filter using a dual-band admittance inverterMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2008Hualiang Zhang Abstract In this article, a second-order dual-band bandpass filter is designed. The filter consists of two dual-band resonators connected by a dual-band admittance inverter. The dual-band resonator unit is made of two shunt stubs that coordinately produce two resonances. A novel dual-band quarter-wavelength line acts as the admittance inverter, providing suitable admittance transformations. To verify the design concept, a filter working at 2 and 5 GHz is devised and fabricated on Rogers' RO3006 printed circuit boards. In addition, the dual-band filter is connected with a bandstop filter to suppress the unwanted spurious response. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1184,1187, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23326 [source] New design concept of dual-mode bandpass filter by using nonorthogonal input and output ports for wireless applicationMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2006Han-Jan Chen Abstract In this paper, new design concept of nonorthogonal input and output (I/O) ports applied to optimize dual-mode bandpass ring filter is proposed. Compared to conventional dual-mode filters, the proposed filter with nonorthogonal I/O could not only support two degenerate modes operation, but also increase design flexibility. Moreover, the design of dual-mode filters would not have an I/O geometry limitation, corresponding to high integration. Finally, a simple structure and high selectivity for the dual-mode bandpass filters were obtained. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 639,641, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21431 [source] Risk Management in Total System Ship DesignNAVAL ENGINEERS JOURNAL, Issue 4 2000C. F. Barker P.E. ABSTRACT Ships are being designed with an increased emphasis on reduced life cycle costs, obtained through means such as reduced crew size, increased automation, and adoption of commercial practices. Ship cost is closely related to the likelihood and consequence of future events, or risk. Ship designers must have tools to assess and manage risks to obtain cost-effective designs. Risk assumptions were built into prescriptive standards, but performance standards are now being used. Ships systems built to varying degrees of acceptable risk are not cost-effective. Underdesigns and overdesigns will result, and the ship ends up only as strong as its "weakest link." The authors propose that the top-down risk management methodology that is currently used for commercial ships be considered for use by naval ship designers in conjunction with both the traditional ship design spiral and the total systems ship design concept. The IMO-endorsed formal safety assessment (FSA) methodology was designed for marine systems. By adopting the FSA approach the Navy will benefit from existing lessons-learned, and will have a smoother transition into the application of commercial standards when the ship is built. [source] Molecular replacement: the probabilistic approach of the program REMO09 and its applicationsACTA CRYSTALLOGRAPHICA SECTION A, Issue 6 2009Rocco Caliandro The method of joint probability distribution functions has been applied to molecular replacement techniques. The rotational search is performed by rotating the reciprocal lattice of the protein with respect to the calculated transform of the model structure; the translation search is performed by fast Fourier transform. Several cases of prior information are studied, both for the rotation and for the translation step: e.g. the conditional probability density for the rotation or the translation of a monomer is found both for ab initio and when the rotation and/or the translation values of other monomers are given. The new approach has been implemented in the program REMO09, which is part of the package for global phasing IL MILIONE [Burla, Caliandro, Camalli, Cascarano, De Caro, Giacovazzo, Polidori, Siliqi & Spagna (2007). J. Appl. Cryst.40, 609,613]. A large set of test structures has been used for checking the efficiency of the new algorithms, which proved to be significantly robust in finding the correct solutions and in discriminating them from noise. An important design concept is the high degree of automatism: REMO09 is often capable of providing a reliable model of the target structure without any user intervention. [source] An overview of the heterogeneous telescope network system: Concept, scalability and operationASTRONOMISCHE NACHRICHTEN, Issue 3 2008R.R. White Abstract In the coming decade there will be an avalanche of data streams devoted to astronomical exploration opening new windows of scientific discovery. The shear volume of data and the diversity of event types (Kantor 2006; Kaiser 2004; Vestrand & Theiler & Wozniak 2004) will necessitate; the move to a common language for the communication of event data, and enabling telescope systems with the ability to not just simply respond, but to act independently in order to take full advantage of available resources in a timely manner. Developed over the past three years, the Virtual Observatory Event (VOEvent) provides the best format for carrying these diverse event messages (White et al. 2006a; Seaman & Warner 2006). However, in order for the telescopes to be able to act independently, a system of interoperable network nodes must be in place, that will allow the astronomical assets to not only issue event notifications, but to coordinate and request specific observations. The Heterogeneous Telescope Network (HTN) is a network architecture that can achieve the goals set forth and provide a scalable design to match both fully autonomous and manual telescope system needs (Allan et al. 2006a;White et al. 2006b; Hessman 2006b). In this paper we will show the design concept of this meta-network and nodes, their scalable architecture and complexity, and how this concept can meet the needs of institutions in the near future. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Carotid artery stenting in high surgical risk patients using the FiberNet® embolic protection system: The EPIC trial results,CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 6 2010FACC, Subbarao Myla MD Abstract Objective: The multicenter EPIC (FiberNet Embolic Protection System in Carotid Artery Stenting Trial) single-arm trial evaluated the 30-day outcomes of a new design concept for embolic protection during carotid artery stenting (CAS). Background: Embolic protection filters available for use during CAS include fixed and over-the-wire systems that rely on embolic material capture within a "basket" structure. The FiberNet® Embolic Protection System (EPS), which features a very low crossing profile, consists of a three-dimensional fiber-based filter distally mounted on a 0.014 inch guidewire with integrated aspiration during filter retrieval. Methods: The trial enrolled 237 patients from 26 centers. Demographics, clinical and lesion characteristics, as well as adverse events through a 30-day follow-up were recorded. The mean age of the patients was 74 years, 64% were male and 20% had symptomatic carotid artery disease. Results: The combined major adverse event (MAE) rate at 30 days for all death, stroke, and myocardial infarction was 3.0%. There were three major strokes (two ischemic and one hemorrhagic) and two minor strokes (both ischemic) for a 2.1% 30-day stroke rate. The procedural technical success rate was 97.5% and macroscopic evidence of debris was reported in 90.9% of the procedures. Conclusions: The FiberNet EPS, used with commercially available stents, produced low stroke rates following CAS in high surgical risk patients presenting with carotid artery disease. The unique filter design including aspiration during retrieval may have contributed to the low 30-day stroke rate reported during CAS in patients considered at high risk for complications following carotid endarterectomy (CEA). © 2009 Wiley-Liss, Inc. [source] Augmented reality agents for user interface adaptationCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 1 2008István Barakonyi Abstract Most augmented reality (AR) applications are primarily concerned with letting a user browse a 3D virtual world registered with the real world. More advanced AR interfaces let the user interact with the mixed environment, but the virtual part is typically rather finite and deterministic. In contrast, autonomous behavior is often desirable in ubiquitous computing (Ubicomp), which requires the computers embedded into the environment to adapt to context and situation without explicit user intervention. We present an AR framework that is enhanced by typical Ubicomp features by dynamically and proactively exploiting previously unknown applications and hardware devices, and adapting the appearance of the user interface to persistently stored and accumulated user preferences. Our framework explores proactive computing, multi-user interface adaptation, and user interface migration. We employ mobile and autonomous agents embodied by real and virtual objects as an interface and interaction metaphor, where agent bodies are able to opportunistically migrate between multiple AR applications and computing platforms to best match the needs of the current application context. We present two pilot applications to illustrate design concepts. Copyright © 2007 John Wiley & Sons, Ltd. [source] Model complexity versus scatter in fatigueFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 11 2004T. SVENSSON ABSTRACT Fatigue assessment in industry is often based on simple empirical models, such as the Wöhler curve or the Paris' law. In contrast, fatigue research to a great extent works with very complex models, far from the engineering practice. One explanation for this discrepancy is that the scatter in service fatigue obscures many of the subtle phenomena that can be studied in a laboratory. Here we use a statistical theory for stepwise regression to investigate the role of scatter in the choice of model complexity in fatigue. The results suggest that the amount of complexity used in different design concepts reflects the appreciated knowledge about input parameters. The analysis also points out that even qualitative knowledge about the neglected complexity may be important in order to avoid systematic errors. [source] WDX Studies on Ceramic Diffusion Barrier Layers of Metal Supported SOECsFUEL CELLS, Issue 6 2009D. Wiedenmann Abstract Solid oxide electrolyser cells (SOECs) have great potential for efficient and economical production of hydrogen fuel. Element diffusion between the Ni-cermet electrode and the metal substrate of metal supported cells (MSC) is a known problem in fuel cell and electrolysis technology. In order to hinder this unintentional mass transport, different ceramic diffusion barrier layers (DBLs) are included in recent cell design concepts. This paper is based on wavelength dispersive X-ray fluorescence investigations of different SOEC and focuses on Fe, Cr and Ni diffusion between the metal grains of the cathode and the metal substrate. Due to the low detection limits and therefore high analytical sensitivity, wavelength dispersive electron probe microanalysis (EPMA) provides a precise method to determine element distribution, absolute element concentration and changes between the reference material and aged cells on a microstructural level by element mappings and concentration profiles. The results of this work show considerable concentration gradients in the metal grains caused by mass exchange during cell operation. Diffusion can be inhibited significantly by integrating different ceramic DBLs of doped LaCrO3 -type or doped LaMnO3 -type perovskite, either by vacuum plasma spraying (VPS) or physical vapour deposition technique (PVD). [source] Photoswitches: From Molecules to MaterialsADVANCED MATERIALS, Issue 31 2010Maria-Melanie Russew Abstract Small organic molecules, capable of undergoing efficient and reversible photochemical reactions to switch them between (at least) two (meta)stable isomers associated with markedly different properties, continue to impact the materials world. Such photoswitches are being implemented in a variety of materials for applications ranging from optical devices to "smart" polymers. All approaches exploit the photoswitching molecular entities as gates, which translate an incoming light stimulus to trigger macroscopic property changes of the materials. In this progress report, the most promising recent examples in this field are highlighted and put in perspective. Moving from supramolecular systems in solution to surfaces and finally to bulk materials, important design concepts are discussed, emphasizing both the challenges as well as the great promise of such truly advanced materials. [source] Understanding the design of information technologies for knowledge management in organizations: a pragmatic perspectiveINFORMATION SYSTEMS JOURNAL, Issue 2 2007Tom Butler Abstract., Researchers report mixed findings on the successful application of information technologies (IT) for knowledge management (KM). The primary difficulty is argued to be the use of information management techniques and concepts to design and develop KM Tools. Also problematic is the existence of a multiplicity of KM technologies, the application and use of which differs across organizations. This paper argues that these problems stem, in part, from the information system field's over-reliance on design concepts from the functionalist paradigm. Hence, our contention that alternative perspectives, which bring into focus issues of ontology and epistemology, need to be brought to bear in order to understand the challenges involved in the design and deployment of IT artefacts in knowledge management systems (KMS). The philosophy of technology, with its emphasis on the primacy of praxis, and which incorporates ontological and epistemological concepts from phenomenology and hermeneutics, is applied to the findings of a participative action research study to illustrate how social actors interpret and understand worldly phenomena and subsequently share their knowledge of the life-world using IT. The outcome of this marriage of situated practical theory and philosophy is a set of design principles to guide the development of a core KM Tool for KMS. [source] Learning the Dynamic Processes of Color and Light in Interior DesignJOURNAL OF INTERIOR DESIGN, Issue 2 2009Tiiu Poldma Ph.D. ABSTRACT Interior environments and their design are profoundly influenced by how designers integrate color and light with form and space. In our increasingly global world, new lighting technologies are changing our perception of color and light and subsequently our interrelationships with one another and with interior space. This alters the choices that we have as designers when we make both color and light decisions. Traditional light and color theories are being challenged with new lighting approaches that are complex, dynamic, and that are changing people's immediate experiences within spaces. Currently, new light technologies alter our perceptual relationships with people and forms, as light, its spectral color, and the forms its affects are more interactive and modulated in real time. Usually, in interior design coursework, students learn about color and light as static theories that they are then asked to apply within the interior design of spaces in subsequent design studios. Through a presentation and examination of the course "Color and Light in Interior Design," this paper proposes considering integrating color and light theories with new contexts of dynamic, integrated human experiences of color and light in interior space. Students acquire learning experiences that integrate theory and practice by understanding the complex interrelationships of light, color, and objects in interior spaces as interactive, and by exploring design concepts in actual environments as a laboratory where they can test theories and their own ideas. The course structure is described and the theories underlying the course goals are explored. Color and light theories are considered in the context of emerging technologies and how phenomenological approaches affect our perceptions and experiences in spaces. Student examples of two of the four course projects are presented as these put theories into practice. The discussion shows that light and color theory, when explored in this way, stimulates both comprehensive and creative responses that integrate new technology with aesthetic theory and functional aspects of well-designed light/color solutions. The integrating of practice into theory stimulates reflective thinking and an understanding of situated contexts in interior design problem solving. The course develops emerging necessities of understanding dynamic color/light concepts that contribute to broadening interior design applied knowledge. [source] Variable-period undulators as synchrotron radiation sourcesJOURNAL OF SYNCHROTRON RADIATION, Issue 3 2003G. K. Shenoy A concept for variable-period undulators for the production of synchrotron radiation from both medium- and high-energy storage rings is described. This concept is based on a staggered array of permeable poles placed in a magnetic solenoid that produces a longitudinal field. The concept permits variations in the short magnetic period of the undulator of as much as 100%. The unique capabilities of such undulators will allow them to be tuned by the variation of the period length and of the solenoid field. The device can be operated at either constant flux or constant power, independent of X-ray energy. It is expected that the new concept will have a major impact on the production and applications of X-rays because of the inherent simplicity and flexibility of the design and the absence of radiation damage. Analyses of the magnetic and mechanical design concepts are presented. [source] Practical Seakeeping Performance Measures for High Speed Displacement VesselsNAVAL ENGINEERS JOURNAL, Issue 4 2006Dr. Kadir Sariöz The seakeeping performance of high-speed displacement vessels is generally assessed, in a probabilistic manner, by using criteria-based measures of merit. Given a set of seakeeping criteria, these measures, such as the Percentage Time of Operation (PTO) and the Seakeeping Performance Index (SPI), could provide an assessment of the operability of the vessel in a specified sea area. The criteria-based measures are based upon the probability of exceeding specified ship motions in a sea environment particular to the vessel's mission. Given the operational area of the vessel, the percentage of time the vessel operates in a particular sea state can be determined by comparing the predicted motions to the motion limiting criteria. However, because the seakeeping criteria are used in a pass/fail manner, the criteria-based procedures give no credit for reducing motions that do not exceed criteria. This may result in misleading conclusions when the relative seakeeping performance of alternative design concepts is compared. It is shown that criteria-free measures, based upon a normalized summation of critical ship responses for a range of ship speeds and wave headings in a specified sea area, may produce more reliable results when the seakeeping performance of alternative designs are compared. This approach also has the clear advantage of not requiring a set of seakeeping criteria, which is subjective in nature. To demonstrate the effect of typical measures of merit on seakeeping performance assessment, six typical high-speed displacement vessel forms are considered in a comparative analysis. Both the criteria-free and criteria-based measures of merit are employed to compare the seakeeping performance of selected vessels. The results indicate that the choice of seakeeping performance measure of merit depends on the nature of seakeeping analysis and criteria-free measures offer a simple, practical, and realistic assessment in comparative seakeeeping studies. [source] New Pulsatile Hydrostatic Pressure Bioreactor for Vascular Tissue-engineered ConstructsARTIFICIAL ORGANS, Issue 2 2010Faisal M. Shaikh Abstract Mechanical conditioning represents a potential means to enhance the biochemical and biomechanical properties of tissue-engineered cell constructs. Bioreactors that can simulate physiologic conditions can play an important role in the preparation of tissue-engineered constructs. Although various forms of bioreactor systems are currently available, these have certain limitations, particularly when these are used for the creation of vascular constructs. The aim of the present report is to describe and validate a novel pressure bioreactor system for the creation of vascular tissue. Here, we present and discuss the design concepts, criteria, as well as the development of a novel pressure bioreactor. The system is compact and easily housed in an incubator to maintain sterility of the construct. Moreover, the proposed bioreactor, in addition to mimicking in vivo pressure conditions, is flexible, allowing different types of constructs to be exposed to various physiologic pressure conditions. The core bioreactor elements can be easily sterilized and have good ergonomic assembly characteristics. This system is a fundamental tool, which may enable us to make further advances in bioreactor technology and tissue engineering. The novel system allows for the application of pressure that may facilitate the growth and development of constructs needed to produce a tissue-engineered vascular graft. [source] Das Magnitude 8.8 Maule (Chile)-Erdbeben vom 27.BAUTECHNIK, Issue 8 2010Februar 2010, Ingenieuranalyse der Erdbebenschäden Das Maule (Chile)-Erdbeben vom 27. Februar 2010 gehört zu den stärksten, weltweit jemals registrierten Erdbeben. Die Bruchzone erstreckt sich über eine Länge von 500 km und eine Breite von 100 km, so dass acht Millionen Einwohner Chiles von dem Erdbeben mehr oder weniger direkt von den Schütterwirkungen betroffen waren. Bilder von spektakulären Schadensfällen aus der ca. 330 km entfernten Hauptstadt prägten die internationale Berichterstattung. Das seismische Ereignis löste einen Tsunami aus, der verheerende Schäden an der Küste Chiles verursachte und auch an den Küsten Hawaiis noch deutlich wahrgenommen werden konnte. Die seismischen Bodenbewegungen wurden bis ins Nachbarland Argentinien verspürt. Die Stärke des Bebens und ereignisspezifische Besonderheiten waren Motivation, im Rahmen einer Erkundungsmission der Ingenieurgruppe der Deutschen TaskForce Erdbeben im betroffenen Gebiet die Bauwerksschäden aufzunehmen und ihre regionale Verteilung zu dokumentieren. In fünf temporär, mit Starkbeben-Sensoren instrumentierten Gebäuden konnten mehrere Nachbeben aufgezeichnet werden, deren Beschleunigungsamplituden für allgemeine Hochbauten in deutschen Erdbebengebieten von Interesse bzw. maßgeblich wären. Die vorliegenden Messdaten ermöglichen die Interpretation der realen Gebäudereaktion und können in Folgeuntersuchungen zur Kalibrierung analytischer Modelle herangezogen werden. Der Beitrag vermittelt einen Eindruck von den erdbebenbedingten Schäden und soll das Verhalten der typischen Bauweisen unter diesen extremen Einwirkungen aufzeigen, das vor Ort festgestellte geringe Schadensausmaß durch die Umsetzung von Baunormen und darin verankerten Bemessungskonzepten erklären und letztlich die Übertragbarkeit dieser Beobachtungen auf andere Erdbebenregionen hinterfragen. In einem Folgebeitrag [1] werden die Schäden aus dem Tsunami einer Ingenieuranalyse unterzogen und die wesentlichen Wirkungsmechanismen bzw. einfachen baulichen Schutzmaßnahmen herausgearbeitet. The Magnitude 8.8 Maule (Chile) Earthquake of February 27, 2010 , Engineering analysis of earthquake damage. The Maule (Chile) February 27, 2010 Earthquake is regarded as one of the strongest earthquakes ever recorded world-wide. The rupture zone reached a length of about 500 km and a width of about 100 km; almost 8 million inhabitants were directly affected by the consequences of the earthquake. Photos from spectacular failure cases in the Capital (330 km away) were documented across the world and dominated the international reporting. The seismic event triggered a tsunami which caused serious damage alongside the coastal border; the waves were observed in the far-distant Hawaii Islands, too. The seismic ground motions were felt in the neighboring country Argentina, as well. The strength of the earthquake and the event-specific characteristics motivated the "Engineering Group of the German Task Force for earthquake" to analyze the building damage and to document their regional distribution. Five multi-storey RC structures were temporarily equipped with Strong-Motion sensors. Several aftershocks could be recorded; the peak acceleration amplitudes were in a level which was of interest for buildings in highest zone of German earthquake regions. In a first attempt, the measurements are used to interpret the response of real buildings in both horizontal directions; in ongoing studies data are used for the calibration of analytical models. The paper provides an overview of the earthquake induced damages in several building types and its variation within different structural systems. Reasons of low to moderate observed damage will be discussed in close relation to the code development and the preferred design concepts. The application of observed effects and derived lessons to other seismic regions is critically reviewed. In a subsequent paper [1] the damage caused by the tsunami is investigated in more detail. The engineering analysis will include the currently used models for the impact description and will elaborate simple, but quite efficient measures of protection. [source] Bemessung von Grundbauwerken aus Stahlbeton nach DIN 1054 (01.03)BETON- UND STAHLBETONBAU, Issue 5 2004Ludger Speier Dr.-Ing. Abstract Abweichend von dem bisher gültigen Konzept der DIN 1054 (Ausgabe November 1976) bezieht sich der Geltungsbereich der Neufassung von Januar 2003 explizit auch auf die Standsicherheit und die Gebrauchstauglichkeit von Bauwerken und Bauteilen im Erd- und Grundbau. Da keine vollständige Übereinstimmung zur neuen Normengeneration besteht, insbesondere zu den Vorschriften zur Bemessung von Stahlbetontragwerken (DIN 1045-1, Teil 1-4, DIN 1055-100, DIN Fachberichte 100-104), existieren Interpretationsspielräume. Es werden die Grundzüge und Differenzen der beiden Konzepte vorgestellt und Anwendungsregeln gegeben. Bemessungsergebnisse bei der Anwendung der neuen Normengeneration am Beispiel eines Tunnelbauwerks in bergmännischer Bauweise werden mit den bisher gültigen Normen (DIN 1045 (07.88), DIN 1054 (11.76), ZTVTunnel Teil I) verglichen. Design of Foundation Construction made of Reinforced Concrete according to DIN 1054 (01.03) Other than the idea given in DIN 1054 (draft november 1976) the scope of the revised draft of january 2003 clearly also refers to the stability as well as the serviceability of construction and structural members concerning ground and foundation work. However, the design concepts proposed in this contribution, do not completely correspond to other regulations of the new "Generation of Standards", in particular to the rules for the design of concrete structural members (DIN 1045-1, part 1-4, DIN 1055-100, DIN Fachberichte 100-104). This leads to interpretation possibilities for the interface between both standards. In the following the main features and differences of both standards are introduced and application rules are proposed. Furthermore, the application of the new "Generation of Standards" is presented within the example of a tunnel structure in mining construction. These results are compared to the results according to the standards which have been valid so far (DIN 1045 (07.88), DIN 1054 (11.76), ZTV-Tunnel part I). [source] Target-Family-Oriented Focused Libraries for Kinases,Conceptual Design Aspects and Commercial AvailabilityCHEMBIOCHEM, Issue 3 2005Olaf Prien Dr. Tailor-made libraries may increase the likelihood of identifying potential lead candidates in early drug-discovery phases. That at least 12 commercial vendors offer their services in providing compound collections of tentative kinase inhibitors reflects the growing interest in kinases within the pharmaceutical industry. Some conceptual design approaches for focused library design for the kinase family are reviewed, and the design concepts of these commercialized libraries is discussed. [source] Recombinant bacteria for environmental release: what went wrong and what we have learnt from itCLINICAL MICROBIOLOGY AND INFECTION, Issue 2009V. De Lorenzo Abstract From a biotechnological point of view, bacteria can be seen as either pathogens to target with new drugs or as biocatalysts for large-scale processes in industry, agriculture or the environment. The last includes the exploitation of bacterial activities for bioremediation of toxic waste either in situ or ex situ. The onset of genetic engineering in the late 70s opened the possibility of tailoring recombinant bacteria for environmental release, aimed at biodegradation of otherwise recalcitrant chemicals. However, a few decades later the outcome of this prospect has been quite meager. The literature counts very few cases where the use of genetically engineered bacteria has been proven to be more efficient than natural microorganisms in elimination of recalcitrant compounds under natural (not laboratory) conditions. Fortunately, the emergence of Systems and Synthetic Biology in the last few years is helping to identify what were the caveats of the former approaches and how to correct them. In addition, robust design concepts imported from process engineering provides fresh approaches to the challenge of designing microorganisms á la carte for environmental applications. [source] Understanding Young Children's Three-Dimensional Creative Potential in Art MakingINTERNATIONAL JOURNAL OF ART & DESIGN EDUCATION, Issue 2 2009Victoria Pavlou This article explores aspects of young children's three-dimensional development in art making. Understanding young children's three-dimensional awareness and development is often a neglected area of early childhood educators' education and practice and often children's creative potential is not fully realised. The present article is based on a small scale qualitative study which focused on understanding 5,6 year-olds' representational intentions in three-dimensional artworks, understanding of visual/design concepts and expressive use of media (scrap paper and mod roc). The findings of the study suggest that young children are able to create satisfying three-dimensional representations giving emphasis on forms, uprightness, balance, movement and modeling of multiple sides. [source] | |||||||||||||||||||||||||||||||||||||