WorldWideScience

Sample records for floor slab assembly

  1. An Analytical Study on Deflection and Stress Resultants of Composite Floor Slabs

    OpenAIRE

    山川, 哲雄; 郝, 洪濤; 田中, 躍一; Yamakawa, Tetsuo; Hao, Hongtao; Tanaka, Youichi

    1993-01-01

    The composite floor slab, which is composed of cast-in-place concrete and casting floor formworks, is assumed to be a double layered floor slab. This floor slab is proposed as ARC (Automation-oriented Reinforced Concrete Constructions) floor systems.Using the equivalent flexural rigidity for the double layered floor slabs consisting of two different elastic moduli, analytical solutions expressed in Fourier series by thin plate theory and by elementary beam theory can be easily applied to the ...

  2. Post-tensioned concrete floor slab design of a shopping centre

    Institute of Scientific and Technical Information of China (English)

    刘洋; 于霞

    2011-01-01

    Post-tensioned Concrete slab can provide large clear span, and also has better performance in crack control and deflection. The topic below introduced the design process of the post-tensioned floor slab of a shopping centre.

  3. Heat Transmission of Slab-on-Ground Industrial Floors with Vertical Perimeter Insulation

    OpenAIRE

    Kocsis, Lajos

    2013-01-01

    The surface heat loss of slab-on-ground industrial floors that are vertically insulated along the footing wall (with the insulation reaching under the ground level), is closely linked with the relatively large floor area of industrial halls. To give a comprehensive heat transmission analysis, the present paper first provides an overview of the U-value requirements for such floors in Hungary and Germany. For the determination of the heat transmission coefficient of slab-on-ground floors with v...

  4. The Influence of the Thickness of the Slab and Concrete Grade on Composite Floors

    OpenAIRE

    Vasile-Mircea Venghiac; Cedric D’Mello

    2010-01-01

    A modern flooring system is the ComFloor Composite Floor Deck from Corus. This type of floor has many advantages involving cost, weight, construction speed, but also disadvantages regarding vibrations induced by human activity. The vibration behaviour of this system was analysed taking into consideration two parameters: the thickness of the slab and the grade of the concrete. Two sets of models were made, one with composite beams and one with steel beams. The purpose was to make a comparison ...

  5. The Influence of the Thickness of the Slab and Concrete Grade on Composite Floors

    Directory of Open Access Journals (Sweden)

    Vasile-Mircea Venghiac

    2010-01-01

    Full Text Available A modern flooring system is the ComFloor Composite Floor Deck from Corus. This type of floor has many advantages involving cost, weight, construction speed, but also disadvantages regarding vibrations induced by human activity. The vibration behaviour of this system was analysed taking into consideration two parameters: the thickness of the slab and the grade of the concrete. Two sets of models were made, one with composite beams and one with steel beams. The purpose was to make a comparison between these two types of flooring systems. Results showed a good improvement created by the composite action of the beams and usefull information regarding the two parameters considered.

  6. Impact sound insulation improvement of wooden floors on concrete slabs

    DEFF Research Database (Denmark)

    Rasmussen, Birgit; Hoffmeyer, Dan; Hansen, Rói

    2014-01-01

    . The measurements indicated up to about 8 dB improvement potential compared to floor constructions typical before the latest change of regulations, namely wooden floors on joists on PE wedges or similar. In addition, tests of small-scale samples (1 m2) – unsuitable for type testing – were performed to provide...... a fast track ranking of different floor supports, giving also the opportunity to compare differences between small-scale floors with those from full-scale measurements. The paper presents results from the laboratory tests of different floor supports....

  7. Numerical and experimental study of a waffle slab designed to serve as a tennis court floor

    Directory of Open Access Journals (Sweden)

    P. F. Schwetz

    Full Text Available Reinforced concrete waffle slabs have become a common option for designers due to a need of rationalization in construction with reduction in costs and deadlines. To better understand the behavior of this structural system, and more realistically quantify stresses and displacements, a full scale waffle slab was tested. The structure, designed to serve as a tennis court floor, was submitted to a load of 12 kN/m2 and instrumented to measure strains and deflections at different locations. The loading process used the floor's constructive base filling material and readings were taken at different loading stages and arrangements during the floor's construction. Test data was compared to results obtained from the matrix analysis program Sistema Computacional TQS v11.0 and from the finite element model program SAP2000 v14.2.2. Slab behavior was as expected, with deflection and bending moments close to those determined by the numerical analysis.

  8. Light-assisted templated self assembly using photonic crystal slabs.

    Science.gov (United States)

    Mejia, Camilo A; Dutt, Avik; Povinelli, Michelle L

    2011-06-06

    We explore a technique which we term light-assisted templated self-assembly. We calculate the optical forces on colloidal particles over a photonic crystal slab. We show that exciting a guided resonance mode of the slab yields a resonantly-enhanced, attractive optical force. We calculate the lateral optical forces above the slab and predict that stably trapped periodic patterns of particles are dependent on wavelength and polarization. Tuning the wavelength or polarization of the light source may thus allow the formation and reconfiguration of patterns. We expect that this technique may be used to design all-optically reconfigurable photonic devices.

  9. Effects of vibration characteristics on the walking discomfort of floating floors on concrete slabs.

    Science.gov (United States)

    Kim, Jae Ho; Jeon, Jin Yong

    2014-10-01

    In the present study, the vibration characteristics of floating floor systems and the discomfort in walking upon them have been studied in concrete slab structures through mock-up floors experiments. Seven types of floor systems, with panels of various sizes and supporting beams with different joist spacings, were constructed based on actual conditions. For the vibration measurement, an ISO rubber ball dropped from a height of 20 cm was used as an impact source to reproduce human walking. The vibration characteristics were evaluated by calculating the vibration acceleration values and the autocorrelation function parameters for the floor structures. Finally, a human walking experiment was conducted to investigate subjective responses to the vibration characteristics of floating floors. From the results, it was found that the vibration acceleration values and walking discomfort varied with the supporting conditions of the floors and that these were highly correlated with each other. It was also found that more than 75% of subjects accepted the floors when the vibration value of the floor in terms of vibration does value (VDV) is below 4.8 ms(-1.75). In addition, a practical regression of the VDV was obtained and design guidelines for floating floors were suggested.

  10. The thermal performance of ground floor slabs - a full scale in-situ experiment

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, H.R.; Rees, S.W. [Cardiff School of Engineering (United Kingdom). Geoenvironmental Engineering Research Centre

    1999-03-01

    A detailed description of a comprehensive in-situ experiment designed to monitor the thermal performance of real ground floor slabs is presented. In particular, the experiment was installed at the time of construction of a modern commercial building and subsequently monitored continuously for a one and a half year period. A detailed account of the design of the experiment and the instrumentation used is provided. Results achieved include transient variations of heat flux through the floor slab, air temperature, ground temperature and ground moisture content. Automatic electronic data logging enabled readings to be taken at thirty minute intervals from most instruments. Therefore both the seasonal and diurnal response of the system were observed. Significant differences in summer and winter heat transfer processes are revealed. The results also show that ground temperature and moisture content may change significantly near the external wall of the building. Underneath the building, temperature and moisture content variations were relatively small. Therefore the presence of an edge effect near the outer boundary wall of the building is revealed. The ability of the ground to act as a thermal store is also indicated by the measured data. The thermal response of two ground floor slabs is presented. The first was constructed of normal weight concrete and the second of light weight concrete. The insulating effect of the light weight concrete is evident from the results obtained. The measured thermal data has been used to determine thermal transmittance values for each floor slab considered. These values have been compared to values calculated adopting the approach outlined in current design guides. In conclusion, the U value calculated using the CIBSE guide was almost identical with the measured value for the normal weight concrete floor slab. However, the method could not be directly applied to the light weight concrete slab. The U-values calculated using the CEN draft

  11. Experiment on the concrete slab for floor vibration evaluation of deteriorated building

    Science.gov (United States)

    Hong, S. U.; Na, J. H.; Kim, S. H.; Lee, Y. T.

    2014-08-01

    Damages from noise and vibration are increasing every year, and most of which are noises between floors in deteriorated building caused by floor impact sound. In this study, the floor vibration of the deteriorated buildings constructed with the concrete slabs of thickness no more than 150 mm was evaluated by the vibration impact sound. This highly reliable study was conducted to assess floor vibration according with the serviceability evaluation standard of Reiher / Meister and Koch and vibration evaluation standard of ISO and AIJ. Designed pressure for the concrete slab sample of floor vibration assessment was 24MPa, and the sample was manufactured pursuant to KS F 2865 and JIS A 1440-2 with size of 3200 mm × 3200 mm × 140 mm. Tests were conducted twice with accelerometers, and Fast Fourier Transform was performed for comparative analysis by the vibration assessment criteria. The peak displacement from Test 1 was in the range of 0.00869 - 0.02540 mm; the value of peak frequency ranged from 18 to 27 Hz, and the average value was 22Hz. The peak acceleration value from Test 2 was in the range of 0.47 - 1.07 % g; the value of peak frequency was 18.5 - 22.57 Hz, and the average was 21Hz. The vibration was apparently recognizable in most cases according to the Reiher/Meister standard. In case of Koch graph for the damage assessment of the structure, the vibration was at the medium level and causes no damage to the building structure. The measured vibration results did not exceed the damage limit or serviceability limit of building according to the vibration assessment criteria of ISO and residential assessment guidelines provided by Architectural Institute of Japan (AIJ).

  12. Suspension bridge with floor slab using precast PC slab; Yukaban ni purekyasuto PC burokku wo mochiita tsuribashi {center_dot} shinonome sakurabashi/tochigiken mibumachi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-10

    As part of park improvement project of across of Kuro River flowing through Mibu Town of Tochigi Prefecture, a suspension bridge with floor plate using precast PC slab was erected. The size of floor block used is 5.5-7.5m in width, 2.5m in length, 14cm in thickness. 38 of these blocks were linked, resin was poured into joint, and stress was applied in bridge axis direction after hardening of resin. By prestressing, these floor slab had performance as reinforcing beam in normal loading condition, high rigidity of floor slab demonstrated excellent vibration stability. and enabled emergency vehicle traffic while this bridge is exclusively pedestrian use in normal time. Erection work was carried out in low water period of the river. Since the river can be reclaimed in low water period, most of erection work was carried out on land. Furthermore, utilizing advantages of precast slab, construction from erection of main tower to bridge completion was finished in only 3 months. (translated by NEDO)

  13. A novel finite element method for designing floor slabs on grade and pavements with loads at edges

    Directory of Open Access Journals (Sweden)

    Hugo Ernesto Camero Sanabria

    2015-08-01

    Full Text Available In the present paper a methodology to design slabs on grade for industrial floors and pavements using bi-dimensional finite elements and integrating the subgrade in the design is presented. The suggested method to design slabs on grade for industrial floors and pavements has been called the Camero Finite Element Method.  An example of an industrial floor designed to be capable of sustaining an infinite number of load applications (or a 50 years lifespan period is here presented in order to be compared with the results of the Camero Finite Element Method, the PCA (Portland Cement Association, and the WRI’s (Wire Reinforcement Institute simplified methods. In this example, an industrial floor is designed to be capable of sustaining an infinite number of load applications comparing the results of the Camero Finite Element Method and the simplified methods of the PCA and WRI. The industrial floor or pavement will be able to resist an infinite number of load applications if it is designed with the Camero Finite Element Method. On the other hand, if it is designed using the PCA and the WRI methods, it will last a few years (in this example, in one year period, the number of axle load applications is equal to the number of allowable repetitions. To conclude, if an industrial floor o pavement is designed with the Camero Finite Element Method, it will be able to sustain an infinite number of load applications (up to 50 years lifespan period.

  14. Aspects of alteration of masonry historical buildings without ring beam of floor slabs

    Directory of Open Access Journals (Sweden)

    Ryszard Chmielewski

    2016-12-01

    Full Text Available Some problems of alteration for building structures of a conventional masonry for which working lifetime is approaching or has exceeded the expected design life are presented. In the course of these works, non-bearing masonry walls are often removed and as a result significant damages to supporting structures are often made, and in extreme cases even building collapses. Building surveyors who prepare a structural appraisal for technical reports of damaged masonry structures, as a solution to the problem, recommend sometimes to make only surface reinforcement of damaged walls. The question of significant change in the load distribution in alteration for buildings of conventional design is complex and in some cases above the recommended surface repairs may not be sufficient to ensure structural reliability or the safety of buildings exploitation. The paper proposes a scope of evaluation and structural analysis of a building, which allows to properly determine the range of the existing threats, and on this basis to carry out adequate repair of damaged masonry structures, including structural strengthening.[b]Keywords:[/b] masonry structures, buildings without ring beam of floor slabs, damages of masonry walls, structural failures and collapses

  15. Light-assisted, templated self assembly using a photonic-crystal slab

    CERN Document Server

    Jaquay, Eric; Mejia, Camilo A; Povinelli, Michelle L

    2013-01-01

    The process of self-assembly is guided by the minimization of free energy, which limits the symmetries available for assembly and ultimately the usefulness of devices fabricated in this fashion. Here, we demonstrate experimentally for the first time a technique which we term light-assisted, templated self assembly. By exciting a guided-resonance mode of a photonic-crystal slab, an optical potential landscape is created above the slab which results in stably trapped, periodic patterns of particles at the potential minima. The underlying symmetry of particle clusters matches that of the photonic-crystal lattice, thus enabling square, rectangular or other symmetries not usually available for assembly due to energy concerns. We anticipate that this technique could be used to tailor the optical characteristics of nanofabricated devices, and the optical trapping techniques demonstrated herein may enable a variety of complex nanomanipulation tools and lab-on-a-chip devices.

  16. Research on Performance Evaluation Test of Cracked Floor Slab%开裂楼板性能评定试验研究

    Institute of Scientific and Technical Information of China (English)

    马洪宁

    2013-01-01

      文章以出现裂缝的某沿街商铺现浇混凝土楼板为例,介绍了如何通过现场静载试验研究受荷后楼板挠度及裂缝的发展情况,从而对楼板进行性能评定,并指出了试验存在的不足之处。%Taking for example a cast-in-place concrete floor slab that has cracked in a street-side shop building, this article introduces how to study the development situation of deflection and crack of the load-bearing floor slab through the on-site static load test, so as to evaluate the performance of the floor slab. It also points out the shortcomings of the test.

  17. Energy Dissipation from Vibrating Floor Slabs due to Human-Structure Interaction

    Directory of Open Access Journals (Sweden)

    James M.W. Brownjohn

    2001-01-01

    Full Text Available Lightweight pre-cast flooring systems using post-tensioning to increase strength but not stiffness are increasingly popular, and vibration serviceability problems tend to govern design of such floors where human occupants are increasingly concerned with vibrations. At the same time as inducing response, stationary human observers can also participate in the response as mitigating influence and it is clear that a human behaves as a highly effective damper, even when seated.

  18. Design of the composite flooring slab with profiled sheets t-153 (ruukki) for a residential building

    OpenAIRE

    Alysheva, Stanislava

    2015-01-01

    The purpose of the thesis was to analyse the structure of the composite slab with profiled sheets as permanent formwork; to work with Russian building norms and carry out the limit state design in order to determine characteristics of the structure and find out if it can be used in residential buildings. The study was commissioned by engineers of company Ruukki rus as they are willing to expand their market from designing industrial buildings to residential apartments. An excel file was cr...

  19. Light-assisted, templated self-assembly using a photonic-crystal slab.

    Science.gov (United States)

    Jaquay, Eric; Martínez, Luis Javier; Mejia, Camilo A; Povinelli, Michelle L

    2013-05-08

    We experimentally demonstrate the technique of light-assisted, templated self-assembly (LATS). We excite a guided-resonance mode of a photonic-crystal slab with 1.55 μm laser light to create an array of optical traps. We demonstrate assembly of a square lattice of 520 nm diameter polystyrene particles spaced by 860 nm. Our results demonstrate how LATS can be used to fabricate reconfigurable structures with symmetries different from traditional colloidal self-assembly, which is limited by free energetic constraints.

  20. Reseach on mechanism model of cracking along the prestressed assembling concrete slab%预应力装配楼板顺板裂缝机理模型研究

    Institute of Scientific and Technical Information of China (English)

    李峰

    2001-01-01

    装配楼板顺板裂缝是预制装配式楼板结构特别是住宅工程中普遍存在的通病,通过分析研究楼板之间协同工作及变形,建立了楼板之间的混凝土铰接模型,探讨了顺板裂缝机理,提出解决顺板裂缝的建议方法。%Cracking along the prestressed concrete slab is a common problem in pre-assembly floor construction, especially in residential strucure. Through the analysing and reseaching of conformed working and distortion between slabs, A model of the slab joined each other with concrete pin was established. Also, A rational method solving the cracking along prestressed slab was suggested by means of discussing the cracking mechanism.

  1. 错层板柱与普通板柱结构体系的弹塑性分析%Elastic Plastic Analysis of Staggered Floor Slab Column and Normal Slab Column Structure System

    Institute of Scientific and Technical Information of China (English)

    王杰; 史佳培

    2015-01-01

    错层板柱结构用地率高、层高低、造价节约,在停车库建筑中应用广泛[1]。但错层使楼板错置,削弱了楼板协调结构整体受力的性能。同时形成竖向短构件,受力集中。本文通过时程分析法对对两种结构进行水平地震作用下弹塑性分析,找出错层板柱结构的的抗震薄弱点。%Staggered floor slab column structure has high land use rate, low layer and low cost, so it is widely used in parking building. But the staggered floor will weaken the performance of internal force coordination. At the same time it forms the short component and causes the stress concentration. In this paper, the elastic plastic analysis of two kinds of structure is conducted through the time history analysis under horizontal earthquake action to find out the weak points of the staggered floor slab column structure.

  2. A Method of Assembling Wall or Floor Elements

    DEFF Research Database (Denmark)

    2002-01-01

    The invention relates to a method of constructing, at the site of use, a building wall (1) or a building floor (1) using a plurality of prefabricated concrete or lightweight concrete plate-shaped wall of floor elements (10), in particular cast elements, which have a front side and a rear side...... as well as longitudinal side edges faces (12), wherein the elements (10), in a first step, are arranged at the site of use in mutual extension and then, in a second step, are connected with each other by means of at least one force-transferring device to form a tight connection. The invention...... is characterized in that a circular ring-shaped depression (20) is provided on the front side and/or the rear side of two adjoining elements (10) after the first step, said circular ring-shaped depression extending in the one as well as the other element (10), that the force-transferring device is a pipe (25...

  3. Application of floating ballast concrete floor slab at diversion tunnel of Baoxing Hydropower Project%浮碴混凝土底板在宝兴水电站引水隧洞中的应用

    Institute of Scientific and Technical Information of China (English)

    尹坤; 胡嘉航

    2014-01-01

    For the diversion tunnel of Baoxing Hydropower Project,field floating ballast concrete floor slab lifting test against external water pressure was conducted during construction. With reference to the testing results and the experience of similar projects,the original plain concrete floor slab construction scheme was optimized and floating ballast concrete floor slab scheme was adopted for the tunnel sections with II~III category surrounding rock ,which had played an active role in cost control and accelerating construction progress due to simplified floor slab cleaning procedures,reduced concrete slab thickness,increased drainage holes on base slab and walls.%在宝兴水电站引水隧洞底板施工过程中,通过现场浮碴混凝土底板抗外水抬动试验,并参考类似工程经验,对原素混凝土底板施工方案进行了优化,在部分Ⅱ-Ⅲ类围岩洞段采用浮碴混凝土底板,简化了底板清理的施工工序,降低了底板混凝土厚度,增加了混凝土底板及边墙排水孔,对控制投资、加快施工进度起到了积极作用。

  4. A new method for designing floor slabs on grade due to the difficulty of applying simplified design methods, amongst them being the Portland Cement Association (PCA and Wire Reinforcement Institute (WRI methods

    Directory of Open Access Journals (Sweden)

    Hugo Ernesto Camero Sanabrial

    2010-04-01

    Full Text Available This article presents a methodology for designing slabs on grade for industrial floors where there is an eccentricity between the slab centroid and the gravity centre loads of the loaded axle of forklift trucks travelling over the floor. An example was used for analysing how Portland Cement Association (PCA and the Wire Reinforcement Institute (WRI methods are inadequate for designing floors sublected to this condition. The new proposal for designing slabs on grade for industrial floors has been called the Camero method. An example of an industrial floor designed to be capable of sustaining an infinite number of load applications (or 50-year life was compared to the results of the Camero method and PCA and WRI’s simplified methods. Industrial floors should be capable of sustaining an infinite number of load applications (50-year life if designed with the Camero method; on the other hand, if designed using PCA and WRI methods they will only last one year (in this example the number of axle load applications in a 1-year period was equal to the number of allowable repetitions because they will not be able to sustain an infinite number of load applications. It was concluded that designing plain concrete slabs (without reinforcement on grade according to PCA and the WRI methods leads to slab fatigue, even though extreme fibre stress should not exceed 50 percent (50% of static modulus of concrete rupture and slabs should sustain an infinite number of load repetitions (infinite amount of forklift truck traffic were considered parameters in their design.

  5. Analysis of the Effect of Cast-in-situ Floor Slab on the Seismic Performance of Frame Structure%考虑现浇楼板影响的框架结构抗震性能分析

    Institute of Scientific and Technical Information of China (English)

    应乘风; 唐兴荣

    2014-01-01

    为了研究现浇楼板对钢筋混凝土框架结构抗震性能的影响,文章利用 pushover 方法对3个钢筋混凝土框架结构模型进行了分析研究,包括不考虑现浇楼板、考虑现浇楼板以及考虑现浇楼板钢筋影响的空间框架结构。通过对计算结果进行分析比较得出一些结论,并对框架结构抗震设计给出一些建议,提出考虑楼板影响的框架结构抗震设计方法,可供实际框架结构设计时参考。%To study the effect of cast-in-situ floor slab on the seismic performance of reinforced con-crete frame structure,three reinforced concrete frame structure models were analyzed by pushover analysis in this paper,the first with no considering the effect of cast-in-situ floor slab,the second considering the effect of cast-in-situ floor slab,and the third considering the effect of cast-in-situ floor slab steel.Conclusions were obtained by analyzing and comparing the results and frame structure seismic design suggestions were pro-posed.The seismic design method with considering the effect of the cast-in-situ floor slab on frame structure was proposed to be referred in the actual frame structure design.

  6. Experimental assessment of improvements in thermal performance from insulating the thermal bridge at the edge of a floor slab

    Directory of Open Access Journals (Sweden)

    N. Arias Jiménez

    2017-06-01

    Full Text Available The problematic of the article rises from the need of improving the thermal quality of the built envelope in the wall complex, specifically in the case of reinforced concrete (most used material in high-rise housing in Chile. Considering the use of insulation on the inside face of the wall, interrupts the continuity of the insulating material where the mezzanine slab and the perimeter walls meet, generating a thermal bridge known as mezzanine front. The purpose then, is to know the impact of the mentioned thermal bridge studying its properties through experimental tests on a thermal chamber. Later, the results will be integrated to a case of study that allows establishing the incidence of the bridge in the overall energetic behavior of through the integration of the results into the Thermal Analysis Simulation software (Tas. Finally, it is concluded a low incidence in the inner heat loses, becoming relevant the behavior of the superficial temperatures.

  7. Technical and economic iimpact factor analysis on unbonded prestressed concrete flat slab floor%无粘结预应力混凝土无梁楼盖的技术经济影响因素分析

    Institute of Scientific and Technical Information of China (English)

    李天成

    2009-01-01

    From the slab span, load rating, prestressed Np values, the market price of the labour material and machine several aspects ,this paper analysis of unbonded prestressed concrete flat plate slab with ordinary concrete fiat plate slab in the consumption of concrete and common steel bar consumption besides project cost per unit area of the different, and its Technical and economic impact on the design of fiat slab floor , then strive to explore a reasonable unbonded prestressed concrete flat slab floor design method.%文章通过无粘结预应力混凝土无梁楼盖与普通混凝土无梁楼盖在混凝土消耗量、普通钢筋消耗量、单位面积工程造价方面研究楼板跨度、荷载等级、预应力Np取值、人材机市场价格对楼盖设计的技术经济性影响,力求探索出合理的无粘结预应力混凝土无梁楼盖设计方法.

  8. 地下室顶板开大洞对嵌固能力的影响%Influence of Large Openings on Fixed Ability of Floor Slabs in a Basement

    Institute of Scientific and Technical Information of China (English)

    马泽峰

    2012-01-01

    针对建筑设计中普遍存在的、为满足某些功能要求而在地下室顶板开设若干较大洞口,从而对地下室顶板的嵌固能力造成一定削弱的情况,从地下室顶板开洞长度、位置等方面入手,通过算例分析,以周期、顶点位移及地震力传递等定量地评价各因素影响水平.详细讨论了楼板在结构中的作用、影响楼板性能的主要因素、影响地下室顶板嵌固能力的主要因素以及计算程序中的楼板单元特性.并以地下室顶板开大洞的实例工程,阐述了对于此类问题的处理措施及效果,明确设计思路,为相似工程提供参考.%In order to satisfy some special functions, large openings must be excavated in floor slabs of basements. These openings would weaken the fixed ability of floor slabs. Based on calculation examples, the functions of floor slabs in structrues are discussed starting from the facets of the opening's length and location on the floor. The factors of period, peak displacement, earthquake force transfer are precisely assessed. Characteristic of floor element in analysis program are introduced. Based on an engineering example of large openings in a basement floor, treatment , designing consideration and results are illustrated for the reference of similar projects.

  9. 谈现浇混凝土楼板裂缝的成因及控制措施%Talking on cracking causes and controlling measures of cast-in-situ concrete floor slab cracks

    Institute of Scientific and Technical Information of China (English)

    白洁

    2012-01-01

    To begin with the types and forms of floor slab cracks,the essay analyzes causes of cast-in-situ concrete floor slab cracks,explores the crack controlling measures,and then introduces the crack processing methods,which has significant guiding meaning for improving construction engineering quality.%从楼板裂缝的种类及形式入手,针对现浇混凝土楼板产生的原因进行了分析,探讨了裂缝的控制措施,同时介绍了裂缝的处理方法,对提高建筑工程质量具有重要的指导意义。

  10. Detection and analysis on the floor-slab cracks of a high-rise residential building%某高层住宅楼楼板裂缝检测及分析

    Institute of Scientific and Technical Information of China (English)

    丘晋文

    2012-01-01

    通过对某高层住宅楼楼板出现的裂缝进行现场检测,分析了裂缝产生的原因,指出该建筑楼板裂缝为混凝土收缩变形裂缝,建议采用环氧树脂注浆进行封闭处理。%Through in-situ detection on the floor-slab cracks of a high-rise residential building,the paper analyzes cracking causes,and then points out that floor-slab cracks belong to concrete contraction deformation cracks,which should be closed and treated with epoxy resin for casting.

  11. The construction technology of cast-in-place hollow floor slab two casting instant-formation%现浇空心楼板二次浇筑一次成型施工技术

    Institute of Scientific and Technical Information of China (English)

    王志宏

    2012-01-01

    Combined with the subsidiary comprehensive building project of ICBC Shanxi branch,mainly described the features,technological process,construction method,quality control,safety measures of cast-in-place hollow floor slab,the floor slab structure of above ground fifteen floors used cast-in-place hollow beamless floor structure system,had good construction quality,gained the praise of construction units and related departments.%结合中国工商银行山西省分行附属综合楼工程,主要叙述了现浇空心楼板特点,工艺流程,施工方法,质量控制,安全措施,地上15层部分楼板结构采用现浇空心无梁楼盖结构体系,施工质量好,得到了建设单位和有关部门的好评。

  12. Analysis and Prevention about the Causes of Cracks on the Reinforced Concrete Cast-in-Place Floor Slab%混凝土现浇楼板裂缝的分析与防控

    Institute of Scientific and Technical Information of China (English)

    王振平

    2015-01-01

    In high-rise residential buildings,reinforced concrete frame cast-in-place reinforced concrete floor slab was widely used. But it was found that cracks often appeared in use of cast-in-place floor slab, cracks had brought many adverse effects to the unit and the owners. Aiming at the phenomenon,this paper analyzed the crack causes and proposed prevention and control measures.%在高层住宅建筑中,钢筋混凝土框架及钢筋混凝土现浇楼板被广泛采用。但在使用中发现,现浇楼板常出现裂缝,裂缝的产生给使用单位和业主带来了诸多不利影响。针对该现象,分析现浇楼板裂缝成因,并提出防控措施。

  13. Application of Engineered Cementitious Composites (ECC) in modular floor panels

    DEFF Research Database (Denmark)

    Lárusson, Lárus Helgi; Fischer, Gregor; Jönsson, Jeppe

    2008-01-01

    This paper describes the design, manufacturing, and structural behavior of a prefabricated floor panel consisting of a modular assembly of a thin-walled ECC slab and steel truss girders. The features of this composite structure include light weight, the modular manufacturing process...... with adaptability to various loading requirements, and the efficient utilization of material resources and industrial byproducts. The work described in this paper is a continuation of previous activities on composite floor panels in which light gage steel joists were integrally cast with the ECC slab. The modular...... concept introduced in this paper aims at improvements in the manufacturing process of the panels by casting the ECC slab separately and subsequently joining it with the steel trusses. The focus of this paper is on design and manufacturing of a prototype modular panel and on its structural behavior under...

  14. 现浇混凝土空心楼盖在工程中的应用%Cast-in-situ Concrete Hollow Floor Slab in Engineering Application

    Institute of Scientific and Technical Information of China (English)

    潘向军; 王守君; 张静芳

    2012-01-01

    介绍了现浇混凝土空心楼盖结构体系的特点及设计思路和方法,并结合某地下停车场工程的设计实例,说明了现浇混凝土空心楼盖技术在工程中的应用.%This paper introduces the cast-in-situ concrete hollow floor structure system characteristic and its design ideas and methods. Combining some underground parking garage engineering design examples籺he cast-in-situ concrete hollow floor technique apply in the project is illustrated.

  15. Effect of cast-in-situ floor slab on collapse modes of RC frame structures under earthquake%现浇楼板对钢筋混凝土框架结构倒塌模式的影响

    Institute of Scientific and Technical Information of China (English)

    汪小林; 顾祥林; 印小晶; 黄庆华

    2013-01-01

    地震作用下钢筋混凝土框架结构通常呈现弱柱型破坏模式而倒塌.针对其破坏特征,将钢筋混凝土框架结构离散为“板-柱”和“梁-柱-节点”体系,结合块体间碰撞作用的冲量模型,基于离散单元法建立考虑构件间碰撞作用的钢筋混凝土框架结构空间倒塌反应计算机仿真系统,并通过2个框架结构模型的倒塌试验对其进行了验证.利用计算机仿真系统模拟分析了现浇楼板对钢筋混凝土框架结构倒塌模式的影响.结果表明:考虑块体间碰撞作用的框架结构倒塌仿真系统可以真实再现地震作用下框架结构的倒塌过程和废墟堆积情况;考虑楼板影响时,强柱型框架结构可能会出现弱柱型倒塌,局部倒塌型框架结构则可能不倒或呈弱柱型倒塌;框架结构抗震设计或评定中应充分考虑现浇楼板对框架抗震性能的影响.%RC frame structures severely damaged, even collapsed in weak column mode were well documented during the past post-earthquake investigations. A collapse simulation system for RC frame structures based on discrete element method was established by discretizing a structure into slab-column discrete system or beam-column-joint discrete system according to the failure characteristic of RC frame structures, and revised with consideration of collision behaviors among fractured components with impulse-based impact model between concrete blocks. The proposed collapse simulation system was effectively verified with two collapse experiments on small-scale frame models. Further simulation was carried out to explore the effect of cast-in-situ floor slab on the collapse performance of RC frame structures under earthquake. The results indicate that, the whole collapse process of a frame structure including debris stacking can be visually simulated by the collapse simulation system with consideration of collision actions among fractured components; due to the effect of cast

  16. The reinforced concrete floor slab crack control in structure design%结构设计中钢筋混凝土楼板裂缝的控制

    Institute of Scientific and Technical Information of China (English)

    柯一沙; 冯东

    2016-01-01

    This paper introduced the kinds and forms of reinforced concrete floor cracks,from the structure design,analyzed the crack reasons, and discussed the measures control of reinforced concrete floor cracks,aimed to guarantee the construction quality of building,extended the building service life.%介绍了钢筋混凝土楼板裂缝的种类和形式,从结构设计的角度,分析了裂缝的产生原因,并探讨了控制钢筋混凝土楼板裂缝产生的措施,旨在保证建筑的施工质量,延长建筑的使用年限。

  17. Moisture redistribution in screeded concrete slabs

    OpenAIRE

    Åhs, Magnus

    2007-01-01

    The principal objective for this licentiate thesis is to develop a methodology and evaluation model in order to make the future relative humidity in a screeded concrete slab predictable. Residual moisture in screeded concrete slabs may redistribute to the top screed surface under semi-permeable flooring, thus elevating the relative humidity, RH, and possibly exceed the critical humidity level. Passing the critical humidity level may result in material damages on the flooring and adhesive. ...

  18. 表面设置防火涂料的压型钢板混凝土组合楼板耐火性能有限元分析%The Finite Element Analysis of the Pressed Steel Concrete Composite Floor Slab Fire Performance by Setting the Fire Retardant Coating

    Institute of Scientific and Technical Information of China (English)

    段静; 麦志亨; 欧俊宏

    2014-01-01

    This article aims at the completed fire test of pr-essed steel concrete composite floor slab and uses the finite element analysis software ABQUAS to discuss the new set fire retardant coating thickness under the ISO834 standard heating environment, and analyzes the internal temperature field distri-bution influence of pressed steel concrete composite floor slab.%本文针对已完成明火试验的压型钢板混凝土组合楼板,利用ABQUAS 有限元分析软件,探讨了ISO834标准升温环境下新型防火涂料设置厚度,对压型钢板混凝土组合楼板的内部温度场分布的影响做了分析。

  19. Novel Radon Sub-Slab Suctioning System

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    the zone below the ground-floor construction. For this purpose a new system of prefabricated lightweight elements is introduced. The effectiveness of the system is demonstrated for the case of a ground-floor reinforced concrete slab situated on top of a rigid insulation layer (consisting of a thermal......A new principle for radon protection is currently presented which makes use of a system of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground-floor slab. The function of this system is based on the principles of pressure reduction within...... a grid of horizontal air ducts with low pressure which are able to remove air and radon from the ground. Results showed the system to be effective in preventing radon infiltrating from the ground through the ground-floor slab, avoiding high concentrations of radon being accumulated inside houses...

  20. “陡坡+跌坎”式消力池板块稳定特性试验研究%Experimental Study on Stilling Basin with Step-down for Floor Slab Stability Characteristics

    Institute of Scientific and Technical Information of China (English)

    罗永钦; 何大明; 张绍春; 白绍学

    2012-01-01

    Floor slab stability of stilling basin with step-down was studied by using a 1:40 physical model. With hydraulic jump occurring in the slope, distribution characteristics of fluctuation pressure and lifting load in the stilling basin was obtained. It was found that the first location of hydraulic jump with the large fluctuation pressure was most prone to instability. The position under step-down was also an instable area when the single-wide discharge reached a certain value. Further analysis indicated that the root-mean-square( RMS) of lifting load was about 0. 55 times than that of fluctuation pressure in the first region of hydraulic jump,0. 2 times than that of other regions;the biggest lifting load was about 4. 2 times than RMS of fluctuation pressure, 1.5 times than that of other regions. The results revealed that the control indicator of stilling basin with step-down was consistent with deflecting and drop stilling basin; lifting load was effectively reduced by using permeable floor slab, and decrease trend was basically exponential distribution with increasing opening ratio.%通过大比尺(1∶40)物理模型,对某大型水电工程溢洪道“陡坡+跌坎”式消力池这一新型消能工底板稳定性进行了试验研究,得到了水跃完全或部分发生在陡坡段时,消力池不同位置板块的脉动压力、板块上举力频幅特性的分布规律与特征.试验表明水跃跃首部位始终是板块最易失稳区域,当单宽流量达到一定值后,跌坎下一段区域也是失稳重点关注区.对试验结果深入分析后表明:水跃跃首区域上举力均方根大致为脉动压力均方根0.55倍,其它区域为0.2倍,水跃跃首区域最大上举力大致为4.2倍脉动压力均方根,其它区域为1.5倍.揭示了此消能工上举力与脉动压力点面转换指标、底板稳定控制指标与挑跌流消力池的一致性;而消力池平底段采用透水底板可有效降低板块上举力,减小响应趋势基

  1. Floor interaction

    DEFF Research Database (Denmark)

    Petersen, Marianne Graves; Krogh, Peter; Ludvigsen, Martin;

    2005-01-01

    Within architecture, there is a long tradition of careful design of floors. The design has been concerned with both decorating floors and designing floors to carry information. Ubiquitous computing technology offers new opportunities for designing interactive floors. This paper presents three...... different interactive floor concepts. Through an urban perspective it draws upon the experiences of floors in architecture, and provides a set of design issues for designing interactive floors....

  2. Prefabricated floor panels composed of fiber reinforced concrete and a steel substructure

    DEFF Research Database (Denmark)

    Lárusson, Lárus H.; Fischer, Gregor; Jönsson, Jeppe

    2013-01-01

    loading at the serviceability and ultimate limit states. The composite construction concept offers flexibility in the assembly process, the ability to adapt to various load and boundary requirements, and efficient utilization of material properties that result in a light weight prefabricated structural......This paper reports on a study on prefabricated composite and modular floor deck panels composed of relatively thin fiber reinforced concrete slabs connected to steel substructures. The study focuses on the design, manufacturing, structural improvements and behavior of the floor systems during...... detailing of these integrally cast deck panels and to modify them by providing individually cast anchor points in the precast ECC slab, which are subsequently used to attach a steel truss substructure.Full-scale experiments were carried out to verify the structural behavior of the integrally cast panels...

  3. Shear and Anchorage Behaviour of Fire Exposed Hollow Core Slabs

    NARCIS (Netherlands)

    Fellinger, J.H.H.

    2004-01-01

    Hollow core (HC) slabs are made of precast concrete with pretensioned strands. These slabs are popular as floor structures in offices and housing. At ambient conditions, the load bearing capacity can be dominated by four different failure modes, i.e. flexure, anchorage, shear compression and shear t

  4. Shear and Anchorage Behaviour of Fire Exposed Hollow Core Slabs

    NARCIS (Netherlands)

    Fellinger, J.H.H.

    2004-01-01

    Hollow core (HC) slabs are made of precast concrete with pretensioned strands. These slabs are popular as floor structures in offices and housing. At ambient conditions, the load bearing capacity can be dominated by four different failure modes, i.e. flexure, anchorage, shear compression and shear

  5. Radon Sub-slab Suctioning System Integrated in Insulating Layer

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    This poster presents a new radon sub-slab suctioning system. This system makes use of a grid of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground floor slab. For this purpose a new system of prefabricated lightweight elements is introduced...

  6. Shear and Anchorage Behaviour of Fire Exposed Hollow Core Slabs

    NARCIS (Netherlands)

    Fellinger, J.H.H.

    2004-01-01

    Hollow core (HC) slabs are made of precast concrete with pretensioned strands. These slabs are popular as floor structures in offices and housing. At ambient conditions, the load bearing capacity can be dominated by four different failure modes, i.e. flexure, anchorage, shear compression and shear t

  7. 装配箱混凝土空心楼盖结构受力性能试验研究%EXPERIMENTAL STUDY ON MECHNICAL PERFORMANCE OF ASSEMBLY BOX CONCRETE HOLLOW FLOOR STRUCTURE WITH ASSEMBLY STYLE

    Institute of Scientific and Technical Information of China (English)

    赵考重; 李自然; 王莉; 孙双军; 房晓朋; 王超

    2011-01-01

    Assembly Box Concrete Hollow Floor is a new-style whole structure-with a cross section of a concrete box composed of small prefabricated components (concrete superposition box) and a cast-in-place concrete rib beam. The mechanical performance of the structure is analyzed in this paper based on the experiment with the test blocks of assembly box concrete hollow floor, and the failure mechanism affected by the load of floor is obtained. The findings prove that the prefabricated box and the cast-in-place concrete rib beam could interact, and in the calculation of floor framing design, a simplified flexural computing could be used, and each rib beam is taken as one computing unit. The top floor of the box could be used as the compressed flange, and the effective width of the compressed flange could be the sum of the two smaller figures, which are of the depth of 12 times of the box floor and the width of the cross section and the net span of a rib beam. The steel bars installed in the tensile area of the bottom floor of the box could fully exert its role, which could be taken into account in the flexural computing. The rack space and width in the bottom box floor of the tensile area are different from the cracks of the rib beam. The crack of the floor should be computed in accordance with reinforced concrete axial tension components, and that of the rib beam should be done according to the flexural member.%装配箱混凝土空心楼盖是一种新型的楼盖形式,是由小型预制构件(混凝土叠合箱)与现浇混凝土肋梁结合成具有连续箱型截面的整体结构.该文通过对装配箱混凝土空心楼板试件的试验,分析了该结构的受力性能,得到了楼盖在荷载作用下的破坏机理.通过分析得到预制箱体与现浇混凝土肋梁能够共同工作,在进行楼盖设计计算时,可简化为T型截面进行抗弯计算.抗弯计算时,每根肋梁为一个计算单元,箱体的顶板(底板)可作为肋梁的受压翼缘,

  8. Influence of concrete slabs on lateral torsional buckling of steel beams

    NARCIS (Netherlands)

    Maljaars, J.; Snijder, H.H.; Hoenderkamp, J.C.D.

    2007-01-01

    The use of pre-cast concrete floor slabs in steel framed structures is quite common. In the de-sign of the steel beams, the lateral restraining effect of the pre-cast concrete slab is normally safely neglected. However, the concrete slab will provide some horizontal restraint, even without special p

  9. Comparison of environmental impacts of building structures with in situ cast floors and with precast concrete floors

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Mesa, Belinda; Pitarch, Angel; Tomas, Ana; Gallego, Teresa [Department of Mechanical Engineering and Construction (ESTCE), Universitat Jaume I, Av. Sos Baynat s/n, Castellon 12071 (Spain)

    2009-04-15

    In this paper, the environmental impacts of two types of slab systems are studied. The first type, a concrete-based one-way spanning slab, is the most common solution in residential buildings in Spain. The second type, a hollow core slab floor, is increasingly becoming more used in buildings, but is not being broadly used in residential buildings as yet. The study is undertaken through the Life Cycle Analysis methodology, applying the EPS 2000 method. The assessment shows that the environmental impact of a building structure with precast concrete floors is 12.2% lower than that with in situ cast floors for the defined functional unit. (author)

  10. Recent research and development in semi-rigid composite joints with precast hollowcore slabs

    OpenAIRE

    Lam, D

    2008-01-01

    Composite structure incorporating steel beams and precast hollowcore slabs is a recently developed composite floor system for building structures. This form of\\ud composite construction is so far limited to simple beam-column connections. Although the concept of semi-rigid composite joints has been widely research in the\\ud past, most of the researches have been carried out on composite joints with metal deck flooring and solid concrete slabs. Research on composite joints with precast\\ud holl...

  11. Influence of cast-in-place floor slab on damage style of frame structures under earthquake%现浇楼板对钢筋混凝土框架结构在地震作用下破坏形式的影响

    Institute of Scientific and Technical Information of China (English)

    阎红霞; 杨庆出; 李吉涛

    2011-01-01

    Many reinforced concrete (RC) frame structures were severely damaged or even collapsed during the May 12, 2008 great Wenchuan earthquake. Based on survey data collected in Dujiangyan, it was found that plastic hinges appeared at column end, instead of beam end, in many frame structures. This did not coincide with "strong column-weak beam" seismic design criterion. It was believed that one of the main reasons was insufficiently understanding the cast-in-place floor slab effect on frame structures. Applying finite element software ABAQUS, 3D elastic-plastic time history simulation of a "strong beam -weak column" RC frame structure in Dujiangyan was analyzed to probe the influence of cast-in-slab on frame seismic performance from structural view. Results showed that RC frame designed according to current codes usually can not achieve "strong column-weak beam" yield mechanism. The numerical results suggested that the rebar in the width of six times of the plate thickness may take part in calculating the bearing capacity of negative moment at the beam end; the model of a frame structure with floor slab is suitable for analyzing the elastic-plastic deflection of frame structures under rare big earthquakes.%“5.12”汶川地震造成一些钢筋混凝土框架结构损坏甚至倒塌.灾后调查发现,框架结构震害特点也一是柱端而非梁端出现塑性铰的“强梁弱柱”破坏形式,这与结构抗震设计概念中的“强柱弱梁”不符.国内外研究表明现浇楼板增大了梁端抗负弯承载力,但其对整个框架结构屈服机制的影响研究依然不足.针对这种现象,应用有限元软件ABAQUS对汶川地震中都江堰市某典型“强梁弱柱”框架进行三维动力弹塑性时程数值模拟,着重从结构角度上分析了现浇楼板对框架结构抗震性能的影响、探讨了负弯矩作用下梁端有效翼缘的取值.经分析,发现按照目前我国规范设计的框架在遭遇大震时较难实观“

  12. Fire resistance of extruded hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    2017-01-01

    Purpose – Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60 and 120 min found...... in most national building regulations. The paper aims to present a detailed analysis of the mechanisms responsible for the loss of loadbearing capacity of hollow-core slabs when exposed to fire. Design/methodology/approach – Furthermore, it compares theoretica calculation and assessment according...... to the structural codes with data derived from a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs. Findings – Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found. Originality...

  13. Fire resistance of extruded hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Giuliani, Luisa; Sørensen, Lars Schiøtt

    2016-01-01

    Prefabricated extruded hollow-core slabs are preferred building components for floor structures in several countries. It is therefore important to be able to document the fire resistance of these slabs proving fulfilment of standard fire resistance requirements of 60- and 120 minutes found in most...... national building regulations. The paper presents a detailed analysis of the mechanisms responsible for the loss of load-bearing capacity of hollow-core slabs when exposed to fire. Furthermore, it compares theoretical calculation and assessment according to the structural codes with data derived from...... a standard fire test and from a thorough examination of the comprehensive test documentation available on fire exposed hollow-core slabs. Mechanisms for loss of load-bearing capacity are clarified, and evidence of the fire resistance is found. For the first time the mechanisms responsible for loss of load...

  14. Managing Coil Epoxy Vacuum Impregnation Systems at the Manufacturing Floor Level To Achieve Ultimate Properties in State-of-the-Art Magnet Assemblies

    CERN Document Server

    Hubrig, Jeffrey G

    2005-01-01

    Liquid epoxy resin impregnation systems remain a state-of-the-art polymer material for vacuum and vacuum/pressure impregnation applications in the manufacture of both advanced and conventional coil winding configurations. Epoxy resins inherent latitude in processing parameters accounts for their continued popularity in engineering applications, but also for the tendency to overlook or misinterpret the requisite processing parameters on the manufacturing floor. Resin system impregnation must be managed in detail in order to achieve device life cycle reliability. This closer look reveals how manufacturing floor level management of material acceptance, handling and storage, pre- and post- impregnation processing and cure can be built into a manufacturing plan to increase manufacturing yield, lower unit cost and ensure optimum life cycle performance of the coil.

  15. Managing Coil Epoxy Vacuum Impregnation Systems at the Manufacturing Floor Level To Achieve Ultimate Properties in State-of-the-Art Magnet Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    J.G. Hubrig; G.H. Biallas

    2005-05-01

    Liquid epoxy resin impregnation systems remain a state-of-the-art polymer material for vacuum and vacuum/pressure impregnation applications in the manufacture of both advanced and conventional coil winding configurations. Epoxy resins inherent latitude in processing parameters accounts for their continued popularity in engineering applications, but also for the tendency to overlook or misinterpret the requisite processing parameters on the manufacturing floor. Resin system impregnation must be managed in detail in order to achieve device life cycle reliability. This closer look reveals how manufacturing floor level management of material acceptance, handling and storage, pre- and post- impregnation processing and cure can be built into a manufacturing plan to increase manufacturing yield, lower unit cost and ensure optimum life cycle performance of the coil.

  16. Radon Sub-slab Suctioning System Integrated in Insulating Layer

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    2013-01-01

    of prefabricated lightweight elements were introduced and demonstrated. The principle was demonstrated on a concrete ground slab floor with a concrete slab on top of a thermal insulation layer above a capillary-breaking layer mounted on stable ground. The thermal insulation and the capillary-breaking layer...... consisted of a rigid insulation material. The new solution integrates the capillary-breaking layer and a pressure reduction zone,denoted the radon–suctioning layer, in one element. The new solution introduces the radonsuctioning layer as a horizontal grid of air ducts with low pressure to catch air...

  17. Behaviour Of Multi-Storied Flat Slab Building Considering Shear Walls: A Review

    Directory of Open Access Journals (Sweden)

    Dhanaji R. Chavan

    2016-10-01

    Full Text Available Recently there has been a considerable increase in the number of tall buildings, both residential and commercial, and modern trend is towards taller structures. Flat slab is most widely used systems in reinforced concrete construction. Flat-slab building structures possesses major advantages over traditional slab-beam-column structures taking a advantages of reduced floor height, shorter construction time, architectural –functional and economical aspects. But in flat slab building columns are directly provides supports to slab with eliminating beams so there is requirement of provision of shear walls to increase the stiffness of building against lateral forces. Shear wall system are one of the most commonly used lateral load resisting in high rise building. Shear wall has high in plane stiffness and strength. The present paper reviews various research works carried out by several researchers on multi-storied buildings provided with flat slab and shear walls.

  18. Processing and properties of large-sized ceramic slabs

    Directory of Open Access Journals (Sweden)

    Fossa, L.

    2010-10-01

    Full Text Available Large-sized ceramic slabs – with dimensions up to 360x120 cm2 and thickness down to 2 mm – are manufactured through an innovative ceramic process, starting from porcelain stoneware formulations and involving wet ball milling, spray drying, die-less slow-rate pressing, a single stage of fast drying-firing, and finishing (trimming, assembling of ceramic-fiberglass composites. Fired and unfired industrial slabs were selected and characterized from the technological, compositional (XRF, XRD and microstructural (SEM viewpoints. Semi-finished products exhibit a remarkable microstructural uniformity and stability in a rather wide window of firing schedules. The phase composition and compact microstructure of fired slabs are very similar to those of porcelain stoneware tiles. The values of water absorption, bulk density, closed porosity, functional performances as well as mechanical and tribological properties conform to the top quality range of porcelain stoneware tiles. However, the large size coupled with low thickness bestow on the slab a certain degree of flexibility, which is emphasized in ceramic-fiberglass composites. These outstanding performances make the large-sized slabs suitable to be used in novel applications: building and construction (new floorings without dismantling the previous paving, ventilated façades, tunnel coverings, insulating panelling, indoor furnitures (table tops, doors, support for photovoltaic ceramic panels.

    Se han fabricado piezas de gran formato, con dimensiones de hasta 360x120 cm, y menos de 2 mm, de espesor, empleando métodos innovadores de fabricación, partiendo de composiciones de gres porcelánico y utilizando, molienda con bolas por vía húmeda, atomización, prensado a baja velocidad sin boquilla de extrusión, secado y cocción rápido en una sola etapa, y un acabado que incluye la adhesión de fibra de vidrio al soporte cerámico y el rectificado de la pieza final. Se han

  19. Super-light concrete decks for building floor slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Castberg, Niels Andreas; Christensen, Jacob

    2014-01-01

    to flexibility, sound insulation and fire resistance compared with present-day prefabricated structures. Full-scale tests and theoretical investigations show that the deck structure performs as intended. Also, that it is possible to assess by calculation the loadbearing capacity in bending and shear, and assess......This paper presents investigations carried out at the Technical University of Denmark (DTU) on a prototype series for a super-lightweight prestressed concrete deck element called the SL-Deck. The intention behind making a new prefabricated deck element is to improve performance with respect...... the pull-out strength of prestressing wires, the fire resistance and the acoustic insulation. Based on the results of the investigations, recommendations are given for further development of the structure before fully automated mass production is established....

  20. Slab Leaf Bowls

    Science.gov (United States)

    Suitor, Cheryl

    2012-01-01

    In science class, fourth graders investigate the structure of plants and leaves from trees and how the process of photosynthesis turns sunlight into sugar proteins. In this article, the author fuses art and science for a creative and successful clay slab project in her elementary art classroom. (Contains 1 online resource.)

  1. Slab Leaf Bowls

    Science.gov (United States)

    Suitor, Cheryl

    2012-01-01

    In science class, fourth graders investigate the structure of plants and leaves from trees and how the process of photosynthesis turns sunlight into sugar proteins. In this article, the author fuses art and science for a creative and successful clay slab project in her elementary art classroom. (Contains 1 online resource.)

  2. Moisture properties of self-levelling flooring compounds

    OpenAIRE

    Anderberg, Anders

    2004-01-01

    Self-levelling flooring compounds (SLC) are used to level substrates (mainly concrete slabs) before applying final floor coverings. Although it is an extensively used product, only limited research has so far been published concerning their moisture properties. This report focuses on moisture properties of SLC and describes methods for determining them. Moisture properties of materials are important for the calculation of drying times and moisture loads and for prediction of ion transport and...

  3. Pelvic Floor Disorders

    Science.gov (United States)

    ... NICHD Research Information Clinical Trials Resources and Publications Pelvic Floor Disorders: Condition Information Skip sharing on social media links Share this: Page Content What is the pelvic floor? The term "pelvic floor" refers to the group ...

  4. Introductory guide to floors and flooring

    CSIR Research Space (South Africa)

    Billingham, PA

    1977-01-01

    Full Text Available ........................................................................ Soft floor coverings 39 Carpets ......................................................................................... 40 Laying carpets ............................................................................. 44 Wooden floors... the glue that holds the finish, causing woodwork to swell and some carpets to rot. It can carry with it dissolved salts from thesoil and thegarden and deposit theseon the floor, spoiling the finish and even flaking stonework. Water vapour can sometimes...

  5. Determination of reinforcing bars for tests of hollow core slabs with continuity

    Directory of Open Access Journals (Sweden)

    A. P. Santos

    Full Text Available The structural designs of floors formed by hollow core slabs usually consider these as simply-supported slabs. In recent years there have been project changes and hollow core slabs with continuity are widely used. The objective of this study is to suggest a way to calculate the reinforcement bars to be used in tests with continuity provided by a structural topping. Thus, this paper presents a method based on the maximum positive resistance moment and maximum shear strength of a hollow core slab. The method is applied to a test in hollow core slab specimens which have the following dimensions: 2 m width, 6 m long, and 21 cm high. The results indicated that the method was satisfactory to the performed test, and can therefore be applied to the other test configurations or even designs.

  6. The Combine Use of Semi-destructive and Non-destructive Methods for Tiled Floor Diagnostics

    Science.gov (United States)

    Štainbruch, Jakub; Bayer, Karol; Jiroušek, Tomáš; Červinka, Josef

    2017-04-01

    The combination of semi-destructive and non-destructive methods was used to asset the conditions of a tiled floor in the historical monument Minaret, situated in the park complex of the Chateau Lednice (South Moravia Region, Czech Republic), before its renovation. Another set of measurements is going to be performed after the conservation works are finished. (The comparison of the results collected during pre- and post-remediation measurements will be known and presented during the General Assembly meeting in Wien.) The diagnostic complex of methods consisted of photogrammetry, resistivity drilling and georadar. The survey was aimed to contour extends of air gaps beneath the tiles and the efficiency of filling gaps by means of injection, consolidation and gluing individual layers. The state chateau Lednice creates a part of the Lednice-Valtice precinct, a UNESCO landmark, and belongs among the greatest historic monuments in Southern Moravia. In the chateau park there is a romantic observation tower in the shape of a minaret built according to the plans of Josef Hardtmuth between 1798-1804. The Minaret has been extensively renovated for many decades including the restoration of mosaic floors from Venetian terazzo. During the static works of the Minaret building between 1999-2000, the mosaic floors in the rooms on the second floor were transferred and put back onto concrete slabs. Specifically, the floor was cut up to tiles and these were glued to square slabs which were then attached to the base plate. The transfer was not successful and the floor restoration was finalized between 2016-2017. The damage consisted in separating the original floor from the concrete plate which led to creating gaps. Furthermore, the layers of the floor were not compact. It was necessary to fill the gaps and consolidate and glue the layers. The existence of air gap between individual layers of the tiles and their degradation was detected using two different diagnostic methods: semi

  7. Mixed-Up Floors.

    Science.gov (United States)

    Shaw, Richard

    2001-01-01

    Examines the maintenance management problems inherent in cleaning multiple flooring materials revealing the need for school officials to keep it simple when choosing flooring types. Also highlighted is a carpet recycling program used by Wright State University (Ohio). (GR)

  8. Topological Susceptibility from Slabs

    CERN Document Server

    Bietenholz, Wolfgang; Gerber, Urs

    2015-01-01

    In quantum field theories with topological sectors, a non-perturbative quantity of interest is the topological susceptibility chi_t. In principle it seems straightforward to measure chi_t by means of Monte Carlo simulations. However, for local update algorithms and fine lattice spacings, this tends to be difficult, since the Monte Carlo history rarely changes the topological sector. Here we test a method to measure chi_t even if data from only one sector are available. It is based on the topological charges in sub-volumes, which we denote as slabs. Assuming a Gaussian distribution of these charges, this method enables the evaluation of chi_t, as we demonstrate with numerical results for non-linear sigma-models.

  9. Design recommendations for long span composite slabs with deep profiled steel sheets

    NARCIS (Netherlands)

    Brekelmans, J.W.P.M.; Daniels, B.J.; Hove, B.W.E.M. van; Koukkari, H.; Stark, J.W.B.; Schuurman, R.G.

    1997-01-01

    As part of the ECSC research project `Steel intensive shallow floor construction', design recommendations for long span composite slabs with deep profiled steel deck have been drafted. These deep profiled steel sheets have depths of at least 200 mm. Test results and design recommendations are

  10. Design recommendations for long span composite slabs with deep profiled steel sheets

    NARCIS (Netherlands)

    Brekelmans, J.W.P.M.; Daniels, B.J.; Hove, B.W.E.M. van; Koukkari, H.; Stark, J.W.B.; Schuurman, R.G.

    1997-01-01

    As part of the ECSC research project `Steel intensive shallow floor construction', design recommendations for long span composite slabs with deep profiled steel deck have been drafted. These deep profiled steel sheets have depths of at least 200 mm. Test results and design recommendations are presen

  11. Design recommendations for long span composite slabs with deep profiled steel sheets

    NARCIS (Netherlands)

    Brekelmans, J.W.P.M.; Daniels, B.J.; Hove, B.W.E.M. van; Koukkari, H.; Stark, J.W.B.; Schuurman, R.G.

    1997-01-01

    As part of the ECSC research project `Steel intensive shallow floor construction', design recommendations for long span composite slabs with deep profiled steel deck have been drafted. These deep profiled steel sheets have depths of at least 200 mm. Test results and design recommendations are presen

  12. Composite slab behavior and strength analysis under static and dynamic loads

    Directory of Open Access Journals (Sweden)

    Florin Radu HARIGA

    2012-07-01

    Full Text Available Steel-framed buildings are typically constructed using steel-deck-reinforced concrete floor slabs. The in-plane (or diaphragm strength and stiffness of the floor system are frequently utilized in the lateral load-resisting system design. This paper presents the results of an experimental research program in which four full size composite diaphragms were vertically loaded to the limit state, under static or dynamic loads. Two test specimens were provided with longitudinal steel-deck ribs, and the other two specimens with cross steel-deck ribs. Typical composite diaphragm limit states are described, and the controlling limit state for each of the full size tests is indicated. The interaction effects between the reinforced concrete slab and the steel girder on the composite slab strength and stiffness were mainly studied.

  13. SUSTAINABLE TRAILER FLOORING

    Directory of Open Access Journals (Sweden)

    John Lu

    2009-05-01

    Full Text Available Different trailer flooring materials, including wood-based, aluminum, steel, and synthetic plastic floors, were evaluated in accordance with their durability and sustainability to our natural environment. Wood-based trailer flooring is an eco-friendly product. It is the most sustainable trailer flooring material compared with fossil fuel-intensive steel, aluminum, and plastics. It is renewable and recyclable. Oak, hard maple, and apitong are strong and durable hardwood species that are currently extensively used for trailer flooring. For manufacture, wood-based flooring is higher in energy efficiency and lower in carbon emission than steel, aluminum and plastics. Moreover, wood per se is a natural product that sequesters carbon. Accordingly, using more wood-based trailer flooring is effective to reduce global warming.

  14. Comparison of performance of simulation models for floor heating

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    only the floor construction, the differences can be directly compared. In this comparison, a two-dimensional model of a slab-on-grade floor including foundation is used as reference. The other models include a one-dimensional model and a thermal network model including the linear thermal transmittance......This paper describes the comparison of performance of simulation models for floor heating with different level of detail in the modelling process. The models are compared in an otherwise identical simulation model containing room model, walls, windows, ceiling and ventilation system. By exchanging...... of the foundation. The result can be also be found in the energy consumption of the building, since up to half the energy consumption is lost through the ground. Looking at the different implementations it is also found, that including a 1m ground volume below the floor construction under a one-dimensional model...

  15. New Packaging for Amplifier Slabs

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thorsness, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Suratwala, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Steele, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rogowski, G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-03-18

    The following memo provides a discussion and detailed procedure for a new finished amplifier slab shipping and storage container. The new package is designed to maintain an environment of <5% RH to minimize weathering.

  16. Optimization of reinforced concrete slabs

    Science.gov (United States)

    Ferritto, J. M.

    1979-01-01

    Reinforced concrete cells composed of concrete slabs and used to limit the effects of accidental explosions during hazardous explosives operations are analyzed. An automated design procedure which considers the dynamic nonlinear behavior of the reinforced concrete of arbitrary geometrical and structural configuration subjected to dynamic pressure loading is discussed. The optimum design of the slab is examined using an interior penalty function. The optimization procedure is presented and the results are discussed and compared with finite element analysis.

  17. Optimization of reinforced concrete slabs

    Science.gov (United States)

    Ferritto, J. M.

    1979-01-01

    Reinforced concrete cells composed of concrete slabs and used to limit the effects of accidental explosions during hazardous explosives operations are analyzed. An automated design procedure which considers the dynamic nonlinear behavior of the reinforced concrete of arbitrary geometrical and structural configuration subjected to dynamic pressure loading is discussed. The optimum design of the slab is examined using an interior penalty function. The optimization procedure is presented and the results are discussed and compared with finite element analysis.

  18. Evaluation of the Impact of Slab Foundation Heat Transfer on Heating and Cooling in Florida

    Energy Technology Data Exchange (ETDEWEB)

    Parker, D. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Kono, J. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Vieira, R. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States); Gu, L. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States)

    2016-09-01

    During the last three decades of energy-efficiency research, there has been limited study of heat transfer to slab-on-grade foundations in cooling-dominated climates. Most experimental research has focused on the impact of slab-on-grade foundations and insulation schemes on heat losses in heating-dominated climates. This is surprising because the floor area in single-family homes is generally equal to wall area, window area, or attic area, all of which have been extensively evaluated for heat-transfer properties. Moreover, slab foundations are the most common foundation type in cooling-dominated climates. Slab-on-grade construction is very popular in southern states, accounting for 77% of new home floors according to 2014 U.S. Census data. There is a widespread perception that tile flooring, as opposed to carpet, provides a cooler home interior in warm climates. Empirical research is needed because building energy simulation software programs running DOE-2 and EnergyPlus engines often rely on simplified models to evaluate the influence of flooring on interior temperature, even though in some cases more detailed models exist. The U.S. Department of Energy Building America Partnership for Improved Residential Construction (BA-PIRC) performed experiments in the Florida Solar Energy Center’s Flexible Residential Test Facility intended to assess for the first time (1) how slab-on-grade construction influences interior cooling in a cooling-dominated climate and (2) how the difference in a carpeted versus uncarpeted building might influence heating and cooling energy use. Two nominally identical side-by-side residential buildings were evaluated during the course of 1 year, from 2014 to 2015: the east building with a pad and carpet floor and the west building with a bare slab floor. A detailed grid shows temperature measurements taken on the slab surface at various locations as well as at depths of 1.0 ft, 2 ft, 5.0 ft, 10.0 ft, and 20.0 ft below the surface. Temperature

  19. Assembly-style building technology theory and practice of ML ceramsite concrete composite slab%ML 陶粒混凝土叠合板装配式建筑技术理论与实践

    Institute of Scientific and Technical Information of China (English)

    李渊

    2015-01-01

    通过ML陶粒混凝土叠合板生产制作、现场施工等方面的阐述,介绍了ML陶粒混凝土叠合板结构体系的施工技术,在此基础上,对该体系所具有的绿色环保、材料节约、缩短工期、降低施工成本、可持续发展等优点做了详细的说明。%The thesis describes the fabrication and in-situ construction of ML ceramsite concrete composite slab,introduces its construction tech-nologies,and illustrates its merits,such as green environmental protection,saving materials,shortening construction duration,reducing construc-tion cost and sustainable development and so on.

  20. Supporting shop floor intelligence

    DEFF Research Database (Denmark)

    Carstensen, Peter; Schmidt, Kjeld; Wiil, Uffe Kock

    1999-01-01

    Many manufacturing enterprises are now trying to introduce various forms of flexible work organizations on the shop floor. However, existing computer-based production planning and control systems pose severe obstacles for autonomous working groups and other kinds of shop floor control to become r......-to-day production planning by supporting intelligent and responsible workers in their situated coordination activities on the shop floor....

  1. Numerical simulation of grooving method for floor heave control in soft rock roadway

    Institute of Scientific and Technical Information of China (English)

    Sun Jin; Wang Lianguo

    2011-01-01

    Grooving method can restrain the deformation and destruction of surrounding rock by transferring the maximum stress to deep rock, bringing about the effective control for floor heave in soft rock roadway.Based on this important effect, and to discuss the relationship between cutting parameters and pressurerelief effect, this paper carried out a numerical simulation of grooving along bottom slab and two sides of gateway with finite difference software FLAC2D. The results show that the control effect on floor heave in soft rock tunnel can be improved by selecting appropriate cutting parameters. Appropriately increasing the crevice depth in the middle of the floor can improve the stress state of bottom slab by stress transfer.So the floor heave can be more effectively controlled. To lengthen the crevice in the comers of roadway can simultaneously transfer the maximum stresses of bottom slab and two sides to deep rock, And promote the pressure-relief effect. Extending the crevice length and crevice width on both sides within a certain range can decrease the stress concentration in the corners of roadway, and reduce the deformation of two sides. The cutting position beneficial to restrain the floor heave is close to the bottom slab.

  2. Rheological evolution of subducting slabs

    Science.gov (United States)

    Hirth, G.

    2016-12-01

    The mechanical behavior of subducting lithosphere depends on both the rheological evolution of the slab and how the slab is modified prior to subduction. Geophysical data demonstrate that the combination of thermal evolution and deformation lead to alteration of the slab at both mid-ocean ridges and the outer rise of subduction zones. In addition, the locations of earthquakes in these locations are generally consistent with both extrapolation of laboratory data that constrain the depth to the brittle-plastic transition, and deformation mechanisms inferred from microstructural analysis of mantle rocks recovered from the oceanic lithosphere. However, the frictional properties of both mantle aggregates and their alteration products suggest that linking the location of lithospheric earthquakes to regions that become hydrothermally altered is not straightforward. Furthermore, the inferred link between the location of intermediate-depth seismicity and the conditions of dehydration reactions is challenged by laboratory studies on dehydration embrittlement. In this presentation, I will introduce these apparent discrepancies; provide some possible resolutions for them based on scaling of laboratory data and discuss the implications for how an integrated understanding of slab rheology informs our understanding of the mechanical and geochemical evolution of the slab.

  3. 分层装配式支撑钢结构工业化建筑体系抗震性能试验研究%Experimental research on seismic performance of floor-by-floor assembled steel braced structures for prefabricated buildings

    Institute of Scientific and Technical Information of China (English)

    周青; 王伟; 陈以一; 童乐为; 余亚超; 杨建行; 刘大伟; 古海贤二

    2012-01-01

    A quasi-static experiment was carried out on a full scale two-story by four-span structural system.Lateral force resisting mechanism,failure modes and hysteretic properties of the improved floor-by-floor assembled steel braced structure were investigated,as well as the evolution of the structural stiffness and strength under horizontal earthquake.Test results show that the braces are the primary members to resist the lateral load,the elastic lateral stiffness is exclusively provided by the braces.The developed new braces demonstrate good ductile behavior.The structural damage evolution under cyclic loading includes compression buckling and tension yielding of braces,partial yielding of column base,cyclic deformation of beam flange,weld cracking and plastic hinge formation at the column bases.The beam-column frame can participate in resisting horizontal seismic force under the conditions of large story drift due to the improved beam through connections.Thus,it can be viewed as the second defense of the structural system.It is recommended that a certain magnification factor for seismic action should be considered in the seismic design to compensate the low energy dissipation capacity.%对2层4跨足尺结构进行了拟静力加载试验,考察了分层装配式支撑钢结构在水平地震作用下的抗侧力机制、破坏模式与滞回特性,以及刚度和承载力的变化规律。试验结果表明,支撑是主要抗侧力构件,结构弹性阶段的抗侧刚度几乎完全由支撑提供,研制的新型支撑具有良好的延性工作性能。结构体系在往复荷载下失效演进过程表现为支撑受压失稳、支撑受拉屈服、柱脚截面部分屈服、节点处梁翼缘循环拉压变形、柱脚端板连接焊缝开裂和柱脚全截面屈服形成塑性铰。改进后的梁贯通式节点可以保证框架在塑性大变形阶段分担相当比例的水平地震力,因而可作为该结构的第2道防线。鉴于结构体系耗能能力

  4. School Flooring Factors

    Science.gov (United States)

    McGrath, John

    2012-01-01

    With all of the hype that green building is receiving throughout the school facility-management industry, it's easy to overlook some elements that may not be right in front of a building manager's nose. It is helpful to examine the role floor covering plays in a green building project. Flooring is one of the most significant and important systems…

  5. 客运专线路基段42号板式无砟道岔运输及组装方案%The Transportation and Assembling Plan for Ballastless Slab Turnout Type No.42 of Passenger Dedicated Railway Subgrade Section

    Institute of Scientific and Technical Information of China (English)

    庹军; 秦飞; 张晓星

    2012-01-01

    The article introduces the successful technology solution for the transportation,lifting and laying of the ballastless slab turnout type No.42 applied on the subgrade section of Beijing-Shijiazhuang Passenger Dedicated Line.In Chinese high speed railway project,it is the first time to adopt the new technology solution for the transportation,lifting and laying of ballastless slab Turnout type No.42.The article focuses on the technology implementation and works out the practical technology solution.The short rails and the fastening systems are transported by the truck,and then assembled in advance.The long rails and the frog part are transported by the train to the site.Two crawler cranes and double traverses used to make flexible lifting at the multipoint and they moved in place one time.%结合京石客运专线路基段42号板式无砟道岔运输及吊装敷设,对国内高铁路基段42号板式无砟道岔首次采用汽车运输短配轨、扣件系统,提前组装,火车运输长配轨、辙叉至现场,采用2台履带吊,双吊梁多点柔性起吊,移动一次就位的设计方案进行研究,并形成了可实施性技术方案。

  6. How mantle slabs drive plate tectonics.

    Science.gov (United States)

    Conrad, Clinton P; Lithgow-Bertelloni, Carolina

    2002-10-04

    The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction.

  7. ARC Code TI: SLAB Spatial Audio Renderer

    Data.gov (United States)

    National Aeronautics and Space Administration — SLAB is a software-based, real-time virtual acoustic environment rendering system being developed as a tool for the study of spatial hearing. SLAB is designed to...

  8. Study of Suitability of Out-of-Codes Tall Slab-Column and Shearwall Structure

    Institute of Scientific and Technical Information of China (English)

    GUO Nan; ZHAO Tingting; LIN Yiying

    2012-01-01

    Abstract:The purpose of this paper is to discuss the suitability of out-of-codes tall slab-column and shearwall structure and to popularize the structure in seismic region.In the research,flat-plate floor was used in slab-column and shearwall structure in the practical engineering,the key parameters of slab-column and shearwall structure and frame-shearwall structure such as deflection,punching shear behavior,story drift and capability curve were worked out by static plastic analysis,elastic-plastic time history analysis and pushover analysis,then the suitability of out-of-codes tall slab-column and shearwall structure was evaluated.The results show that the out-of-codes tall slab-column and shearwall structure studies could satisfy the require of deflection and punching shear behavior,the story drift under 7 degree expected rare earthquake waves could satisfy the limit value in the codes and the seismic design spectrum was crossed by the capability curve of the structure and the structure could not collapse.The conclusion is that slab-column and shearwall structure with reasonable design built in Ⅱ soil site of intensity 7 seismic fortification zone can be designed higher than the limit height in the codes.

  9. Strengthening of monolithic floor slabs of residential buildings that have wall design sustems УСИЛЕНИЕ МОНОЛИТНЫХ ПЛИТ ПЕРЕКРЫТИЙ ЖИЛЫХ ЗДАНИЙ СТЕНОВОЙ КОНСТРУКТИВНОЙ СИСТЕМЫ

    Directory of Open Access Journals (Sweden)

    Malakhova Anna Nikolaevna

    2012-12-01

    Full Text Available The author proposes several structural solutions aimed at the reinforcement of monolithic floor slabs by means of fastening metal stripes onto the surface of slabs, laying supplementary reinforcement rods inside indents and attaching them by dowels. The author describes a force redistribution pattern identified in the course of analysis of monolithic floor slabs of buildings that have a wall design system. The author provides recommendations concerning the method of trial loading designated for the assessment of the true bearing capacity of floor slabs of residential buildings. The monolithic nature of reinforced slabs is attained by supplementary dowel connections. The dowel joint of old and new concrete elements takes the transverse shearing force in the event of bending to assure the monolithic behaviour of elements. Efficient behaviour of a monolithic slab is attained by means of a reliable connection between supplementary reinforcement rods and reinforcement rods inside slabs. Elements made of composite materials have been recently applied to strengthen reinforced concrete structures. These materials are basically composed of polymer tars and reinforcement materials (glass fiber, carbon and aramid fibers. Polymer sheets, stripes and fabric replace metal sheets, stripes and reinforcing meshes.Предложены конструктивные решения по усилению монолитных плит перекрытия: путем закрепления к поверхности плиты металлических полос и путем прокладки дополнительных арматурных стержней в штрабах со шпонками. Показано использование механизма перераспределения усилий при расчете монолитных плит перекрытия в зданиях стеновой конструктивной системы.

  10. A Sea Floor Penetrometer.

    Science.gov (United States)

    processed through an analog-to-digital (A/D) converter, and stored in the memory of a mini-computer. Computer algorithms are applied to the deceleration data to provide real-time sea floor classification.

  11. Radiant Floor Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.

    2008-01-01

    In many countries, hydronic radiant floor systems are widely used for heating all types of buildings such as residential, churches, gymnasiums, hospitals, hangars, storage buildings, industrial buildings, and smaller offices. However, few systems are used for cooling.This article describes a floor...... cooling system that includes such considerations as thermal comfort of the occupants, which design parameters will influence the cooling capacity and how the system should be controlled. Examples of applications are presented....

  12. INFLUENCES OF EDGING ROLL SHAPE ON THE PLASTIC STRAIN DISTRIBUTION OF SLAB DURING MULTI-PASS V-H ROLLING PROCESS

    Institute of Scientific and Technical Information of China (English)

    H.L. Yu; X.H. Liu; C.S. Li; X.M. Zhao; Y. Kusaba

    2006-01-01

    Multi-pass slab vertical-horizontal (V-H) rolling process with variable edging roll shape have been simulated with explicit dynamic finite element method and updating geometric method. The distributions of plastic strain contour in slab during rolling process with different edging roll and under different rolling stage have been obtained. The results show that there exist two thin strain assembling zones in slab when the flat edging roll is used, and there just exist one strain assembling zone in slab when the edging roll with groove is used. And compared the deformation equality between flat edging roll and edging rollwith groove, the lateris better than the former, which supplies the theory prove to the slab deformation distribution during V-H rolling process and is helpful for predicting the slab texture.

  13. Transient Temperature Analysis of Slab in Erdemir

    Institute of Scientific and Technical Information of China (English)

    (U)nal Camdali; Murat Tunc; Sedat Sisbot

    2008-01-01

    A transient thermal model was developed for slab furnaces in Eregli Iron and Steel Worlds (Erdemir) in Turkey and the model was solved using the FlexPDE computer program. This program uses the finite element method. Program codes were written to solve the temperature distribution of slabs that are put into furnace at 25℃ and removed at about 1 250℃. To obtain the optimum slab exit temperature variation, the necessary air temperature inside the furnace was calculated to be 1 390℃. The slab temperature versus time and the temperature variation inside the slab were depicted.

  14. Method for Bubbledeck Concrete Slab with Gaps

    Directory of Open Access Journals (Sweden)

    Sergiu Călin

    2009-01-01

    Full Text Available The composite slabs are made of BubbleDeck type slab elements with spherical gaps, poured in place on transversal and longitudinal directions. By introducing the gaps leads to a 30...50\\% lighter slab which reduces the loads on the columns, walls and foundations, and of course of the entire building. BubbleDeck slab elements are plates with ribs on two directions made of reinforced concrete or precast concrete with spherical shaped bubbles. These slab elements have a bottom and an upper concrete part connected with vertical ribs that go around the gaps.

  15. Modelling floor heating systems using a validated two-dimensional ground coupled numerical model

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Kragh, Jesper; Roots, Peter

    2005-01-01

    the floor. This model can be used to design energy efficient houses with floor heating focusing on the heat loss through the floor construction and foundation. It is found that it is impor-tant to model the dynamics of the floor heating system to find the correct heat loss to the ground, and further......This paper presents a two-dimensional simulation model of the heat losses and tempera-tures in a slab on grade floor with floor heating which is able to dynamically model the floor heating system. The aim of this work is to be able to model, in detail, the influence from the floor construction...... and foundation on the performance of the floor heating sys-tem. The ground coupled floor heating model is validated against measurements from a single-family house. The simulation model is coupled to a whole-building energy simu-lation model with inclusion of heat losses and heat supply to the room above...

  16. [Pelvic floor and pregnancy].

    Science.gov (United States)

    Fritel, X

    2010-05-01

    Congenital factor, obesity, aging, pregnancy and childbirth are the main risk factors for female pelvic floor disorders (urinary incontinence, anal incontinence, pelvic organ prolapse, dyspareunia). Vaginal delivery may cause injury to the pudendal nerve, the anal sphincter, or the anal sphincter. However the link between these injuries and pelvic floor symptoms is not always determined and we still ignore what might be the ways of prevention. Of the many obstetrical methods proposed to prevent postpartum symptoms, episiotomy, delivery in vertical position, delayed pushing, perineal massage, warm pack, pelvic floor rehabilitation, results are disappointing or limited. Caesarean section is followed by less postnatal urinary incontinence than vaginal childbirth. However this difference tends to disappear with time and following childbirth. Limit the number of instrumental extractions and prefer the vacuum to forceps could reduce pelvic floor disorders after childbirth. Ultrasound examination of the anal sphincter after a second-degree perineal tear is useful to detect and repair infra-clinic anal sphincter lesions. Scientific data is insufficient to justify an elective cesarean section in order to avoid pelvic floor symptoms in a woman without previous disorders.

  17. Cooling Floor AC Systems

    Science.gov (United States)

    Jun, Lu; Hao, Ding; Hong, Zhang; Ce, Gao Dian

    The present HVAC equipments for the residential buildings in the Hot-summer-and-Cold-winter climate region are still at a high energy consuming level. So that the high efficiency HVAC system is an urgently need for achieving the preset government energy saving goal. With its advantage of highly sanitary, highly comfortable and uniform of temperature field, the hot-water resource floor radiation heating system has been widely accepted. This paper has put forward a new way in air-conditioning, which combines the fresh-air supply unit and such floor radiation system for the dehumidification and cooling in summer or heating in winter. By analyze its advantages and limitations, we found that this so called Cooling/ Heating Floor AC System can improve the IAQ of residential building while keep high efficiency quality. We also recommend a methodology for the HVAC system designing, which will ensure the reduction of energy cost of users.

  18. Metallurgical quality of CSP thin slabs

    Institute of Scientific and Technical Information of China (English)

    Deguang Zhou; Jie Fu; Yonglin Kang; Zhongbing Wang; Jing Li; Zhongbo Xu

    2004-01-01

    The casting structure, chemical composition segregation, dendrite arm space, inclusiona and during the CSP (compact strip production) rolling process were investigated. The results show that the CSP thin slab has a feature of uniform fme grains, more columnar crystals, less central porosity and segregation etc. There is no great difference in macrostructure between the CSP thin slab and conventional slab; however, the fine dendrite structure of the CSP slab is more uniform. Moreover, the central porosity and segregation are obviously improved after the first pass; and the dendrite is bent along the rolling direction rather than broken into pieces.Small inclusions with the diameter less than 10 μm in the CSP slab are dominantly consisted of aluminates formed by A1 deoxidation and Ca treatment and not floating out of the melt. The large size inclusions found in the continuous casting slab are very few.

  19. Higher order modes in photonic crystal slabs.

    Science.gov (United States)

    Gansch, Roman; Kalchmair, Stefan; Detz, Hermann; Andrews, Aaron M; Klang, Pavel; Schrenk, Werner; Strasser, Gottfried

    2011-08-15

    We present a detailed investigation of higher order modes in photonic crystal slabs. In such structures the resonances exhibit a blue-shift compared to an ideal two-dimensional photonic crystal, which depends on the order of the slab mode and the polarization. By fabricating a series of photonic crystal slab photo detecting devices, with varying ratios of slab thickness to photonic crystal lattice constant, we are able to distinguish between 0th and 1st order slab modes as well as the polarization from the shift of resonances in the photocurrent spectra. This method complements the photonic band structure mapping technique for characterization of photonic crystal slabs. © 2011 Optical Society of America

  20. Pelvic floor muscle function in women with pelvic floor dysfunction

    DEFF Research Database (Denmark)

    Tibaek, Sigrid; Dehlendorff, Christian

    2014-01-01

    The objectives of this study were to investigate the level of pelvic floor muscle (PFM) function in women with pelvic floor dysfunction (PFD) referred by gynaecologists and urologists for in-hospital pelvic floor muscle training (PFMT), and to identity associated factors for a low level of PFM fu...

  1. Pelvic floor muscle training exercises

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003975.htm Pelvic floor muscle training exercises To use the sharing features on this page, please enable JavaScript. Pelvic floor muscle training exercises are a series of exercises ...

  2. A slab expression in the Gibraltar arc?

    Science.gov (United States)

    Nijholt, Nicolai; Govers, Rob; Wortel, Rinus

    2017-04-01

    The present-day geodynamic setting of the Gibraltar arc region results from several Myrs of subduction rollback in the overall (oblique) convergence of Africa and Iberia. As for most rollback settings in a convergence zone, the interaction of these two components is complex and distinctly non-stationary. Gibraltar slab rollback is considered to have stalled, or at least diminished largely in magnitude, since the late Miocene/early Pliocene, suggesting that the effect of the slab on present-day surface motions is negligible. However, GPS measurements indicate that the Gibraltar arc region has an anomalous motion with respect to both Iberia and Africa, i.e., the Gibraltar arc region does not move as part of the rigid Iberian, or the rigid African plate. A key question is whether this surface motion is an expression of the Gibraltar slab. Seismic activity in the Gibraltar region is diffuse and considerable in magnitude, making it a region of high seismic risk. Unlike the North African margin to the east, where thrust earthquakes dominate the focal mechanism tables, a complex pattern is observed with thrust, normal and strike-slip earthquakes in a region stretching between the northern Moroccan Atlas across the Gibraltar arc and Alboran Sea (with the Trans-Alboran Shear Zone) to the Betics of southern Spain. Even though no large mega-thrust earthquakes have been observed in recent history, slab rollback may not have completely ceased. However, since no activity has been observed in the accretionary wedge, probably since the Pliocene, it is likely that the subduction interface is locked. In this study, we perform a series of numerical models in which we combine the relative plate convergence, variable magnitude of friction on fault segments, regional variations in gravitational potential energy and slab pull of the Gibraltar slab. We seek to reproduce the GPS velocities and slip sense on regional faults and thereby determine whether the Gibraltar slab has an effect on

  3. Chronic pelvic floor dysfunction.

    Science.gov (United States)

    Hartmann, Dee; Sarton, Julie

    2014-10-01

    The successful treatment of women with vestibulodynia and its associated chronic pelvic floor dysfunctions requires interventions that address a broad field of possible pain contributors. Pelvic floor muscle hypertonicity was implicated in the mid-1990s as a trigger of major chronic vulvar pain. Painful bladder syndrome, irritable bowel syndrome, fibromyalgia, and temporomandibular jaw disorder are known common comorbidities that can cause a host of associated muscular, visceral, bony, and fascial dysfunctions. It appears that normalizing all of those disorders plays a pivotal role in reducing complaints of chronic vulvar pain and sexual dysfunction. Though the studies have yet to prove a specific protocol, physical therapists trained in pelvic dysfunction are reporting success with restoring tissue normalcy and reducing vulvar and sexual pain. A review of pelvic anatomy and common findings are presented along with suggested physical therapy management.

  4. Slab stagnation and detachment under northeast China

    Science.gov (United States)

    Honda, Satoru

    2016-03-01

    Results of tomography models around the Japanese Islands show the existence of a gap between the horizontally lying (stagnant) slab extending under northeastern China and the fast seismic velocity anomaly in the lower mantle. A simple conversion from the fast velocity anomaly to the low-temperature anomaly shows a similar feature. This feature appears to be inconsistent with the results of numerical simulations on the interaction between the slab and phase transitions with temperature-dependent viscosity. Such numerical models predict a continuous slab throughout the mantle. I extend previous analyses of the tomography model and model calculations to infer the origins of the gap beneath northeastern China. Results of numerical simulations that take the geologic history of the subduction zone into account suggest two possible origins for the gap: (1) the opening of the Japan Sea led to a breaking off of the otherwise continuous subducting slab, or (2) the western edge of the stagnant slab is the previous subducted ridge, which was the plate boundary between the extinct Izanagi and the Pacific plates. Origin (2) suggesting the present horizontally lying slab has accumulated since the ridge subduction, is preferable for explaining the present length of the horizontally lying slab in the upper mantle. Numerical models of origin (1) predict a stagnant slab in the upper mantle that is too short, and a narrow or non-existent gap. Preferred models require rather stronger flow resistance of the 660-km phase change than expected from current estimates of the phase transition property. Future detailed estimates of the amount of the subducted Izanagi plate and the present stagnant slab would be useful to constrain models. A systematic along-arc variation of the slab morphology from the northeast Japan to Kurile arcs is also recognized, and its understanding may constrain the 3D mantle flow there.

  5. Turbulence in the cylindrical slab

    Energy Technology Data Exchange (ETDEWEB)

    Gentle, K. W.; Rowan, W. L.; Williams, C. B.; Brookman, M. W. [Institute of Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

    2014-09-15

    The cylindrical slab was the first and simplest model of intrinsically unstable microturbulence. The Helimak is an experimental realization of this model. Although finite, it is sufficiently large to escape boundary effects, with dimensionless parameters similar to those of a tokamak edge or scrape off layer. The essential drive is interchange-like, a pressure gradient with unfavorable magnetic curvature, leading to a non-linearly saturated state of large-amplitude turbulence, Δn{sub rms}/n ∼ 0.5. The nonlinear processes governing this saturation are unique, unlike any of those posited for the much weaker turbulence typical of confined plasma, e.g., in a tokamak. Neither linear stability theory, quasi-linear theory, zonal flows, nor flow shear stabilization is consistent with the observations. The mechanisms determining the non-linearly saturated state constitute an important challenge to our understanding of strongly nonlinear systems.

  6. Commensurate germanium light emitters in silicon-on-insulator photonic crystal slabs.

    Science.gov (United States)

    Jannesari, R; Schatzl, M; Hackl, F; Glaser, M; Hingerl, K; Fromherz, T; Schäffler, F

    2014-10-20

    We report on the fabrication and characterization of silicon-on-insulator (SOI) photonic crystal slabs (PCS) with commensurately embedded germanium quantum dot (QD) emitters for near-infrared light emission. Substrate pre-patterning defines preferential nucleation sites for the self-assembly of Ge QDs during epitaxial growth. Aligned two-dimensional photonic crystal slabs are then etched into the SOI layer. QD ordering enhances the photoluminescence output as compared to PCSs with randomly embedded QDs. Rigorously coupled wave analysis shows that coupling of the QD emitters to leaky modes of the PCS can be tuned via their location within the unit cell of the PCS.

  7. Cretaceous Arctic magmatism: Slab vs. plume? Or slab and plume?

    Science.gov (United States)

    Gottlieb, E. S.; Miller, E. L.; Andronikov, A. V.; Brumley, K.; Mayer, L. A.; Mukasa, S. B.

    2010-12-01

    Tectonic models for the Cretaceous paleogeographic evolution of the Arctic Ocean and its adjacent landmasses propose that rifting in the Amerasia Basin (AB) began in Jura-Cretaceous time, accompanied by the development of the High Arctic Large Igneous Province (HALIP). During the same timespan, deformation and slab-related magmatism, followed by intra-arc rifting, took place along the Pacific side of what was to become the Arctic Ocean. A compilation and comparison of the ages, characteristics and space-time variation of circum-Arctic magmatism allows for a better understanding of the role of Pacific margin versus Arctic-Atlantic plate tectonics and the role of plume-related magmatism in the origin of the Arctic Ocean. In Jura-Cretaceous time, an arc built upon older terranes overthrust the Arctic continental margins of North America and Eurasia, shedding debris into foreland basins in the Brooks Range, Alaska, across Chukotka, Russia, to the Lena Delta and New Siberian Islands region of the Russian Arctic. These syn-tectonic sediments have some common sources (e.g., ~250-300 Ma magmatic rocks) as determined by U-Pb detrital zircon geochronology. They are as young as Valanginian-Berriasian (~136 Ma, Gradstein et al., 2004) and place a lower limit on the age of formation of the AB. Subsequent intrusions of granitoid plutons, inferred to be ultimately slab-retreat related, form a belt along the far eastern Russian Arctic continental margin onto Seward Peninsula and have yielded a continuous succession of zircon U-Pb ages from ~137-95 Ma (n=28) and a younger suite ~91-82 Ma (n=16). All plutons dated were intruded in an extensional tectonic setting based on their relations to wall-rock deformation. Regional distribution of ages shows a southward migration of the locus of magmatism during Cretaceous time. Basaltic lavas as old as 130 Ma and as young as 80 Ma (40Ar/39Ar)) erupted across the Canadian Arctic Islands, Svalbard and Franz Josef Land and are associated with

  8. Sausage oscillations of coronal plasma slabs

    Science.gov (United States)

    Hornsey, C.; Nakariakov, V. M.; Fludra, A.

    2014-07-01

    Context. Sausage oscillations are observed in plasma non-uniformities of the solar corona as axisymmetric perturbations of the non-uniformity. Often, these non-uniformities can be modelled as field-aligned slabs of the density enhancement. Aims: We perform parametric studies of sausage oscillations of plasma slabs, aiming to determine the dependence of the oscillation period on its parameters, and the onset of leaky and trapped regimes of the oscillations. Methods: Slabs with smooth transverse profiles of the density of a zero-beta plasma are perturbed by an impulsive localised perturbation of the sausage symmetry. In particular, the slab can contain an infinitely thin current sheet in its centre. The initial value problem is then solved numerically. The numerical results are subject to spectral analysis. The results are compared with analytical solutions for a slab with a step-function profile and also with sausage oscillations of a plasma cylinder. Results: We established that sausage oscillations in slabs generally have the same properties as in plasma cylinders. In the trapped regime, the sausage oscillation period increases with the increase in the longitudinal wavelength. In the leaky regime, the dependence of the period on the wavelength experiences saturation, and the period becomes independent of the wavelength in the long-wavelength limit. In the leaky regime the period is always longer than in the trapped regime. The sausage oscillation period in a slab is always longer than in a cylinder with the same transverse profile. In slabs with steeper transverse profiles, sausage oscillations have longer periods. The leaky regime occurs at shorter wavelengths in slabs with smoother profiles.

  9. [Pelvic floor muscle training and pelvic floor disorders in women].

    Science.gov (United States)

    Thubert, T; Bakker, E; Fritel, X

    2015-05-01

    Our goal is to provide an update on the results of pelvic floor rehabilitation in the treatment of urinary incontinence and genital prolapse symptoms. Pelvic floor muscle training allows a reduction of urinary incontinence symptoms. Pelvic floor muscle contractions supervised by a healthcare professional allow cure in half cases of stress urinary incontinence. Viewing this contraction through biofeedback improves outcomes, but this effect could also be due by a more intensive and prolonged program with the physiotherapist. The place of electrostimulation remains unclear. The results obtained with vaginal cones are similar to pelvic floor muscle training with or without biofeedback or electrostimulation. It is not known whether pelvic floor muscle training has an effect after one year. In case of stress urinary incontinence, supervised pelvic floor muscle training avoids surgery in half of the cases at 1-year follow-up. Pelvic floor muscle training is the first-line treatment of post-partum urinary incontinence. Its preventive effect is uncertain. Pelvic floor muscle training may reduce the symptoms associated with genital prolapse. In conclusion, pelvic floor rehabilitation supervised by a physiotherapist is an effective short-term treatment to reduce the symptoms of urinary incontinence or pelvic organ prolapse.

  10. Building America Case Study: Impact of Slab-Foundation Heat Transfer on Space-Conditioning Energy Use in Florida, Cocoa, Florida

    Energy Technology Data Exchange (ETDEWEB)

    2016-12-01

    Heat transfer to slab foundations has remained an area of building science with poor understanding over the last three decades of energy efficiency research. This is somewhat surprising since the area of floors in single family homes is generally equal to wall, or windows or attics which have been extensively evaluated. Research that has been done has focused in the impact of slab on grade foundations and insulation schemes on heat losses associated with heating in predominantly heating dominated climates. Slab on grade construction is very popular in cooling-dominated southern states where it accounts for 77 percent of new home floors according to U.S. Census data in 2014. There is a widespread conception that tile flooring, as opposed to carpet, makes for a cooler home interior in warm climates. Empirical research is needed as building energy simulations such as DOE-2 and EnergyPlus rely on simplified models to evaluate these influences. BA-PIRC performed experiments over an entire year from 2014-2015 in FSEC's Flexible Residential Test Facilities (FRTF) intended to assess for the first time 1) slab on grade influence in a cooling dominated climate, and 2) how the difference in a carpeted vs. uncarpeted building might influence heating and cooling. Two identical side by side residential buildings were evaluated, the East with pad and carpet and the west with a bare slab floor. A highly detailed grid of temperature measurements were taken on the slab surface at various locations as well as at depths of 1, 2.5, 5, 10 and 20 feet.

  11. Deterioration of the Floor of Interior Courtyard of Sultan Hassan Mosque in Cairo, Egypt.

    Science.gov (United States)

    Nazel, Tarek

    The college- mosque of Sultan Hassan is considered one of the finest examples of Islamic architecture not only in Egypt but also in the East. Its open interior courtyard is paved with three different types of marble slabs. These marble slabs suffer from severe deterioration. Causes of this deterioration were determined accurately through the ocular examination of the courtyard and confirmed by the laboratory tests which were carried out on samples representing the three common types of marble used in the floor namely the white, the red and the black marble. Sun light and heat are the main deterioration factors and the consequent thermal expansion is the main property which led to the detected deterioration phenomena. Types and mechanisms of deterioration affected the floor were described and explained.

  12. 人防地下室楼盖选型%Selection on Civil Air Defense Basement Floor System

    Institute of Scientific and Technical Information of China (English)

    马东亚

    2015-01-01

    Through the selection and comprehensive analysis of civil air defense basement floor system, it can be found that the occupancy floor height, construction cost, concrete and steel bar cost of beam and slab of Girderless floor are less than those of other floor systems.Girderless floor has huge comprehensive benefits.%进行人防地下室楼盖选型,综合分析比较可以得到:无梁楼盖相对于其他形式楼盖占用层高最少,施工费用最低,梁和板混凝土和钢筋材料费最少,综合效益最好。

  13. Radiation pressure of active dispersive chiral slabs.

    Science.gov (United States)

    Wang, Maoyan; Li, Hailong; Gao, Dongliang; Gao, Lei; Xu, Jun; Qiu, Cheng-Wei

    2015-06-29

    We report a mechanism to obtain optical pulling or pushing forces exerted on the active dispersive chiral media. Electromagnetic wave equations for the pure chiral media using constitutive relations containing dispersive Drude models are numerically solved by means of Auxiliary Differential Equation Finite Difference Time Domain (ADE-FDTD) method. This method allows us to access the time averaged Lorentz force densities exerted on the magnetoelectric coupling chiral slabs via the derivation of bound electric and magnetic charge densities, as well as bound electric and magnetic current densities. Due to the continuously coupled cross-polarized electromagnetic waves, we find that the pressure gradient force is engendered on the active chiral slabs under a plane wave incidence. By changing the material parameters of the slabs, the total radiation pressure exerted on a single slab can be directed either along the propagation direction or in the opposite direction. This finding provides a promising avenue for detecting the chirality of materials by optical forces.

  14. Crust rheology, slab detachment and topography

    Science.gov (United States)

    Duretz, T.; Gerya, T. V.

    2012-04-01

    The collision between continents following the closure of an ocean can lead to the subduction of continental crust. The introduction of buoyant crust within subduction zones triggers the development of extensional stresses in slabs which eventually result in their detachment. The dynamic consequences of slab detachment affects the development of topography, the exhumation of high-pressure rocks and the geodynamic evolution of collision zones. We employ two-dimensional thermo-mechanical modelling in order to study the importance of crustal rheology on the evolution of spontaneous subduction-collision systems and the occurrence of slab detachment. The modelling results indicate that varying the rheological structure of the crust can results in a broad range of collisional evolutions involving slab detachment, delamination (associated to slab rollback), or the combination of both mechanisms. By enhancing mechanical coupling at the Moho, a strong crust leads to the deep subduction of the crust (180 km). These collisions are subjected to slab detachment and subsequent coherent exhumation of the crust accommodated by eduction (inversion of subduction sense) and thrusting. In these conditions, slab detachment promotes the development of a high (> 4.5 km) and narrow (delamination of the lithosphere, preventing slab detachment to occur. Further shortening leads to buckling and thickening of the crust resulting in the development of topographic bulging on the lower plate. Collisions involving rheologically layered crust are characterised by a decoupling level at mid-crustal depths. These initial condition favours the delamination of the upper crust as well as the deep subduction of the lower crust. These collisions are thus successively affected by delamination and slab detachment and both processes contribute to the exhumation of the subducted crust. A wide (> 200 km) topographic plateau develops as the results of the buoyant extrusion of the upper crust onto the foreland

  15. Estimation of the Reliability of Plastic Slabs

    DEFF Research Database (Denmark)

    Pirzada, G. B. : Ph.D.

    and the concrete but in this thesis these material properties are modelled by stochastic variables. The probabilistic analysis performed in this thesis is mainly based on work by Thoft-Christensen & Baker (9) and Thoft-Christensen & Murotsu (10). Since considerable information about these basic materials used...... in reinforced concrete slabs and the loading is available it is highly probable that other aspects of slab failure, i.e. the punching shear failure and buckling failure, can be included in the probabilistic approach....

  16. Mantle wedge serpentinization effects on slab dips

    Directory of Open Access Journals (Sweden)

    Eh Tan

    2017-01-01

    Full Text Available The mechanical coupling between a subducting slab and the overlying mantle wedge is an important factor in controlling the subduction dip angle and the flow in mantel wedge. This paper investigates the role of the amount of mantle serpentinization on the subduction zone evolution. With numerical thermos-mechanical models with elasto-visco-plastic rheology, we vary the thickness and depth extent of mantle serpentinization in the mantle wedge to control the degree of coupling between the slab and mantle wedge. A thin serpentinized mantle layer is required for stable subduction. For models with stable subduction, we find that the slab dip is affected by the down-dip extent and the mantle serpentinization thickness. A critical down-dip extent exists in mantle serpentinization, determined by the thickness of the overriding lithosphere. If the down-dip extent does not exceed the critical depth, the slab is partially coupled to the overriding lithosphere and has a constant dip angle regardless of the mantle serpentinization thickness. However, if the down-dip extent exceeds the critical depth, the slab and the base of the overriding lithosphere would be separated and decoupled by a thick layer of serpentinized peridotite. This allows further slab bending and results in steeper slab dip. Increasing mantle serpentinization thickness will also result in larger slab dip. We also find that with weak mantle wedge, there is no material flowing from the asthenosphere into the serpentinized mantle wedge. All of these results indicate that serpentinization is an important ingredient when studying the subduction dynamics in the mantle wedge.

  17. Photocatalytic, highly hydrophilic porcelain stoneware slabs

    Science.gov (United States)

    Raimondo, M.; Guarini, G.; Zanelli, C.; Marani, F.; Fossa, L.; Dondi, M.

    2011-10-01

    Photocatalytic, highly hydrophilic industrial porcelain stoneware large slabs were realized by deposition of nanostructured TiO2 coatings. Different surface finishing and experimental conditions were considered in order to assess the industrial feasibility. Photocatalytic and wetting behaviour of functionalized slabs mainly depends on surface phase composition in terms of anatase/rutile ratio, this involving - as a key issue - the deposition of TiO2 on industrially sintered products with an additional annealing step to strengthen coatings' performances and durability.

  18. Floor heating maximizes residents` comfort

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkanen, P.; Wikstroem, T.

    1996-11-01

    Storing heat in floors by using economical night-time electricity does not increase the specific consumption of heating. According to studies done by IVO, the optimum housing comfort is achieved if the room is heated mainly by means of floor heating that is evened out by window or ceiling heating, or by a combination of all three forms of heating. (orig.)

  19. Floor heating maximizes residents` comfort

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkanen, P.; Wikstroem, T.

    1996-11-01

    Storing heat in floors by using economical night-time electricity does not increase the specific consumption of heating. According to studies done by IVO, the optimum housing comfort is achieved if the room is heated mainly by means of floor heating that is evened out by window or ceiling heating, or by a combination of all three forms of heating. (orig.)

  20. Anorectal and pelvic floor anatomy

    NARCIS (Netherlands)

    J. Stoker

    2009-01-01

    The anorectum and pelvic floor are crucial in maintaining continence, facilitating evacuation, providing pelvic organ support while in females the pelvic floor is part of the birth canal. The anal sphincter is a multilayered cylindrical structure, including the smooth muscle internal sphincter and t

  1. Laparoscopy for pelvic floor disorders.

    Science.gov (United States)

    Van Geluwe, B; Wolthuis, A; D'Hoore, A

    2014-02-01

    Surgical treatment of pelvic floor disorders has significantly evolved during the last decade, with increasing understanding of anatomy, pathophysiology and the minimally-invasive 'revolution' of laparoscopic surgery. Laparoscopic pelvic floor repair requires a thorough knowledge of pelvic floor anatomy and its supportive components before repair of defective anatomy is possible. Several surgical procedures have been introduced and applied to treat rectal prolapse syndromes. Transabdominal procedures include a variety of rectopexies with the use of sutures or prosthesis and with or without resection of redundant sigmoid colon. Unfortunately there is lack of one generally accepted standard treatment technique. This article will focus on recent advances in the management of pelvic floor disorders affecting defecation, with a brief overview of contemporary concepts in pelvic floor anatomy and different laparoscopic treatment options.

  2. Effects of change in slab geometry on the mantle flow and slab fabric in Southern Peru

    Science.gov (United States)

    Knezevic Antonijevic, Sanja; Wagner, Lara S.; Beck, Susan L.; Long, Maureen D.; Zandt, George; Tavera, Hernando

    2016-10-01

    The effects of complex slab geometries on the surrounding mantle flow field are still poorly understood. Here we combine shear wave velocity structure with Rayleigh wave phase anisotropy to examine these effects in southern Peru, where the slab changes its geometry from steep to flat. To the south, where the slab subducts steeply, we find trench-parallel anisotropy beneath the active volcanic arc that we attribute to the mantle wedge and/or upper portions of the subducting plate. Farther north, beneath the easternmost corner of the flat slab, we observe a pronounced low-velocity anomaly. This anomaly is caused either by the presence of volatiles and/or flux melting that could result from southward directed, volatile-rich subslab mantle flow or by increased temperature and/or decompression melting due to small-scale vertical flow. We also find evidence for mantle flow through the tear north of the subducting Nazca Ridge. Finally, we observe anisotropy patterns associated with the fast velocity anomalies that reveal along strike variations in the slab's internal deformation. The change in slab geometry from steep to flat contorts the subducting plate south of the Nazca Ridge causing an alteration of the slab petrofabric. In contrast, the torn slab to the north still preserves the primary (fossilized) petrofabric first established shortly after plate formation.

  3. Descending lithosphere slab beneath the Northwest Dinarides from teleseismic tomography

    Science.gov (United States)

    Šumanovac, Franjo; Dudjak, Darko

    2016-12-01

    The area of study covers the marginal zone between the Adriatic microplate (African plate) and the Pannonian segment (Eurasian plate). We present a tomography model for this area, with special emphasis on the northwest Dinarides. A dense distribution of temporary seismic stations in the area of the Northern Dinarides along with permanent seismic stations located in the area, allowed us to construct this P-wave tomographic model. We assembled our travel-time dataset based on 26 seismic stations were used to collect the dataset. Teleseismic events were recorded for a period of 18 months and a set of 76 distant earthquakes were used to calculate the P-wave travel-time residuals. We calculated relative rather than absolute arrival-time residuals in the inversion to obtain depths of 0-400 km. We imaged a pronounced fast velocity anomaly below the NW Dinarides which directly indicates a lithosphere slab downgoing beneath the Dinarides. This fast anomaly extends towards the NW direction to at least 250 km depth, and we interpreted it as a descending lithosphere slab. The thrusting of the Adriatic microplate may be brought about by sub-lithosphere rising movement beneath the Pannonian region, along with a push from African plate. In our interpretation, the Adriatic lower lithosphere has been detached from the crust, and steeply sinks beneath the Dinarides. A lithosphere model of the contact between the Adriatic microplate and Pannonian tectonic segment was constructed based on the tomographic velocity model and results of previous crustal studies.

  4. Constructive solutions for beamless capitalless floors with prestressed reinforcement

    Directory of Open Access Journals (Sweden)

    Bardysheva Yuliya Anatol'evna

    2014-07-01

    Full Text Available In the article the authors present advanced constructions of prestressed reinforced concrete flat ceiling, where high-strength ropes in elastic shell are used as stressed reinforcement. The novelty of the solution lays in diagonal arrangement of hard valves and use of high-strength ropes in a flexible shell of "Monostrand" type. This type of prestress, in our opinion, is the most acceptable from technical point of view for selective reinforcement of separate tense rods or cables. The use of pre-stressed reinforcement in the form of individual rods or cables increases the rigidity and crack resistance of concrete beamless slabs. The use of high-strength ropes in the monostrand-type shell makes it possible to prestress in frames of single cell plate or floor in general and to reduce labour input for stressing armature. The paper presents original solution with diagonal position of the valve. The authors suggest the use of prestressed diagonal valves as in all cells of the floor with the cells of the same or only slightly different size and in separate cells of the floor (for roofs with different cells. The diagonal location of stressed reinforcement proposed in the work is an efficient solution for extending the range of dimensions and loads size.

  5. Crustal Ages of the Ocean Floor - Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Crustal Ages of the Ocean Floor Poster was created at NGDC using the Crustal Ages of the Ocean Floor database draped digitally over a relief of the ocean floor...

  6. Magnetohydrodynamic Waves in an Asymmetric Magnetic Slab

    Science.gov (United States)

    Allcock, Matthew; Erdélyi, Robert

    2017-02-01

    Analytical models of solar atmospheric magnetic structures have been crucial for our understanding of magnetohydrodynamic (MHD) wave behaviour and in the development of the field of solar magneto-seismology. Here, an analytical approach is used to derive the dispersion relation for MHD waves in a magnetic slab of homogeneous plasma enclosed on its two sides by non-magnetic, semi-infinite plasma with different densities and temperatures. This generalises the classic magnetic slab model, which is symmetric about the slab. The dispersion relation, unlike that governing a symmetric slab, cannot be decoupled into the well-known sausage and kink modes, i.e. the modes have mixed properties. The eigenmodes of an asymmetric magnetic slab are better labelled as quasi-sausage and quasi-kink modes. Given that the solar atmosphere is highly inhomogeneous, this has implications for MHD mode identification in a range of solar structures. A parametric analysis of how the mode properties (in particular the phase speed, eigenfrequencies, and amplitudes) vary in terms of the introduced asymmetry is conducted. In particular, avoided crossings occur between quasi-sausage and quasi-kink surface modes, allowing modes to adopt different properties for different parameters in the external region.

  7. Accidents due to falls from roof slabs

    Directory of Open Access Journals (Sweden)

    Bruno Alves Rudelli

    Full Text Available CONTEXT AND OBJECTIVE Falls from the roof slabs of houses are accidents of high potential severity that occur in large Brazilian cities and often affect children and adolescents. The aims of this study were to characterize the factors that predispose towards this type of fall involving children and adolescents, quantify the severity of associated lesions and suggest preventive measures. DESIGN AND SETTING Descriptive observational prospective longitudinal study in two hospitals in the metropolitan region of São Paulo. METHODS Data were collected from 29 cases of falls from roof slabs involving children and adolescents between October 2008 and October 2009. RESULTS Cases involving males were more prevalent, accounting for 84%. The predominant age group was schoolchildren (7 to 12 years old; 44%. Leisure activities were most frequently being practiced on the roof slab at the time of the fall (86%, and flying a kite was the most prevalent game (37.9%. In 72% of the cases, the children were unaccompanied by an adult responsible for them. Severe conditions such as multiple trauma and traumatic brain injuries resulted from 79% of the accidents. CONCLUSION Falls from roof slabs are accidents of high potential severity, and preventive measures aimed towards informing parents and guardians about the dangers and risk factors associated with this type of accident are needed, along with physical protective measures, such as low walls around the slab and gates with locks to restrict free access to these places.

  8. Accidents due to falls from roof slabs.

    Science.gov (United States)

    Rudelli, Bruno Alves; Silva, Marcelo Valerio Alabarce da; Akkari, Miguel; Santili, Claudio

    2013-01-01

    CONTEXT AND OBJECTIVE Falls from the roof slabs of houses are accidents of high potential severity that occur in large Brazilian cities and often affect children and adolescents. The aims of this study were to characterize the factors that predispose towards this type of fall involving children and adolescents, quantify the severity of associated lesions and suggest preventive measures. DESIGN AND SETTING Descriptive observational prospective longitudinal study in two hospitals in the metropolitan region of São Paulo. METHODS Data were collected from 29 cases of falls from roof slabs involving children and adolescents between October 2008 and October 2009. RESULTS Cases involving males were more prevalent, accounting for 84%. The predominant age group was schoolchildren (7 to 12 years old; 44%). Leisure activities were most frequently being practiced on the roof slab at the time of the fall (86%), and flying a kite was the most prevalent game (37.9%). In 72% of the cases, the children were unaccompanied by an adult responsible for them. Severe conditions such as multiple trauma and traumatic brain injuries resulted from 79% of the accidents. CONCLUSION Falls from roof slabs are accidents of high potential severity, and preventive measures aimed towards informing parents and guardians about the dangers and risk factors associated with this type of accident are needed, along with physical protective measures, such as low walls around the slab and gates with locks to restrict free access to these places.

  9. The Design of a Semi-Prefabricated LVL-Concrete Composite Floor

    Directory of Open Access Journals (Sweden)

    David Yeoh

    2012-01-01

    Full Text Available This paper describes the design of a novel semi-prefabricated LVL-concrete composite floor that has been developed in New Zealand. In this solution, the floor units made from LVL joists and plywood are prefabricated in the factory and transported to the building site. The units are then lifted onto the supports and connected to the main frames of the building and to the adjacent units. Finally, a concrete topping is poured on top of the units in order to form a continuous slab connecting all the units. Rectangular notches cut from the LVL joists and reinforced with coach screws provide the composite action between the concrete slab and the LVL joists. This system proved to be an effective modular solution that ensures rapid construction. A design procedure based on the use of the effective flexural stiffness method, also known as the “gamma method” is proposed for the design of the composite floor at ultimate and serviceability limit states, in the short and long term. By comparison with the experimental results, it is shown that the proposed method leads to conservative design. A step-by-step design worked example of this novel semi-prefabricated composite floor concludes the paper.

  10. Evaluation of the resistance to progressive collapse of monolithic reinforced concrete frame buildingswith separate amplified floors

    Directory of Open Access Journals (Sweden)

    Domarova Ekaterina Vladimirovna

    2014-02-01

    Full Text Available In the article the authors propose a simplified method of dynamic analysis of the resistance to progressive collapse of a fragment of the building bearing system with amplified floors. This method is based on representing the building bearing system as a dynamic model with a denumerable number of degrees of freedom, in which the resistance of the system is provided mainly by the behavior of the columns. The degrees of freedom number is determined by the number of floors «hanging» to amplified floors. Thecontribution of slabs in the total system resistance is not taken into account. Stress-strain state of the columns is determined by the non-linear resistance diagram, including three stages: elastic, elastic with cracks and plastic stage connected with plastic yield in the steel of the columns. The criterion of sustainability to the progressive collapse is relative strain of steel of the undestroyed columns. A numerical example of the calculation of the building resistance to progressive collapse in case of sudden destruction of one vertical element based on proposed theoretical method is offered. A model with two numbers of degrees was considered. The suggested method allows estimating the strength, deformability and stability of monolithic reinforced concrete frame buildings with separate amplified floors. In the future it is intended to complicate the model by the accounting for the influence of deformation and constructive solution of the slabs on the stiffness characteristics of the model as a system with a finite number of degrees of freedom.

  11. Tests and Evaluation of Upgraded Flat-Plate and Waffle-Slab Floor Systems

    Science.gov (United States)

    1983-12-01

    tested in the LBLG. The LBLG (Figure 2.J9) is a large, three-dimensional device designed pri- marily to test underground protective structures...34 Report AIWL-TR-74-102, Octo- ber 1974, Air Force Weapons Laboratory, Kirtland Air Force Base, N. Mex . 9. M. E. Criswell; "Strength and Behavior of...35th St. Commander, Air Force Weapons Laboratory, AFSC Chicago, Ill. 60616 ATTN: SUL, Technical Library Kirtland Air Force Base, N. Mex . 87117 Director

  12. NUMERICAL ANALYSIS OF THE BEHAVIOR OF FLAT SLABS PRESTRESSED CONCRETE FLOORS

    OpenAIRE

    MARIA VANESSA LA TORRE CUBAS

    2012-01-01

    Lajes lisas de concreto protendido com cordoalhas engraxadas não aderentes têm sido empregadas em pavimentos de edificações com frequência nos últimos anos. Essa solução estrutural é ideal quando se tem uma distribuição regular dos pilares. Além disso, sabe-se que lajes de concreto protendido oferecem vantagens técnicas sobre a solução tradicional em concreto armado, principalmente para vencer vãos maiores e onde muitas vezes se exigem seções mais esbeltas. O objetivo desta dissertação é esta...

  13. Flooring choices for newborn ICUs.

    Science.gov (United States)

    White, R D

    2007-12-01

    Floors are a major element of newborn intensive care unit (NICU) construction. They provide visual cues, sound control, and with certain materials, some degree of physical comfort for workers. Flooring materials may entail a significant cost for installation and upkeep and can have substantial ecological impact, both in the choice of the flooring itself, as well as the substances used to clean it. In this article the important aspects to consider for each factor are explored and recommendations are offered for appropriate choices in various NICU areas.

  14. Slab tears and intermediate-depth seismicity

    Science.gov (United States)

    Meighan, Hallie E.; Ten Brink, Uri; Pulliam, Jay

    2013-01-01

    Active tectonic regions where plate boundaries transition from subduction to strike slip can take several forms, such as triple junctions, acute, and obtuse corners. Well-documented slab tears that are associated with high rates of intermediate-depth seismicity are considered here: Gibraltar arc, the southern and northern ends of the Lesser Antilles arc, and the northern end of Tonga trench. Seismicity at each of these locations occurs, at times, in the form of swarms or clusters, and various authors have proposed that each marks an active locus of tear propagation. The swarms and clusters start at the top of the slab below the asthenospheric wedge and extend 30–60 km vertically downward within the slab. We propose that these swarms and clusters are generated by fluid-related embrittlement of mantle rocks. Focal mechanisms of these swarms generally fit the shear motion that is thought to be associated with the tearing process.

  15. Channel Floor Yardangs

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Released 19 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. The yardangs in this image are forming in channel floor deposits. The channel itself is funneling the wind to cause the erosion. Image information: VIS instrument. Latitude 4.5, Longitude 229.7 East (133.3 West). 19 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from

  16. The shop floor scheduling game

    NARCIS (Netherlands)

    Riezebos, Jan; Slomp, Jannes

    1995-01-01

    The aim of the shop floor scheduling game is getting participants acquainted with: - developing robust planning and scheduling procedures; - accepting orders under uncertainty and competition; - using information from cost accounting in scheduling; - creating an adequate communication structure

  17. Photon transport in thin disordered slabs

    Indian Academy of Sciences (India)

    Venkatesh Gopal; S Anantha Ramakrishna; A K Sood; N Kumar

    2001-06-01

    We examine using Monte Carlo simulations, photon transport in optically `thin’ slabs whose thickness is only a few times the transport mean free path *, with particles of different scattering anisotropies. The confined geometry causes an auto-selection of only photons with looping paths to remain within the slab. The results of the Monte Carlo simulations are borne out by our analytical treatment that incorporates directional persistence by the use of the Ornstein–Uhlenbeck process, which interpolates between the short time ballistic and long time diffusive regimes.

  18. Functional anatomy of pelvic floor

    OpenAIRE

    Salvatore Rocca Rossetti

    2016-01-01

    Generally, descriptions of the pelvic floor are discordant, since its complex structures and the complexity of pathological disorders of such structures; commonly the descriptions are sectorial, concerning muscles, fascial developments, ligaments and so on. On the contrary to understand completely nature and function of the pelvic floor it is necessary to study it in the most unitary view and in the most global aspect, considering embriology, philogenesy, anthropologic development and its mul...

  19. Low frequency vibration tests on a floating slab track in an underground laboratory

    Institute of Scientific and Technical Information of China (English)

    De-yun DING; Wei-ning LIU; Ke-fei LI; Xiao-jing SUN; Wei-feng LIU

    2011-01-01

    Low frequency vibrations induced by underground railways have attracted increasing attention in recent years. To obtain the characteristics of low frequency vibrations and the low frequency performance of a floating slab track (FST), low frequency vibration tests on an FST in an underground laboratory at Beijing Jiaotong University were carried out. The FST and an unbalanced shaker SBZ30 for dynamic simulation were designed for use in low frequency vibration experiments. Vibration measurements were performed on the bogie of the unbalanced shaker, the rail, the slab, the tunnel invert, the tunnel wall, the tunnel apex, and on the ground surface at distances varying from 0 to 80 m from the track. Measurements were also made on several floors of an adjacent building. Detailed results of low frequency vibration tests were reported. The attenuation of low frequency vibrations with the distance from the track was presented, as well as the responses of different floors of the building. The experimental results could be regarded as a reference for developing methods to control low frequency vibrations and for adopting countermeasures.

  20. Mantle circulation and the lateral migration of subducted slabs

    Science.gov (United States)

    Garfunkel, Z.; Anderson, C. A.; Schubert, G.

    1986-01-01

    The geometry of transverse migration of subducted lithospheric slabs is examined, and the way in which this influences the flow in the mantle is studied. The migration of subducted slabs generally appears to be retrograde (at rates of 10-25 mm/yr), so that the descent of material is actually steeper than the slab dip. Retrograde slab migration is probably caused by the tendence of negatively buoyant slabs to sink in the surrounding mantle. The properties of the flow driven by such retrograde slab migration are explored in simple two-dimensional models. The results are used as a guide to infer the contribution of retrograde slab motion to the more complex mantle flow and to examine some consequences of the additional component of mantle flow. It is shown that slab migration is an important factor that causes mantle flow to be geometrically complex and time dependent.

  1. Tangential Floor in a Classroom Setting

    Science.gov (United States)

    Marti, Leyla

    2012-01-01

    This article examines floor management in two classroom sessions: a task-oriented computer lesson and a literature lesson. Recordings made in the computer lesson show the organization of floor when a task is given to students. Temporary or "incipient" side floors (Jones and Thornborrow, 2004) emerge beside the main floor. In the literature lesson,…

  2. Distributed TLDs in RC floors and their vibration reduction efficiency

    Institute of Scientific and Technical Information of China (English)

    Ye Lieping; Lu Xinzheng; Qu Zhe; Hou Jianqun

    2008-01-01

    A novel distributed tuned liquid damper (DTLD) for reducing vibration in structures is proposed in this paper. The basic working principle of the DTLDs is to fill the empty space inside the pipes or boxes of cast-in-situ hollow reinforced concrete (RC) floor slabs with water or other liquid. The pipes or boxes then work as a series of small TLDs inside the structure, to increase the damping ratio of the entire structural system. Numerical simulation that accounts for the fluid-structure coupling effect is carried out to evaluate the vibration-reduction efficiency of the DTLDs. The results show that the DTLDs are able to considerably increase the damping of the structure and thus reduce its vibration. An additional benefit is that the DTLDs do not require architectural space to be added to the structure.

  3. Lifetime Reliability Assessment of Concrete Slab Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    A procedure for lifetime assesment of the reliability of short concrete slab bridges is presented in the paper. Corrosion of the reinforcement is the deterioration mechanism used for estimating the reliability profiles for such bridges. The importance of using sensitivity measures is stressed. Fi...

  4. Retrofitting of RC Slabs Against Explosive Loads

    Institute of Scientific and Technical Information of China (English)

    WU Chengqing; OEHLERS Deric John; XIA Shaohua

    2006-01-01

    With the increase of terrorist bomb attacks on buildings,there is a need to develop advanced retrofitting techniques to strengthen structures against blast loads.Currently,several guidelines including an Australian version for retrofitting reinforced concrete (RC) structures are available for the design of retrofitting systems against seismic and monotonic loads using steel or fibre reinforced polymer (FRP) plates that can be either adhesively bonded to the surface or near surface mounted to the concrete cover.However,none of these guidelines provide advice suitable for retrofitting structures subjected to blast loads.In this paper,numerical models are used to simulate the performance of retrofitted RC slabs subjected to blast loads.Airblast pressure distributions on the surface of the slabs estimated in a previous study are used as input in the analysis.A material damage model developedpreviously for concrete and an elastoplastic model for steel bars are employed in this research for modelling reinforced concrete behaviour due to explosive loads.The material models and blast loading are coded into a finite element computer program LS-DYNA3D to do the analysis.With the numerical model,parametric studies are conducted to investigate RC slabs retrofitted by either externally bonded or near-surface mounted plates or GFRP sheets subjected to blast loads.Discussion is made on the effectiveness of the retrofitting system for RC slabs against blast loads.

  5. Numerical Evaluations of Functionally Graded RC Slabs

    Directory of Open Access Journals (Sweden)

    M. Mastali

    2014-01-01

    Full Text Available Nowadays, using fibrous materials is used widely in strengthening applications such as cross-section enlargement and using functionally graded reinforced concrete. Functionally graded reinforced concrete is used as multireinforced concrete layers that can be reinforced by different fiber types. The objective of this research was to address the structural benefits of functionally graded concrete materials by performing analytical simulations. In order to achieve this purpose, in the first stage of this study, three functionally graded reinforced concretes by steel and polypropylene (PP were experimentally tested under flexural loading. Inverse analysis was applied to obtain the used material properties of reinforced concrete by FEMIX software. After obtaining the material properties, to assess the performance of proposed slabs, some other cases were proposed and numerically evaluated under flexural and shear loading. The results showed that increasing steel fiber in reinforced entire cross section led to achieve better shear and flexural performance while the best performance of reinforced functionally graded slabs was achieved for slab at 1% fiber content. In the second stage, nineteen reinforced functionally graded RC slabs with steel bars were simulated and assessed and some other cases were considered which were not experimentally tested.

  6. Longitudinal shear resistance of composite slabs

    NARCIS (Netherlands)

    Schuurman, R.G.; Stark, J.W.B.

    1996-01-01

    Verification methods for longitudinal shear. currently in use, are empirical. This applies for both the m-k method as the Partial Shear Connection method. Parameters and mechanisms determining the behaviour of the shear connection in composite slabs are not directly considered in these methods. A

  7. Plastic design of continuous composite slabs

    NARCIS (Netherlands)

    Stark, J.W.B.; Brekelmans, J.W.P.M.

    1996-01-01

    Most current regulations for continuous composite slabs contain rules that limit the application of plastic analysis in the design process. In this paper, results of numerical studies for positive and negative bending and experimental results for negative bending are presented. From these

  8. Benchmark Experiment for Beryllium Slab Samples

    Institute of Scientific and Technical Information of China (English)

    NIE; Yang-bo; BAO; Jie; HAN; Rui; RUAN; Xi-chao; REN; Jie; HUANG; Han-xiong; ZHOU; Zu-ying

    2015-01-01

    In order to validate the evaluated nuclear data on beryllium,a benchmark experiment has been performed at China Institution of Atomic Energy(CIAE).Neutron leakage spectra from pure beryllium slab samples(10cm×10cm×11cm)were measured at 61°and 121°using timeof-

  9. All-polymer photonic crystal slab sensor

    DEFF Research Database (Denmark)

    Hermannsson, Pétur Gordon; Sørensen, Kristian Tølbøl; Vannahme, Christoph;

    2015-01-01

    An all-polymer photonic crystal slab sensor is presented, and shown to exhibit narrow resonant reflection with a FWHM of less than 1 nm and a sensitivity of 31 nm/RIU when sensing media with refractive indices around that of water. This results in a detection limit of 4.5x10-6 RIU when measured...

  10. Effects of Edge Restraint on Slab Behavior

    Science.gov (United States)

    1986-02-01

    manufactured limestone sand fine aggregate. Two batches were prepared, one for each of the different thickness slab groups. A total of thirty-eight 4...Building Code Require- ments" 1983; Detroit, Mich. 4. T. Takehira, A. T. Derecho , and M. Iqbal; "Design Criteria for De- flection Capacity of

  11. Cost analysis of reinforced concrete slabs and columns

    OpenAIRE

    Spuś, Piotr

    2013-01-01

    The construction industry is increasingly looking for solutions that are both simple and effective and that provide cost savings, speed and flexibility of execution. Two-way slabs are a form of construction unique to reinforced concrete comparing with the other major structural materials. It is an efficient, economical, and widely used structural system. The present dissertation aims to analyze and compare costs between four types of slabs: waffle slab with recuperate molds, flat slabs wit...

  12. Abrupt tectonics and rapid slab detachment with grain damage

    OpenAIRE

    2015-01-01

    Subduction zones are delineated by Earth’s ocean trenches, and are where tectonic plates sink into the mantle as cold heavy slabs, which in turn drive plate motion. But slabs can detach from their surface plates, thus altering tectonic driving forces. Slab detachment can occur if thick crust from continents or oceanic plateaux is swept by plate motion into the subduction zone, thus plugging it up. Detachment is also accelerated because mineral grains in the slab become smaller during deformat...

  13. Reinforcement of the concrete base slab of the ATLAS cavern

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Photo 02: UX15 cavern, preparation for concreting of base slab first lift. Photo 05: UX15 cavern, placing of reinforcement for base slab first lift. Photo 07: UX15 cavern, preparation for concreting of base slab first lift. Photo 09: UX15 cavern, placing of reinforcement for base slab first lift. Photo 10: UX15 cavern, view into PX14 shaft above. Photo 12: UX15 cavern, temporary access platform of RB16 tunnel. Photo 15: UJ17 chamber, invert excavation.

  14. Development of a Leave-in-Place Slab Edge Insulating Form System

    Energy Technology Data Exchange (ETDEWEB)

    Marc Hoeschele; Eric Lee

    2009-08-31

    homes with radiant floor heating), the most practical insulation strategy is to secure rigid foam insulation, such as Dow Styrofoam{trademark}, to the inside of the wooden slab edge forms. An alternative is to clad insulation to the perimeter of the slab after the slab has been poured and cured. In either case, the foam must have a 'termite strip' that prevents termites from creating hidden tunnels through or behind the foam on their way to the wall framing above. Frequently this termite strip is a piece of sheet metal that must be fabricated for each project. The above-grade portion of the insulation also needs to be coated for appearance and to prevent damage from construction and UV degradation. All these steps add time, complexity, and expense to the insulating process.

  15. Functional anatomy of pelvic floor

    Directory of Open Access Journals (Sweden)

    Salvatore Rocca Rossetti

    2016-03-01

    Full Text Available Generally, descriptions of the pelvic floor are discordant, since its complex structures and the complexity of pathological disorders of such structures; commonly the descriptions are sectorial, concerning muscles, fascial developments, ligaments and so on. On the contrary to understand completely nature and function of the pelvic floor it is necessary to study it in the most unitary view and in the most global aspect, considering embriology, philogenesy, anthropologic development and its multiple activities others than urological, gynaecological and intestinal ones. Recent acquirements succeeded in clarifying many aspects of pelvic floor activity, whose musculature has been investigated through electromyography, sonography, magnetic resonance, histology, histochemistry, molecular research. Utilizing recent research concerning not only urinary and gynecologic aspects but also those regarding statics and dynamics of pelvis and its floor, it is now possible to study this important body part as a unit; that means to consider it in the whole body economy to which maintaining upright position, walking and behavior or physical conduct do not share less than urinary, genital, and intestinal functions. It is today possible to consider the pelvic floor as a musclefascial unit with synergic and antagonistic activity of muscular bundles, among them more or less interlaced, with multiple functions and not only the function of pelvic cup closure.

  16. Functional anatomy of pelvic floor.

    Science.gov (United States)

    Rocca Rossetti, Salvatore

    2016-03-31

    Generally, descriptions of the pelvic floor are discordant, since its complex structures and the complexity of pathological disorders of such structures; commonly the descriptions are sectorial, concerning muscles, fascial developments, ligaments and so on. On the contrary to understand completely nature and function of the pelvic floor it is necessary to study it in the most unitary view and in the most global aspect, considering embriology, philogenesy, anthropologic development and its multiple activities others than urological, gynaecological and intestinal ones. Recent acquirements succeeded in clarifying many aspects of pelvic floor activity, whose musculature has been investigated through electromyography, sonography, magnetic resonance, histology, histochemistry, molecular research. Utilizing recent research concerning not only urinary and gynecologic aspects but also those regarding statics and dynamics of pelvis and its floor, it is now possible to study this important body part as a unit; that means to consider it in the whole body economy to which maintaining upright position, walking and behavior or physical conduct do not share less than urinary, genital, and intestinal functions. It is today possible to consider the pelvic floor as a musclefascial unit with synergic and antagonistic activity of muscular bundles, among them more or less interlaced, with multiple functions and not only the function of pelvic cup closure.

  17. Mantle Response to a Slab Gap and Three-dimensional Slab Interaction in Central America

    Science.gov (United States)

    Jadamec, M. A.; Fischer, K. M.

    2013-12-01

    Seismically constrained global slab geometries suggest the Middle America-South American subduction system contains a gap on the order of 500 km separating the east-dipping Cocos and Nazca slabs at depth (Gudmundsson and Sambridge, 1998; Syracuse and Abers, 2006; Hayes et al., 2012). The location of the gap correlates with tectonic features impinging on the Pacific side of the Middle America trench, in particular the incoming young buoyant oceanic lithosphere and oceanic ridges associated with the Galapagos hotspot and Cocos-Nazca spreading center (Protti et al., 1994; Mann et al., 2007; Muller et al., 2008). Moreover, geochemical studies focusing on the arc chemistry in the Central American volcanic front argue for a slab window of some kind in this region (Johnston and Thorkelson, 1997; Abratis and Worner, 2001; Hoernle et al., 2008). We use high-resolution, three-dimensional (3D) geodynamic modeling of the Middle America-South American subduction system to investigate the role of the incoming young oceanic lithosphere and a gap between the Cocos and Nazca slabs in controlling mantle flow velocity and geochemical signatures beneath Central America. The geodynamic models are geographically referenced with the geometry and thermal structure for the overriding and subducting plates based on geological and geophysical observables and constructed with the multi-plate subduction generator code, SlabGenerator (Jadamec and Billen, 2010; Jadamec et al., 2012; Jadamec and Billen, 2012). The viscous flow simulations are solved using the mantle convection finite-element code, CitcomCU (Zhong, 2006), modified by Jadamec and Billen (2010) to take into account the experimentally derived flow law for olivine and allow for variable 3D plate interface geometries and magnitudes of inter-plate coupling. The 3D numerical models indicate the gap between the Cocos and Nazca slabs serves as a conduit for Pacific-Cocos mantle to pass into the Caribbean, with toroidal flow around the

  18. Occurrences of thermophilic Campylobacter in pigs slaughtered at Morogoro slaughter slabs, Tanzania.

    Science.gov (United States)

    Mdegela, Robinson H; Laurence, Kibona; Jacob, Petro; Nonga, Hezron Emmanuel

    2011-01-01

    Occurrences of thermophlic Campylobacter in pigs and pig carcasses was investigated in a cross-sectional study that was carried out in three selected slaughter slabs in Morogoro municipality, Tanzania. Before sampling, the slab hygiene, slaughter, carcass dressing, and meat handling was assessed. Fecal samples were collected from 66 slaughter pigs at the kill floor. After slaughter, a 100-cm(2) area on medial surface of the thigh muscles of dressed carcasses was sampled using sterile cotton swabs. Thereafter, the jejunal, cecal, and colon contents were also sampled. The samples were subjected to standard bacteriological examination using Skirrows protocol. In all slaughter slabs visited, it was found that pig slaughter, dressing, and meat handling was done on the ground under unhygienic condition. All the slaughter slab environment were dirty and had neither tap water or drainage systems. Thermophilic Campylobacter prevalence in slaughtered pig was 66.7% while contamination rate of dressed carcasses was 10.6%. Of the Campylobacter-positive carcasses, five (12.2%) were from the animals which were also positive to Campylobacter. The isolation rate of Campylobacter in the cecum was higher (34.8%) compared to the small intestines (28.8%) and colon (16.7%) although the difference was not statistically significant (P > 0.05). Campylobacter jejuni was the most prevalent species as it constituted 74% of all isolates, while Campylobacter coli was isolated at 26%. This suggests possible risks of infection to people through consumption of contaminated pork or through contact with infected pigs. Cecum was found to be the major part of intestine highly colonized by Campylobacter.

  19. HEAT TRANSFER ANALYSIS DURING ROLLING OF THIN SLAB IN CSP

    Institute of Scientific and Technical Information of China (English)

    W.F. Wu; Y.H. Feng; X.X. Zhang

    2006-01-01

    A mathematical model has been built to numerically predict the thermal history of thin slab during CSP (compact strip process) rolling. To estimate the temperature distribution in the slab more accurately, the mathematical model combines heat transfer in the slab, in the roll, and at the roll-slab interface during bite. The numerical results agree with on-site running data, which proves the reliability of the mathematical model. The results show that roll chilling has a significant effect on the temperature distribution in the slab.

  20. Thin-slab casting – New possibilities

    Indian Academy of Sciences (India)

    Amit Chatterjee; Sanjay Chandra

    2001-02-01

    Changes in the IT industry are known to proceed at a scorching pace. In sharp contrast, the rate of development in the steel industry is generally slow. Nonetheless, The impact of recent technical developments on the steel industry has been quite significant. The production chain from iron ore to final rolled steel is a long one and the shortening of this length has long been the endeavour of scientists and engineers. The initial development came in the form of speeding up the process of steelmaking by reducing the slow open-hearth process (8 h tap-to-tap time) with the 45 min tap-tp-tap time of the Basic Oxygen Furnace (BOF) process. Significant developments thereafter have been in the process of continuous production of billets and blooms from liquid steel thereby doing away with the large blooming mills needed for rolling ingots. For a fairly long time after the stabilisation of continuous casting. hot rolling involved reheating thick (200-250 mm) slabs and reducing them in a hot-strip mill. The advent of thin-slab casters has made even these large hot-strip mills redundant. The new installtion produce thin slabs (50-70 mm) that are directly rolled into strips without the need of an intermediate furnace for raising the stock temperature; the so-called tunnel furance prior to the rolling stands serving only to equalise stock temperatures. Additionally, what started as a step for reducing investment in hot rolling has, in fact, given new opportunity for direct hot rolling of thickness that were, for long, considered to be feasible only through the cold-rolling route. This article discuss the slow but steady encroachment of hot-rolled sheets into the domain of strip thickness hitherto produced by cold rolling and tries to show how the development of thin-slab casters has allowed this process to be accelerated. A techno-economic analysis of thin-slab casting has been presented along with the benefits that arise when a thin-slab caster is linked to the blast furnace

  1. Evidence of fire resistance of hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes...... is therefore going on in the Netherlands about the fire resistance of hollow-core slabs. In 2014 the producers of hollow-core slabs have published a report of a project called Holcofire containing a collection of 162 fire tests on hollow-core slabs giving for the first time an overview of the fire tests made....... The present paper analyses the evidence now available for assessment of the fire resistance of extruded hollow-core slabs. The 162 fire tests from the Holcofire report are compared against the requirements for testing from the product standard for hollow-core slabs EN1168 and knowledge about the possible...

  2. Radiative transfer model for contaminated rough slabs

    CERN Document Server

    Andrieu, François; Schmidt, Frédéric; Schmitt, Bernard

    2015-01-01

    We present a semi-analytical model to simulate bidirectional reflectance distribution function (BRDF) spectra of a rough slab layer containing impurities. This model has been optimized for fast computation in order to analyze hyperspectral data. We designed it for planetary surfaces ices studies but it could be used for other purposes. It estimates the bidirectional reflectance of a rough slab of material containing inclusions, overlaying an optically thick media (semi-infinite media or stratified media, for instance granular material). The inclusions are supposed to be close to spherical, and of any type of other material than the ice matrix. It can be any type of other ice, mineral or even bubbles, defined by their optical constants. We suppose a low roughness and we consider the geometrical optics conditions. This model is thus applicable for inclusions larger than the considered wavelength. The scattering on the inclusions is assumed to be isotropic. This model has a fast computation implementation and th...

  3. Subduction zone earthquakes and stress in slabs

    Science.gov (United States)

    Vassiliou, M. S.; Hager, B. H.

    1988-01-01

    Simple viscous fluid models of subducting slabs are used to explain observations of the distribution of earthquakes as a function of depth and the orientation of stress axes of deep (greater than 300 km) and intermediate (70-300 km) earthquakes. Results suggest the following features in the distribution of earthquakes with depth: (1) an exponential decrease from shallow depths down to 250 to 300 km, (2) a minimum near 250 to 300 km, and (3) a deep peak below 300 km. Many shallow subducting slabs show only the first characteristic, while deeper extending regions tend to show all three features, with the deep peak varying in position and intensity. These data, combined with the results on the stress orientations of various-depth earthquakes, are consistent with the existence of a barrier of some sort at 670-km depth and a uniform viscosity mantle above this barrier.

  4. Behavior of Partially Restrained Reinforced Concrete Slabs.

    Science.gov (United States)

    1986-09-01

    Takehira, Derecho , and Iqbal [34] followed a similar approach to arrive at recommended design criteria for 1 the Naval Facilities Engineering Command...Datta, T. K., "Ultimate Strength of Reinforced Concrete Slab-Beam Systems: A New Approach," r Indian Concrete Journal, Bombay, India , Vol. 47, 1973, pp...Journal of Solids and Structures, Vol. 1, 1965, pp. 97-111. 34. Takehira, T., Derecho , A.T., and Iqbal, M., "Design Criteria for Deflection Capacity

  5. Electrostatics in Periodic Slab Geometries II

    OpenAIRE

    de Joannis, Jason; Arnold, Axel; Holm, Christian

    2002-01-01

    In a previous paper a method was developed to subtract the interactions due to periodically replicated charges (or other long-range entities) in one spatial dimension. The method constitutes a generalized "electrostatic layer correction" (ELC) which adapts any standard 3D summation method to slab-like conditions. Here the implementation of the layer correction is considered in detail for the standard Ewald (EW3DLC) and the PPPM mesh Ewald (PPPMLC) methods. In particular this method offers a s...

  6. Continental underplating after slab break-off

    Science.gov (United States)

    Magni, V.; Allen, M. B.; van Hunen, J.; Bouilhol, P.

    2017-09-01

    We present three-dimensional numerical models to investigate the dynamics of continental collision, and in particular what happens to the subducted continental lithosphere after oceanic slab break-off. We find that in some scenarios the subducting continental lithosphere underthrusts the overriding plate not immediately after it enters the trench, but after oceanic slab break-off. In this case, the continental plate first subducts with a steep angle and then, after the slab breaks off at depth, it rises back towards the surface and flattens below the overriding plate, forming a thick horizontal layer of continental crust that extends for about 200 km beyond the suture. This type of behaviour depends on the width of the oceanic plate marginal to the collision zone: wide oceanic margins promote continental underplating and marginal back-arc basins; narrow margins do not show such underplating unless a far field force is applied. Our models show that, as the subducted continental lithosphere rises, the mantle wedge progressively migrates away from the suture and the continental crust heats up, reaching temperatures >900 °C. This heating might lead to crustal melting, and resultant magmatism. We observe a sharp peak in the overriding plate rock uplift right after the occurrence of slab break-off. Afterwards, during underplating, the maximum rock uplift is smaller, but the affected area is much wider (up to 350 km). These results can be used to explain the dynamics that led to the present-day crustal configuration of the India-Eurasia collision zone and its consequences for the regional tectonic and magmatic evolution.

  7. Benchmark Experiment for Beryllium Slab Samples

    Institute of Scientific and Technical Information of China (English)

    NIE; Yang-bo; BAO; Jie; HAN; Rui; RUAN; Xi-chao; REN; Jie; HUANG; Han-xiong; ZHOU; Zu-ying

    2013-01-01

    The neutron leakage spectra were measured at 60°from pure beryllium slab samples(10 cm×10 cm×5 cm and 10 cm×10 cm×11 cm)by TOF method.The experimental results were compared with the calculated ones by MCNP5 simulation,using the evaluated data of beryllium from CENDL3.1,

  8. Wave Scattering by Superluminal Spacetime Slab

    CERN Document Server

    Deck-Léger, Zoé-Lise

    2016-01-01

    Spacetime media offers new opportunities for wave manipulation. Here we study superluminal slabs, and show that the amplitudes of the reflected waves are controlled by the velocity of the medium. In addition, the backward wave continuously scans from the specular to the collinear angle. A diagrammatic method is provided for insight into the deflection angles. A fundamental symmetry between sub- and superluminal scattering is derived from this diagrammatic description.

  9. Convection in Slab and Spheroidal Geometries

    Science.gov (United States)

    Porter, David H.; Woodward, Paul R.; Jacobs, Michael L.

    2000-01-01

    Three-dimensional numerical simulations of compressible turbulent thermally driven convection, in both slab and spheroidal geometries, are reviewed and analyzed in terms of velocity spectra and mixing-length theory. The same ideal gas model is used in both geometries, and resulting flows are compared. The piecewise-parabolic method (PPM), with either thermal conductivity or photospheric boundary conditions, is used to solve the fluid equations of motion. Fluid motions in both geometries exhibit a Kolmogorov-like k(sup -5/3) range in their velocity spectra. The longest wavelength modes are energetically dominant in both geometries, typically leading to one convection cell dominating the flow. In spheroidal geometry, a dipolar flow dominates the largest scale convective motions. Downflows are intensely turbulent and up drafts are relatively laminar in both geometries. In slab geometry, correlations between temperature and velocity fluctuations, which lead to the enthalpy flux, are fairly independent of depth. In spheroidal geometry this same correlation increases linearly with radius over the inner 70 percent by radius, in which the local pressure scale heights are a sizable fraction of the radius. The effects from the impenetrable boundary conditions in the slab geometry models are confused with the effects from non-local convection. In spheroidal geometry nonlocal effects, due to coherent plumes, are seen as far as several pressure scale heights from the lower boundary and are clearly distinguishable from boundary effects.

  10. Convection in Slab and Spheroidal Geometries

    Science.gov (United States)

    Porter, David H.; Woodward, Paul R.; Jacobs, Michael L.

    2000-01-01

    Three-dimensional numerical simulations of compressible turbulent thermally driven convection, in both slab and spheroidal geometries, are reviewed and analyzed in terms of velocity spectra and mixing-length theory. The same ideal gas model is used in both geometries, and resulting flows are compared. The piecewise-parabolic method (PPM), with either thermal conductivity or photospheric boundary conditions, is used to solve the fluid equations of motion. Fluid motions in both geometries exhibit a Kolmogorov-like k(sup -5/3) range in their velocity spectra. The longest wavelength modes are energetically dominant in both geometries, typically leading to one convection cell dominating the flow. In spheroidal geometry, a dipolar flow dominates the largest scale convective motions. Downflows are intensely turbulent and up drafts are relatively laminar in both geometries. In slab geometry, correlations between temperature and velocity fluctuations, which lead to the enthalpy flux, are fairly independent of depth. In spheroidal geometry this same correlation increases linearly with radius over the inner 70 percent by radius, in which the local pressure scale heights are a sizable fraction of the radius. The effects from the impenetrable boundary conditions in the slab geometry models are confused with the effects from non-local convection. In spheroidal geometry nonlocal effects, due to coherent plumes, are seen as far as several pressure scale heights from the lower boundary and are clearly distinguishable from boundary effects.

  11. Technical evaluation of a solar heating system having conventional hydronic solar collectors and a radiant panel slab. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Starr, R.J.

    1984-04-01

    A simple innovative solar heating design (Solar Option One) using conventional hydronic solar collectors and a radiant panel slab was constructed. An objective of hybrid solar design is to combine the relative advantages of active and passive design approaches while minimizing their respective disadvantages. A test house using the Solar Option One heating system was experimentally monitored to determine its energy based performance during the 1982-83 heating season. The test residence is located in Lyndonville, Vermont, an area which has a characteristically cold and cloudy climate. The two story residence has a floor area of about 1400 square feet and is constructed on a 720 square foot 5.5 inch thick floor slab. A 24 inch packed gravel bed is located beneath the slab and the slab-gravel bed is insulated by two inches of polystyrene insulation. The test building is of frame construction and uses insulation levels which have become commonplace throughout the country. The structure would not fall into the superinsulated category but was tightly constructed so as to have a low infiltration level. The building is sun-tempered in that windows were concentrated somewhat on the South side and all but avoided on the North. A solar greenhouse on the South side of the building was closed off from the structure permanently throughout the testing so as to better observe the solar heating invention without confounding variables. The monitoring equipment generated an internal gain of about 17,000 BTUs per day, roughly the equivalent of occupancy by two persons. A full description of the experimental testing program is given. System efficiency and performance are reported.

  12. Steel-board composite floors

    NARCIS (Netherlands)

    Couchman, G.H.; Tomà, A.W.; Brekelmans, J.W.P.M.; Brande, E.L.M.G. van den

    1999-01-01

    Work currently underway in Holland aDd the UK aims to increase the already considerable potential for light steel framing in buildings by developing rules for so-called "dry composites". This paper discusses both theoretical and experimental work to develop validated design mies for floor systems co

  13. Branding on the Shop Floor

    DEFF Research Database (Denmark)

    Gyimóthy, Szilvia; Jonas, Louise Rygaard

    2010-01-01

    , a Danish supermarket chain. During the implementation of the “Best Butcher in Town”-project, Kvickly’s shop floor becomes an engineered servicescape where the norms of good salesmanship must be performed. By documenting the disloyal behaviour of butchers, we demonstrate that the affective commitment...

  14. Timber floors strengthened with concrete

    NARCIS (Netherlands)

    Blass, H.J.; Linden, M.L.R. van der; Schlager, M.

    1998-01-01

    Timber-concrete composite (tcc) beams may be used for the renovation of old timber floors. Although these systems are not new (Pokulka, 1997) and form a simple and practical solution, they are not widely adopted. One of the reasons for this is the Jack of uniform design rules. In this research progr

  15. Steel-board composite floors

    NARCIS (Netherlands)

    Couchman, G.H.; Tomà, A.W.; Brekelmans, J.W.P.M.; Brande, E.L.M.G. van den

    1999-01-01

    Work currently underway in Holland aDd the UK aims to increase the already considerable potential for light steel framing in buildings by developing rules for so-called "dry composites". This paper discusses both theoretical and experimental work to develop validated design mies for floor systems

  16. Timber floors strengthened with concrete

    NARCIS (Netherlands)

    Blass, H.J.; Linden, M.L.R. van der; Schlager, M.

    1998-01-01

    Timber-concrete composite (tcc) beams may be used for the renovation of old timber floors. Although these systems are not new (Pokulka, 1997) and form a simple and practical solution, they are not widely adopted. One of the reasons for this is the Jack of uniform design rules. In this research

  17. Viscous Dissipation and Criticality of Subducting Slabs

    Science.gov (United States)

    Riedel, Mike; Karato, Shun; Yuen, Dave

    2016-04-01

    Rheology of subducting lithosphere appears to be complicated. In the shallow part, deformation is largely accomodated by brittle failure, whereas at greater depth, at higher confining pressures, ductile creep is expected to control slab strength. The amount of viscous dissipation ΔQ during subduction at greater depth, as constrained by experimental rock mechanics, can be estimated on the basis of a simple bending moment equation [1,2] 2ɛ˙0(z) ∫ +h/2 2 M (z) = h ṡ -h/2 4μ(y,z)y dy , (1) for a complex multi-phase rheology in the mantle transition zone, including the effects of a metastable phase transition as well as the pressure, temperature, grain-size and stress dependency of the relevant creep mechanisms; μ is here the effective viscosity and ɛ˙0(z) is a (reference) strain rate. Numerical analysis shows that the maximum bending moment, Mcrit, that can be sustained by a slab is of the order of 1019 Nm per m according to Mcrit˜=σp ∗h2/4, where σp is the Peierl's stress limit of slab materials and h is the slab thickness. Near Mcrit, the amount of viscous dissipation grows strongly as a consequence of a lattice instability of mantle minerals (dislocation glide in olivine), suggesting that thermo-mechanical instabilities become prone to occur at places where a critical shear-heating rate is exceeded, see figure. This implies that the lithosphere behaves in such cases like a perfectly plastic solid [3]. Recently available detailed data related to deep seismicity [4,5] seems to provide support to our conclusion. It shows, e.g., that thermal shear instabilities, and not transformational faulting, is likely the dominating mechanism for deep-focus earthquakes at the bottom of the transition zone, in accordance with this suggested "deep criticality" model. These new findings are therefore briefly outlined and possible implications are discussed. References [1] Riedel, M. R., Karato, S., Yuen, D. A. Criticality of Subducting Slabs. University of Minnesota

  18. Raise the Floor When Remodeling Science Labs

    Science.gov (United States)

    Nation's Schools, 1972

    1972-01-01

    A new remodeling idea adopts the concept of raised floor covering gas, water, electrical, and drain lines. The accessible floor has removable panels set into an adjustable support frame 24 inches above a concrete subfloor. (Author)

  19. How Are Pelvic Floor Disorders Commonly Treated?

    Science.gov (United States)

    ... Information Clinical Trials Resources and Publications How are pelvic floor disorders commonly treated? Skip sharing on social media ... Treatment Nonsurgical treatments commonly used for PFDs include: Pelvic floor muscle training (PFMT). Also called Kegel (pronounced KEY- ...

  20. How Are Pelvic Floor Disorders Diagnosed?

    Science.gov (United States)

    ... Information Clinical Trials Resources and Publications How are pelvic floor disorders diagnosed? Skip sharing on social media links ... fee ). This test is used to evaluate the pelvic floor and rectum while the patient is having a ...

  1. Tectonic controls on earthquake size distribution and seismicity rate: slab buoyancy and slab bending

    Science.gov (United States)

    Nishikawa, T.; Ide, S.

    2014-12-01

    There are clear variations in maximum earthquake magnitude among Earth's subduction zones. These variations have been studied extensively and attributed to differences in tectonic properties in subduction zones, such as relative plate velocity and subducting plate age [Ruff and Kanamori, 1980]. In addition to maximum earthquake magnitude, the seismicity of medium to large earthquakes also differs among subduction zones, such as the b-value (i.e., the slope of the earthquake size distribution) and the frequency of seismic events. However, the casual relationship between the seismicity of medium to large earthquakes and subduction zone tectonics has been unclear. Here we divide Earth's subduction zones into over 100 study regions following Ide [2013] and estimate b-values and the background seismicity rate—the frequency of seismic events excluding aftershocks—for subduction zones worldwide using the maximum likelihood method [Utsu, 1965; Aki, 1965] and the epidemic type aftershock sequence (ETAS) model [Ogata, 1988]. We demonstrate that the b-value varies as a function of subducting plate age and trench depth, and that the background seismicity rate is related to the degree of slab bending at the trench. Large earthquakes tend to occur relatively frequently (lower b-values) in shallower subduction zones with younger slabs, and more earthquakes occur in subduction zones with deeper trench and steeper dip angle. These results suggest that slab buoyancy, which depends on subducting plate age, controls the earthquake size distribution, and that intra-slab faults due to slab bending, which increase with the steepness of the slab dip angle, have influence on the frequency of seismic events, because they produce heterogeneity in plate coupling and efficiently inject fluid to elevate pore fluid pressure on the plate interface. This study reveals tectonic factors that control earthquake size distribution and seismicity rate, and these relationships between seismicity and

  2. 7 CFR 2902.39 - Floor strippers.

    Science.gov (United States)

    2010-01-01

    ... Floor strippers. (a) Definition. Products that are formulated to loosen waxes, resins, or varnishes from floor surfaces. They can be in either liquid or gel form, and may also be used with or without... 7 Agriculture 15 2010-01-01 2010-01-01 false Floor strippers. 2902.39 Section 2902.39...

  3. A STUDY ON THE WHEELSET/SLAB TRACK VERTICAL INTERACTION

    Directory of Open Access Journals (Sweden)

    Traian MAZILU

    2012-05-01

    Full Text Available This paper deals with the interaction between a moving wheelset and a slab track due to the short-pitch corrugated rail. The wheelset is modeled using a free-free Timoshenko beam with attached rigid bodies as the axle boxes, wheels and brake discs. The slab track model consists of elastically supported double Euler-Bernoulli beams. In fact, both wheelset and slab track are symmetric structures and the issue of the wheelset/slab track interaction is reduced to the wheel/rail interaction. The nonlinear equations of motion describing the wheelset/slab track interaction due to the short-pitch corrugated rail are solved using the time-domain Green’s functions method and the convolution theorem. The wheelset/slab track interaction due to the short-pitch corrugated rail exhibits a critical velocity when the vibration reaches the maximum level

  4. Obesity and pelvic floor dysfunction.

    Science.gov (United States)

    Ramalingam, Kalaivani; Monga, Ash

    2015-05-01

    Obesity is associated with a high prevalence of pelvic floor disorders. Patients with obesity present with a range of urinary, bowel and sexual dysfunction problems as well as uterovaginal prolapse. Urinary incontinence, faecal incontinence and sexual dysfunction are more prevalent in patients with obesity. Uterovaginal prolapse is also more common than in the non-obese population. Weight loss by surgical and non-surgical methods plays a major role in the improvement of these symptoms in such patients. The treatment of symptoms leads to an improvement in their quality of life. However, surgical treatment of these symptoms may be accompanied by an increased risk of complications in obese patients. A better understanding of the mechanism of obesity-associated pelvic floor dysfunction is essential.

  5. [Surgical dilemmas. Sinus floor elevation].

    Science.gov (United States)

    ten Bruggenkate, C M; Schulten, E A J M; Zijderveld, S A

    2008-12-01

    Limited alveolar bone height prevents the placement of dental implants. Sinus floor elevation is an internal augmentation of the maxillary sinus that allows implants to be placed. The principle of this surgical procedure is the preparation of a 'top hinge door', that is raised together with the Schneiderian membrane in the cranial direction. The space which created under this lid is filled with a bone transplant. Autogenous bone is the standard transplant material, despite the fact that a second surgery site is necessary. Under certain circumstances bone substitutes can be used, with a longer healing phase. If sufficient alveolar bone height is available to secure implant stability, simultaneous implantation and sinus floor elevation are possible. Considering the significant anatomical variation in the region of the maxillary sinus, a sound knowledge of the anatomy is of great importance.

  6. Branding on the Shop Floor

    OpenAIRE

    Szilvia Gyimóthy; Louise Rygaard Jonas

    2010-01-01

    Service branding is a particular form of emotional management, where employees are regarded as adaptable media, who can be trained to convey corporate values while interacting with customers. This paper examines the identity work of butchers during the brand revitalisation campaign of Kvickly, a Danish supermarket chain. During the implementation of the “Best Butcher in Town”-project, Kvickly’s shop floor becomes an engineered servicescape where the norms of good salesmanship must be performe...

  7. Linear Alkylbenzenesulfonates in indoor Floor Dust

    DEFF Research Database (Denmark)

    Wolkoff, Peder; Madsen, Jørgen Øgaard

    1999-01-01

    The amount of Linear Alkylbenzenesulfonates (LAS) in the particle fraction of floor dust sampled from 7 selected public buildings varied between 34 and 1500 microgram per gram dust, while the contents of the fibre fractions generally were higher with up to 3500 microgram LAS/g dust. The use...... of a cleaning agent with LAS resulted in an increase of the amount of LAS in the floor dust after floor wash relative to just before floor wash. However, the most important source of LAS in the indoor floor dust appears to be residues of detergent in clothing. Thus, a newly washed shirt contained 2960 microgram...

  8. Hybrid slab-microchannel gel electrophoresis system

    Science.gov (United States)

    Balch, Joseph W.; Carrano, Anthony V.; Davidson, James C.; Koo, Jackson C.

    1998-01-01

    A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.

  9. Photonic crystal slab quantum well infrared photodetector

    Science.gov (United States)

    Kalchmair, S.; Detz, H.; Cole, G. D.; Andrews, A. M.; Klang, P.; Nobile, M.; Gansch, R.; Ostermaier, C.; Schrenk, W.; Strasser, G.

    2011-01-01

    In this letter we present a quantum well infrared photodetector (QWIP), which is fabricated as a photonic crystal slab (PCS). With the PCS it is possible to enhance the absorption efficiency by increasing photon lifetime in the detector active region. To understand the optical properties of the device we simulate the PCS photonic band structure, which differs significantly from a real two-dimensional photonic crystal. By fabricating a PCS-QWIP with 100x less quantum well doping, compared to a standard QWIP, we are able to see strong absorption enhancement and sharp resonance peaks up to temperatures of 170 K.

  10. Photonic crystal slab quantum cascade detector

    Energy Technology Data Exchange (ETDEWEB)

    Reininger, Peter, E-mail: peter.reininger@tuwien.ac.at; Schwarz, Benedikt; Harrer, Andreas; Zederbauer, Tobias; Detz, Hermann; Maxwell Andrews, Aaron; Gansch, Roman; Schrenk, Werner; Strasser, Gottfried [Institute for Solid State Electronics and Center for Micro- and Nanostructures, Vienna University of Technology, Floragasse 7, Vienna 1040 (Austria)

    2013-12-09

    In this Letter, we demonstrate the design, fabrication, and characterization of a photonic crystal slab quantum cascade detector (PCS-QCD). By employing a specifically designed resonant cavity, the performance of the photodetector is improved in three distinct ways. The PCS makes the QCD sensitive to surface normal incident light. It resonantly enhances the photon lifetime inside the active zone, thus increasing the photocurrent significantly. And, the construction form of the device inherently decreases the noise. Finally, we compare the characteristics of the PCS-QCD to a PCS - quantum well infrared photodetector and outline the advantages for certain fields of applications.

  11. Automated inspection of hot steel slabs

    Science.gov (United States)

    Martin, Ronald J.

    1985-01-01

    The disclosure relates to a real time digital image enhancement system for performing the image enhancement segmentation processing required for a real time automated system for detecting and classifying surface imperfections in hot steel slabs. The system provides for simultaneous execution of edge detection processing and intensity threshold processing in parallel on the same image data produced by a sensor device such as a scanning camera. The results of each process are utilized to validate the results of the other process and a resulting image is generated that contains only corresponding segmentation that is produced by both processes.

  12. Damage Function Rating Procedure for Flat Slab Basement Shelters.

    Science.gov (United States)

    1982-12-01

    with solid heads at the columns . These types of slabs are 33 I r~ Omm- D6U0St - m . -I ig. "-.TyiaaFalSasontucin 34 -4 called ribbed, or " waffle ", slabs ...and for design purposes are considered flat slabs with the solid heads at the columns performing the same function as the drop panels. Waffle flat...she:.ers, an upgrading method must be developed and verified by test for these critical stress areas adjacent to the column supports. Waffle Slabs

  13. CFRP strengthened openings in two-way concrete slabs

    DEFF Research Database (Denmark)

    Enochsson, O.; Lundqvist, J.; Täljsten, Björn

    2006-01-01

    Rehabilitation and strengthening of concrete structures with externally bonded fibre reinforced polymers (FRPs) has been a viable technique for at least a decade. An interesting and useful application is strengthening of slabs or walls where openings are introduced. In these situations, FRP sheets....... In this paper, laboratory tests on I I slabs with openings, loaded with a distributed load are presented together with analytical and numerical evaluations. Six slabs with openings have been strengthened with carbon fibre reinforced polymers (CFRPs) sheets. These slabs are compared with traditionally steel...

  14. Gain of double-slab Cherenkov free-electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Li, D. [Institute for laser Technology, suita, Osaka 565-0871 (Japan)], E-mail: dazhi_li@hotmail.com; Huo, G. [Petroleum development center, Shengli Oilfield, SINOPEC, Dongying 257001 (China); Imasak, K. [Institute for laser Technology, suita, Osaka 565-0871 (Japan); Asakawa, M. [Department of pure and applied physics, Faculty of Engineering Science, Kansai University, Osaka 564-8680 (Japan)

    2009-07-21

    A formula is derived for the small-signal gain of a double-slab Cherenkov free-electron laser. The simplified model is composed of a rectangular wave-guide partially filled with two lined parallel dielectric slabs and a sheet electron beam. The theory describes the electron beam as a plasma dielectric moving between the two dielectric slabs. With the help of hydrodynamic approximation, we derived the dispersion equation and the formula of small-signal gain. Through numerical computing, we studied an ongoing experiment of double-slab Cherenkov free-electron laser, and worked out the synchronous frequency and single-pass gain.

  15. Evidence of fire resistance of hollow-core slabs

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl; Sørensen, Lars Schiøtt; Giuliani, Luisa

    Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes) are predo......Hollow-core slabs have during the past 50 years comprised a variety of different structures with different cross-sections and reinforcement. At present the extruded hollow-core slabs without cross-reinforcement in the bottom flange and usually round or oval longitudinal channels (holes...

  16. A STUDY ON THE WHEELSET/SLAB TRACK VERTICAL INTERACTION

    OpenAIRE

    2012-01-01

    This paper deals with the interaction between a moving wheelset and a slab track due to the short-pitch corrugated rail. The wheelset is modeled using a free-free Timoshenko beam with attached rigid bodies as the axle boxes, wheels and brake discs. The slab track model consists of elastically supported double Euler-Bernoulli beams. In fact, both wheelset and slab track are symmetric structures and the issue of the wheelset/slab track interaction is reduced to the wheel/rail interaction. The n...

  17. Control of exceptional points in photonic crystal slabs

    DEFF Research Database (Denmark)

    Kaminski, Piotr Marek; Taghizadeh, Alireza; Breinbjerg, Olav

    2017-01-01

    Various ways of controlling the extent of the ring of exceptional points in photonic crystal slabs are investigated. The extent of the ring in photonic crystal slabs is found to vary with the thickness of the slab. This enables recovery of Dirac cones in open, non-Hermitian systems......, such as a photonic crystal slab. In this case, all three bands exhibit a bound state in the continuum in close proximity of the Γ point. These results may lead to new designs of small photonic-crystal-based lasers exhibiting high-quality factors....

  18. The Planning and Digital Design for Welding Production Line of the Car Rear Floor

    Directory of Open Access Journals (Sweden)

    Zhang Chun-Yan

    2013-06-01

    Full Text Available The last two sub-assembly welding production line of the car rear floor is designed in this paper. Firstly, the welding production line of the car rear floor is complete planned and designed from global aspect by analysis the structure of body-in-white and the car rear floor; Secondly, each working position fixture are designed and the location of all fixture are arranged according to location and spot welding requirements with the CATIA software. Finally, the conveying appliance of welding production line for the car rear floor are detailed planed, according to the production program, the economic requirements to complete a three-dimensional design of delivery devices, ergonomic simulation and dynamic interference checking in the process of material transportation are realized in virtual simulation platform DELMIA software, to ensure the production line design is reasonable and feasible from theory.

  19. Radiative transfer model for contaminated rough slabs.

    Science.gov (United States)

    Andrieu, François; Douté, Sylvain; Schmidt, Frédéric; Schmitt, Bernard

    2015-11-01

    We present a semi-analytical model to simulate the bidirectional reflectance distribution function (BRDF) of a rough slab layer containing impurities. This model has been optimized for fast computation in order to analyze massive hyperspectral data by a Bayesian approach. We designed it for planetary surface ice studies but it could be used for other purposes. It estimates the bidirectional reflectance of a rough slab of material containing inclusions, overlaying an optically thick media (semi-infinite media or stratified media, for instance granular material). The inclusions are assumed to be close to spherical and constituted of any type of material other than the ice matrix. It can be any other type of ice, mineral, or even bubbles defined by their optical constants. We assume a low roughness and we consider the geometrical optics conditions. This model is thus applicable for inclusions larger than the considered wavelength. The scattering on the inclusions is assumed to be isotropic. This model has a fast computation implementation and thus is suitable for high-resolution hyperspectral data analysis.

  20. [Functional aspects of pelvic floor surgery].

    Science.gov (United States)

    Wagenlehner, F M E; Gunnemann, A; Liedl, B; Weidner, W

    2009-11-01

    Pelvic floor dysfunctions are frequently seen in females. The human pelvic floor is a complex structure and heavily stressed throughout female life. Recent findings in the functional anatomy of the pelvic floor have led to a much better understand-ing, on the basis of which enormous improvements in the therapeutic options have arisen. The pelvic floor activity is regulated by three main muscular forces that are responsible for vaginal tension and suspension of the pelvic floor -organs, bladder and rectum. For different reasons laxity in the vagina or its supporting ligaments as a result of altered connective tissue can distort this functional anatomy. A variety of symptoms can derive from these pelvic floor dysfunctions, such as urinary urge and stress incontinence, abnormal bladder emptying, faecal incontinence, obstructive bowel disease syndrome and pelvic pain. Pelvic floor reconstruction is nowadays driven by the concept that in the case of pelvic floor symptoms restoration of the anatomy will translate into restoration of the physiology and ultimately improve the patients' symptoms. The exact surgical reconstruction of the anatomy is there-fore almost exclusively focused on the restoration of the lax pelvic floor ligaments. An exact identification of the anatomic lesions preoperatively is eminently necessary, to allow for an exact anatomic reconstruction with respect to the muscular forces of the pelvic floor.

  1. Shear and anchorage behaviour of fire exposed hollow core slabs

    NARCIS (Netherlands)

    Fellinger, J.H.H.; Stark, J.; Walraven, J.C.

    2005-01-01

    The fire resistance of hollow core slabs is currently assessed considering flexural failure only. However, fire tests showed that shear or anchorage failure can also govern the load bearing behaviour. As the shear and anchorage capacity of these slabs rely on the tensile strength of the concrete, th

  2. How to produce flat slabs: insights from numeric modeling

    Science.gov (United States)

    Constantin Manea, Vlad; Perez-Gussinye, Marta; Manea, Marina

    2010-05-01

    Flat slab subduction occurs at ~10% of the active convergent margins and it is assumed that subduction of oceanic aseismic ridges or seamount chains is the main mechanism to produce very low angle subduction slabs. However, recent numeric and analog modeling showed that ridges alone of moderate dimensions subducted perpendicular to the trench are not sufficient to produce flat-slab geometries. Therefore an alternative mechanism able to produce flat-slabs is required. In this paper we present dynamic numeric modeling results of subduction in the vicinity of thick continental lithosphere, as a craton for example. We tailored our modeling setup for the Chilean margins at ~31° and our models are integrated back in time 30 Myr. Modeling results show that a craton thickness of 200 km or more when approaching the trench is capable of blocking the asthenospheric flow in the mantle wedge and increasing considerably the suction force. We were able to produce a flat slab that fits well the flat slab geometry in Chile (based on seismicity) and stress distribution. We conclude that thick cratons located in the vicinity of subduction zones, are capable to produce very low angle slabs, and probable a combination of buoyant ridge subduction with a neighbor thick craton represent a better mechanism to produce flat slabs.

  3. Ultimate deformation capacity of reinforced concrete slabs underblast load

    NARCIS (Netherlands)

    Doormaal, J.C.A.M. van; Weerheijm, J.

    1996-01-01

    In this paper a test method to determine the deformation capacity and the resistance-deformation curve of blast-loaded slabs is described. This method was developed at TNO-PML. The method has been used to determine the ultimate deformation capacity of some simply supported reinforced concrete slabs

  4. Superluminal pulse reflection from a weakly absorbing dielectric slab

    CERN Document Server

    Wang, L G; Wang, Li-Gang; Zhu, Shi-Yao

    2006-01-01

    Group delay for a reflected light pulse from a weakly absorbing dielectric slab is theoretically investigated, and large negative group delay is found for weak absorption near a resonance of the slab ($Re(kd)=m\\pi$). The group delays for both the reflected and transmitted pulses will be saturated with the increase of the absorption.

  5. Shear capacity of slabs under a combination of loads

    NARCIS (Netherlands)

    Lantsoght, E.O.L.; Van der Veen, C.; Walraven, J.C.

    2013-01-01

    Existing solid slab bridges under a combination of wheel loads and distributed traffic loads sometimes do not fulfil the code requirements for shear. However, reinforced concrete slabs loaded close to the support are subjected to shear stresses which might result in a failure mode of combined punchi

  6. Ultimate deformation capacity of reinforced concrete slabs underblast load

    NARCIS (Netherlands)

    Doormaal, J.C.A.M. van; Weerheijm, J.

    1996-01-01

    In this paper a test method to determine the deformation capacity and the resistance-deformation curve of blast-loaded slabs is described. This method was developed at TNO-PML. The method has been used to determine the ultimate deformation capacity of some simply supported reinforced concrete slabs

  7. On Early Age Crack Formation in FRC Slabs

    DEFF Research Database (Denmark)

    Olesen, John Forbes; Stang, Henrik

    1997-01-01

    The problem of early age crack formation in FRC slabs due to restrained temperature and shrinkage deformations, is given an analytical treatment. A model taking into account the ageing properties of the tensile softening curve and the continued development in the temperature and shrinkage...... deformations after crack initiation, is presented. Based on this model a design strategy for FRC slabs is outlined....

  8. Influence of weak layer heterogeneity and slab properties on slab tensile failure propensity and avalanche release area

    Directory of Open Access Journals (Sweden)

    J. Gaume

    2014-12-01

    Full Text Available Dry-snow slab avalanches are generally caused by a sequence of fracture processes including failure initiation in a weak snow layer underlying a cohesive slab followed by crack propagation within the weak layer (WL and tensile fracture through the slab. During past decades, theoretical and experimental work has gradually improved our knowledge of the fracture process in snow. However, our limited understanding of crack propagation and fracture arrest propensity prevents the evaluation of avalanche release sizes and thus impedes hazard assessment. To address this issue, slab tensile failure propensity is examined using a mechanically-based statistical model of the slab–WL system based on the finite element method. This model accounts for WL heterogeneity, stress redistribution by elasticity of the slab and the slab possible tensile failure. Two types of avalanche release are distinguished in the simulations: (1 full-slope release if the heterogeneity is not sufficient to stop crack propagation and to trigger a tensile failure within the slab, (2 partial-slope release if fracture arrest and slab tensile failure occurs due to the WL heterogeneity. The probability of these two release types is presented as a function of the characteristics of WL heterogeneity and of the slab. One of the main outcomes is that, for realistic values of the parameters, the tensile failure propensity is mainly influenced by slab properties. Hard and thick snow slabs are more prone to wide-scale crack propagation and thus lead to larger avalanches (full-slope release. In this case, the avalanche size is mainly influenced by topographical and morphological features such as rocks, trees, slope curvature and the spatial variability of the snow depth as it is often claimed in the literature.

  9. Electromagnetic Tunneling and Resonances in Pseudochiral Omega Slabs

    Science.gov (United States)

    Razzaz, Faroq; Alkanhal, Majeed A. S.

    2017-01-01

    This paper presents theoretical investigation of the electromagnetic wave tunneling and anomalous transmission around the trapped modes in a pseudochiral omega slab. The dispersion relation, the conditions of the trapped modes, and the evanescent wave coupling and tunneling in two different reciprocal pseudochiral omega slab structures are derived. The Berreman’s matrix method is applied to obtain the transmission coefficients across the pseudochiral omega slab. When the structure is perturbed, a resonance phenomenon is detected around the trapped modes. This resonance results in transmission anomalies (total transmission and total reflection) and dramatic field amplifications around the trapped modes. The number of the discrete trapped modes and then the resonance frequencies are prescribed by the parameters of the pseudochiral omega slab such as the value of the omega parameter and its orientation and the slab thickness. PMID:28165058

  10. Numerical Study of FRP Reinforced Concrete Slabs at Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Masoud Adelzadeh

    2014-02-01

    Full Text Available One-way glass fibre reinforced polymer (GFRP reinforced concrete slabs at elevated temperatures are investigated through numerical modeling. Serviceability and strength requirements of ACI-440.1R are considered for the design of the slabs. Diagrams to determine fire endurance of slabs by employing “strength domain” failure criterion are presented. Comparisons between the existing “temperature domain” method with the more representative “strength domain” method show that the “temperature domain” method is conservative. Additionally, a method to increase the fire endurance of slabs by placing FRP reinforcement in two layers is investigated numerically. The amount of fire endurance gained by placing FRP in two layers increases as the thickness of slab increases.

  11. Punching strength of reinforced concrete flat slabs without shear reinforcement

    Directory of Open Access Journals (Sweden)

    P. V. P. Sacramento

    Full Text Available Punching strength is a critical point in the design of flat slabs and due to the lack of a theoretical method capable of explaining this phenomenon, empirical formulations presented by codes of practice are still the most used method to check the bearing capacity of slab-column connections. This paper discusses relevant aspects of the development of flat slabs, the factors that influence the punching resistance of slabs without shear reinforcement and makes comparisons between the experimental results organized in a database with 74 slabs carefully selected with theoretical results using the recommendations of ACI 318, EUROCODE 2 and NBR 6118 and also through the Critical Shear Crack Theory, presented by Muttoni (2008 and incorporated the new fib Model Code (2010.

  12. Electromagnetic Tunneling and Resonances in Pseudochiral Omega Slabs.

    Science.gov (United States)

    Razzaz, Faroq; Alkanhal, Majeed A S

    2017-02-06

    This paper presents theoretical investigation of the electromagnetic wave tunneling and anomalous transmission around the trapped modes in a pseudochiral omega slab. The dispersion relation, the conditions of the trapped modes, and the evanescent wave coupling and tunneling in two different reciprocal pseudochiral omega slab structures are derived. The Berreman's matrix method is applied to obtain the transmission coefficients across the pseudochiral omega slab. When the structure is perturbed, a resonance phenomenon is detected around the trapped modes. This resonance results in transmission anomalies (total transmission and total reflection) and dramatic field amplifications around the trapped modes. The number of the discrete trapped modes and then the resonance frequencies are prescribed by the parameters of the pseudochiral omega slab such as the value of the omega parameter and its orientation and the slab thickness.

  13. Drug release from slabs and the effects of surface roughness.

    Science.gov (United States)

    Kalosakas, George; Martini, Dimitra

    2015-12-30

    We discuss diffusion-controlled drug release from slabs or thin films. Analytical and numerical results are presented for slabs with flat surfaces, having a uniform thickness. Then, considering slabs with rough surfaces, the influence of a non-uniform slab thickness on release kinetics is numerically investigated. The numerical release profiles are obtained using Monte Carlo simulations. Release kinetics is quantified through the stretched exponential (or Weibull) function and the resulting dependence of the two parameters of this function on the thickness of the slab, for flat surfaces, and the amplitude of surface fluctuations (or the degree of thickness variability) in case of roughness. We find that a higher surface roughness leads to a faster drug release. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Characterizing wet slab and glide slab avalanche occurrence along the Going-to-the-Sun Road, Glacier National Park, Montana, USA

    Science.gov (United States)

    Peitzsch, Erich H.; Hendrikx, Jordy; Fagre, Daniel B.; Reardon, Blase

    2010-01-01

    Wet slab and glide slab snow avalanches are dangerous and yet can be particularly difficult to predict. Both wet slab and glide slab avalanches are thought to depend upon free water moving through the snowpack but are driven by different processes. In Glacier National Park, Montana, both types of avalanches can occur in the same year and affect the Going-to-the-Sun Road (GTSR). Both wet slab and glide slab avalanches along the GTSR from 2003-2010 are investigated. Meteorological data from two high-elevation weather stations and one SNOTEL site are used in conjunction with an avalanche database and snowpit profiles. These data were used to characterize years when only glide slab avalanches occurred and those years when both glide slab and wet slab avalanches occurred. Results of 168 glide slab and 57 wet slab avalanches along the GTSR suggest both types of avalanche occurrence depend on sustained warming periods with intense solar radiation (or rain on snow) to produce free water in the snowpack. Differences in temperature and net radiation metrics between wet slab and glide slab avalanches emerge as one moves from one day to seven days prior to avalanche occurrence. On average, a more rapid warming precedes wet slab avalanche occurrence. Glide slab and wet slab avalanches require a similar amount of net radiation. Wet slab avalanches do not occur every year, while glide slab avalanches occur annually. These results aim to enhance understanding of the required meteorological conditions for wet slab and glide slab avalanches and aid in improved wet snow avalanche forecasting.

  15. Software sensor for slab reheating furnace

    Institute of Scientific and Technical Information of China (English)

    Zhihua Xiong; Guohong Huang; Huihe Shao

    2005-01-01

    It has long been thought that a reheating furnace, with its inherent measurement difficulties and complex dynamics, posed almost insurmountable problems to engineers in steel plants. A novel software sensor is proposed to make more effective use of those measurements that are already available, which has great importance both to slab quality and energy saving. The proposed method is based on the mixtures of Gaussian processes (GP) with the expectation maximization (EM) algorithm employed for parameter estimation of the mixture of models. The mixture model can alleviate the computational complexity of GP and also accords with the changes of operating condition in practical processes. It is demonstrated by on-line estimation of the furnace gas temperature in 1580 reheating furnace in Baosteel Corporation (Group).

  16. Laser applications in machining slab materials

    Science.gov (United States)

    Zhang, Xiaoping

    1990-10-01

    Since the invention of the laser back in 1960, laser technology has been extensively applied in many fields of science and technology. These has been a history of nearly two decades of using lasers as an energy source in machining materials, such as cutting, welding, ruling and boring, among other operations. With the development of flexible automation in production, the advantages of laser machining have has grown more and more obvious. The combination of laser technology and computer science further promotes the enhancement and upgrading of laser machining and related equipment. At present, many countries are building high quality laser equipment for machining slab materials, such as the Coherent and Spectra Physics corporations in the United States, the Trumpf Corporation in West Germany, the Amada Corporation in Japan, and the Bystronic Corporation in Switzerland, among other companies.

  17. Half-disordered photonic crystal slabs.

    Science.gov (United States)

    Beque, V; Keilman, J; Citrin, D S

    2016-08-10

    Optical transmission spectra of finite-thickness slabs of two-dimensional triangular-lattice photonic crystals of air holes in a dielectric matrix with various concentrations of randomly located vacancies (absent air holes) are studied. We focus on structures in which only one half of the structure-the incidence or transmission side-is disordered. We find vacancy-induced scattering gives rise to a strong difference in the two cases; for light incident on the disordered side, high transmission within the photonic pseudogap at normal incidence is predicted, in strong contrast to the opposite case, where low transmission is predicted throughout the pseudogap, as is observed in the case of an ideal structure with no defects.

  18. The pelvic floor in health and disease.

    OpenAIRE

    Shelton, A A; Welton, M L

    1997-01-01

    Normal pelvic floor function involves a set of learned and reflex responses that are essential for the normal control and evacuation of stool. A variety of functional disturbances of the pelvic floor, including incontinence and constipation, are not life threatening, but can cause significant distress to affected patients. Understanding the normal anatomy and physiology of the pelvic floor is essential to understanding and treating these disorders of defecation. This article describes the nor...

  19. Pelvic floor muscle rehabilitation using biofeedback.

    Science.gov (United States)

    Newman, Diane K

    2014-01-01

    Pelvic floor muscle exercises have been recommended for urinary incontinence since first described by obstetrician gynecologist Dr. Arnold Kegel more than six decades ago. These exercises are performed to strengthen pelvic floor muscles, provide urethral support to prevent urine leakage, and suppress urgency. In clinical urology practice, expert clinicians also teach patients how to relax the muscle to improve bladder emptying and relieve pelvic pain caused by muscle spasm. When treating lower urinary tract symptoms, an exercise training program combined with biofeedback therapy has been recommended as first-line treatment. This article provides clinical application of pelvic floor muscle rehabilitation using biofeedback as a technique to enhance pelvic floor muscle training.

  20. Three-dimensional Numerical Models of the Cocos-northern Nazca Slab Gap

    Science.gov (United States)

    Jadamec, M.; Fischer, K. M.

    2012-12-01

    In contrast to anisotropy beneath the middle of oceanic plates, seismic observations in subduction zones often indicate mantle flow patterns that are not easily explained by simple coupling of the subducting and overriding plates to the mantle. For example, in the Costa Rica-Nicaragua subduction zone local S shear wave splitting measurements combined with geochemical data indicate trench parallel flow in the mantle wedge with flow rates of 6.3-19 cm/yr, which is on order of or may be up to twice the subducting plate velocity. We construct geographically referenced high-resolution three-dimensional (3D) geodynamic models of the Cocos-northern Nazca subduction system to investigate what is driving the northwest directed, and apparently rapid, trench-parallel flow in the mantle wedge beneath Costa Rica-Nicaragua. We use the SlabGenerator code to construct a 3D plate configuration that is used as input to the community mantle convection code, CitcomCU. Models are run on over 400 CPUs on XSEDE, with a mesh resolution of up to 3 km at the plate boundary. Seismicity and seismic tomography delineate the shape and depth of the Cocos and northern Nazca slabs. The subducting plate thermal structure is based on a plate cooling model and ages from the seafloor age grid. Overriding plate thickness is constrained by the ages from the sea floor age grid where available and the depth to the lithosphere-asthenosphere boundary from the greatest negative gradient in absolute shear wave velocity. The geodynamic models test the relative controls of the change in the dip of the Cocos plate and the slab gap between the Cocos and northern Nazca plates in driving the mantle flow beneath Central America. The models also investigate the effect of a non-Newtonian rheology in dynamically generating a low viscosity mantle wedge and how this controls mantle flow rates. To what extent the Cocos-northern Nazca slab gap channelizes mantle flow between Central and South America has direct application

  1. The Basement Flat beam Floor Structure Design%地下室无梁楼盖结构设计探讨

    Institute of Scientific and Technical Information of China (English)

    印江涛; 洪亮

    2014-01-01

    在设计地下室无梁楼盖结构时,应重点关注其结构形式和计算方法。通过对无梁楼盖结构形式的计算方法进行研究,提议优先采用不等厚无梁楼盖,同时给出普通车库、1.5 m厚覆土顶板和核6级人防顶板结构的计算方法,从而为地下室无梁楼盖结构的设计提供参考。%In the design of the basement structure without slab-column system, should focus on its structural form and calculation method. The calculation method of slab-column system structure was based on the research, proposed the priority of flat slab floor using different thickness, ordinary garage, 1.5 m thick overburden soil are put forward in the roof and nuclear grade 6 civil air defense of roof structure calculation method, which is the basement slab floor structure design to provide the reference.

  2. Behavior of FRP Link Slabs in Jointless Bridge Decks

    Directory of Open Access Journals (Sweden)

    Aziz Saber

    2012-01-01

    Full Text Available The paper investigated the use of fiberglass-reinforced plastic (FRP grid for reinforcement in link slabs for jointless bridge decks. The design concept of link slab was examined based on the ductility of the fiberglass-reinforced plastic grid to accommodate bridge deck deformations. The implementation of hybrid simulation assisted in combining the experimental results and the theoretical work. The numerical analyses and the experimental work investigated the behavior of the link slab and confirmed its feasibility. The results indicated that the technique would allow simultaneous achievement of structural need, lower flexural stiffness of the link slab approaching the behavior of a hinge, and sustainability need of the link slab. The outcome of the study supports the contention that jointless concrete bridge decks may be designed and constructed with fiberglass-reinforced plastic grid link slabs. This concept would also provide a solution to a number of deterioration problems associated with bridge deck joints and can be used during new construction of bridge decks. The federal highway administration provided funds to Louisiana Department of Transportation through the innovative bridge research and development program to implement the use of FRP grid as link slab.

  3. Power dissipation and temperature distribution in piezoelectric ceramic slabs.

    Science.gov (United States)

    Thomas, D; Ebenezer, D D; Srinivasan, Sivakumar M

    2010-10-01

    A method is presented to determine power dissipation in one-dimensional piezoelectric slabs with internal losses and the resulting temperature distribution. The length of the slab is much greater than the lateral dimensions. Losses are represented using complex piezoelectric coefficients. It is shown that the spatially non-uniform power dissipation density in the slab can be determined by considering either hysteresis loops or the Poynting vector. The total power dissipated in the slab is obtained by integrating the power dissipation density over the slab and is shown to be equal to the power input to the slab for special cases of mechanically and electrically excited slabs. The one-dimensional heat equation that includes the effect of conduction and convection, and the boundary conditions, are then used to determine the temperature distribution. When the analytical expression for the power dissipation density is simple, direct integration is used. It is shown that a modified Fourier series approach yields the same results. For other cases, the temperature distribution is determined using only the latter approach. Numerical results are presented to illustrate the effects of internal losses, heat conduction and convection coefficients, and boundary conditions on the temperature distribution.

  4. Impact Resistance Behaviour of Banana Fiber Reinforced Slabs

    Science.gov (United States)

    Che Muda, Zakaria; Syamsir, Agusril; Nasharuddin Mustapha, Kamal; Rifdy Samsudin, Muhamad; Thiruchelvam, Sivadass; Usman, Fathoni; Beddu, Salmia; Liyana Mohd Kamal, Nur; Ashraful Alam, Md; Birima, Ahmed H.; Zaroog, O. S.

    2016-03-01

    This paper investigate the performance of banana fibre reinforced slabs 300mm × 300mm size with varied thickness subjected to low impact projectile test. A self-fabricated drop-weight impact test rig with a steel ball weight of 1.25 kg drop at 1 m height has been used in this research work. The main variables for the study is to find the relationship of the impact resistance against the BF contents and slab thickness. A linear relationship has been established between first and ultimate crack resistance against BF contents and slab thickness by the experiment. The linear relationship has also been established between the service (first) crack and ultimate crack resistance against the BF contents for a constant spacing for various banana fibre reinforced slab thickness. The increment in BF content has more effect on the first crack resistance than the ultimate crack resistance. The linear relationship has also been established between the service (first) crack and ultimate crack resistance against the various slab thickness. Overall 1.5% BF content with slab thickness of 40 mm exhibit better first and ultimate crack resistance up to 16 times and up to 17 times respectively against control slab (without BF)

  5. Exact exchange plane-wave-pseudopotential calculations for slabs.

    Science.gov (United States)

    Engel, Eberhard

    2014-05-14

    The exact exchange of density functional theory is applied to both free-standing graphene and a Si(111) slab, using the plane-wave pseudopotential (PWPP) approach and a periodic repetition of the supercell containing the slab. It is shown that (i) PWPP calculations with exact exchange for slabs in supercell geometry are basically feasible, (ii) the width of the vacuum required for a decoupling of the slabs is only moderately larger than in the case of the local-density approximation, and (iii) the resulting exchange potential vx shows an extended region, both far outside the surface of the slab and far from the middle of the vacuum region between the slabs, in which vx behaves as -e(2)/z, provided the width of the vacuum is chosen sufficiently large. This last result is corroborated by an analytical analysis of periodically repeated jellium slabs. The intermediate -e(2)/z behavior of vx can be used for an absolute normalization of vx and the total Kohn-Sham potential, which, in turn, allows the determination of the work function.

  6. A modularized pulse forming line using glass-ceramic slabs.

    Science.gov (United States)

    Wang, Songsong; Shu, Ting; Yang, Hanwu

    2012-08-01

    In our lab, a kind of glass-ceramic slab has been chosen to study the issues of applying solid-state dielectrics to pulse forming lines (PFLs). Limited by the manufacture of the glass-ceramic bulk with large sizes, a single ceramic slab is hard to store sufficient power for the PFL. Therefore, a modularized PFL design concept is proposed in this paper. We regard a single ceramic slab as a module to form each single Blumlein PFL. We connect ceramic slabs in series to enlarge pulse width, and stack the ceramic Blumlein PFLs in parallel to increase the output voltage amplitude. Testing results of a single Blumlein PFL indicate that one ceramic slab contributes about 11 ns to the total pulse width which has a linear relation to the number of the ceramic slabs. We have developed a prototype facility of the 2-stage stacked Blumlein PFL with a length of 2 ceramic slabs. The PFL is dc charged up to 5 kV, and the output voltage pulse of 10 kV, 22 ns is measured across an 8 Ω load. Simulation and experiment results in good agreement demonstrate that the modularized design is reasonable.

  7. Effects of floor design and floor cleaning on ammonia emission from cubicle houses for dairy cows

    NARCIS (Netherlands)

    Braam, C.R.; Ketelaars, J.J.M.H.; Smits, M.C.J.

    1997-01-01

    The traditional slatted floor was compared with 2 different solid floor systems: a non-sloped (L) and a 3% one-sided sloped floor (S), combined with a highly frequent (96 times/day) or normal (12 times/day) removal of manure by a scraper. NH3 emissions were measured continuously over 2 separate 2-we

  8. Comparison between Ribbed Slab Structure using Lightweight Foam Concrete and Solid Slab Structure using Normal Concrete

    Directory of Open Access Journals (Sweden)

    Mohd Zailan Sulieman

    2010-03-01

    Full Text Available

    The aim of this study is to demonstrate that one-way ribbed slab with lightweight foam concrete can be used to reduce the dead load on slab concrete structure. This would allow the structural designer to reduce the size of column, footing and other load

  9. Branding on the Shop Floor

    Directory of Open Access Journals (Sweden)

    Szilvia Gyimóthy

    2010-09-01

    Full Text Available Service branding is a particular form of emotional management, where employees are regarded as adaptable media, who can be trained to convey corporate values while interacting with customers. This paper examines the identity work of butchers during the brand revitalisation campaign of Kvickly, a Danish supermarket chain. During the implementation of the “Best Butcher in Town”-project, Kvickly’s shop floor becomes an engineered servicescape where the norms of good salesmanship must be performed. By documenting the disloyal behaviour of butchers, we demonstrate that the affective commitment towards corporate brand values is closely related with self-enactment opportunities of occupational communities. Total service-orientation threatens butchers’ perception of autonomy and may therefore result in the emergence of resistant sub-cultures.

  10. Performance Analysis and Optimization of Dowels in Jointed Concrete Floors

    CERN Document Server

    Ghauch, Ziad; Tabbara, Mazen

    2012-01-01

    This study examines the performance of traditional round dowels in concrete floors and attempts to optimize the design of dowels through Finite Element (FE) analysis. A new type of Double-Tapered Round (DTR) dowels is proposed, and the performance of DTR dowels is compared to that of traditional cylindrical dowels. Linear Elastic (LE) analysis are performed in Abaqus (v-6.11) order to identify the optimized geometry of DTR dowels that would achieve (1) highest load transfer across adjacent slabs through shear action, and (2) lowest bearing stresses on the concrete. LE analyses are complemented by nonlinear FE analysis. The Riks method available in Abaqus/Standard, coupled with the Concrete Damaged Plasticity (CDP) model is used to simulate the degradation of concrete surrounding both DTR the traditional cylindrical dowels. Results obtained show that the use of DTR dowels can reduce bearing stresses at the face of the joint by as much 2.2 times as compared to traditional cylindrical dowels. While adequate load...

  11. Broadband high reflectivity in subwavelength-grating slab waveguides

    CERN Document Server

    Cui, Xuan; Zhou, Zhongxiang

    2015-01-01

    We computationally study a subwavelength dielectric grating structure, show that slab waveguide modes can be used to obtain broadband high reflectivity, and analyze how slab waveguide modes influence reflection. A structure showing interference between Fabry-Perot modes, slab waveguide modes, and waveguide array modes is designed with ultra-broadband high reflectivity. Owing to the coupling of guided modes, the region with reflectivity R > 0.99 has an ultra-high bandwidth ( {\\Delta}f/f > 30%). The incident-angle region with R > 0.99 extends over a range greater than 40{\\deg}. Moreover, an asymmetric waveguide structure is studied using a semiconductor substrate.

  12. Fringe integral equation method for a truncated grounded dielectric slab

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Maci, S.; Toccafondi, A.

    2001-01-01

    The problem of scattering by a semi-infinite grounded dielectric slab illuminated by an arbitrary incident TMz polarized electric field is studied by solving a new set of “fringe” integral equations (F-IEs), whose functional unknowns are physically associated to the wave diffraction processes...... occurring at the truncation. The F-IEs are obtained by subtracting from the surface/surface integral equations pertinent to the truncated slab, an auxiliary set of equations obtained for the canonical problem of an infinite grounded slab illuminated by the same source. The F-IEs are solved by the method...

  13. Performance and damages of R.C. slabs in fire

    DEFF Research Database (Denmark)

    Giuliani, Luisa; Gentili, Filippo

    2015-01-01

    slabs with complex geometry exposed to fire and assessing the entity of the damage on the basis of the decrement of the load bearing capacity at the end of the fire. By considering this quantity for different time of exposure to a standard fire, a curve is obtained that provides important information...... on the vulnerability of the slab to the fire action and can be used for optimizing the design on the basis of the required class of resistance or for choosing between different slab alternatives....

  14. Interaction of an ion bunch with a plasma slab

    Energy Technology Data Exchange (ETDEWEB)

    Krasovitskiy, V. B., E-mail: krasovit@mail.ru [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Turikov, V. A. [Peoples’ Friendship University of Russia (Russian Federation)

    2016-11-15

    Charge neutralization of a short ion bunch passing through a plasma slab is studied by means of numerical simulation. It is shown that a fraction of plasma electrons are trapped by the bunch under the action of the collective charge separation field. The accelerated electrons generated in this process excite beam−plasma instability, thereby violating the trapping conditions. The process of electron trapping is also strongly affected by the high-frequency electric field caused by plasma oscillations at the slab boundaries. It is examined how the degree of charge neutralization depends on the parameters of the bunch and plasma slab.

  15. Biomechanics of the pelvic floor musculature

    NARCIS (Netherlands)

    Janda, S.

    2006-01-01

    The present thesis was motivated by two main goals. The first research goal of the thesis was to understand the complex biomechanical behaviour of the pelvic floor muscles. The second goal was to study the mechanism of the pelvic organ prolapse (genital prolapse). The pelvic floor in humans is a ve

  16. 9 CFR 91.26 - Concrete flooring.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Concrete flooring. 91.26 Section 91.26... LIVESTOCK FOR EXPORTATION Inspection of Vessels and Accommodations § 91.26 Concrete flooring. (a) Pens aboard an ocean vessel shall have a 3 inch concrete pavement, proportioned and mixed to give 2000 psi...

  17. Floor vibrations due to walking loads

    NARCIS (Netherlands)

    Donkervoort, D.R.; Hoenderkamp, J.C.D.; Oosterhout, G.P.C. van

    1999-01-01

    Traditionally floors are designed for static strength and stiffness. Improved methods of construction and design, using high strength-lightweight materials, have resulted in strong and stiff floors that display unsatisfactory dynamic behaviour when exposed to walking loads. The paper discusses a met

  18. [Functional rehabilitation of the pelvic floor].

    Science.gov (United States)

    Minschaert, M

    2003-09-01

    Pelvic floor revalidation is devoted to conserve perineal functions as statics, urinary continence and sexual harmony. The therapeutics includes preventive and curative actions, and is based upon muscular and neuromuscular properties of pelvic floor. The different steps are: information, local muscular work, behavioral education, biofeedback, functional electrostimulation, intraabdominal pressure control. The therapeutics is only continued if clinical improvement is demonstrated after 10 sessions.

  19. Laparoscopic Pelvic Floor Repair Using Polypropylene Mesh

    Directory of Open Access Journals (Sweden)

    Shih-Shien Weng

    2008-09-01

    Conclusion: Laparoscopic pelvic floor repair using a single piece of polypropylene mesh combined with uterosacral ligament suspension appears to be a feasible procedure for the treatment of advanced vaginal vault prolapse and enterocele. Fewer mesh erosions and postoperative pain syndromes were seen in patients who had no previous pelvic floor reconstructive surgery.

  20. Imaging pelvic floor disorders. 2. rev. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, Jaap [Amsterdam Univ. (Netherlands). Dept. of Radiology; Taylor, Stuart A. [University College Hospital, London (United Kingdom). Dept. of Specialist X-Ray; DeLancey, John O.L. (eds.) [Michigan Univ., Ann Arbor, MI (United States). L4000 Women' s Hospital

    2008-07-01

    This volume builds on the success of the first edition of imaging pelvic floor disorders and is aimed at those practitioners with an interest in the imaging, diagnosis and treatment of pelvic floor dysfunction. Concise textual information from acknowledged experts is complemented by high-quality diagrams and images to provide a thorough update of this rapidly evolving field. Introductory chapters fully elucidate the anatomical basis underlying disorders of the pelvic floor. State of the art imaging techniques and their application in pelvic floor dysfunction are then discussed in detail. Additions since the first edition include consideration of the effect of aging and new chapters on perineal ultrasound, functional MRI and MRI of the levator muscles. The closing sections of the book describe the modern clinical management of pelvic floor dysfunction, including prolapse, urinary and faecal incontinence and constipation, with specific emphasis on the integration of diagnostic and treatment algorithms. (orig.)

  1. Investigation of floor heating with thermal storage

    Institute of Scientific and Technical Information of China (English)

    LIN Zhen-guo; ZHANG Su-yun; FU Xiang-zhao; WANG Yong

    2006-01-01

    Based on experimental data, the energy storage performances of floor radiant heating system were investigated.Based on experimental data, the energy storage performances of floor radiant heating system were investigated. The decrease of indoor air temperature after the stopping of floor heating was compared with that of fan-coil heating system. The increase of indoor air temperature after the stopping of floor cooling system was analyzed. The results show that the floor heating system has good thermal storage performance, which can be used to a night-running model to obtain the energy-saving benefits efficient and economic running cost, and still can be used for "shifting peak load to off-peak" macroscopically.

  2. Numerical Calculation of Concrete Slab Response to Blast Loading

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiaoqing; HAO Hong; KUZNETSOV Valerian A; WASCHL John

    2006-01-01

    In the present paper,a dynamic plastic damage model for concrete has been employed to estimate responses of a reinforced concrete slab subjected to blast loading.The interaction between the blast wave and the concrete slab is considered in 3D simulation.In the first stage,the initial detonation and blast wave propagation is modelled in 2D simulation before the blast wave reaches the concrete slab,then the results obtained from 2D calculation are remapped to a 3D model.The calculated blast load is compared with that obtained from TM5-1300.Numerical results of the concrete slab response are compared with the explosive test carried out in the Weapons System Division,Defence Science and Technology Organisation,Department of Defence,Australia.

  3. Active split-ring metamaterial slabs for magnetic resonance imaging

    CERN Document Server

    Lopez, Marcos A; Freire, Manuel J; Behr, Volker C; Jakob, Peter M; Marques, Ricardo

    2011-01-01

    In this work, it is analyzed the ability of split-ring metamaterial slabs with zero/high permeability to reject/confine the radiofrequency magnetic field in magnetic resonance imaging systems. Using an homogenization procedure, split-ring slabs have been designed and fabricated to work in a 1.5T system. Active elements consisting of pairs of crossed diodes are inserted in the split-rings. With these elements, the permeability of the slabs can be automatically switched between a unity value when interacting with the strong excitation field of the transmitting body coil, and zero or high values when interacting with the weak field produced by protons in tissue. Experiments are shown for different configurations where these slabs can help to locally increase the signal-to-noise-ratio.

  4. Formation mechanism of internal cracks in continuously cast slab

    Institute of Scientific and Technical Information of China (English)

    Guosen Zhu; Xinhua Wang; Huixiang Yu; Jiongming Zhang; Wanjun Wang

    2004-01-01

    In order to make clear the formation mechanism of centerline cracks in continuously cast slabs, the form, distribution and other characteristics of the cracks were analyzed. The final solidification point, surface temperature of the slabs and strain in solidifying shell were investigated. The results were that: (1) Five relatively low temperature zones exist on slab surface below the three water spraying nozzles and near the two edges, respectively, which corresponds to the places of centerline cracks and triangle-zone cracks. (2) Centerline cracks and triangle-zone cracks occur because of weak secondary cooling, uneven cooling along slab width,and large variation of roll gap. (3) After minimizing the variation of roll gap and applying the new secondary cooling pattern, the occurring frequency of centerline and triangle-zone cracks minimizes to zero.

  5. Waveform effects of a metastable olivine tongue in subducting slabs

    Science.gov (United States)

    Vidale, John E.; Williams, Quentin; Houston, Heidi

    1991-01-01

    Velocity models of subducting slabs with a kinetically-depressed olivine to beta- and gamma-spinel transition are constructed, and the effect that such structures would have on teleseismic P waveforms are examined using a full-wave finite-difference method. These 2D calculations yielded waveforms at a range of distances in the downdip direction. The slab models included a wedge-shaped, low-velocity metastable olivine tongue (MOTO) to a depth of 670 km, as well as a plausible thermal anomaly; one model further included a 10-km-thick fast layer on the surface of the slab. The principal effect of MOTO is to produce grazing reflections at wide angles off the phase boundary, generating a secondary arrival 0 to 4 seconds after the initial arrival depending on the take-off angle. The amplitude and timing of this feature vary with the lateral location of the seismic source within the slab cross-section.

  6. Casimir effect for two lossy dispersive dielectric slabs

    Science.gov (United States)

    Matloob, R.; Keshavarz, A.; Sedighi, D.

    1999-11-01

    The electromagnetic field is quantized using the Green's-function method for the geometry of a Fabry-Perot cavity, made up of two identical lossy dispersive slabs of finite thickness. The dielectric functions of the slabs are assumed to be an arbitrary complex function of frequency obeying causality requirements. The attractive Casimir force between the two slabs is calculated by the help of the latter field operators, via evaluating the difference between the vacuum pressures on both sides of each slab. Special attention is paid to the limiting case of the Casimir effect for two conducting plates. The Lorentz model of the dielectric function is used to demonstrate the variation of the force in terms of plasma frequency. The Casimir force expression is also related to the imaginary part of the response function. The latter expression is used to introduce the repulsive Casimir force between two conducting plates located inside a Fabry-Perot cavity.

  7. Innovation on RC Waffle and Ribbed Slab Analysis Models

    Directory of Open Access Journals (Sweden)

    P. Hájek

    2000-01-01

    Full Text Available Waffle and ribbed reinforced concrete slabs are widely used in building constructions in view of the flexibility design and structural efficiency. The wide range of reinforced concrete and composite waffle and ribbed slabs has been theoretically analysed and tested from the point of view of structural behaviour within the research performed in the last years. The results of the experimental investigation, supported by theoretical conclusions, have confirmed significantly better structural properties of the composite waffle slabs (composed from RC and ceramic fillers than the assumptions usually considered in common analysis models. New analysis equivalent models for structural analysis RC and composite waffle and ribbed structures have been developed and compared with the test results. In the paper are presented some generalized conclusions as a basis for the formulation of principles of an optimized design of RC waffle and ribbed slab structures.

  8. Radiative Transfer Model for Translucent Slab Ice on Mars

    Science.gov (United States)

    Andrieu, F.; Schmidt, F.; Douté, S.; Schmitt, B.; Brissaud, O.

    2016-09-01

    We developed a radiative transfer model that simulates in VIS/NIR the bidirectional reflectance of a contaminated slab layer of ice overlaying a granular medium, under geometrical optics conditions to study martian ices.

  9. Evaluation of precast concrete slabs using a heavy vehicle simulator

    CSIR Research Space (South Africa)

    Kohler, E

    2008-10-01

    Full Text Available -controlled conditions and that fully cured precast slabs can potentially be open to traffic almost immediately upon installation, making them attractive for use on heavily travelled highways. This paper describes an accelerated pavement testing experiment conducted...

  10. Hot dense magnetized ultrarelativistic spinor matter in a slab

    CERN Document Server

    Sitenko, Yu A

    2016-01-01

    Properties of hot dense ultrarelativistic spinor matter in a slab of finite width, placed in a transverse uniform magnetic field, are studied. The admissible set of boundary conditions is determined by the requirement that spinor matter be confined inside the slab. In thermal equilibrium, the chiral separation effect in the slab is shown to depend both on temperature and chemical potential; this is distinct from the unrealistic case of the magnetic field filling the unbounded (infinite) medium, when the effect is temperature-independent. In the realistic case of the slab, a stepwise behaviour of the axial current density at zero temperature is smoothed out as temperature increases, turning into a linear behaviour at infinitely large temperature. A choice of boundary conditions can facilitate either augmentation or attenuation of the chiral separation effect; in particular, the effect can persist even at zero chemical potential, if temperature is nonzero. Thus the boundary condition can serve as a source that ...

  11. Waveform effects of a metastable olivine tongue in subducting slabs

    Science.gov (United States)

    Vidale, John E.; Williams, Quentin; Houston, Heidi

    1991-01-01

    Velocity models of subducting slabs with a kinetically-depressed olivine to beta- and gamma-spinel transition are constructed, and the effect that such structures would have on teleseismic P waveforms are examined using a full-wave finite-difference method. These 2D calculations yielded waveforms at a range of distances in the downdip direction. The slab models included a wedge-shaped, low-velocity metastable olivine tongue (MOTO) to a depth of 670 km, as well as a plausible thermal anomaly; one model further included a 10-km-thick fast layer on the surface of the slab. The principal effect of MOTO is to produce grazing reflections at wide angles off the phase boundary, generating a secondary arrival 0 to 4 seconds after the initial arrival depending on the take-off angle. The amplitude and timing of this feature vary with the lateral location of the seismic source within the slab cross-section.

  12. Benchmark study for total enery electrons in thick slabs

    Science.gov (United States)

    Jun, I.

    2002-01-01

    The total energy deposition profiles when highenergy electrons impinge on a thick slab of elemental aluminum, copper, and tungsten have been computed using representative Monte Carlo codes (NOVICE, TIGER, MCNP), and compared in this paper.

  13. TEMPERATURE HETEROGENEITY OF TRAVELLING FIRE AND ITS INFLUENCE ON COMPOSITE STEEL-CONCRETE FLOOR

    Directory of Open Access Journals (Sweden)

    Kamila Horová

    2016-04-01

    Full Text Available In order to follow modern trends in contemporary building architecture, which is moving off the limits of current fire design models, assumption of homogeneous temperature conditions used for structural fire analysis needs to be revised. In this paper fire dynamics of travelling fire is investigated experimentally by conducting fire test in two-storey experimental building. To evaluate the impact of travelling fire on the mechanical behaviour of a structure, the spatial and temporal evolution of the gas temperature calculated in NIST code FDS, which was validated to experimental measurements, is applied to the composite floor of dimensions 9.0 m by 9.0 m. Mechanical behaviour of the composite slab highly affected by regions of high temperatures and areas with only elevated temperatures is solved in code Vulcan. To highlight the severity of spreading fire causing non-uniform temperature conditions, which after-effects differ from traditional methods, a comparison of both methods is introduced. The calculation of mechanical behaviour of the composite floor is repeated in a series of three different thermal loading cases. Results of all cases are then compared in terms of vertical displacement and axial force in several positions of the composite floor.

  14. Flexural Behavior of Two-Way Sandwiched Slabs

    OpenAIRE

    Pachpande, Jivan Vilas

    2015-01-01

    This dissertation presents the details of the findings of a study focused on evaluating the structural behavior of three-dimensional (3D) cementitious sandwich panels with Expanded Polystyrene (EPS) foam core for two-way slab applications. In this study, both theoretical and finite element numerical analysis procedures were adopted to predict the performance of such slabs under out-of-plane loading conditions. The results from theoretical and finite element analysis were verified by compariso...

  15. Analysis of flat slab building with and without shear wall

    OpenAIRE

    Dhanaji R. Chavan; Mohite D. D.; Dr. C. P. Pise; Pawar Y. P; Kadam S.S.; Deshmukh C. M.

    2016-01-01

    The analytical research carried out to study the behaviour flat slab building with and without shear wall reported in the present work. For analysis 15 storied flat slab building is analyzed for seismic behaviour. Response spectrum method is used for analysis considering different shear wall positions using ETABS software. Five different positions of shear wall were studied for analysis. From this analysis shear wall at core having square shape is most suitable case for construction of shear ...

  16. Analysis of flat slab building with and without shear wall

    Directory of Open Access Journals (Sweden)

    Dhanaji R. Chavan

    2016-10-01

    Full Text Available The analytical research carried out to study the behaviour flat slab building with and without shear wall reported in the present work. For analysis 15 storied flat slab building is analyzed for seismic behaviour. Response spectrum method is used for analysis considering different shear wall positions using ETABS software. Five different positions of shear wall were studied for analysis. From this analysis shear wall at core having square shape is most suitable case for construction of shear wall.

  17. Slab Tracking and Controlling on Hot Plate Rolling Line

    Institute of Scientific and Technical Information of China (English)

    姚小兰; 邓波; 梁启宏; 李保奎

    2004-01-01

    By studying the slab moving in detail in the plate rolling process, the problem of slab tracking and controlling was solved by using the distributed control system. The problems of rhythm control for the big-complex system, the exchange of manual and automatic operations, the data exchange between the levelⅠ, TCS (technology control system) and levelⅡ, PCS (process control system), are solved. By this way, the automatic level of the plate production line is improved.

  18. Problem of punching shear in slabs on culumns

    OpenAIRE

    Bartol, Jože

    2007-01-01

    Existing technical solutions enabling sufficient punching resistance failure of flot slabs were analyzed. The reasons that ultimately lead to punching shear and the consequences of shear punching were examined as well. The main causes of punching shear are the condensed shear stresses in the part of the slab that is in contact with the columns. Symbols used at punching shear and an overlook of elements with appropriate reinforcement calculation were presented. The control exten...

  19. Repulsive Casimir forces with finite-thickness slabs

    Science.gov (United States)

    Zhao, R.; Koschny, Th.; Economou, E. N.; Soukoulis, C. M.

    2011-02-01

    We use the extended Lifshitz theory to study the behaviors of the Casimir forces between finite-thickness effective medium slabs. We first study the interaction between a semi-infinite Drude metal and a finite-thickness magnetic slab with or without substrate. For no substrate, the large distance d dependence of the force is repulsive and goes as 1/d5; for the Drude metal substrate, a stable equilibrium point appears at an intermediate distance that can be tuned by the thickness of the slab. We then study the interaction between two identical chiral metamaterial slabs, with and without substrate. For no substrate, the finite thickness of the slabs D does not significantly influence the repulsive character of the force at short distances, while the attractive character at large distances becomes weaker and behaves as 1/d6; for the Drude metal substrate, the finite thickness of the slabs D does not influence the repulsive force too much at short distances until D=0.05λ0.

  20. Seismic Evidence for Possible Slab Melting from Strong Scattering Waves

    Directory of Open Access Journals (Sweden)

    Cheng-Horng Lin

    2011-01-01

    Full Text Available Slab melting in young and hot subduction zones has been studied using geochemical observations and thermal modelling, but there are few data from seismic studies to confirm slab melting. Also the detailed geometry in the deep part of the melting slab is often ambiguous in that the intraslab earthquakes within the Wadati-Benioff zone are only limited to shallower depths. To improve our understanding of both the seismic features and geometry found in a young and hot subducted slab, I analyzed anomalous moonquake-like seismograms that were generated by an intermediate-depth earthquake recorded in central Japan. For this study, possible reflected (or scattered sources were examined using detailed analyses of particle motions and a grid search for travel-time differences between the direct and later P-waves. The results show that using strong seismic scattering, slab melting is likely occurring in the deeper, flexing part of the subducted Philippine Sea plate. Because the subducted Philippine Sea plate in central Japan is young and therefore hot, partial melting might have taken place to produce abundant melting spots in the subducted slab. Melting spots, identified as ¡§bright spots,¡¨ could efficiently reflect or scatter seismic energy and generate many later phases with large amplitudes.

  1. CYCLIC TEMPERATURE LOADING RESIDUAL FLEXURAL STRENGHT OF REFRACTORY SLABS

    Directory of Open Access Journals (Sweden)

    Ondřej Holčapek

    2017-05-01

    Full Text Available This paper describes the effect of cyclic elevated temperature loading on refractory slabs made from high performance, fibre reinforced cement composite. Slabs were produced from aluminous cement-based composites, reinforced by different dosages of basalt fibres. The composite investigated in this study had self-compacting characteristics. The slabs used were exposed to different thermal loading – 600 °C, 1000 °C, six times applied 600 °C and 1000 °C. Then, flexural strength was investigated in all groups of slabs, including group reference slabs with no thermal loading. The results show that the appropriate combination of aluminous cement, natural basalt aggregate, fine filler and basalt fibres in dosage 1.00% of volume is able to successfully resist to cyclic temperature loading. Tensile strength in bending of these slabs (after cyclic temperature loading at 600 °C achieved 6.0 MPa. It was demonstrated that it is possible to use this composite for high extensive conditions in real industrial conditions.

  2. Strengthening of RC bridge slabs using CFRP sheets

    Directory of Open Access Journals (Sweden)

    Fahmy A. Fathelbab

    2014-12-01

    Full Text Available Many old structures became structurally insufficient to carry the new loading conditions requirements. Moreover, they suffer from structural degradation, reinforcement steel bars corrosion, bad weather conditions…etc. Many official authorities in several countries had recognized many old bridges and buildings as structurally deficient by today’s standards. Due to these reasons, structural strengthening became an essential requirement and different strengthening techniques appeared in market. Fiber Reinforced Polymer (FRP strengthening techniques established a good position among all other techniques, giving excellent structural results, low time required and moderate cost compared with the other techniques. The main purpose of this research is to study analytically the strengthening of a reinforced concrete bridge slabs due to excessive loads, using externally bonded FRP sheets technique. A commercial finite element program ANSYS was used to perform a structural linear and non-linear analysis for strengthened slab models using several schemes of FRP sheets. A parametric study was performed to evaluate analytically the effect of changing both FRP stiffness and FRP schemes in strengthening RC slabs. Comparing the results with control slab (reinforced concrete slab without strengthening it is obvious that attaching FRP sheets to the RC slab increases its capacity and enhances the ductility/toughness.

  3. Pelvic floor and sexual male dysfunction

    Directory of Open Access Journals (Sweden)

    Antonella Pischedda

    2013-04-01

    Full Text Available The pelvic floor is a complex multifunctional structure that corresponds to the genito- urinary-anal area and consists of muscle and connective tissue. It supports the urinary, fecal, sexual and reproductive functions and pelvic statics. The symptoms caused by pelvic floor dysfunction often affect the quality of life of those who are afflicted, worsening significantly more aspects of daily life. In fact, in addition to providing support to the pelvic organs, the deep floor muscles support urinary continence and intestinal emptying whereas the superficial floor muscles are involved in the mechanism of erection and ejaculation. So, conditions of muscle hypotonia or hypertonicity may affect the efficiency of the pelvic floor, altering both the functionality of the deep and superficial floor muscles. In this evolution of knowledge it is possible imagine how the rehabilitation techniques of pelvic floor muscles, if altered and able to support a voiding or evacuative or sexual dysfunction, may have a role in improving the health and the quality of life.

  4. Ultrasound Imaging of the Pelvic Floor.

    Science.gov (United States)

    Stone, Daniel E; Quiroz, Lieschen H

    2016-03-01

    This article discusses the background and appraisal of endoluminal ultrasound of the pelvic floor. It provides a detailed anatomic assessment of the muscles and surrounding organs of the pelvic floor. Different anatomic variability and pathology, such as prolapse, fecal incontinence, urinary incontinence, vaginal wall cysts, synthetic implanted material, and pelvic pain, are easily assessed with endoluminal vaginal ultrasound. With pelvic organ prolapse in particular, not only is the prolapse itself seen but the underlying cause related to the anatomic and functional abnormalities of the pelvic floor muscle structures are also visualized.

  5. Pulsations, interpulsations, and sea-floor spreading.

    Science.gov (United States)

    Pessagno, E. A., Jr.

    1973-01-01

    It is postulated that worldwide transgressions (pulsations) and regressions (interpulsations) through the course of geologic time are related to the elevation and subsidence of oceanic ridge systems and to sea-floor spreading. Two multiple working hypotheses are advanced to explain major transgressions and regressions and the elevation and subsidence of oceanic ridge systems. One hypothesis interrelates the sea-floor spreading hypothesis to the hypothesis of sub-Mohorovicic serpentinization. The second hypothesis relates the sea-floor spreading hypothesis to a hypothesis involving thermal expansion and contraction.

  6. Standing sausage modes in curved coronal slabs

    Science.gov (United States)

    Pascoe, D. J.; Nakariakov, V. M.

    2016-09-01

    Context. Magnetohydrodynamic waveguides such as dense coronal loops can support standing modes. The ratios of the periods of oscillations for different longitudinal harmonics depend on the dispersive nature of the waveguide and so may be used as a seismological tool to determine coronal parameters. Aims: We extend models of standing sausage modes in low β coronal loops to include the effects of loop curvature. The behaviour of standing sausage modes in this geometry is used to explain the properties of observed oscillations that cannot be accounted for using straight loop models. Methods: We perform 2D numerical simulations of an oscillating coronal loop, modelled as a dense slab embedded in a potential magnetic field. The loop is field-aligned and so experiences expansion with height in addition to being curved. Standing sausage modes are excited by compressive perturbations of the loop and their properties are studied. Results: The spatial profiles of standing sausage modes are found to be modified by the expanding loop geometry typical for flaring loops and modelled by a potential magnetic field in our simulations. Longitudinal harmonics of order n > 1 have anti-nodes that are shifted towards the loop apex and the amplitude of anti-nodes near the loop apex is smaller than those near the loop footpoints. Conclusions: We find that the observation of standing sausage modes by the Nobeyama Radioheliograph in a flaring coronal loop on 12 January 2000 is consistent with interpretation in terms of the global mode (n = 1) and third harmonic (n = 3). This interpretation accounts for the period ratio and spatial structure of the observed oscillations.

  7. Parameters determination and bolting control of gateway floor

    Institute of Scientific and Technical Information of China (English)

    GOU Pan-feng; XlN Ya-jun

    2011-01-01

    Gateway floor heave control is the key to guarantee mine safe and efficient production.Through analysis of floor instability characteristics and bolting control,gateway floor strata show second level stress under abutment pressure,which causes plastic flow failure in floor strata; gateway floor instability shows mainly shear-break slippage of “triangle sliding body”.Mechanics of floor bolting is mainly a function of connection and combination.Main area of bolting control lies in two gateway floor angles.The paper analyzes mechanics principle of gateway floor instability,constructs stability mechanics model of gateway floor bolting,obtains gateway floor stability criterion of different bolting angles and optimum formula of bolting parameters,carries out the engineering example,and guides better field application.It provides theoretical base for bolting gateway floor instability control.

  8. Do Open Floor Plans Invite Overeating?

    Science.gov (United States)

    ... among American adults. Rollings and Wells suggested that future studies might explore the effect of floor plan openness in settings where overeating can occur, such as residential kitchens; college, school and workplace cafeterias; and buffet-style ...

  9. Constructing international floors for language learning ends ...

    African Journals Online (AJOL)

    ... international floors for language learning ends: reflectng on a teacher upgrading course. ... The researcher, who participated as a teacher trainer in the TRANSNET-RIEP project, used ... Both dialogues were based on pre-reading activities.

  10. Mantle flow and dynamic topography associated with slab window opening

    Science.gov (United States)

    Guillaume, Benjamin; Moroni, Monica; Funiciello, Francesca; Martinod, Joseph; Faccenna, Claudio

    2010-05-01

    A slab window is defined as an 'hole' in the subducting lithosphere. In the classical view, slab windows develop where a spreading ridge intersects a subduction zone. The main consequences of this phenomenon are the modifications of the physical, chemical and thermal conditions in the backarc mantle that in turn affect the tectonic and magmatic evolution of the overriding plate. In this work, we perform dynamically self-consistent mantle-scale laboratory models, to evaluate how the opening of a window in the subducting panel influences the geometry and the kinematics of the slab, the mantle circulation pattern and, finally, the overriding plate dynamic topography. The adopted setup consists in a two-layer linearly viscous system simulating the roll-back of a fixed subducting plate (simulated using silicone putty) into the upper mantle (simulated using glucose syrup). Our experimental setting is also characterized by a constant-width rectangular window located at the center of a laterally confined slab, modeling the case of the interaction of a trench-parallel spreading ridge with a wide subduction zone. We find that the geometry and the kinematics of the slab are only minorly affected by the opening of a slab window. On the contrary, slab induced mantle circulation, quantified using Feature Tracking image analysis technique, is strongly modified and produces a peculiar non-isostatic topographic signal on the overriding plate. Assuming that our modeling results can be representative of the natural behavior of subduction zones, we compare them to the Patagonian subduction zone finding that anomalous backarc volcanism that developed since middle Miocene could result from the lateral flowage of subslab mantle, and that part of the Patagonian uplift could be dynamically supported.

  11. Strength Behaviour Of Biomass Fiber-Reinforced Concrete Slab

    Directory of Open Access Journals (Sweden)

    Chai Teck Jung

    2012-05-01

    Full Text Available This paper investigates the compressive strength and flexural strength of biomass fibre-reinforced concrete slab. The main objective of this study is to examine the effect of biomass aggregate and fibre glass on the concrete slab strength. The biomass aggregate is used to replace the natural aggregates. A total of 36 slab samples (250 mm x 600 mm x 50mm thick and 36 numbers of 150 mm cube samples containing 0%, 30%, 60% and 100% biomass aggregate were prepared.  The E-class fibre and Supracoat SP800 were added to increase the strength and to achieve the required workability. All the samples were cured in water with room temperature of around 27oC and tested at the age of 7, 14 and 28 days respectively. The result showed that cube specimens containing 30% biomass aggregate concrete achieved minimum strength of 15 MPa at 28 days. The flexural strength for slab specimens containing 30% biomass aggregate, Supracoat SP 800 and fibre glass gained higher strength compared with control specimens. The 100% biomass aggregate slab achieved 88% of the control specimen strength. The workability was between 150 mm to 170mm slump. The density of the specimens was reduced 20% for cube and 28% for slab compared with control specimens. It can be concluded that the biomass aggregate has good potential as partial aggregate replacement in slab construction when combined with the use of glass fibre and superplasticizer. However, more research needs to be carried out to self-compacting biomass aggregate concrete for sustainable construction

  12. Modeling the surface photovoltage of silicon slabs with varying thickness.

    Science.gov (United States)

    Vazhappilly, Tijo; Kilin, Dmitri S; Micha, David A

    2015-04-10

    The variation with thickness of the energy band gap and photovoltage at the surface of a thin semiconductor film are of great interest in connection with their surface electronic structure and optical properties. In this work, the change of a surface photovoltage (SPV) with the number of layers of a crystalline silicon slab is extracted from models based on their atomic structure. Electronic properties of photoexcited slabs are investigated using generalized gradient and hybrid density functionals, and plane wave basis sets. Si(1 1 1) surfaces have been terminated by hydrogen atoms to compensate for dangling bonds and have been described by large supercells with periodic boundary conditions. Calculations of the SPV of the Si slabs have been done in terms of the reduced density matrix of the photoactive electrons including dissipative effects due to their interaction with medium phonons and excitons. Surface photovoltages have been calculated for model Si slabs with 4-12, and 16 layers, to determine convergence trends versus slab thickness. Band gaps and the inverse of the SPVs have been found to scale nearly linearly with the inverse thickness of the slab, while the electronic density of states increases quadratically with thickness. Our calculations show the same trends as experimental values indicating band gap reduction and absorption enhancement for Si films of increasing thickness. Simple arguments on confined electronic structures have been used to explain the main effects of changes with slab thickness. A procedure involving shifted electron excitation energies is described to improve results from generalized gradient functionals so they can be in better agreement with the more accurate but also more computer intensive values from screened exchange hybrid functionals.

  13. Tomographic imaging of the effects of Peruvian flat slab subduction on the Nazca slab and surrounding mantle under central and southern Peru

    Science.gov (United States)

    Scire, A. C.; Zandt, G.; Beck, S. L.; Bishop, B.; Biryol, C. B.; Wagner, L. S.; Long, M. D.; Minaya, E.; Tavera, H.

    2014-12-01

    The modern central Peruvian Andes are dominated by a laterally extensive region of flat slab subduction. The Peruvian flat slab extends for ~1500 km along the strike of the Andes, correlating with the subduction of the Nazca Ridge in the south and the theorized Inca Plateau in the north. We have used data from the CAUGHT and PULSE experiments for finite frequency teleseismic P- and S-wave tomography to image the Nazca slab in the upper mantle below 95 km depth under central Peru between 10°S and 18°S as well as the surrounding mantle. Since the slab inboard of the subducting Nazca Ridge is mostly aseismic, our results provide important constraints on the geometry of the subducting Nazca slab in this region. Our images of the Nazca slab suggest that steepening of the slab inboard of the subducting Nazca Ridge locally occurs ~100 km further inland than was indicated in previous studies. The region where we have imaged the steepening of the Nazca slab inboard of the Nazca Ridge correlates with the location of the Fitzcarrald Arch, a long wavelength upper plate topographic feature which has been suggested to be a consequence of ridge subduction. When the slab steepens inboard of the flat slab region, it does so at a very steep (~70°) angle. The transition from the Peruvian flat slab to the more normally dipping slab south of 16°S below Bolivia is characterized by an abrupt bending of the slab anomaly in the mantle in response to the shift from flat to normal subduction. The slab anomaly appears to be intact south of the Nazca Ridge with no evidence for tearing of the slab in response to the abrupt change in slab dip. A potential tear in the slab is inferred from an observed offset in the slab anomaly north of the Nazca Ridge extending subparallel to the ridge axis between 130 and 300 km depth. A high amplitude (-5-6%) slow S-wave velocity anomaly is observed below the projection of the Nazca Ridge. This anomaly appears to be laterally confined to the mantle

  14. Vaginal childbirth and pelvic floor disorders

    OpenAIRE

    Memon, Hafsa U.; Handa, Victoria L.

    2013-01-01

    Childbirth is an important event in a woman’s life. Vaginal childbirth is the most common mode of delivery and it has been associated with increased incidence of pelvic floor disorders later in life. In this article, the authors review and summarize current literature associating pelvic floor disorders with vaginal childbirth. Stress urinary incontinence and pelvic organ prolapse are strongly associated with vaginal childbirth and parity. The exact mechanism of injury associating vaginal deli...

  15. Anonymous electronic trading versus floor trading

    OpenAIRE

    Franke, Günter; Hess, Dieter

    1995-01-01

    This paper compares the attractiveness of floor trading and anonymous electronic trading systems. It is argued that in times of low information intensity the insight into the order book of the electronic trading system provides more valuable information than floor trading, but in times of high information intensity the reverse is true. Thus, the electronic system's market share in trading activity should decline in times of high information intensity. This hypothesis is tested by data on BUND...

  16. WOODEN FLOORING – BETWEEN PRESENT AND FUTURE

    OpenAIRE

    Ivan CISMARU; Marius FILIPAȘCU; Olimpia-Minerva ȚURCAȘ (DIACONU); Adriana FOTIN

    2015-01-01

    The paper aims at presenting a systematization of the wood floors, both in terms of the areas of application, and in terms of the fastening solutions and structures in constructions. In this respect, an extensive bibliographic research was achieved, on the researchers’ preoccupations. Starting from the current situation and forecasting the future, from the point of view of the chances held by wooden flooring, in competition with other types of materials, we dare say the wooden flo...

  17. Anonymous electronic trading versus floor trading

    OpenAIRE

    Franke, Günter; Hess, Dieter

    1995-01-01

    This paper compares the attractiveness of floor trading and anonymous electronic trading systems. It is argued that in times of low information intensity the insight into the order book of the electronic trading system provides more valuable information than floor trading, but in times of high information intensity the reverse is true. Thus, the electronic system's market share in trading activity should decline in times of high information intensity. This hypothesis is tested by data on BUND...

  18. New regulations for hollow core slabs after premature partial collapse

    NARCIS (Netherlands)

    Overbeek, T. van; Breunese, A.; Gijsbers, J.; Both, K.; Maljaars, J.; Noordijk, L.

    2010-01-01

    In October 2007, a floor made up of pre-cast prestressed hollow core floor elements suffered early partial collapse during a fire in a carpark of a moderately high new building in Rotterdam, predominantly in use for housing and for limited enterprise. The damage pattern revealed horizontal cracks

  19. New regulations for hollow core slabs after premature partial collapse

    NARCIS (Netherlands)

    Overbeek, T. van; Breunese, A.; Gijsbers, J.; Both, K.; Maljaars, J.; Noordijk, L.

    2010-01-01

    In October 2007, a floor made up of pre-cast prestressed hollow core floor elements suffered early partial collapse during a fire in a carpark of a moderately high new building in Rotterdam, predominantly in use for housing and for limited enterprise. The damage pattern revealed horizontal cracks th

  20. Calibrating a large slab vessel: A battle of the bulge

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, I.R. [Westinghouse Idaho Nuclear Co., Inc., Idaho Falls, ID (United States). Safeguards and Security Section

    1993-12-31

    The accurate measurement of volume in slab vessels can be difficult because slab vessels expand--in spite of internal or external supports--as they are filled. One form of bulging is elastic deflection, a gradual expansion of the vessel wall resulting from an increased weight of contained solution. As part of an upgrade to the Idaho Chemical Processing Plant, slab tanks were proposed as accountability measurement vessels. A 1960 liter slab tank prototype was set up for preliminary calibrations. Two series of calibrations were conducted: the first using water, and the second using aluminum nitrate. It was conjectured that the increased weight of aluminum nitrate would cause the vessel walls to deflect more than they did for an equal level of water, resulting in a greater volume. As expected, a significant expansion was observed with the aluminum nitrate, but some of the deflection proved to be permanent rather than elastic. The consequence is that considerably more effort will be required to calibrate slab vessels for uranium accountability. Not only must a calibration curve (or family of curves) be developed giving volume as a function of both liquid level and density, but, if possible, a determination must be made as to when the deflection is no longer temporary.

  1. The subduction dichotomy of strong plates and weak slabs

    Science.gov (United States)

    Petersen, Robert I.; Stegman, Dave R.; Tackley, Paul J.

    2017-03-01

    A key element of plate tectonics on Earth is that the lithosphere is subducting into the mantle. Subduction results from forces that bend and pull the lithosphere into the interior of the Earth. Once subducted, lithospheric slabs are further modified by dynamic forces in the mantle, and their sinking is inhibited by the increase in viscosity of the lower mantle. These forces are resisted by the material strength of the lithosphere. Using geodynamic models, we investigate several subduction models, wherein we control material strength by setting a maximum viscosity for the surface plates and the subducted slabs independently. We find that models characterized by a dichotomy of lithosphere strengths produce a spectrum of results that are comparable to interpretations of observations of subduction on Earth. These models have strong lithospheric plates at the surface, which promotes Earth-like single-sided subduction. At the same time, these models have weakened lithospheric subducted slabs which can more easily bend to either lie flat or fold into a slab pile atop the lower mantle, reproducing the spectrum of slab morphologies that have been interpreted from images of seismic tomography.

  2. Investigations on Efficiently Interfaced Steel Concrete Composite Deck Slabs

    Directory of Open Access Journals (Sweden)

    K. N. Lakshmikandhan

    2013-01-01

    Full Text Available The strength of the composite deck slab depends mainly on the longitudinal shear transfer mechanism at the interface between steel and concrete. The bond strength developed by the cement paste is weak and causes premature failure of composite deck slab. This deficiency is effectively overcame by a shear transferring mechanism in the form of mechanical interlock through indentations, embossments, or fastening studs. Development of embossment patterns requires an advanced technology which makes the deck profile expensive. Fastening studs by welding weakens the joint strength and also escalates the cost. The present investigation is attempted to arrive at a better, simple interface mechanism. Three types of mechanical connector schemes are identified and investigated experimentally. All of the three shear connector schemes exhibited full shear interaction with negligible slip. The strength and stiffness of the composite slabs with shear connectors are superior about one and half time compared to these of the conventional reinforced concrete slabs and about twice compared to these of composite slabs without mechanical shear connectors. The scheme2 and scheme3 shear connector mechanisms integrate deck webs and improve strength and stiffness of the deck, which can effectively reduce the cost of formworks and supports efficiently.

  3. Fossil slabs attached to unsubducted fragments of the Farallon plate.

    Science.gov (United States)

    Wang, Yun; Forsyth, Donald W; Rau, Christina J; Carriero, Nina; Schmandt, Brandon; Gaherty, James B; Savage, Brian

    2013-04-02

    As the Pacific-Farallon spreading center approached North America, the Farallon plate fragmented into a number of small plates. Some of the microplate fragments ceased subducting before the spreading center reached the trench. Most tectonic models have assumed that the subducting oceanic slab detached from these microplates close to the trench, but recent seismic tomography studies have revealed a high-velocity anomaly beneath Baja California that appears to be a fossil slab still attached to the Guadalupe and Magdalena microplates. Here, using surface wave tomography, we establish the lateral extent of this fossil slab and show that it is correlated with the distribution of high-Mg andesites thought to derive from partial melting of the subducted oceanic crust. We also reinterpret the high seismic velocity anomaly beneath the southern central valley of California as another fossil slab extending to a depth of 200 km or more that is attached to the former Monterey microplate. The existence of these fossil slabs may force a reexamination of models of the tectonic evolution of western North America over the last 30 My.

  4. A novel & affordable interactive floor for educational applications

    DEFF Research Database (Denmark)

    Boisen, Ulrik; Hansen, Anders Juul; Knudsen, Lars;

    2011-01-01

    This article examines two research areas: How interactive floors can be used beneficially in an educational context, and how an interactive floor can be created which is mobile and relatively inexpensive.......This article examines two research areas: How interactive floors can be used beneficially in an educational context, and how an interactive floor can be created which is mobile and relatively inexpensive....

  5. 76 FR 7098 - Dealer Floor Plan Pilot Program

    Science.gov (United States)

    2011-02-09

    ... ADMINISTRATION 13 CFR Parts 120 and 121 Dealer Floor Plan Pilot Program AGENCY: U.S. Small Business... Dealer Floor Plan Pilot Program to make available 7(a) loan guaranties for lines of credit that provide floor plan financing. This new Dealer Floor Plan Pilot Program was created in the Small Business Jobs...

  6. Slab detachment of subducted Indo-Australian plate beneath Sunda arc, Indonesia

    Indian Academy of Sciences (India)

    Bhaskar Kundu; V K Gahalaut

    2011-04-01

    Necking, tearing, slab detachment and subsequently slab loss complicate the subduction zone processes and slab architecture. Based on evidences which include patterns of seismicity, seismic tomography and geochemistry of arc volcanoes, we have identified a horizontal slab tear in the subducted Indo-Australian slab beneath the Sunda arc. It strongly reflects on trench migration, and causes along-strike variations in vertical motion and geochemically distinct subduction-related arc magmatism. We also propose a model for the geodynamic evolution of slab detachment.

  7. Sequence assembly

    DEFF Research Database (Denmark)

    Scheibye-Alsing, Karsten; Hoffmann, S.; Frankel, Annett Maria

    2009-01-01

    Despite the rapidly increasing number of sequenced and re-sequenced genomes, many issues regarding the computational assembly of large-scale sequencing data have remain unresolved. Computational assembly is crucial in large genome projects as well for the evolving high-throughput technologies...

  8. IMPROVEMENT OF SLAB REHEATING PROCESS AT USIMINAS THROUGH MATHEMATICAL SIMULATION

    Directory of Open Access Journals (Sweden)

    Antônio Adel dos Santos

    2012-09-01

    Full Text Available Basic characteristics and application examples of the mathematical simulator for reheating process in walking-beam type furnaces, that has been developed and applied to Usiminas plate mill line at Ipatinga, are shown in this paper. This is a bi-dimensional mathematical model solved by the finite volume method, validated by temperature measurements inside the slab during heating and coded as a visual tool. Among these applications, the following can be highlighted: (i determination of suitable furnace zone temperatures and residence times for processing steels by accelerated cooling technology; (ii determination of slab average temperature at discharging as well as at each zone exit, supplying data to be fed to the automation system at the comissioning stage; (iii analyses of slab thermal distribution through the reheating process, enabling operational optimization

  9. Systematic effects induced by a flat isotropic dielectric slab

    CERN Document Server

    Macculi, C; Cortiglioni, S; Peverini, O A; Tascone, R; Zannoni, M; Carretti, Ettore; Cortiglioni, Stefano; Macculi, Claudio; Peverini, Oscar Antonio; Tascone, Riccardo; Zannoni, Mario

    2006-01-01

    The instrumental polarization induced by a flat isotropic dielectric slab in microwave frequencies is faced. We find that, in spite of its isotropic nature, such a dielectric can produce spurious polarization either by transmitting incoming anisotropic diffuse radiation or emitting when it is thermally inhomogeneous. We present evaluations of instrumental polarization generated by materials usually adopted in Radioastronomy, by using the Mueller matrix formalism. As an application, results for different slabs in front of a 32 GHz receiver are discussed. Such results are based on measurements of their complex dielectric constant. We evaluate that a 0.33 cm thick Teflon slab introduces negligible spurious polarization ($< 2.6 \\times 10^{-5}$ in transmission and $< 6 \\times 10^{-7}$ in emission), even minimizing the leakage ($< 10^{-8}$ from $Q$ to $U$ Stokes parameters, and viceversa) and the depolarization ($\\sim 1.3 \\times 10^{-3}$).

  10. Casimir Force on Real Materials - the Slab and Cavity Geometry

    CERN Document Server

    Ellingsen, S A; Brevik, Iver; Ellingsen, Simen A.

    2006-01-01

    We analyse the potential of the geometry of a slab in a planar cavity for the purpose of Casimir force experiments. The force and its dependence on temperature, material properties and finite slab thickness are investigated both analytically and numerically for slab and walls made of aluminium and teflon FEP respectively. We conclude that such a setup is ideal for measurements of the temperature dependence of the Casimir force. By numerical calculation it is shown that temperature effects are dramatically larger for dielectrics, suggesting that a dielectric such as teflon FEP whose properties vary little within a moderate temperature range, should be considered for experimental purposes. We finally discuss the subtle but fundamental matter of the various Green's two-point function approaches present in the literature and show how they are different formulations describing the same phenomenon.

  11. Efficient Vortex Generation in Subwavelength Epsilon-Near-Zero Slabs

    Science.gov (United States)

    Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo

    2017-03-01

    We show that a homogeneous and isotropic slab, illuminated by a circularly polarized beam with no topological charge, produces vortices of order 2 in the opposite circularly polarized components of the reflected and transmitted fields, as a consequence of the transverse magnetic and transverse electric asymmetric response of the rotationally invariant system. In addition, in the epsilon-near-zero regime, we find that vortex generation is remarkably efficient in subwavelength thick slabs up to the paraxial regime. This physically stems from the fact that a vacuum paraxial field can excite a nonparaxial field inside an epsilon-near-zero slab since it hosts slowly varying fields over physically large portions of the bulk. Our theoretical predictions indicate that epsilon-near-zero media hold great potential as nanophotonic elements for manipulating the angular momentum of the radiation, since they are available without resorting to complicated micro- or nanofabrication processes and can operate even at very small (ultraviolet) wavelengths.

  12. Photonic-crystal slab for terahertz-wave technology platform

    Science.gov (United States)

    Fujita, Masayuki

    2016-03-01

    Photonic crystals manipulate photons in a manner analogous to solid-state crystals, and are composed of a dielectric material with a periodic refractive index distribution. In particular, two-dimensional photonic-crystal slabs with high index contrasts (semiconductor/air) are promising for practical applications, owing to the strong optical confinement in simple, thin planar structures. This paper presents the recent progress on a silicon photonic-crystal slab as a technology platform in the terahertz-wave region, which is located between the radio and light wave regions (0.1-10 THz). Extremely low-loss (edge effect are demonstrated. Terahertz photonic-crystal slabs hold the potential for developing ultralow-loss, compact terahertz components and integrated devices used in applications including wireless communication, spectroscopic sensing, and imaging.

  13. Can slabs melt beneath forearcs in hot subduction zones?

    Science.gov (United States)

    Ribeiro, J.; Maury, R.; Gregoire, M.

    2015-12-01

    At subduction zones, thermal modeling predict that the shallow part of the downgoing oceanic crust (test the hypothesis that adakites are pristine slab melts. We find that adakites from Baja California and Philippines formed by two distinct petrogenetic scenarios. In Baja California, hydrous mantle melts mixed/mingled with high-pressure (HP) adakite-type, slab melts within a lower crustal (~30 km depth) magma storage region before stalling into the upper arc crust (~7-15 km depth). In contrast, in the Philippines, primitive mantle melts stalled and crystallized within lower and upper crustal magma storage regions to produce silica-rich melts with an adakitic signature. Thereby, slab melting is not required to produce an adakitic geochemical fingerprint in hot subduction zones. However, our results also suggest that the downgoing crust potentially melted beneath Baja California.

  14. Requalification analysis of a circular composite slab for seismic load

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, M.G.; Kot, C.A.

    1992-11-01

    The circular roof slab of an existing facility was analyzed to requalify the structure for supporting a significant seismic load that it was not originally designed for. The slab has a clear span of 66 ft and consists of a 48 in thick reinforced concrete member and a steel liner plate. Besides a number of smaller penetrations, the slab contains two significant cutouts: a 9 ft square opening and a 3 ft dia hole. The issues that complicated the analysis of this non-typical structure, i.e., composite action and nonlinear stiffness of reinforced concrete (R. C.) sections, are discussed. It was possible to circumvent the difficulties by making conservative and simplifying assumptions. If codes incorporate guidelines on practical methods for dynamic analysis of R. C. structures, some of the unneeded conservatism could be eliminated in future designs.

  15. Dynamic triggering of deep earthquakes within a fossil slab

    Science.gov (United States)

    Cai, Chen; Wiens, Douglas A.

    2016-09-01

    The 9 November 2009 Mw 7.3 Fiji deep earthquake is the largest event in a region west of the Tonga slab defined by scattered seismicity and velocity anomalies. The main shock rupture was compact, but the aftershocks were distributed along a linear feature at distances of up to 126 km. The aftershocks and some background seismicity define a sharp northern boundary to the zone of outboard earthquakes, extending westward toward the Vitiaz deep earthquake cluster. The northern earthquake lineament is geometrically similar to tectonic reconstructions of the relict Vitiaz subduction zone at 8-10 Ma, suggesting the earthquakes are occurring in the final portion of the slab subducted at the now inactive Vitiaz trench. A Coulomb stress change calculation suggests many of the aftershocks were dynamically triggered. We propose that fossil slabs contain material that is too warm for earthquake nucleation but may be near the critical stress susceptible to dynamic triggering.

  16. Efficient Vortex Generation in Subwavelength Epsilon-Near-Zero Slabs.

    Science.gov (United States)

    Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo

    2017-03-10

    We show that a homogeneous and isotropic slab, illuminated by a circularly polarized beam with no topological charge, produces vortices of order 2 in the opposite circularly polarized components of the reflected and transmitted fields, as a consequence of the transverse magnetic and transverse electric asymmetric response of the rotationally invariant system. In addition, in the epsilon-near-zero regime, we find that vortex generation is remarkably efficient in subwavelength thick slabs up to the paraxial regime. This physically stems from the fact that a vacuum paraxial field can excite a nonparaxial field inside an epsilon-near-zero slab since it hosts slowly varying fields over physically large portions of the bulk. Our theoretical predictions indicate that epsilon-near-zero media hold great potential as nanophotonic elements for manipulating the angular momentum of the radiation, since they are available without resorting to complicated micro- or nanofabrication processes and can operate even at very small (ultraviolet) wavelengths.

  17. Numerical models of slab migration in continental collision zones

    Directory of Open Access Journals (Sweden)

    V. Magni

    2012-09-01

    Full Text Available Continental collision is an intrinsic feature of plate tectonics. The closure of an oceanic basin leads to the onset of subduction of buoyant continental material, which slows down and eventually stops the subduction process. In natural cases, evidence of advancing margins has been recognized in continental collision zones such as India-Eurasia and Arabia-Eurasia. We perform a parametric study of the geometrical and rheological influence on subduction dynamics during the subduction of continental lithosphere. In our 2-D numerical models of a free subduction system with temperature and stress-dependent rheology, the trench and the overriding plate move self-consistently as a function of the dynamics of the system (i.e. no external forces are imposed. This setup enables to study how continental subduction influences the trench migration. We found that in all models the slab starts to advance once the continent enters the subduction zone and continues to migrate until few million years after the ultimate slab detachment. Our results support the idea that the advancing mode is favoured and, in part, provided by the intrinsic force balance of continental collision. We suggest that the advance is first induced by the locking of the subduction zone and the subsequent steepening of the slab, and next by the sinking of the deepest oceanic part of the slab, during stretching and break-off of the slab. These processes are responsible for the migration of the subduction zone by triggering small-scale convection cells in the mantle that, in turn, drag the plates. The amount of advance ranges from 40 to 220 km and depends on the dip angle of the slab before the onset of collision.

  18. [Aging-related changes of the female pelvic floor].

    Science.gov (United States)

    Scheiner, David; Betschart, Cornelia; Perucchini, Daniele

    2010-01-01

    The pelvic floor as lower closure of the abdominal cavity has to withstand the abdominal pressure. Meanwhile, the pelvic floor has to allow physiologic functions like micturition, defecation, sexual function and reproduction. But while pregnancy and vaginal delivery damage the pelvic floor directly, chronic stress like caugh, heavy lifting, or obesity lead to a chronic overstraining of the pelvic floor. Aging, structural changes, and possibly estrogen deficiency have a negative impact on the pelvic floor.

  19. Total pelvic floor ultrasound for pelvic floor defaecatory dysfunction: a pictorial review.

    Science.gov (United States)

    Hainsworth, Alison J; Solanki, Deepa; Schizas, Alexis M P; Williams, Andrew B

    2015-01-01

    Total pelvic floor ultrasound is used for the dynamic assessment of pelvic floor dysfunction and allows multicompartmental anatomical and functional assessment. Pelvic floor dysfunction includes defaecatory, urinary and sexual dysfunction, pelvic organ prolapse and pain. It is common, increasingly recognized and associated with increasing age and multiparity. Other options for assessment include defaecation proctography and defaecation MRI. Total pelvic floor ultrasound is a cheap, safe, imaging tool, which may be performed as a first-line investigation in outpatients. It allows dynamic assessment of the entire pelvic floor, essential for treatment planning for females who often have multiple diagnoses where treatment should address all aspects of dysfunction to yield optimal results. Transvaginal scanning using a rotating single crystal probe provides sagittal views of bladder neck support anteriorly. Posterior transvaginal ultrasound may reveal rectocoele, enterocoele or intussusception whilst bearing down. The vaginal probe is also used to acquire a 360° cross-sectional image to allow anatomical visualization of the pelvic floor and provides information regarding levator plate integrity and pelvic organ alignment. Dynamic transperineal ultrasound using a conventional curved array probe provides a global view of the anterior, middle and posterior compartments and may show cystocoele, enterocoele, sigmoidocoele or rectocoele. This pictorial review provides an atlas of normal and pathological images required for global pelvic floor assessment in females presenting with defaecatory dysfunction. Total pelvic floor ultrasound may be used with complementary endoanal ultrasound to assess the sphincter complex, but this is beyond the scope of this review.

  20. 17 CFR 1.62 - Contract market requirement for floor broker and floor trader registration.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Contract market requirement for floor broker and floor trader registration. 1.62 Section 1.62 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION GENERAL REGULATIONS UNDER THE COMMODITY EXCHANGE ACT Miscellaneous § 1...

  1. Bayesian Inference for Structured Spike and Slab Priors

    DEFF Research Database (Denmark)

    Andersen, Michael Riis; Winther, Ole; Hansen, Lars Kai

    2014-01-01

    Sparse signal recovery addresses the problem of solving underdetermined linear inverse problems subject to a sparsity constraint. We propose a novel prior formulation, the structured spike and slab prior, which allows to incorporate a priori knowledge of the sparsity pattern by imposing a spatial...... Gaussian process on the spike and slab probabilities. Thus, prior information on the structure of the sparsity pattern can be encoded using generic covariance functions. Furthermore, we provide a Bayesian inference scheme for the proposed model based on the expectation propagation framework. Using...

  2. Tunneling properties of electromagnetic wave in slab superconducting material

    Institute of Scientific and Technical Information of China (English)

    Khem B. Thapa; Sanjay Srivastava; Alka Vishwakarma; S. P. Ojha

    2011-01-01

    When the electromagnetic wave propagates through a slab superconducting material in microwave ranges, tunneling properties of the electromagnetic wave at critical temperature are investigated theoretically. The transmittance and the reflectance of the slab superconducting material vary with the thickness of material as well as the refractive index of substrates.The high transmittance is found for thin superconductor at low wavelength region.However, optical properties are strongly dependent upon temperature and incidence wavelength. The electromagnetic wave is totally transmitted without loss for incidence wavelength (λ = 5000 nm) due to the zero refractive index and infinite penetration depth of the superconductor at the critical temperature.

  3. Repulsive Casimir forces with finite-thickness slabs

    OpenAIRE

    Zhao, R.; Koschny, Th.; Economou, E. N.; C M Soukoulis

    2010-01-01

    We use the extended Lifshitz theory to study the behaviors of the Casimir forces between finite-thickness effective medium slabs. We first study the interaction between a semi-infinite Drude metal and a finite-thickness magnetic slab with or without substrate. For no substrate, the large distance $d$ dependence of the force is repulsive and goes as $1/d^5$; for the Drude metal substrate, a stable equilibrium point appears at an intermediate distance which can be tuned by the thickness of the ...

  4. Three dimensional super-resolution in metamaterial slab lenses

    CERN Document Server

    Mesa, F; Freire, M; Baena, J D

    2005-01-01

    This letter presents a theoretical and experimental study on the viability of obtaining three dimensional super-resolution (i.e. resolution overcoming the diffraction limit for all directions in space) by means of metamaterial slab lenses. Although the source field cannot be actually reproduced at the back side of the lens with super-resolution in all space directions, the matching capabilities of metamaterial slabs does make it possible the detection of images with three-dimensional super-resolution. This imaging takes place because of the coupling between the evanescent space harmonic components of the field generated at both the source and the detector.

  5. Spalling of concrete: A synthesis of experimental tests on slabs

    Directory of Open Access Journals (Sweden)

    Taillefer Nicolas

    2013-09-01

    Full Text Available The article reviews the results of many commercial or research tests carried out in CSTB on middle size concrete slabs. They concern 22 concrete slabs, made of normal and high strength concrete, for a rather wide range of thickness and compressive strength classes. Test procedures and a synthesis of main results are presented in order to provide deeper understanding of near-reality conditions of concrete structures. The tests concerned both new and existing tunnels. Results are detailed in relation with main parameters that are identified as impacting spalling in previous studies, such as concrete composition, concrete properties and specimen size.

  6. Spalling tests on embedded cores and slabs: A comparative study

    Directory of Open Access Journals (Sweden)

    Pimienta P.

    2013-09-01

    Full Text Available A comparative analysis of the spalling of (a cores made of 3 concrete mixes embedded into 3 slabs made of the 3 same concrete mixes; and (b 3 reference slabs made again of the same 3 concrete mixes has been made. Samples have been exposed to the French Increased HydroCarbon temperature curve. Results confirm that concrete spalling phenomena is not only related to the material properties. Concrete spalling is also very much influenced by the geometry of the samples.

  7. Bayesian Inference for Structured Spike and Slab Priors

    DEFF Research Database (Denmark)

    Andersen, Michael Riis; Winther, Ole; Hansen, Lars Kai

    2014-01-01

    Sparse signal recovery addresses the problem of solving underdetermined linear inverse problems subject to a sparsity constraint. We propose a novel prior formulation, the structured spike and slab prior, which allows to incorporate a priori knowledge of the sparsity pattern by imposing a spatial...... Gaussian process on the spike and slab probabilities. Thus, prior information on the structure of the sparsity pattern can be encoded using generic covariance functions. Furthermore, we provide a Bayesian inference scheme for the proposed model based on the expectation propagation framework. Using...

  8. Links between fluid circulation, temperature, and metamorphism in subducting slabs

    Science.gov (United States)

    Spinelli, G.A.; Wang, K.

    2009-01-01

    The location and timing of metamorphic reactions in subducting lithosph??re are influenced by thermal effects of fluid circulation in the ocean crust aquifer. Fluid circulation in subducting crust extracts heat from the Nankai subduction zone, causing the crust to pass through cooler metamorphic faci??s than if no fluid circulation occurs. This fluid circulation shifts the basalt-to-eclogite transition and the associated slab dehydration 14 km deeper (35 km farther landward) than would be predicted with no fluid flow. For most subduction zones, hydrothermal cooling of the subducting slab will delay eclogitization relative to estimates made without considering fluid circulation. Copyright 2009 by the American Geophysical Union.

  9. Resonance-enhanced optical forces between coupled photonic crystal slabs.

    Science.gov (United States)

    Liu, Victor; Povinelli, Michelle; Fan, Shanhui

    2009-11-23

    The behaviors of lateral and normal optical forces between coupled photonic crystal slabs are analyzed. We show that the optical force is periodic with displacement, resulting in stable and unstable equilibrium positions. Moreover, the forces are strongly enhanced by guided resonances of the coupled slabs. Such enhancement is particularly prominent near dark states of the system, and the enhancement effect is strongly dependent on the types of guided resonances involved. These structures lead to enhancement of light-induced pressure over larger areas, in a configuration that is directly accessible to externally incident, free-space optical beams.

  10. Orbital floor reconstruction with resorbable polydioxanone implants.

    Science.gov (United States)

    Gierloff, Matthias; Seeck, Niels Gunnar Karl; Springer, Ingo; Becker, StephanThomas; Kandzia, Christian; Wiltfang, Jörg

    2012-01-01

    Many different materials are proposed for reconstruction of traumatic orbital floor defects. Donor-site morbidity of autologous transplants and infections or extrusions of nonresorbable implants lead to a widespread use of resorbable, alloplastic materials such as polydioxanone (PDS). The goal of this study was to evaluate the prevalence of orbital floor fracture-related problems after surgical treatment using PDS. Ophthalmologic and clinical examinations were performed at 194 patients before orbital floor reconstruction, 14 days and 6 months after surgery (approximate defect sizes: 2 cm², n=47). Clinical findings including the ocular motility, the sensibility of the infraorbital nerve, and the position of the globe were evaluated. For statistical analysis of categorical data, confidence intervals of percentages were determined. Linear relationships between 2 variables were assessed with Pearson correlation analysis. A reduced ocular motility was diagnosed in 60 patients (31%) before surgery; in 14 patients (7%), 2 weeks; and in 10 patients (5%), 6 months after surgery. Infraorbital hypesthesia was found in 120 patients (62%) before surgery; in 47 patients (24%), 2 weeks; and in 35 patients (18%), 6 months after surgery. An enophthalmos was present in 10 patients (5%) before surgery, and in 4 patients (2%), 6 months after surgery. Our data suggest that PDS is a suitable implant for orbital floor reconstruction with acceptable low rates of infraorbital hypesthesia, bulbus motility disturbances, and enophthalmos. Polydioxanone can also be used for orbital floor defects exceeding 2 cm².

  11. Glazed Tiles as Floor Finish in Nigeria

    Directory of Open Access Journals (Sweden)

    Toyin Emmanuel AKINDE

    2013-09-01

    Full Text Available Tile is no doubt rich in antiquity; its primordial  show, came as mosaic with primary prospect in sacred floor finish before its oblivion, courtesy of, later consciousness towards wall finish in banquets, kitchens, toilets, restaurants and even bars. Today, its renaissance as floor finish is apparent in private and public architectural structures with prevalence in residential, recreational, commercial, governmental and other spaces. In Nigeria, the use of glazed tiles as floor finish became apparent, supposedly in mid-twentieth century; and has since, witnessed ever increasing demands from all sundry; a development that is nascent and has necessitated its mass  production locally with pockets of firms in the country. The latter however, is a resultant response to taste cum glazed tiles affordability, whose divergent sophistication in design, colour, size and shape is believed preferred to terrazzo, carpet and floor flex tile. Accessible as glazed tile and production is, in recent times; its dearth of a holistic literature in Nigeria is obvious. In the light of the latter, this paper examine glazed tiles as floor finish in Nigeria, its advent, usage, production, challenge, benefit and prospect with the hope of opening further frontier in discipline specifics.

  12. WOODEN FLOORING – BETWEEN PRESENT AND FUTURE

    Directory of Open Access Journals (Sweden)

    Ivan CISMARU

    2015-06-01

    Full Text Available The paper aims at presenting a systematization of the wood floors, both in terms of the areas of application, and in terms of the fastening solutions and structures in constructions. In this respect, an extensive bibliographic research was achieved, on the researchers’ preoccupations. Starting from the current situation and forecasting the future, from the point of view of the chances held by wooden flooring, in competition with other types of materials, we dare say the wooden flooring or the wood in combination with other materials are not likely to be eliminated from the “civil-engineering market”. The wood floors are likely to develop as an application, especially in the area of the “special floors”, specific to the indoor sports or social halls; and even for some industrial sectors, with strict operating conditions (elasticity, thermal insulation, soundproofing that cannot be provided by other types of materials or structures. Starting from this last observation, the paper also aims at submitting current opinions with respect to this type of floors, both in the light of the current databases and in the light of the future researches, to this end

  13. Effects of Floor Covering Resistance of a Radiant Floor on System Energy and Exergy Performances

    DEFF Research Database (Denmark)

    Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

    2016-01-01

    Floor covering resistance (material and thickness) can be influenced by subjective choices (architectural design, interior design, texture, etc.) with significant effects on the performance of a radiant heating and cooling system. To study the effects of floor covering resistance on system...... performance, a water-based radiant floor heating and cooling system (dry, wooden construction) was considered to be coupled to an air-to-water heat pump, and the effects of varying floor covering resistances (0.05 m2K/W, 0.09 m2K/W and 0.15 m2K/W) on system performance were analyzed in terms of energy...... and exergy. In order to achieve the same heating and cooling outputs, higher average water temperatures are required in the heating mode (and lower temperatures in the cooling mode) with increasing floor covering resistance. These temperature requirements decrease the heat pump’s performance (lower...

  14. Punching Shear Behavior of Continuous Bubbled Reinforced Reactive Powder Concrete Slab

    Directory of Open Access Journals (Sweden)

    Mohammad Redha K. Mahmood

    2017-03-01

    Full Text Available This paper presents an experimental investigation on punching shear behavior of continuous bubbled reinforced Reactive Powder Concrete (RPC slabs. Bubbled slab is one of the various types of voided slabs. It consists of bubbles placed inside a concrete slab which will reduce the self-weight of the structure by about 35% (Tina Lai 2009. On the other hand, using RPC make it possible for structural member to have smaller dimensions due to the great strength of this type of concrete. In this study, these two method to increase the building spaces dimensions by reducing self-weigh of the structure by using bubbled slabs and to decrease the structural members' dimensions by using RPC have been investigated together. To study the punching shear behavior of continuous bubbled flat slabs such as the ultimate load carrying capacity, central deflection and slabs crack pattern at the ultimate load, nine different types of slabs were tested. The parameters of the study were type of concrete (RPC and Normal Concrete (NC, bubbles diameter to slab thickness ratio (D/t of (0.6 and 0.7, bubbles location (at all slab area, started from distance D and 1.5D from the center slab and solid slab. The test results show that the crack pattern and ultimate load capacity as well as maximum deflection depends on all of the mentioned parameters, were by increasing (D/t ratio the ultimate load capacity increases about (6.49 and 9.58% for slabs with bubbles started at distance 2D and 3D, respectively. But in the slabs with bubbles at all slab area the ultimate load and the maximum deflection decreases about (6.63 and 9.47% and (7.96 and 6.84% for RPC and NC slabs, respectively. Also, the solid slab increases the ultimate load about (5.28% compare to bubbled slab at all area. It was found that by removing bubbles from center of the slab at distance 2D and 3D the ultimate load will increase about (14.72 and 8.76%, respectively for slabs with (D/t = 0.6 compare to slabs with

  15. Imaging of the posterior pelvic floor

    Energy Technology Data Exchange (ETDEWEB)

    Stoker, Jaap [Department of Radiology, Academic Medical Center, University of Amsterdam (Netherlands); Bartram, Clive I.; Halligan, Steve [Intestinal Imaging Centre, St. Mark' s Hospital, London (United Kingdom)

    2002-04-01

    Disorders of the posterior pelvic floor are relatively common. The role of imaging in this field is increasing, especially in constipation, prolapse and anal incontinence, and currently imaging is an integral part of the investigation of these pelvic floor disorders. Evacuation proctography provides both structural and functional information for rectal voiding and prolapse. Dynamic MRI may be a valuable alternative as the pelvic floor muscles are visualised, and it is currently under evaluation. Endoluminal imaging is important in the management of anal incontinence. Both endosonography and endoanal MRI can be used for detection of anal sphincter defects. Endoanal MRI has the advantage of simultaneously evaluating external sphincter atrophy, which is an important predictive factor for the outcome of sphincter repair. Many aspects of constipation and prolapse remain incompletely understood and treatment is partly empirical; however, imaging has a central role in management to place patients into treatment-defined groups. (orig.)

  16. Synthetic biomaterials for pelvic floor reconstruction.

    Science.gov (United States)

    Karlovsky, Matthew E; Kushner, Leslie; Badlani, Gopal H

    2005-09-01

    Pelvic organ prolapse and stress urinary incontinence increase with age. The increasing proportion of the aging female population is likely to result in a demand for care of pelvic floor prolapse and incontinence. Experimental evidence of altered connective tissue metabolism may predispose to pelvic floor dysfunction, supporting the use of biomaterials, such as synthetic mesh, to correct pelvic fascial defects. Re-establishing pelvic support and continence calls for a biomaterial to be inert, flexible, and durable and to simultaneously minimize infection and erosion risk. Mesh as a biomaterial has evolved considerably throughout the past half century to the current line that combines ease of use, achieves good outcomes, and minimizes risk. This article explores the biochemical basis for pelvic floor attenuation and reviews various pelvic reconstructive mesh materials, their successes, failures, complications, and management.

  17. Resolution Ability and Surface Bright Spots of a Lossy Left-handed Material Slab

    Institute of Scientific and Technical Information of China (English)

    LI Chao; LI Fang

    2006-01-01

    @@ The imaging quality of a lossy left-handed material (LHM) slab is studied. The exact solution is obtained for the interaction of a monochromatic source with a lossy LHM slab by Fourier integrals in wave number domain.

  18. Importance of bulk states for the electronic structure of semiconductor surfaces: implications for finite slabs.

    Science.gov (United States)

    Sagisaka, Keisuke; Nara, Jun; Bowler, David

    2017-04-12

    We investigate the influence of slab thickness on the electronic structure of the Si(1 0 0)- p([Formula: see text]) surface in density functional theory (DFT) calculations, considering both density of states and band structure. Our calculations, with slab thicknesses of up to 78 atomic layers, reveal that the slab thickness profoundly affects the surface band structure, particularly the dangling bond states of the silicon dimers near the Fermi level. We find that, to precisely reproduce the surface bands, the slab thickness needs to be large enough to completely converge the bulk bands in the slab. In the case of the Si(1 0 0) surface, the dispersion features of the surface bands, such as the band shape and width, converge when the slab thickness is larger than 30 layers. Complete convergence of both the surface and bulk bands in the slab is only achieved when the slab thickness is greater than 60 layers.

  19. Anatomical aspects of sinus floor elevations.

    Science.gov (United States)

    van den Bergh, J P; ten Bruggenkate, C M; Disch, F J; Tuinzing, D B

    2000-06-01

    Inadequate bone height in the lateral part of the maxilla forms a contra-indication for implant surgery. This condition can be treated with an internal augmentation of the maxillary sinus floor. This sinus floor elevation, formerly called sinus lifting, consists of a surgical procedure in which a top hinge door in the lateral maxillary sinus wall is prepared and internally rotated to a horizontal position. The new elevated sinus floor, together with the inner maxillary mucosa, will create a space that can be filled with graft material. Sinus lift procedures depend greatly on fragile structures and anatomical variations. The variety of anatomical modalities in shape of the inner aspect of the maxillary sinus defines the surgical approach. Conditions such as sinus floor convolutions, sinus septum, transient mucosa swelling and narrow sinus may form a (usually relative) contra-indication for sinus floor elevation. Absolute contra-indications are maxillary sinus diseases (tumors) and destructive former sinus surgery (like the Caldwell-Luc operation). The lateral sinus wall is usually a thin bone plate, which is easily penetrated with rotating or sharp instruments. The fragile Schneiderian membrane plays an important role for the containment of the bonegraft. The surgical procedure of preparing the trap door and luxating it, together with the preparation of the sinus mucosa, may cause a mucosa tear. Usually, when these perforations are not too large, they will fold together when turning the trap door inward and upward, or they can be glued with a fibrin sealant, or they can be covered with a resorbable membrane. If the perforation is too large, a cortico-spongious block graft can be considered. However, in most cases the sinus floor elevation will be deleted. Perforations may also occur due to irregularities in the sinus floor or even due to immediate contact of sinus mucosa with oral mucosa. Obstruction of the antro-nasal foramen is, due to its high location, not a

  20. Shear and anchorage behaviour of fire exposed hollow core slabs

    NARCIS (Netherlands)

    Fellinger, J.

    2005-01-01

    The fire resistance of hollow core slabs is currently assessed considering flexural failure only. However, fire tests show that shear or anchorage failure can also govern the load bearing behaviour. This paper is based on the dissertation by the author1 and discusses existing and new fire tests. It

  1. Excitonic Doppler-Rabi Oscillations in a Moving Organic Slab

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    It is theoretically shown that excitonic Doppler-Rabi oscillations can occur in an organic slab moving along the axis of a high-Q cavity. Due to the √N enhancement of the vacuum Rabi frequency, this effect can be more easily observed than that in a moving two-level atom.

  2. CFRP strengthened openings in two-way concrete slabs

    DEFF Research Database (Denmark)

    Enochsson, O.; Lundqvist, J.; Täljsten, Björn

    2006-01-01

    Rehabilitation and strengthening of concrete structures with externally bonded fibre reinforced polymers (FRPs) has been a viable technique for at least a decade. An interesting and useful application is strengthening of slabs or walls where openings are introduced. In these situations, FRP sheet...

  3. Some consequences of the subduction of young slabs

    NARCIS (Netherlands)

    England, P.; Wortel, R.

    The negative buoyancy force exerted by a subducting oceanic slab depends on its descent velocity, and strongly on its age. For lithosphere close to thermal equilibrium, this force dominates by a large margin the resisting forces arising from friction on the plate boundary and compositional buoyancy.

  4. Electromagnetic fluctuation-induced interactions in randomly charged slabs

    Science.gov (United States)

    Rezvani, Vahid; Sarabadani, Jalal; Naji, Ali; Podgornik, Rudolf

    2012-09-01

    Randomly charged net-neutral dielectric slabs are shown to interact across a featureless dielectric continuum with long-range electrostatic forces that scale with the statistical variance of their quenched random charge distribution and inversely with the distance between their bounding surfaces. By accounting for the whole spectrum of electromagnetic field fluctuations, we show that this long-range disorder-generated interaction extends well into the retarded regime where higher order (non-zero) Matsubara frequencies contribute significantly. This occurs even for highly clean samples with only a trace amount of charge disorder and shows that disorder effects can be important down to the nanoscale. As a result, the previously predicted non-monotonic behavior for the total force between dissimilar slabs as a function of their separation distance is substantially modified by higher order contributions, and in almost all cases of interest, we find that the equilibrium inter-surface separation is shifted to substantially larger values compared to predictions based solely on the zero-frequency component. This suggests that the ensuing non-monotonic interaction is more easily amenable to experimental detection. The presence of charge disorder in the intervening dielectric medium between the two slabs is shown to lead to an additional force that can be repulsive or attractive depending on the system parameters and can, for instance, wash out the non-monotonic behavior of the total force when the intervening slab contains a sufficiently large amount of disorder charges.

  5. Eigenvalues of collective emission in multi-slice slab configurations

    Energy Technology Data Exchange (ETDEWEB)

    Friedberg, Richard [Department of Physics, Columbia University, New York, NY 10027 (United States); Manassah, Jamal T. [HMS Consultants, Inc., PO Box 592, New York, NY 10028 (United States)], E-mail: jmanassah@gmail.com

    2008-06-02

    We compute the eigenmodes of collective emission from multi-slice slab configurations, using the transfer matrix formalism. We elucidate within this formalism the phenomena of 'Invisible Gaps' in multiple-slice configuration and of 'Precocious Superradiance' in periodic structures previously observed in numerical solutions of Maxwell-Bloch equations.

  6. Topological optical Bloch oscillations in a deformed slab waveguide.

    Science.gov (United States)

    Longhi, Stefano

    2007-09-15

    Spatial Bloch oscillations of light waves of purely topological origin are theoretically shown to exist in weakly deformed slab waveguides. As the optical rays trapped in the deformed waveguide can roll freely, wave diffraction is strongly affected by the topology of the deformed surface, which can be tailored to simulate the effect of a tilted periodic refractive index.

  7. Fire-exposed continuous span composite steel-concrete slabs

    NARCIS (Netherlands)

    Both, C.

    1996-01-01

    From experimental evidence, it was concluded that existing rules for the calculation of the behaviour of fire-exposed composite beams and slabs often lead to conservative solutions. Furthermore, the range of common applications had grown beyond the limits of existing calculation mies. It was feit

  8. Fire-exposed continuous span composite steel-concrete slabs

    NARCIS (Netherlands)

    Both, K.

    1996-01-01

    From experimental evidence, it was concluded that existing rules for the calculation of the behaviour of fire-exposed composite beams and slabs often lead to conservative solutions. Furthermore, the range of common applications had grown beyond the limits of existing calculation rules. It was felt

  9. Fire-exposed continuous span composite steel-concrete slabs

    NARCIS (Netherlands)

    Both, K.

    1996-01-01

    From experimental evidence, it was concluded that existing rules for the calculation of the behaviour of fire-exposed composite beams and slabs often lead to conservative solutions. Furthermore, the range of common applications had grown beyond the limits of existing calculation rules. It was felt t

  10. Study of global stability of tall buildings with prestressed slabs

    Directory of Open Access Journals (Sweden)

    L. A. Feitosa

    Full Text Available The use of prestressed concrete flat slabs in buildings has been increasing in recent years in the Brazilian market. Since the implementation of tall and slender buildings a trend in civil engineering and architecture fields, arises from the use of prestressed slabs a difficulty in ensuring the overall stability of a building without beams. In order to evaluate the efficiency of the main bracing systems used in this type of building, namely pillars in formed "U" in elevator shafts and stairs, and pillars in which the lengths are significantly larger than their widths, was elaborated a computational models of fictional buildings, which were processed and analyzed using the software CAD/TQS. From the variation of parameters such as: geometry of the pillars, thick slabs, characteristic strength of the concrete, reduceofthe coefficient of inertia for consideration of non-linearities of the physical elements, stiffness of the connections between slabs and pillars, among others, to analyze the influence of these variables on the overall stability of the building from the facing of instability parameter Gama Z, under Brazilian standard NBR 6118, in addition to performing the processing of building using the P-Delta iterative calculation method for the same purpose.

  11. Designing Meta Material Slabs Exhibiting Negative Refraction Using Topology Optimization

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Sigmund, O.

    2016-01-01

    This paper proposes a topology optimization based approach for designing meta materials exhibiting a desired negative refraction with high transmission at a given angle of incidence and frequency. The approach considers a finite slab of meta material consisting of axis-symmetric designable unit...

  12. Lower Bound Limit Analysis Of Slabs With Nonlinear Yield Criteria

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Damkilde, Lars

    2002-01-01

    A finite element formulation of the limit analysis of perfectly plastic slabs is given. An element with linear moment fields for which equilibrium is satisfied exactly is used in connection with an optimization algorithm taking into account the full nonlinearity of the yield criteria. Both load...

  13. Electromagnetic fluctuation-induced interactions in randomly charged slabs.

    Science.gov (United States)

    Rezvani, Vahid; Sarabadani, Jalal; Naji, Ali; Podgornik, Rudolf

    2012-09-21

    Randomly charged net-neutral dielectric slabs are shown to interact across a featureless dielectric continuum with long-range electrostatic forces that scale with the statistical variance of their quenched random charge distribution and inversely with the distance between their bounding surfaces. By accounting for the whole spectrum of electromagnetic field fluctuations, we show that this long-range disorder-generated interaction extends well into the retarded regime where higher order (non-zero) Matsubara frequencies contribute significantly. This occurs even for highly clean samples with only a trace amount of charge disorder and shows that disorder effects can be important down to the nanoscale. As a result, the previously predicted non-monotonic behavior for the total force between dissimilar slabs as a function of their separation distance is substantially modified by higher order contributions, and in almost all cases of interest, we find that the equilibrium inter-surface separation is shifted to substantially larger values compared to predictions based solely on the zero-frequency component. This suggests that the ensuing non-monotonic interaction is more easily amenable to experimental detection. The presence of charge disorder in the intervening dielectric medium between the two slabs is shown to lead to an additional force that can be repulsive or attractive depending on the system parameters and can, for instance, wash out the non-monotonic behavior of the total force when the intervening slab contains a sufficiently large amount of disorder charges.

  14. Thermal Performance Analysis of Reinforced Concrete Floor Structure with Radiant Floor Heating System in Apartment Housing

    Directory of Open Access Journals (Sweden)

    Young-Sun Jeong

    2015-01-01

    Full Text Available The use of the resilient materials in the radiant floor heating systems of reinforced concrete floor in apartment housing is closely related to the reduction of the floor impact sound and the heating energy loss. This study examined the thermal conductivity of expanded polystyrene (EPS foam used for the resilient material in South Korea and analysed the thermal transfer of reinforced concrete floor structure according to the thermal conductivity of the resilient materials. 82 EPS specimens were used to measure the thermal conductivity. The measured apparent density of EPS resilient materials ranged between 9.5 and 63.0 kg/m3, and the thermal conductivity ranged between 0.030 and 0.046 W/(m·K. As the density of resilient materials made of expanded polystyrene foam increases, the thermal conductivity tends to proportionately decrease. To set up reasonable thermal insulation requirements for radiant heating floor systems, the thermal properties of floor structure according to thermal insulation materials must be determined. Heat transfer simulations were performed to analyze the surface temperature, heat loss, and heat flow of floor structure with radiant heating system. As the thermal conductivity of EPS resilient material increased 1.6 times, the heat loss was of 3.4% increase.

  15. Slab melting and magma formation beneath the southern Cascade arc

    Science.gov (United States)

    Walowski, K. J.; Wallace, P. J.; Clynne, M. A.; Rasmussen, D. J.; Weis, D.

    2016-07-01

    The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Lassen segment of the Cascade arc, where previous work has demonstrated across-arc geochemical variations related to subduction enrichment, and H-isotope data suggest that H2O in basaltic magmas is derived from the final breakdown of chlorite in the mantle portion of the slab. We use naturally glassy, olivine-hosted melt inclusions (MI) from the tephra deposits of eight primitive (MgO > 7 wt%) basaltic cinder cones to quantify the pre-eruptive volatile contents of mantle-derived melts in this region. The melt inclusions have B concentrations and isotope ratios that are similar to mid-ocean ridge basalt (MORB), suggesting extensive dehydration of the downgoing plate prior to reaching sub-arc depths and little input of slab-derived B into the mantle wedge. However, correlations of volatile and trace element ratios (H2O/Ce, Cl/Nb, Sr/Nd) in the melt inclusions demonstrate that geochemical variability is the result of variable addition of a hydrous subduction component to the mantle wedge. Furthermore, correlations between subduction component tracers and radiogenic isotope ratios show that the subduction component has less radiogenic Sr and Pb than the Lassen sub-arc mantle, which can be explained by melting of subducted Gorda MORB beneath the arc. Agreement between pMELTS melting models and melt inclusion volatile, major, and trace element data suggests that hydrous slab melt addition to the mantle wedge can produce the range in primitive compositions erupted in the Lassen region. Our results provide further evidence that chlorite-derived fluids from the mantle portion of the

  16. High-power diode-pumped Tm:YLF slab laser

    CSIR Research Space (South Africa)

    Schellhorn, M

    2009-06-01

    Full Text Available The aim is to develop a high-power Tm:YLF slab laser which can be utilized to pump a Ho slab laser. A 68 W Tm:YLF slab laser was recently presented in [1] pumped from one end by a single 6-bar stack delivering ~300 W of pump power. In this work, we...

  17. Slab melting and magma generation beneath the southern Cascade Arc

    Science.gov (United States)

    Walowski, K. J.; Wallace, P. J.; Clynne, M. A.

    2014-12-01

    Magma formation in subduction zones is interpreted to be caused by flux melting of the mantle wedge by fluids derived from dehydration of the downgoing oceanic lithosphere. In the Cascade Arc and other hot-slab subduction zones, however, most dehydration reactions occur beneath the forearc, necessitating a closer investigation of magma generation processes in this setting. Recent work combining 2-D steady state thermal models and the hydrogen isotope composition of olivine-hosted melt inclusions from the Lassen segment of the Cascades (Walowski et al., 2014; in review) has shown that partial melting of the subducted basaltic crust may be a key part of the subduction component in hot arcs. In this model, fluids from the slab interior (hydrated upper mantle) rise through the slab and cause flux-melting of the already dehydrated MORB volcanics in the upper oceanic crust. In the Shasta and Lassen segments of the southern Cascades, support for this interpretation comes from primitive magmas that have MORB-like Sr isotope compositions that correlate with subduction component tracers (H2O/Ce, Sr/P) (Grove et al. 2002, Borg et al. 2002). In addition, mass balance calculations of the composition of subduction components show ratios of trace elements to H2O that are at the high end of the global arc array (Ruscitto et al. 2012), consistent with the role of a slab-derived melt. Melting of the subducted basaltic crust should contribute a hydrous dacitic or rhyolitic melt (e.g. Jego and Dasgupta, 2013) to the mantle wedge rather than an H2O-rich aqueous fluid. We are using pHMELTS and pMELTS to model the reaction of hydrous slab melts with mantle peridotite as the melts rise through the inverted thermal gradient in the mantle wedge. The results of the modeling will be useful for understanding magma generation processes in arcs that are associated with subduction of relatively young oceanic lithosphere.

  18. Modal analysis for floors in lightweight buildings

    DEFF Research Database (Denmark)

    Sjökvist, Lars-Göran; Brunskog, Jonas

    2007-01-01

    constructions usually consist of plates that are stiffened by beams and by the dividing walls. In this study the wave equation for a plate is expanded by Fourier series and an analytical solution in terms of the eigenmodes of the entire system is presented. The studied system consists of one lightweigt floor...

  19. Timber-concrete composite floor systems

    NARCIS (Netherlands)

    Linden, M.L.R. van der; Blass, H.J.

    1996-01-01

    Timber-concrete composite (tcc) beams may be used for the renovation of old timber floors. Although these systems are a simple and practical solution, they are not widely adopted. One of the reasons for this is the lack of uniform design mies. In this research programme shear tests on four different

  20. Modal analysis for floors in lightweight buildings

    DEFF Research Database (Denmark)

    Sjökvist, Lars-Göran; Brunskog, Jonas

    2007-01-01

    constructions usually consist of plates that are stiffened by beams and by the dividing walls. In this study the wave equation for a plate is expanded by Fourier series and an analytical solution in terms of the eigenmodes of the entire system is presented. The studied system consists of one lightweigt floor...

  1. Timber-concrete composite floor systems

    NARCIS (Netherlands)

    Linden, M.L.R. van der; Blass, H.J.

    1996-01-01

    Timber-concrete composite (tcc) beams may be used for the renovation of old timber floors. Although these systems are a simple and practical solution, they are not widely adopted. One of the reasons for this is the lack of uniform design mies. In this research programme shear tests on four different

  2. Engagement and Floor Control in Hybrid Meetings

    NARCIS (Netherlands)

    op den Akker, Hendrikus J.A.; Devanthéry, V.; Zwiers, Jakob; Hondorp, G.H.W.; van Dijk, Elisabeth M.A.G.; Kulyk, Olga Anatoliyivna; Hofs, D.H.W.; Nijholt, Antinus; Reidsma, Dennis

    2010-01-01

    The Human Media Interaction group of the University of Twente has developed a User Engagment and Floor Control Demonstrator, a system that uses modules for online speech recognition, real-time visual focus of attention as well as a module that signals who is being addressed by the speaker. A

  3. Load Absorption Characteristics of Tyre Production Waste Rubber for Playground Floor Systems

    Directory of Open Access Journals (Sweden)

    Abdul Ghani A.N.

    2014-01-01

    Full Text Available The floor surfaces where slides and swings are placed in parks and playrooms should be soft and thick to ensure that whenever a child falls, the surface can withstand the impact and minimize injuries to the child. Shredded tyres from waste tyres or waste rubber from tyre manufacturing could become beneficial as shock absorber material which can be used as a playground floor. In this study, rubber cubes and rubber pads with 5%, 8% and 10% SBR mixes were prepared for mechanical testing. Two types of floor design surfaces with and without plywood on the surface were assembled for the shock test. Gmax and HIC of this waste rubber flooring system were investigated using the compression test for the rubber cube and the drop test for the rubber pad. The criteria of general protection standards are 200g for optimum acceleration and 1000 for HIC. The Gmax and HIC results indicated that the material and system could ensure a safe fall from up to 1.0m height.

  4. Functional imaging of the pelvic floor

    Energy Technology Data Exchange (ETDEWEB)

    Lienemann, Andreas E-mail: andreaslienemann@web.de; Fischer, Tanja

    2003-08-01

    Introduction/Objective: Pelvic floor dysfunction and associated pelvic organ prolapse represent a major problem in our present-day society, mostly afflicting parous women. Magnetic resonance imaging (MRI) is assuming an increasingly important role in the more accurate delineation of the extent of the problem. This article briefly reviews one of the main radiological methods for the dynamic evaluation of the pelvic floor: functional cine MRI. Methods and Material: Out of the literature the smallest common denominator for functional cine MRI can be defined as follows: high field system; patient either in supine or sitting position; fast gradient echo sequence; midsagittal slice orientation; either a stack of slices or repeated measurements at the same slice position with the patient at rest or straining; image analysis using the pubococcygeal reference line. Results: All except two publications stress the usefulness of functional cine MRI in the evaluation of patients with organ descent and prolapse. This well accepted method allows for the visualization of all relevant structures in the anterior, middle and posterior compartment. It is especially useful in the detection of enteroceles, and provides a reliable postoperative follow-up tool. Isolated urinary or stool incontinence are not an indication for functional cine MRI, as is the case in patients with equivocal clinical findings. To date it does not allow for real 3D imaging of the pelvic floor or sufficient determination of fascial defects. Discussion: Functional cine MRI of the pelvic floor is a promising new imaging method for the detection of organ descent and prolapse in patients with equivocal clinical findings. The combination of function and morphology allows for an innovative view of the pelvic floor, and thus adds to our understanding of the various interactions of the structures.

  5. Light-assisted, templated self-assembly of gold nanoparticle chains.

    Science.gov (United States)

    Jaquay, Eric; Martínez, Luis Javier; Huang, Ningfeng; Mejia, Camilo A; Sarkar, Debarghya; Povinelli, Michelle L

    2014-09-10

    We experimentally demonstrate the technique of light-assisted, templated self-assembly (LATS) to trap and assemble 200 nm diameter gold nanoparticles. We excite a guided-resonance mode of a photonic-crystal slab with 1.55 μm laser light to create an array of optical traps. Unlike our previous demonstration of LATS with polystyrene particles, we find that the interparticle interactions play a significant role in the resulting particle patterns. Despite a two-dimensionally periodic intensity profile in the slab, the particles form one-dimensional chains whose orientations can be controlled by the incident polarization of the light. The formation of chains can be understood in terms of a competition between the gradient force due to the excitation of the mode in the slab and optical binding between particles.

  6. TESTS ON STRUCTURALLY DEFICIENT RC SLABS STRENGTHENED WITH FIBRE REINFORCED POLYMER (FRP) COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    S.T. Smith; S.J. Kim

    2004-01-01

    This paper reports the results of a series of tests on fibre reinforced polymer (FRP) strengthened reinforced concrete (RC) slabs, which were recently undertaken at the University of Technology,Sydney. The slabs were reinforced with high-strength low-ductile steel reinforcement and strengthened with either carbon FRP (CFRP) or glass FRP (GFRP) composites. The unstrengthened control slabs failed by fracture of the steel tension reinforcement while the FRP strengthened slabs failed by debonding of the FRP followed by rupture of the tension steel. The FRP-strengthened slabs were stronger than their unstrengthened counterparts and displayed considerable ductility.

  7. An investigation on the behaviour and stiffness of reinforced concrete slabs subjected to torsion

    Science.gov (United States)

    Nguyen, M. C. T.; Pham, P. T.

    2017-01-01

    This paper presents an investigation on RC slab under torsion, by both experiment and finite element analysis. The torsion tests were done on three similar square RC slabs with dimensions of 1900×1900×150 mm. The behaviour of slabs at pre-cracking and post-cracking of concrete phases were investigated, via Load-displacement, twisting moment-curvature relationships, and torsional stiffness of slabs. The experimental results are compared with the FEA and the results in literatures. The torsional stiffness of slab at the phase of concrete cracked and steel yield is about 1/25 of the stiffness at the pre-cracking phase.

  8. Enhanced bandgap in annular photonic-crystal silicon-on-insulator asymmetric slabs.

    Science.gov (United States)

    Hou, Jin; Citrin, D S; Wu, Huaming; Gao, Dingshan; Zhou, Zhiping

    2011-06-15

    Photonic band structures of annular photonic-crystal (APC) silicon-on-insulator (SOI) asymmetric slabs with finite thickness were investigated by the three-dimensional plane-wave expansion method. The results show that for a broad range of air-volume filling factors, APC slabs can exhibit a significantly larger bandgap than conventional circular-hole photonic-crystal (PC) slabs. Bandgap enhancements over conventional air hole PC SOI slabs as large as twofold are predicted for low air-volume filling factors below 15%. This desirable behavior suggests a potential for APC SOI slabs to serve as the basis of various optical cavities, waveguides, and mirrors.

  9. Assessment of pelvic floor dysfunctions using dynamic magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Hoda Salah Darwish

    2014-03-01

    Conclusion: Dynamic MRI is an ideal, non invasive technique which does not require patient preparation for evaluation of pelvic floor. It acts as one stop shop for diagnosing single or multiple pelvic compartment involvement in patients with pelvic floor dysfunction.

  10. Testing of the Anorectal and Pelvic Floor Area

    Science.gov (United States)

    ... Disorders of the Large Intestine Disorders of the Pelvic Floor Motility Testing Personal Stories Contact About GI Motility ... Disorders of the Large Intestine Disorders of the Pelvic Floor Motility Testing Personal Stories Contact Anorectal and Pelvic ...

  11. Floor Vibrations - as Induced and Reduced by Humans

    DEFF Research Database (Denmark)

    Pedersen, Lars

    . The appropriateness and accuracy of this modelling approach is evaluated. Implications of human-floor interaction are studied with focus on the impact of the interaction on the size of vibration levels of human-occupied floors and on the impact on floor dynamic characteristics. The influence of the interaction......The work is a contribution to the problem of modelling human-induced dynamic loads on floors and to the problem of modelling the interaction between stationary crowds of people and a vibrating floor. Experimental investigations are made to examine, update and refine currently available models....... As for dynamic loads focus is placed on heel impact excitation and actions of jumping people causing floor vibrations. As for interaction between stationary humans and the vibrating floor focus is on modelling humans as oscillating spring-mass-damper systems attached to the floor rather than as simple added mass...

  12. A novel & affordable interactive floor for educational applications

    DEFF Research Database (Denmark)

    Boisen, Ulrik; Hansen, Anders Juul; Knudsen, Lars

    2011-01-01

    This article examines two research areas: How interactive floors can be used beneficially in an educational context, and how an interactive floor can be created which is mobile and relatively inexpensive....

  13. Severe bleeding after sinus floor elevation using the transcrestal technique

    DEFF Research Database (Denmark)

    Jensen, Simon Storgard; Eriksen, Jacob; Schiodt, Morten

    2012-01-01

    To present a rare but clinically significant complication to sinus floor elevation (SFE) using the transcrestal technique.......To present a rare but clinically significant complication to sinus floor elevation (SFE) using the transcrestal technique....

  14. Formaldehyde and TVOC emission behavior of laminate flooring by structure of laminate flooring and heating condition.

    Science.gov (United States)

    An, Jae-Yoon; Kim, Sumin; Kim, Hyun-Joong

    2011-03-15

    Formaldehyde was measured with a desiccator, a 20 L chamber and the FLEC method. The formaldehyde emission rate from laminate was the highest at 32 °C using the desiccator, which then decreased with time. The formaldehyde emission using the 20 L small chamber and FLEC showed a similar tendency. There was a strong correlation between the formaldehyde and total volatile organic compounds (TVOCs) with both types of floorings using the two different methods. The formaldehyde emission rate and TVOC results were higher when tested using the FLEC method than with the 20 L small chamber method. The emission rate was affected by the joint edge length in laminate flooring. Toluene, ethylbenzene and xylene were the main VOCs emitted from laminate flooring, and there were more unidentified VOCs emitted than identified VOCs. The samples heated with a floor heating system emitted more formaldehyde than those heated using an air circulation system due to the temperature difference between the bottom panel and flooring. The TVOC emission level of the samples was higher when an air circulation system was used than when a floor heating system was used due to the high ventilation rate.

  15. Sabot assembly

    Energy Technology Data Exchange (ETDEWEB)

    Bzorgi, Fariborz

    2016-11-08

    A sabot assembly includes a projectile and a housing dimensioned and configured for receiving the projectile. An air pressure cavity having a cavity diameter is disposed between a front end and a rear end of the housing. Air intake nozzles are in fluid communication with the air pressure cavity and each has a nozzle diameter less than the cavity diameter. In operation, air flows through the plurality of air intake nozzles and into the air pressure cavity upon firing of the projectile from a gun barrel to pressurize the air pressure cavity for assisting in separation of the housing from the projectile upon the sabot assembly exiting the gun barrel.

  16. Deflection of Resilient Materials for Reduction of Floor Impact Sound

    OpenAIRE

    Jung-Yoon Lee; Jong-Mun Kim

    2014-01-01

    Recently, many residents living in apartment buildings in Korea have been bothered by noise coming from the houses above. In order to reduce noise pollution, communities are increasingly imposing bylaws, including the limitation of floor impact sound, minimum thickness of floors, and floor soundproofing solutions. This research effort focused specifically on the deflection of resilient materials in the floor sound insulation systems of apartment houses. The experimental program involved condu...

  17. Knowledge of the pelvic floor in nulliparous women

    OpenAIRE

    Neels, Hedwig; Wyndaele, Jean-Jacques; Tjalma, Wiebren A. A.; De Wachter, Stefan; Wyndaele, Michel; Vermandel, Alexandra

    2016-01-01

    [Purpose] Proper pelvic floor function is important to avoid serious dysfunctions including incontinence, prolapse, and sexual problems. The current study evaluated the knowledge of young nulliparous women about their pelvic floor and identified what additional information they wanted. [Subjects and Methods] In this cross-sectional survey, a validated, 36 item questionnaire was distributed to 212 nulliparous women. The questionnaire addressed demography, pelvic floor muscles, pelvic floor dys...

  18. Recognition and Management of Nonrelaxing Pelvic Floor Dysfunction

    OpenAIRE

    Faubion, Stephanie S.; Shuster, Lynne T.; Bharucha, Adil E.

    2012-01-01

    Nonrelaxing pelvic floor dysfunction is not widely recognized. Unlike in pelvic floor disorders caused by relaxed muscles (eg, pelvic organ prolapse or urinary incontinence, both of which often are identified readily), women affected by nonrelaxing pelvic floor dysfunction may present with a broad range of nonspecific symptoms. These may include pain and problems with defecation, urination, and sexual function, which require relaxation and coordination of pelvic floor muscles and urinary and ...

  19. Complete Pelvic Floor Repair in Treating Fecal Incontinence

    OpenAIRE

    Lee, Patrick Y. H.; Steele, Scott R

    2005-01-01

    Fecal incontinence is associated with 20 to 40% of the patients with pelvic floor prolapse. Successful management of fecal incontinence requires not only an understanding of anorectal function but also a thorough understanding of pelvic floor anatomy and how pelvic floor prolapse affects fecal continence. Imaging techniques have been instrumental in visualizing pelvic floor prolapse and have helped correlate surgical findings. Stabilization of the perineal body appears to be a key component t...

  20. Analysis of the Behaviour of Composite Steel and Steel Fiber Reinforced Concrete Slabs

    Directory of Open Access Journals (Sweden)

    Mindaugas Petkevičius

    2011-04-01

    Full Text Available There was a pending influence of steel fiber on the strength and stiffness of composite steel–concrete slabs under statical short–time load. Steel profiled sheeting and steel fiber reinforced concrete were used for specimens. Four composite slabs were made. Experimental investigations into the behaviour and influence of steel fiber reinforced concrete in composite slabs were conducted. Transverse, longitudinal, shear deformation and deflection of the slab were measured. The results indicated that the use of steel fiber in composite slabs was effective: strength was 20–24 % higher and the meanings of deflections under the action of the bending moment were 0,6MR (where MR is the bending moment at failure of the slabs and were 16–18 % lower for slabs with usual concrete. Article in Lithuanian

  1. Investigation of Effect of Slab Opening Location to the Shear Stress

    Directory of Open Access Journals (Sweden)

    Burak Yön

    2010-01-01

    Full Text Available In this study, it is investigated the effect of slab opening location in reinforced concrete building to the structural behavior. For investigation of slab irregularity, three multi storey irregular structures that have different slab opening locations in structure plans and one regular structure are designed. Linear dynamic analyses are performed for the structure models using Time History Analysis method. 13 March 1992 Erzincan Earthquake acceleration records are used for these analyses. It is assumed that slabs of selected structures are modeled as elastic diaphragm. SAP2000 Structural Analysis Program is used in the analyses. Values of slab that near space shear stress obtained from dynamic analyses of selected structures are comparatively evaluated. According to analyses results, it is determined that location of slab opening of structures reasonably both affects the behavior of structures and occurs great slab shear stress.

  2. What Do You Really Know About Floor Finishes & Strippers?

    Science.gov (United States)

    Wirth, T. J.

    1972-01-01

    An independent testing laboratory reveals the results of comparative studies done on vinyl flooring and the question of to wax or not to wax'' and which waxes work best with what flooring; and provides six evaluation tips on floor strippers. (EA)

  3. Pelvic floor function during and after first pregnancy

    NARCIS (Netherlands)

    Brummen, H.J. van

    2006-01-01

    This study evaluated the effects the first pregnancy and childbirth on the pelvic floor. Pregnancy and vaginal delivery can negatively affect pelvic floor function. Micturition symptoms, defecation symptoms and sexual dysfunction are all signs of an impaired pelvic floor function. These symptoms are

  4. Factors affecting the use of hardwood flooring in urban rehabilitation

    Science.gov (United States)

    Robert L. Jr. Nevel; Robert L. Jr. Nevel

    1973-01-01

    The continued use of hardwood flooring in urban rehabilitation is being threatened. A study of the influences that determine the choice of flooring indicates that economic, physical, or technological factors dominate. Most factors affecting the use of hardwood flooring are related to cost, availability, and compatibility. Of these factors, time and cost of installation...

  5. Flexural Behavior of Continuous Bubbled Reinforced Reactive Powder Concrete Flat Slab

    Directory of Open Access Journals (Sweden)

    Mohammad Redha K. Mahmood

    2017-05-01

    Full Text Available This paper presents an experimental investigation on flexural behavior of continuous bubbled reinforced Reactive Powder Concrete (RPC flat slabs. Bubbled slab is one of the various types of voided slabs. It consist of bubbles placed inside a concrete slab which will reduce the self-weight of the structure by about 35% (Tina Lai 2009. On the other hand, using RPC make it possible for structural member to have smaller dimensions due to the great strength of this type of concrete. In this study these two method are used to increase the building spaces dimensions by reducing self-weigh of the structure by using bubbled slabs and to decrease the structural members' dimensions by using RPC have been investigated together. To study the flexural behavior of continuous bubbled flat slabs such as the ultimate load carrying capacity, central deflection and slabs crack pattern at the ultimate load, seven types of slabs were tested. The parameters of the study were type of concrete (RPC and Normal Concrete (NC, bubbles diameter to slab thickness ratio (D/t of (0.6 and 0.7, type of loading (distributed and line load and solid slab. The test results show that the crack pattern and ultimate load capacity as well as maximum deflection depends on all of the mentioned parameters, were by increasing (D/t ratio the ultimate load capacity increases about (7.36%, 5.46% and 16.52% for RPC slabs under distributed load, line load and NC slabs, respectively. The solid slab increases the ultimate load about (4.05% compare to bubbled slab. Also, the line load decreases the ultimate load compare to distributed load by (3.45-5.16% for different (D/t ratio, and using the NC also decreases the ultimate load compare to RPC by (48-52.13% for different (D/t ratio

  6. Slab2 - Providing updated subduction zone geometries and modeling tools to the community

    Science.gov (United States)

    Hayes, G. P.; Hearne, M. G.; Portner, D. E.; Borjas, C.; Moore, G.; Flamme, H.

    2015-12-01

    The U.S. Geological Survey database of global subduction zone geometries (Slab1.0) combines a variety of geophysical data sets (earthquake hypocenters, moment tensors, active source seismic survey images of the shallow subduction zone, bathymetry, trench locations, and sediment thickness information) to image the shape of subducting slabs in three dimensions, at approximately 85% of the world's convergent margins. The database is used extensively for a variety of purposes, from earthquake source imaging, to magnetotelluric modeling. Gaps in Slab1.0 exist where input data are sparse and/or where slabs are geometrically complex (and difficult to image with an automated approach). Slab1.0 also does not include information on the uncertainty in the modeled geometrical parameters, or the input data used to image them, and provides no means to reproduce the models it described. Currently underway, Slab2 will update and replace Slab1.0 by: (1) extending modeled slab geometries to all global subduction zones; (2) incorporating regional data sets that may describe slab geometry in finer detail than do previously used teleseismic data; (3) providing information on the uncertainties in each modeled slab surface; (4) modifying our modeling approach to a fully-three dimensional data interpolation, rather than following the 2-D to 3-D steps of Slab1.0; (5) migrating the slab modeling code base to a more universally distributable language, Python; and (6) providing the code base and input data we use to create our models, such that the community can both reproduce the slab geometries, and add their own data sets to ours to further improve upon those models in the future. In this presentation we describe our vision for Slab2, and the first results of this modeling process.

  7. Dynamics of Mantle Circulation Associated with Slab Window Formation: Insights from 3D Laboratory Models

    Science.gov (United States)

    Guillaume, B.; Funiciello, F.; Moroni, M.; Faccenna, C.; Martinod, J.

    2009-12-01

    Slab window can form either by the intersection of a spreading ridge with a subduction zone or because of internal deformation of the slab that leads to its disruption. The main consequences of this phenomenon are the modifications of the physical, chemical and thermal conditions in the backarc mantle that in turn affect the tectonic and magmatic evolution of the overriding plate. We performed laboratory models of a two-layer linear viscous slab (silicone putty)-upper mantle (glucose syrup) system to quantitatively investigate the pattern of mantle circulation within the slab window (using Feature Tracking image analysis technique) and its influence on the kinematics of the system. Two different geometries have been tested considering a window located (a) at slab edges or (b) within the slab. Kinematic consequences of slab window have been explored to understand the dynamics of the mantle-slab interaction. Configuration (a) implies a reduction of the slab width (W) during subduction and is characterized by toroidal fluxes around the slab edges. The abrupt opening of lateral slab windows produces an acceleration of the trench retreat and subduction velocity, such as 40% for a three-fold width reduction. We interpret this behavior as mostly due to the decrease in the toroidal flow inside subduction windows, scaling with W2. Configuration (b) has been designed to explore the pattern of mantle flow within the window in the case of a laterally constrained subduction system. Slab window, which had a width (Ww) fixed to 15 % of the slab width, opened in the trench-perpendicular direction. It produced the formation of two toroidal mantle cells, centered on the slab midpoint and laterally growing as the slab window enlarged. Particles extruded through the slab window did not mix with particles located in the mantle wedge, the boundary between both reaching distances from the trench up to 3×Ww in the trench-perpendicular direction, and up to 1.5×Ww from the window edge in

  8. Optimal Material Layout - Applied on Reinforced Concrete Slabs

    DEFF Research Database (Denmark)

    Dollerup, Niels; Jepsen, Michael S.; Damkilde, Lars

    2015-01-01

    to determine the optimal material layout of a slab in the ultimate load state, based on simple inputs such as outer geometry, boundary conditions, multiple load cases and design domains. The material layout of the optimal design can either be fully orthotropic or isotropic, or a combination with a predefined......This paper introduces a general, finite-element-based optimisation tool for improving the material layout of concrete structures. The application presented is general and exemplified by material optimisation of reinforced concrete slabs. By utilising the optimisation tool, it is possible...... coupling between design domains and reinforcement directions. The implementation is a lower bound formulation, resulting in a convex optimisation problem that consists of a number of linear constraints from the equilibrium equations and a number of convex non-linear constraints from the yield criteria...

  9. Designing Meta Material Slabs Exhibiting Negative Refraction Using Topology Optimization

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Sigmund, O.

    2016-01-01

    This paper proposes a topology optimization based approach for designing meta materials exhibiting a desired negative refraction with high transmission at a given angle of incidence and frequency. The approach considers a finite slab of meta material consisting of axis-symmetric designable unit...... cells subjected to an exterior field. The unit cell is designed to achieve the desired properties based on tailoring the response of the meta material slab underthe exterior field. The approach is directly applicable to physical problems modeled by the Helmholtz equation, such as acoustic, elastic...... and electromagnetic wave problems. Acoustic meta materials with unit cell size on the order of half the wave length are considered as examples. Optimized designs are presented and their performance under varying frequency and angle of incidence is investigated....

  10. Characteristics of shell thickness in a slab continuous casting mold

    Institute of Scientific and Technical Information of China (English)

    Di-feng Wu; Shu-sen Cheng; Zi-jian Cheng

    2009-01-01

    The key to reduce shell breakout in the continuous casting process is to control shell thickness in the mold.A numerical simulation on the turbulent flow and heat transfer coupled with solidification in the slab mold using the volume of fluid (VOF) model and the enthalpy-porosity scheme was conducted and the emphasis was put upon the flow effect on the shell thickness profiles in longitudinal and transverse directions.The results show that the jet acts a stronger impingement on the shell of narrow face,which causes a zero-increase of shell thickness in a certain range near the impingement point.The thinnest shell on the slab cross-section locates primarily in the center of the narrow face,and secondly near the comer of the wide face.Nozzle optimization can obviously increase the shell thickness and make it more uniform.

  11. Oscillating Casimir force between two slabs in a Fermi sea

    DEFF Research Database (Denmark)

    Li-Wei, Chen; Guo-Zhen, Su; Jin-Can, Chen

    2012-01-01

    The Casimir effect for two parallel slabs immersed in an ideal Fermi sea is investigated at both zero and nonzero temperatures. It is found that the Casimir effect in a Fermi gas is distinctly different from that in an electromagnetic field or a massive Bose gas. In contrast to the familiar result...... that the Casimir force decreases monotonically with the increase of the separation L between two slabs in an electromagnetic field and a massive Bose gas, the Casimir force in a Fermi gas oscillates as a function of L. The Casimir force can be either attractive or repulsive, depending sensitively on the magnitude...... of L. In addition, it is found that the amplitude of the Casimir force in a Fermi gas decreases with the increase of the temperature, which also is contrary to the case in a Bose gas, since the bosonic Casimir force increases linearly with the increase of the temperature in the region T

  12. Non-Fourier heat conduction in an exponentially graded slab

    Science.gov (United States)

    Raveshi, M. R.

    2016-03-01

    The present article investigates one-dimensional non-Fourier heat conduction in a functionally graded material by using the differential transformation method. The studied geometry is a finite functionally graded slab, which is initially at a uniform temperature and suddenly experiences a temperature rise at one side, while the other side is kept insulated. A general non-Fourier heat transfer equation related to the functionally graded slab is derived. The problem is solved in the Laplace domain analytically, and the final results in the time domain are obtained by using numerical inversion of the Laplace transform. The obtained results are compared with the exact solution to verify the accuracy of the proposed method, which shows excellent agreement.

  13. Bolometric detection of ferromagnetic resonance in YIG slab

    Science.gov (United States)

    Tu, Sa; Białek, Marcin; Zhang, Youguang; Zhao, Weisheng; Yu, Haiming; Ansermet, Jean-Philippe

    2017-10-01

    The resistance of the Pt bar deposited on the YIG slab was monitored while the magnetic field was ramped through the ferromagnetic resonance with the YIG slab facing a coplanar waveguide resonator excited at 4.3 GHz excitation. The resistance change provides detection of the ferromagnetic resonance with a high signal-to-noise ratio. It is ascribed to a change in the temperature of the Pt bars. The thermal origin of the signal is confirmed by the observation that the signal vanishes when field modulation is applied at frequencies above 6 Hz. The spin pumping effect was vanishingly small, and the anisotropic magnetoresistance of the Pt bar, though quite easily observed, would imply a rectification voltage that is much smaller than the bolometric effect.

  14. Laplace-Fourier analysis and instabilities of a gainy slab

    CERN Document Server

    Hågenvik, Hans Olaf

    2015-01-01

    The idealization of monochromatic plane waves leads to considerable simplifications in the analysis of electromagnetic systems. However, for active systems this idealization may be dangerous due to the presence of growing waves. Here we consider a gainy slab, and use a realistic incident beam, which is both causal and has finite width. This clarifies some apparent paradoxes arising from earlier analyses of this setup. In general it turns out to be necessary to involve complex frequencies $\\omega$ and/or complex transversal wavenumbers $k_x$. Simultaneously real $\\omega$ and $k_x$ cannot describe amplified waves in a slab which is infinite in the transversal direction. We also show that the only possibility to have an absolute instability for a finite width beam, is if a normally incident plane wave would experience an instability.

  15. Negotiating Multicollinearity with Spike-and-Slab Priors.

    Science.gov (United States)

    Ročková, Veronika; George, Edward I

    2014-08-01

    In multiple regression under the normal linear model, the presence of multicollinearity is well known to lead to unreliable and unstable maximum likelihood estimates. This can be particularly troublesome for the problem of variable selection where it becomes more difficult to distinguish between subset models. Here we show how adding a spike-and-slab prior mitigates this difficulty by filtering the likelihood surface into a posterior distribution that allocates the relevant likelihood information to each of the subset model modes. For identification of promising high posterior models in this setting, we consider three EM algorithms, the fast closed form EMVS version of Rockova and George (2014) and two new versions designed for variants of the spike-and-slab formulation. For a multimodal posterior under multicollinearity, we compare the regions of convergence of these three algorithms. Deterministic annealing versions of the EMVS algorithm are seen to substantially mitigate this multimodality. A single simple running example is used for illustration throughout.

  16. Factors affecting the deterioration of concrete pavement slabs

    Directory of Open Access Journals (Sweden)

    N.M. Morozov

    2015-11-01

    Full Text Available The behavior of constructions under actual operating conditions is affected by exposure to the environment. It is important that concrete roads and airport pavings are resistant not only to mechanical damage, but also to the effects of alternate freezing and thawing. The causes of early failure in concrete have been shown using prefabricated road slabs as an example. The causes of loss of performance properties of the roadway have been established, which are primarily dependent on the quality of raw materials in the concrete. It was found that, aside from durability, uniformity and porosity are important factors in determining the frost resistance of concrete roadways. It was shown that high aluminate content in the cement leads to concrete destruction in the first year of structure use. The results may also indirectly indicate a violation of forming technology during slab production.

  17. Electromagnetic wave propagation through a slab of a dispersive medium

    CERN Document Server

    Ismail, Mohamed

    2016-01-01

    A method is proposed for the analysis of the propagation of electromagnetic waves through a homogeneous slab of a medium with Drude-Lorentz dispersion behavior, and excited by a causal sinusoidal source. An expression of the time dependent field, free from branch-cuts in the plane of complex frequencies, is established. This method provides the complete temporal response in both the steady-state and transient regimes in terms of discrete poles contributions. The Sommerfeld and Brillouin precursors are retrieved and the corresponding set of poles are identified. In addition, the contribution in the transient field of the resonance frequency in the Drude-Lorentz model is exhybited, and the effect of reflections resulting from the refractive index mismatch at the interfaces of the slab are analyzed.

  18. Assembling consumption

    DEFF Research Database (Denmark)

    Assembling Consumption marks a definitive step in the institutionalisation of qualitative business research. By gathering leading scholars and educators who study markets, marketing and consumption through the lenses of philosophy, sociology and anthropology, this book clarifies and applies...... societies. This is an essential reading for both seasoned scholars and advanced students of markets, economies and social forms of consumption....

  19. Dichromatic nonlinear eigenmodes in slab waveguide with chi(2) nonlinearity.

    Science.gov (United States)

    Darmanyan, S A; Nevière, M

    2001-03-01

    The existence of purely nonlinear eigenmodes in a waveguiding structure composed of a slab with quadratic nonlinearity surrounded by (non)linear claddings is reported. Modes having bright and dark solitonlike shapes and consisting of two mutually locked harmonics are identified. Asymmetrical modes are shown to exist in symmetrical environments. Constraints for the existence of the modes are derived in terms of parameters of guiding structure materials.

  20. Transverse Mode Formation in Longitudinally Pumped Miniature Slab Lasers

    Institute of Scientific and Technical Information of China (English)

    XU Jian-Qiu; YE Xin; FANG Tao

    2006-01-01

    The formation of transverse modes in longitudinally pumped miniature slab lasers is investigated theoretically and experimentally. The longitudinally non-uniform gain-guiding is studied by expanding the electric field into the Hermite-Gaussian functions that satisfy boundary conditions of the resonator. Non-Gaussian transversal beam profiles in the near field are found and the beam diameter is reduced when the pump spot becomes smaller. The experimental observation agrees with the theoretical calculation.

  1. End-Pumped Tm:YAG Ceramic Slab Lasers

    Institute of Scientific and Technical Information of China (English)

    CHENG Xiao-Jin; XU Jian-Qiu; ZHANG Wen-Xin; JIANG Sen-Xue; PAN Yu-Bai

    2009-01-01

    Lasers from a Tm:YAG ceramic aare reported for the first time to our best knowledge. The Tm:YAG ceramic slab is end-pumped by a laser diode with central wavelength 792nm. At room temperature, the maximum continuous-wave output power is 4.5 W, and the sloping efficiency is obtained to be 20.5%. The laser spectrum of the Tm: YAG ceramic is centered at 2015 nm.

  2. Beam splitting by a plane-parallel absorptive slab.

    Science.gov (United States)

    Halevi, P

    1982-10-01

    A study of the transmission of inhomogeneous electromagnetic waves through an interface between a transparent and an absorbing medium leads to the prediction of a novel effect. A beam of unpolarized light passing through a dissipative plane-parallel slab splits into two parallel beams. The electric field in one beam is perpendicular to the plane of incidence, whereas in the other beam it is parallel to this plane.

  3. Oscillation modes and transmission into a Fibonacci slab

    Science.gov (United States)

    Castro-Arce, Lamberto; Molinar-Tabares, Martin; Campos-Garcia, Julio; Figueroa-Navarro, Carlos; Isasi-Siqueiros, Leonardo; Manzanares-Martinez, Betsabe

    In our contribution we developed a study on the behavior of the transmission modes and a Pt / Zn slab of a Fibonacci array of longitudinal and transverse acoustic waves. We have worked with arrangements from n = 1 to10 and has managed to find the energy bands and transmission, filling factor 0.4 observing the appearance of Pseudo-Gaps in the evolution of the study when the arrangement Fibonacci increases. We acknowledge the support of SNI CONACYT.

  4. Hydrogen sensor based on metallic photonic crystal slabs.

    Science.gov (United States)

    Nau, D; Seidel, A; Orzekowsky, R B; Lee, S-H; Deb, S; Giessen, H

    2010-09-15

    We present a hydrogen sensor based on metallic photonic crystal slabs. Tungsten trioxide (WO(3)) is used as a waveguide layer below an array of gold nanowires. Hydrogen exposure influences the optical properties of this photonic crystal arrangement by gasochromic mechanisms, where the photonic crystal geometry leads to sharp spectral resonances. Measurements reveal a change of the transmission depending on the hydrogen concentration. Theoretical limits for the detection range and sensitivity of this approach are discussed.

  5. An Incursion on Punching of Reinforced Concrete Flat Slabs

    OpenAIRE

    2009-01-01

    Starting from the early 60s continuous studies have been made regarding punching of concrete flat slabs. The evolution of technology and calculus systems influenced this engineering branch. Nowadays is possible to account in structural analysis all the non-linear behaviour of reinforced and prestressed concrete and to get the most close structural response in comparison with the real behaviour. As a controversy matter, several tests and theories have been developed. Nowadays researchers try t...

  6. DESIGN METHOD OF BENDING CAPACITY OF CONTINUOUS COMPOSITE SLAB

    Directory of Open Access Journals (Sweden)

    Liu Jin

    2016-04-01

    Full Text Available This paper presents a calculation method for predicting the ultimate loading capacity of continuous composite slabs. Only the small scale slide block test was needed to determine few mechanical parameters, and less cost had to be paid, in comparison to the conventional m-k method. Various load conditions and parameters were considered. Comparisons between test results and predicted results have shown that the proposed method has enough precision. Furthermore, the simplified method was also proposed for practical design.

  7. Temperature distribution of an infinite slab under point heat source

    Directory of Open Access Journals (Sweden)

    Wu Zhao-Chun

    2014-01-01

    Full Text Available The temperature field in an infinite slab under an instantaneous or continuous point heat source is studied numerically. The numerical results reveal the temperature distribution and its change regularity, which are significant for the temperature control encountered in many practical manufacturing processes, such as the laser treatment processes on the surface of films, welding and cutting, and even the design of measuring devices for thermal properties of material.

  8. Project B: Improved Liquid Steel Feed For Slab Casters

    Energy Technology Data Exchange (ETDEWEB)

    Brent S. Isaacson; Mike Slepian; Thomas Richter

    1998-10-01

    This report describes the completion of the development of an electromagnetic valve to control liquid steel flow for improved liquid steel feeding for slab casters. Achievements result from a joint research effort between Westinghouse Science and Technology Center, North American Refractories and U.S. Steel. This effort is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. Department of Energy (DOE) and fifteen North American steel makers.

  9. Technical Report: Optimizing the Slab Yard Planning and Crane Scheduling Problem using a Two-Stage Approach

    DEFF Research Database (Denmark)

    Hansen, Anders Dohn; Clausen, Jens

    2008-01-01

    In this paper, we present The Slab Yard Planning and Crane Scheduling Problem. The problem has its origin in steel production facilities with a large throughput. A slab yard is used as a buffer for slabs that are needed in the upcoming production. Slabs are transported by cranes and the problem c...

  10. RFID Data Cleaning for Shop Floor Applications

    Science.gov (United States)

    Ziekow, Holger; Ivantysynova, Lenka; Günter, Oliver

    In several case studies we found that shop-floor applications in manufacturing pose special challenges to cleaning RFID data. The underlying problem in many scenarios is the uncertainty about the exact location of observed RFID tags. Simple filter s provided in common middleware solutions do not cope well with these challenges. Therefore we have developed an approach based on maximum-likelihood estimation to infer a tag's location within the reader range. This enables improved RFID data cleaning in a number of application scenarios. We stress the benefits of our approach along exemplary application scenarios that we found in manufacturing. In simulations and experiments with real world data we show that our approach outperforms existing solutions. Our approach can extend RFID middleware or reader firmware, to improve the use of RFID in a range of shop-floor applications.

  11. Construction Technology Analysis of Concrete Composite Box Net Floor%混凝土叠合箱网梁楼盖施工技术分析

    Institute of Scientific and Technical Information of China (English)

    叶雷杰

    2014-01-01

    Concrete composite box net floor is a special ribbed slab floor, from prefabricated composite box and cast nets (rib) beam combination, its characteristic is flat at the botom, saving materials and large cavity net beam structure stress. The author combining with practical experiences makes a simple analysis of the composite box net beamceiling te- chnique in this paper.%混凝土叠合箱网梁楼盖是一种特殊的密肋梁楼盖,由预制叠合箱和现浇网(肋)梁组合而成,特点是底部平整、节约耗材和大空腔网梁构造受力等。笔者结合实际经验,在本文中简单地分析了叠合箱网梁楼盖技术。

  12. Electromagnetic and ultrasonic investigations on a roman marble slab

    Science.gov (United States)

    Capizzi, Patrizia; Cosentino, Pietro L.

    2010-05-01

    The archaeological Museum of Rome (Museo delle Terme di Diocleziano) asked our group about the physical consistency of a marble slab (II - III century AD) that has recently fallen down during the transportation for an exhibition. In fact, due to insurance conflict, it was necessary to control the new fractures due to the recent accident and distinguish them from the ancient ones. The sculptured slab (today's size is 1280 x 70 x 9 cm), cut at the ends for a re-use as an inscription in the rear face, was restored (assemblage of different broken parts and cleaning) in contemporary times. We used different methodologies to investigate the slab: namely a pacometer (Protovale Elcometer) to individuate internal coupling pins, GPR (2000 MHz) and Ultrasonic (55 kHz) tomographic high-density surveys to investigate the internal extension of all the visible fractures and to search for the unknown internal ones. For every methodology used the quality of the acquired data was relatively high. They have been processed and compared to give a set of information useful for the bureaucratic problems of the Museum. Later on, the data have been processed in depth, for studying how to improve the data processing and for extracting all the information contained in the whole set of experimental data. Finally, the results of such a study in depth are exposed in detail.

  13. Calibrating a large slab vessel: A battle of the bulge

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, I.R.

    1993-10-01

    Slab tanks (critically-safe-by-geometry vessels) were proposed for the storage of concentrated, highly-enriched uranium solution in the design of the Fuel Processing Restoration (FPR) Facility at the Idaho Chemical Processing Plant (ICPP). Currently, measurements of bulk mass in ICPP annular vessels have standard deviations on the order of 0.2%, or less. ICPP personnel felt that their inexperience with the aforementioned expansions would prevent them from attaining comparable precision with slab tanks. To help assess the measurement accuracy of slab vessels, a full-scale mockup of those proposed for the FPR Facility was installed for test calibrations. These calibrations were designed to detect vessel expansion under differing conditions. This paper will compare the base-line, water calibrations with those of the higher-density aluminum nitrate, and any observed deflection will be described using vessel calibration techniques. The calibration using water at an elevated temperature was not performed due to the difficulty of maintaining the elevated temperature. This calibration probably will not be conducted because the construction of the FPR Facility has been halted.

  14. Prediction of temperature distribution in the hot rolling of slabs

    Science.gov (United States)

    Serajzadeh, S.; Karimi Taheri, A.; Mucciardi, F.

    2002-03-01

    In the process of continuous hot slab rolling, it is vital to know the temperature distribution within the slab along the length of the rolling mill because temperature is the dominant parameter controlling the kinetics of metallurgical transformations and the flow stress of the rolled metal. In other words, the microstructural changes, the mechanical properties as well as the final dimensions of the product and roll-force depend on the temperature distribution within the metal being rolled. In this paper, a mathematical model based on the finite element method is utilized to predict the temperature distribution and microstructural changes during the continuous hot slab rolling process. The effects of various parameters such as the heat of deformation, the work-roll temperature, the rolling speed, and the heat transfer coefficient between the work-roll and the metal are all taken into account in the analyses. To verify the validity of the model and the generated computer code, a comparison is carried out between the theoretical and plant-recorded results.

  15. Reducing Railway Noise with Porous Sound-Absorbing Concrete Slabs

    Directory of Open Access Journals (Sweden)

    Caiyou Zhao

    2014-01-01

    Full Text Available The effect of porous sound-absorbing concrete slabs on railway noise reduction is examined in this paper. First, the acoustical absorption coefficients of porous concrete materials with various aggregate types, gradations, fibre contents, and compaction indexes are measured in the laboratory. The laboratory results show that porous concrete that uses a composite of expanded perlite and slag as aggregate can not only obtain good acoustical absorption properties but also satisfy mechanical requirements. Also, the gradation of the combined aggregate has a significant effect on the acoustic absorption performance of the porous concrete, with an optimal aggregate gradation of 1~3 mm. Furthermore, the fibre content and compaction index affect both the strength and the acoustic absorption property of the porous concrete, with the optimum value of 0.3% and 1.6, respectively. Then, the findings from the laboratory studies are used to make porous sound-absorbing concrete slabs, which are applied in a test section. The measurements indicate that porous sound-absorbing concrete slabs can significantly reduce railway noise at different train speeds and that the amount of the noise reduction changes roughly linearly with speed when the train is traveling at less than 200 km/h. The maximum noise reduction is 4.05 dB at a speed of 200 km/h.

  16. High Performance Slab-on-Grade Foundation Insulation Retrofits

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Mosiman, Garrett E. [NorthernSTAR, St. Paul, MN (United States)

    2015-09-01

    ?A more accurate assessment of SOG foundation insulation energy savings than traditionally possible is now feasible. This has been enabled by advances in whole building energy simulation with 3-dimensional foundation modelling integration at each time step together with an experimental measurement of the site energy savings of SOG foundation insulation. Ten SOG insulation strategies were evaluated on a test building to identify an optimum retrofit insulation strategy in a zone 6 climate (Minneapolis, MN). The optimum insulation strategy in terms of energy savings and cost effectiveness consisted of two components: (a) R-20 XPS insulation above grade, and, (b) R-20 insulation at grade (comprising an outer layer of R-10 insulation and an interior layer of R-12 poured polyurethane insulation) tapering to R-10 XPS insulation at half the below-grade wall height (the lower half of the stem wall was uninsulated). The optimum insulation strategy was applied to single and multi-family residential buildings in climate zone 4 - 7. The highest site energy savings of 5% was realized for a single family home in Duluth, MN, and the lowest savings of 1.4 % for a 4-unit townhouse in Richmond, VA. SOG foundation insulation retrofit simple paybacks ranged from 18 to 47 years. There are other benefits of SOG foundation insulation resulting from the increase in the slab surface temperatures. These include increased occupant thermal comfort, and a decrease in slab surface condensation particularly around the slab perimeter.

  17. Wet or dry bandages for plaster back-slabs?

    Science.gov (United States)

    Baliga, Santosh; Finlayson, D

    2012-12-01

    Cotton crêpe and stretch bandages are commonly used in back-slabs and casts in orthopaedic practice. In theory they allow swelling to occur after injury while splinting the fracture. The application of a wet bandage prevents the Plaster-of-Paris (POP) setting too rapidly, giving time to apply a mould or attain correct limb position. However, we hypothesised that a wet bandage contracts upon drying and may cause constriction of the splint. This study aimed at determining whether there was any significant change in length of commonly used bandages when wet as well as any further change when left to dry again. Two types of bandage were evaluated. 250 mm strips of bandage were dipped into water, gently squeezed and laid flat on a bench. The bandage was then immediately measured in length. The strips were then left to dry and re-measured. This experimental study shows that both cotton crepe and cling significantly shrink by around 7% when wet. This phenomenon has the potential to significantly increase the pressure exerted on the limb by a back-slab. We speculate that the application of wet bandages is why some back-slabs may need released. It is therefore recommended that bandages should be applied only in the dry form. Copyright © 2011 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  18. On the consistency of seismically imaged lower mantle slabs.

    Science.gov (United States)

    Shephard, G E; Matthews, K J; Hosseini, K; Domeier, M

    2017-09-08

    The geoscience community is increasingly utilizing seismic tomography to interpret mantle heterogeneity and its links to past tectonic and geodynamic processes. To assess the robustness and distribution of positive seismic anomalies, inferred as subducted slabs, we create a set of vote maps for the lower mantle with 14 global P-wave or S-wave tomography models. Based on a depth-dependent threshold metric, an average of 20% of any given tomography model depth is identified as a potential slab. However, upon combining the 14 models, the most consistent positive wavespeed features are identified by an increasing vote count. An overall peak in the most robust anomalies is found between 1000-1400 km depth, followed by a decline to a minimum around 2000 km. While this trend could reflect reduced tomographic resolution in the middle mantle, we show that it may alternatively relate to real changes in the time-dependent subduction flux and/or a mid-lower mantle viscosity increase. An apparent secondary peak in agreement below 2500 km depth may reflect the degree-two lower mantle slow seismic structures. Vote maps illustrate the potential shortcomings of using a limited number or type of tomography models and slab threshold criteria.

  19. Concrete floor-bovine claw contact pressures related to floor roughness and deformation of the claw.

    Science.gov (United States)

    Franck, A; De Belie, N

    2006-08-01

    The intention of this research was to study the impact of concrete floor surface roughness on a bovine claw model and to assess the deformation of the bovine claw model under load. The pressure distribution between the floor and the claw is the key method in this research. Monitoring foot-to-ground pressure distributions may provide insight into the relation between high local pressures and foot lesions. Concrete floor samples were made with 5 different finishing methods. Their roughness was determined by measuring the heights of the "peaks and the valleys" of the surface with a high-precision laser beam. The smoothest surface was the sample finished with a metal float (surface roughness R(a) = 0.062 mm) and the roughest surface occurred with the heavily sandblasted sample (surface roughness R(a) = 0.488 mm). The roughness of the concrete floor samples was related to the mean and peak contact pressures that can occur in a laboratory test bench between floor and bovine claw. It was found that the claw itself has approximately 2 times more effect on these contact pressures than the surface roughness. Peak pressures found were high enough (up to 111 MPa) to cause damage to the bovine claw sole horn. The strains occurring in the horn wall were measured and related to the floor-finishing method and the load. Strain gauge measurements indicated that it is difficult to predict what kind of deformation of the claw wall will occur at a certain location. Different strains will occur for different floor-finishing methods. The corresponding stresses in the horn wall did not exceed the yield stress (14 and 11 MPa for dorsal and abaxial wall horn, respectively).

  20. Ocean floor mounting of wave energy converters

    Science.gov (United States)

    Siegel, Stefan G

    2015-01-20

    A system for mounting a set of wave energy converters in the ocean includes a pole attached to a floor of an ocean and a slider mounted on the pole in a manner that permits the slider to move vertically along the pole and rotate about the pole. The wave energy converters can then be mounted on the slider to allow adjustment of the depth and orientation of the wave energy converters.

  1. [Functional anatomy of the pelvic floor].

    Science.gov (United States)

    Yiou, René; Delmas, Vincent

    2013-01-01

    The pelvic floor is the support of the pelvic viscera. The levator ani muscle (LA) with its two bundles (pubo- and iliococcygeus) is the major component of this pelvic floor. LA is formed essentially by type I fibers (slow twitch, with high oxidative capability and presence of slow myosin) as in postural muscles. The aerobic metabolism makes LA fragile to excentric contraction and to mitochondrial dysfunction. The innervation of the pelvic floor comes from the 2nd, 3rd, 4th anterior sacral roots; denervation affects pelvic dynamism. Perineum includes the musculofascial structures under the LA: ventrally the striated sphincter of urethra and the ischiocavernosus and bulbospongiosus, caudally the fatty tissue filling the ischioanal fossa. Pelvic fascia covers the muscles ; it presents reinforcements : the uterosacral and cardinal ligaments, the arcus tendineus fascia pelvis (ATFP) and the arcus tendineus levator ani (ATLA). The pelvis statics is supported by the combined action of all this anatomical structures anteriorly forming the perineal "hammock," medially the uterosacral and cardinal ligaments, posteriorly the rectovaginal fascia and the perineal body. The angles formed by the pelvic viscera with their evacuation ducts participate to the pelvic statics. During the pelvic dynamics the modification of these angles expresses the action of the musculofascial structures.

  2. Some Passive Damping Sources on Flooring Systems besides the TMD

    DEFF Research Database (Denmark)

    Pedersen, Lars

    2010-01-01

    Impulsive loads and walking loads can generate problematic structural vibrations in flooring-systems. Measures that may be taken to mitigate the problem would often be to consider the implementation of a tuned mass damper or even more advanced vibration control technologies; this in order to add...... damping to the structure. Basically also passive humans on a floor act as a damping source, but it also turns out from doing system identification tests with a floor strip that a quite simple set-up installed on the floor (cheap and readily at hand) might do a good job in terms of reducing vertical floor...

  3. Flooring-systems and their interaction with furniture and humans

    DEFF Research Database (Denmark)

    Frier, Christian; Pedersen, Lars; Andersen, Lars Vabbersgaard

    2017-01-01

    Flooring-system designs may be sensitive in terms of their vibrational performance due the risk that serviceability-limit-state problems may be encountered. For evaluating the vibrational performance of a flooring system at the design stage, decisions must be made by the engineer in charge...... of computations. Passive humans and/or furniture are often present on a floor. Typically, these masses and their way of interacting with the floor mass are ignored in predictions of vibrational behaviour of the flooring system. Utilizing a shell finite-element model, the paper explores and quantifies how non...

  4. Complete pelvic floor repair in treating fecal incontinence.

    Science.gov (United States)

    Lee, Patrick Y H; Steele, Scott R

    2005-02-01

    Fecal incontinence is associated with 20 to 40% of the patients with pelvic floor prolapse. Successful management of fecal incontinence requires not only an understanding of anorectal function but also a thorough understanding of pelvic floor anatomy and how pelvic floor prolapse affects fecal continence. Imaging techniques have been instrumental in visualizing pelvic floor prolapse and have helped correlate surgical findings. Stabilization of the perineal body appears to be a key component to the success of pelvic floor repair and fecal continence, but the optimal repair is far from being established.

  5. Upper Mantle Flow Beneath the Subducted Nazca Plate: Slab Contortions and Flattening (Invited)

    Science.gov (United States)

    Russo, R. M.

    2010-12-01

    The form of asthenospheric flow beneath subducted lithospheric slabs can be discerned using splitting of shear waves emanating from earthquakes in the slabs themselves. However, the subducted Nazca plate’s abrupt changes in morphology from a planar slab dipping 30° ENE beneath the central Andes to large areas of flat-lying slab beneath Peru, to the north, and Argentina, to the south, are a potential complication to the sub-slab mantle flow. S waves from earthquakes in the Nazca slab reveal details of the upper mantle flow field below and in the vicinity of the slab. Nazca slab earthquakes large enough to be well recorded (M > 5.4, typically), and deep enough to separate S from pS and sS (30-40 km or more), are suitable for such study, and, for events between 1990 and 2010, recording stations are mostly well-distributed azimuthally about the source event. The S waves were recorded at seismic stations at teleseismic distances from the events, and were corrected for known sub-station seismic anisotropy. Thus, the shear wave splitting engendered during their passage through the asthenospheric upper mantle beneath the slab was isolated, and asthenospheric deformation fabrics resulting from plastic flow beneath the slab mapped in some detail. Shear wave splitting fast directions and upper mantle flow beneath the Nazca plate are most often trench-parallel, consistent with trench-parallel upper mantle flow beneath the slab. Fast splitting polarizations at high angle to the strike of the slab occur in the transition regions from flat to normally dipping slab. Upper mantle flow beneath the slab in these regions appears to be channeled by the slab contortion. Upper mantle flow oceanward of the Nazca slab also appears to change abruptly from trends at a high angle to the Peru-Chile trench to trench-parallel as the top of the Nazca slab attains a depth of around 75 km. Trench-parallel sub-slab flow appears to develop once the asthenosphere beneath the Nazca plate is affected

  6. Numerical Modeling of Flat Slab Formation in Central Chile

    Science.gov (United States)

    Manea, M.; Perez-Gussinye, M.; Manea, V.; Fernandez, M.

    2009-12-01

    Subduction of oceanic plates beneath large continental masses is a rare process and at present it occurs only along western South America and Central Mexico. Likewise, flat subduction, understood here as where the slab enters at a normal angle and reverses its curvature to flatten at ~70-120 km depth, only occurs at present beneath South America. In general, the angle at which subduction occurs in the depth range of ~100 to ~200 km reflects the balance between negative buoyancy of the slab, elastic resistance of the slab to change the angle of subduction, and non-hydrostatic pressure forces induced by subduction-driven flow within the asthenosphere. The latter force, known as suction force, acts to prevent the slab from sinking into the mantle, and its magnitude increases with increasing subduction velocity, narrowness and viscosity decrease of the mantle wedge [Manea and Gurnis, 2007]. Recent observations show that the upper plate structure varies along the Andean margin, indicating that it is thicker and stronger above flat subduction zones and suggesting a correlation between upper plate structure and subduction angle [Pérez-Gussinyé et al., 2008; Booker et al., 2004]. In this study we use numerical models to explore the extent to which upper plate structure, through its influence on asthenospheric wedge shape and viscosity, can affect the angle of subduction. We test for which upper plate thickness and asthenospheric viscosity repeated cycles of steep and flat subduction are reproduced and compare our results to estimations of lithospheric thickness and the duration of flat and steep subduction cycles hypothesized along the Andean margin. Our models are constrained by realistic plate velocities in hot spot reference frame for both Nazca and South American plates [Muller et al., 2008], the Miocene-Present shortening for the Andes [Schelart et al., 2007] and realistic Nazca plate age distribution [Sdrolias and Muller, 2006]. Using the finite element package

  7. Design of energy efficient building with radiant slab cooling

    Science.gov (United States)

    Tian, Zhen

    2007-12-01

    Air-conditioning comprises a substantial fraction of commercial building energy use because of compressor-driven refrigeration and fan-driven air circulation. Core regions of large buildings require year-round cooling due to heat gains from people, lights and equipment. Negative environmental impacts include CO2 emissions from electric generation and leakage of ozone-depleting refrigerants. Some argue that radiant cooling simultaneously improves building efficiency and occupant thermal comfort, and that current thermal comfort models fail to reflect occupant experience with radiant thermal control systems. There is little field evidence to test these claims. The University of Calgary's Information and Communications Technology (ICT) Building, is a pioneering radiant slab cooling installation in North America. Thermal comfort and energy performance were evaluated. Measurements included: (1) heating and cooling energy use, (2) electrical energy use for lighting and equipment, and (3) indoor temperatures. Accuracy of a whole building energy simulation model was evaluated with these data. Simulation was then used to compare the radiant slab design with a conventional (variable air volume) system. The radiant system energy performance was found to be poorer mainly due to: (1) simultaneous cooling by the slab and heating by other systems, (2) omission of low-exergy (e.g., groundwater) cooling possible with the high cooling water temperatures possible with radiant slabs and (3) excessive solar gain and conductive heat loss due to the wall and fenestration design. Occupant thermal comfort was evaluated through questionnaires and concurrent measurement of workstation comfort parameters. Analysis of 116 sets of data from 82 occupants showed that occupant assessment was consistent with estimates based on current thermal comfort models. The main thermal comfort improvements were reductions in (1) local discomfort from draft and (2) vertical air temperature stratification. The

  8. Detecting lower-mantle slabs beneath Asia and the Aleutians

    Science.gov (United States)

    Schumacher, L.; Thomas, C.

    2016-06-01

    To investigate the descend of subducted slabs we search for and analyse seismic arrivals that reflected off the surface of the slab. In order to distinguish between such arrivals and other seismic phases, we search for waves that reach a seismic array with a backazimuth deviating from the theoretical backazimuth of the earthquake. Source-receiver combinations are chosen in a way that their great circle paths do not intersect the slab region, hence the direct arrivals can serve as reference. We focus on the North and Northwest Pacific region by using earthquakes from Japan, the Philippines and the Hindu Kush area recorded at North American networks (e.g. USArray, Alaska and Canada). Using seismic array techniques for analysing the data and record information on slowness, backazimuth and traveltime of the observed out-of-plane arrivals we use these measurements to trace the wave back through a 1-D velocity model to its scattering/reflection location. We find a number of out-of-plane reflections. Assuming only single scattering, most out-of-plane signals have to travel as P-to-P phases and only a few as S-to-P phases, due to the length of the seismograms we processed. The located reflection points present a view of the 3-D structures within the mantle. In the upper mantle and the transition zone they correlate well with the edges of fast velocity regions in tomographic images. We also find reflection points in the mid- and lower mantle and their locations generally agree with fast velocities mapped by seismic tomography models suggesting that in the subduction regions we map, slabs enter the lower mantle. To validate our approach, we calculate and process synthetic seismograms for 3-D wave field propagation through a model containing a slab-like heterogeneity. We show, that depending on the source-receiver geometry relative to the reflection plane, it is indeed possible to observe and back-trace out-of-plane signals.

  9. First application of second-generation steel-free deck slabs for bridge rehabilitation

    Science.gov (United States)

    Eden, Ruth; Klowak, Chad; Mufti, Aftab A.; Tadros, Gamil; Bakht, Baidar; Loewen, Eric

    2004-07-01

    The arching action in concrete deck slabs for girder bridges is utilized fully in steel-free deck slabs. These concrete slabs, requiring no tensile reinforcement, are confined longitudinally by making them composite with the girders, and transversely by external steel straps connecting the top flanges of external girders. Between 1995 and 1999, five steel-free deck slabs without any tensile reinforcement were cast on Canadian bridges. All these slabs developed fairly wide full-depth cracks roughly midway between the girders. While extensive fatigue testing done in the past three years has confirmed that the presence of even wide cracks does not pose any danger to the safety of the structures, wide cracks are generally not acceptable to bridge engineers. The developers of the steel-free deck slabs have now conceded that these slabs should be reinforced with a crack-control mesh of nominal glass fibre reinforced polymer (GFRP) bars. Steel-free deck slabs with crack-control meshes are being referred as the second generation slabs. With the help of testing on full-scale models, it has been found that deck slabs with GFRP bars have the best fatigue resistance and those with steel bars the worst.

  10. Pelvic floor dysfunction in inflammatory bowel disease.

    Science.gov (United States)

    Bondurri, A; Maffioli, A; Danelli, P

    2015-12-01

    Advances in tailored medical therapy and introduction of biologic agents for inflammatory bowel disease (IBD) treatment have ensured long-term disease remission. Some patients, however, still report defecatory symptoms. Patients present with a wide spectrum of conditions - anal incontinence, obstructed defecation and pelvic pain among the most frequent - that have a great impact on their quality of life. Due to IBD diagnosis, little relevance is attributed to this type of symptoms and their epidemiologic distribution is unknown. Pathogenetic hypotheses are currently under investigation. Routine diagnostic workflow and therapeutic options in pelvic floor service are often underused. The evaluation of these disorders starts with an endoscopy to rule out ongoing disease; the following diagnostic workflow is the same as in patients without IBD. For fecal incontinence and obstructed defecation, simple conservative therapy with dietary modifications and appropriate fluid intake is effective in most cases. In non-responding patients, anorectal physiology tests and imaging are required to select patients for pelvic floor muscle training and biofeedback. These treatments have been proven effective in IBD patients. Some new minimally invasive alternative strategies are available for IBD patients, as sacral nerve and posterior tibial nerve stimulation; for other ones (e.g., bulking agent implantation) IBD still remains an exclusion criterion. In order to preserve anatomical areas that could be useful for future reconstructive techniques, surgical options to cure pelvic floor dysfunction are indicated only in a small group of IBD patients, due to the high risk of failure in wound healing and to the possible side effects of surgery, which can lead to anal incontinence or to a possible proctectomy. A particular issue among defecatory symptoms in patients with IBD is paradoxical puborectalis contraction after restorative proctocolectomy: if this disorder is properly diagnosed, a

  11. 3D Monte-Carlo transport calculations of whole slab reactor cores: validation of deterministic neutronic calculation routes

    Energy Technology Data Exchange (ETDEWEB)

    Palau, J.M. [CEA Cadarache, Service de Physique des Reacteurs et du Cycle, Lab. de Projets Nucleaires, 13 - Saint-Paul-lez-Durance (France)

    2005-07-01

    This paper presents how Monte-Carlo calculations (French TRIPOLI4 poly-kinetic code with an appropriate pre-processing and post-processing software called OVNI) are used in the case of 3-dimensional heterogeneous benchmarks (slab reactor cores) to reduce model biases and enable a thorough and detailed analysis of the performances of deterministic methods and their associated data libraries with respect to key neutron parameters (reactivity, local power). Outstanding examples of application of these tools are presented regarding the new numerical methods implemented in the French lattice code APOLLO2 (advanced self-shielding models, new IDT characteristics method implemented within the discrete-ordinates flux solver model) and the JEFF3.1 nuclear data library (checked against JEF2.2 previous file). In particular we have pointed out, by performing multigroup/point-wise TRIPOLI4 (assembly and core) calculations, the efficiency (in terms of accuracy and computation time) of the new IDT method developed in APOLLO2. In addition, by performing 3-dimensional TRIPOLI4 calculations of the whole slab core (few millions of elementary volumes), the high quality of the new JEFF3.1 nuclear data files and revised evaluations (U{sup 235}, U{sup 238}, Hf) for reactivity prediction of slab cores critical experiments has been stressed. As a feedback of the whole validation process, improvements in terms of nuclear data (mainly Hf capture cross-sections) and numerical methods (advanced quadrature formulas accounting validation results, validation of new self-shielding models, parallelization) are suggested to improve even more the APOLLO2-CRONOS2 standard calculation route. (author)

  12. Dump assembly

    Science.gov (United States)

    Goldmann, Louis H.

    1986-01-01

    A dump assembly having a fixed conduit and a rotatable conduit provided with overlapping plates, respectively, at their adjacent ends. The plates are formed with openings, respectively, normally offset from each other to block flow. The other end of the rotatable conduit is provided with means for securing the open end of a filled container thereto. Rotation of the rotatable conduit raises and inverts the container to empty the contents while concurrently aligning the conduit openings to permit flow of material therethrough.

  13. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    5th April, 2016 – Ordinary General Assembly of the Staff Association! In the first semester of each year, the Staff Association (SA) invites its members to attend and participate in the Ordinary General Assembly (OGA). This year the OGA will be held on Tuesday, April 5th 2016 from 11:00 to 12:00 in BE Auditorium, Meyrin (6-2-024). During the Ordinary General Assembly, the activity and financial reports of the SA are presented and submitted for approval to the members. This is the occasion to get a global view on the activities of the SA, its financial management, and an opportunity to express one’s opinion, including taking part in the votes. Other points are listed on the agenda, as proposed by the Staff Council. Who can vote? Only “ordinary” members (MPE) of the SA can vote. Associated members (MPA) of the SA and/or affiliated pensioners have a right to vote on those topics that are of direct interest to them. Who can give his/her opinion? The Ordinary General Asse...

  14. Implications of Electrical Conductivity Structure Associated With the Nazca Slab Beneath Argentina

    Science.gov (United States)

    Booker, J. R.; Pomposiello, C.; Favetto, A.; Burd, A.

    2005-12-01

    From 1998 to 2005 we have collected more than 100 magnetotelluric (MT) sites in the Sierras Pampeanas of Argentina between 27°S and 33°S. The main targets of these investigations were initially active structures within this thick-skinned tectonics province. However, it became clear as we progressed that the subducted Nazca slab, which is anonymously flat under this area was generating observable electrical structures at mantle depth. The high resistivity of the crystalline crust and the generally thin, but conductive sedimentary cover of much of this area provide a favorable situation for the penetration of electromagnetic energy deep into the mantle. Our longest profile extends from near Chile to near Uruguay at 31.5°S, where the flat slab is widest. The flattest portion of the slab is both electrically conductive and seismically active. This seismic activity terminates eastward at almost the same place that the slab conductor ends and the overlying lithosphere becomes seismically active and electrically conductive. A unifying explanation is that as the slab descends to its flat portion at 100 km it dehydrates. The free water raises pore pressure and triggers earthquakes. As the slab progresses eastward, the fluids leak upward out of the slab into the lithosphere, the slab pore pressure drops, electrical pathways close and the slab becomes resistive and quiet. An intriguing possibility is that the wet lithosphere created in this process sets the stage for a massive volcanic flare-up if the slab dip increases and an asthenospheric wedge reforms. Further east, the slab plunges nearly vertically into the mantle when it meets the electrically resistive and presumably mechanically strong backstop of the root of the Rio de la Plata Craton. A near vertical conductor is found between the plunging slab and the resistive root. This conductor rises to the base of the lithosphere, but does not penetrate. It is almost certainly due to partial melt, but whether this melting

  15. Composition and formation of Palaeozoic Erlangping ophiolitic slab, North Qinling: Evidence from geology and geochemistry

    Institute of Scientific and Technical Information of China (English)

    孙勇; 卢欣祥; 韩松; 张国伟

    1996-01-01

    The analyses based on the protolith formation, metamorphic and deformation reveal that the Erlangping Group is composed of different lithological slices, without any significance in stratigraphy. It is therefore to discard the Erlangping Group into the Damiao slab, the Erlangping ophiolitic slab and the Xiaozhai slab. The Erlangping ophiolitic slab only includes the former Huoshenmiao Formation and it is mainly composed of massive basalts, pillow basalts, sheet dikes, gabbro and a few of ultramafic intrusions with patches of plagiogranite, overlain by radiolarian silicolites. A lot of microfossils were discovered in the silicolites that mark the Erlangping ophiolitic slab mainly formed in the Early to Middle Ordovician. In geochemistry, most of the basalts and diabase dikes are consistent with N-MORB except a few of samples effected by alteration. The Erlangping ophiolitic slab represents a remnant piece of ancient ocean crust which is most suitable to a back-arc basin setting. A mean 207Pb/206Pb age of

  16. Numerical Analysis of Dynamic Behavior of RC Slabs Under Blast Loading

    Institute of Scientific and Technical Information of China (English)

    DU Hao; LI Zhongxian

    2009-01-01

    In Order to reduce economic and life losses due to terrorism or accidental explosion threats,reinforced concrete(RC)slabs of buildings need to be designed or retrofitted to resist blast loading.In this paper the dynamic behavior Of RC slabs under blast loading and its influencing factors are studied.The numerical model of an RC slab subjected to blast loading is established using the explicit dynamic analysis software.Both the strain rate effect and the damage accumulation are taken into account in the material model.The dynamic responses of the RC slab subiected to blast loading are analyzed,and the influence of concrete strength,thickness and reinforcement ratio on the behavior of the RC slab under blast loading iS numerically investigated.Based on the numerical results.some principles for blast-resistant design and retrofitting are proposed to improve the behavior of the RC slab subjected to blast loading.

  17. Fabrication slab waveguide based polymethyl methacrylate (PMMA) with spin coating method

    Science.gov (United States)

    Andriawan, Alan; Pramono, Yono Hadi; Masoed, Asnawi

    2016-11-01

    Fabrication and characterization slab waveguide based polymethyl methacrylate (PMMA) has been carried out. Slab waveguide fabrication done by the spin coating method. Slab waveguide fabrication process carried out by the rotational speed of 1000, 2000, and 3000 rpm respectively played for 10 seconds. Then the slab waveguides heated using a hot plate. Heating process starting from room temperature then increased 5°C to 70°C with a 5 minute warm-up time interval. From the results of characterization fabricated slab waveguides to determine the film thickness is made. Then made observations on the waveguide by passing the light beam He-Ne laser on the thin layer through a single mode optical fiber. From the results of characterization is known that the fabrication of a slab waveguide with a layer thickness of 166 μm. From this research it is known that polymethyl methacrylate (PMMA) can be used as a waveguide with a spin coating method.

  18. Extraordinary wavelength reduction in terahertz graphene-cladded photonic crystal slabs

    CERN Document Server

    Williamson, Ian A D; Wang, Zheng

    2015-01-01

    Photonic crystal slabs have been widely used in nanophotonics for light confinement, dispersion engineering, nonlinearity enhancement, and other unusual effects arising from their structural periodicity. Sub-micron device sizes and mode volumes are routine for silicon-based photonic crystal slabs, however spectrally they are limited to operate in the near infrared. Here, we show that two single-layer graphene sheets allow silicon photonic crystal slabs with submicron periodicity to operate in the terahertz regime, with an extreme 100x wavelength reduction and excellent out-of-plane confinement. The graphene-cladded photonic crystal slabs exhibit band structures closely resembling those of ideal two-dimensional photonic crystals, with broad two-dimensional photonic band gaps even when the slab thickness approaches zero. The overall photonic band structure not only scales with the graphene Fermi level, but more importantly scales to lower frequencies with reduced slab thickness. Just like ideal 2D photonic crys...

  19. Influence of Dog-Bone Apex on Shape During Slab Horizontal Rolling Process

    Institute of Scientific and Technical Information of China (English)

    YU Hai-liang; LIU Xiang-hua; LI Chang-sheng; WANG Guo-dong

    2007-01-01

    The deformation of slab with dog-bone shape during the horizontal rolling process was simulated using FEM, and the influences of apical dislocation of dog-bone on the slab spread as well as the minimum crop end loss and the lost width at slab head and tail were analyzed. The results show that with the increase in the apical dislocation of dog-bone (LA), the slab spread and the minimum crop end loss at slab head and tail decrease, while the lost width at slab head and tail increases. Meanwhile, the relationships of S/LA-LA, LH/LA-LA, WH/LA-LA, LT/LA-LA, and WT/LA-LA were obtained.

  20. Cenozoic tectonics of western North America controlled by evolving width of Farallon slab.

    Science.gov (United States)

    Schellart, W P; Stegman, D R; Farrington, R J; Freeman, J; Moresi, L

    2010-07-16

    Subduction of oceanic lithosphere occurs through two modes: subducting plate motion and trench migration. Using a global subduction zone data set and three-dimensional numerical subduction models, we show that slab width (W) controls these modes and the partitioning of subduction between them. Subducting plate velocity scales with W(2/3), whereas trench velocity scales with 1/W. These findings explain the Cenozoic slowdown of the Farallon plate and the decrease in subduction partitioning by its decreasing slab width. The change from Sevier-Laramide orogenesis to Basin and Range extension in North America is also explained by slab width; shortening occurred during wide-slab subduction and overriding-plate-driven trench retreat, whereas extension occurred during intermediate to narrow-slab subduction and slab-driven trench retreat.

  1. Deflection of resilient materials for reduction of floor impact sound.

    Science.gov (United States)

    Lee, Jung-Yoon; Kim, Jong-Mun

    2014-01-01

    Recently, many residents living in apartment buildings in Korea have been bothered by noise coming from the houses above. In order to reduce noise pollution, communities are increasingly imposing bylaws, including the limitation of floor impact sound, minimum thickness of floors, and floor soundproofing solutions. This research effort focused specifically on the deflection of resilient materials in the floor sound insulation systems of apartment houses. The experimental program involved conducting twenty-seven material tests and ten sound insulation floating concrete floor specimens. Two main parameters were considered in the experimental investigation: the seven types of resilient materials and the location of the loading point. The structural behavior of sound insulation floor floating was predicted using the Winkler method. The experimental and analytical results indicated that the cracking strength of the floating concrete floor significantly increased with increasing the tangent modulus of resilient material. The deflection of the floating concrete floor loaded at the side of the specimen was much greater than that of the floating concrete floor loaded at the center of the specimen. The Winkler model considering the effect of modulus of resilient materials was able to accurately predict the cracking strength of the floating concrete floor.

  2. Deflection of Resilient Materials for Reduction of Floor Impact Sound

    Directory of Open Access Journals (Sweden)

    Jung-Yoon Lee

    2014-01-01

    Full Text Available Recently, many residents living in apartment buildings in Korea have been bothered by noise coming from the houses above. In order to reduce noise pollution, communities are increasingly imposing bylaws, including the limitation of floor impact sound, minimum thickness of floors, and floor soundproofing solutions. This research effort focused specifically on the deflection of resilient materials in the floor sound insulation systems of apartment houses. The experimental program involved conducting twenty-seven material tests and ten sound insulation floating concrete floor specimens. Two main parameters were considered in the experimental investigation: the seven types of resilient materials and the location of the loading point. The structural behavior of sound insulation floor floating was predicted using the Winkler method. The experimental and analytical results indicated that the cracking strength of the floating concrete floor significantly increased with increasing the tangent modulus of resilient material. The deflection of the floating concrete floor loaded at the side of the specimen was much greater than that of the floating concrete floor loaded at the center of the specimen. The Winkler model considering the effect of modulus of resilient materials was able to accurately predict the cracking strength of the floating concrete floor.

  3. A Coupled Computational Scheme on Thermal and Phase Structures of Subducting Slabs

    Institute of Scientific and Technical Information of China (English)

    JING Zhi-Cheng; MNG Jie-Yuan

    2001-01-01

    The thermodynamic processes undergone by olivine, the chief mineral of subducting slabs, are important in studying the mechanisms of deep-focus earthquakes and the interaction between slabs and the surrounding mantle. We propose a modified coupling scheme to calculate the thermal and phase structures of slabs, which presents a high computational' accuracy at an accessible CPU expense. Using the new code of computation, we have calculated the thermal and phase structures of the Kurile subduction zone.

  4. Effect of aseismic ridge subduction on slab geometry and overriding plate deformation: Insights from analogue modeling

    OpenAIRE

    Martinod, Joseph; Guillaume, Benjamin; Espurt, Nicolas; Faccenna, Claudio; Funiciello, Francesca; Regard, Vincent

    2013-01-01

    International audience; We present analogue models simulating the subduction of a buoyant ridge beneath an advancing overriding plate whose velocity is imposed by lateral boundary conditions. We analyze the 3D geometry of the slab, the deformation and topography of the overriding plate. Ridge subduction diminishes the dip of the slab, eventually leading to the appearance of a horizontal slab segment. This result contrasts with that obtained in free subduction experiments, in which ridge subdu...

  5. Failure analysis of edge flat-slab column connections with shear reinforcement

    OpenAIRE

    2013-01-01

    Flat-slab column connections are susceptible to brittle failure, which lead to the necessity of improving ductility and ultimate strength. In case of edge connections, the behaviour at ultimate state is highly influenced by nonsymmetrical distribution of stresses originated by a moment transfer between the slab and the column. The paper presents the test results of three full-scale reinforced concrete flat-slab edge connections with stud-rail shear reinforcement subjected to concentrated load...

  6. The dynamics of double slab subduction from numerical and semi-analytic models

    Science.gov (United States)

    Holt, A.; Royden, L.; Becker, T. W.

    2015-12-01

    Regional interactions between multiple subducting slabs have been proposed to explain enigmatic slab kinematics in a number of subduction zones, a pertinent example being the rapid pre-collisional plate convergence of India and Eurasia. However, dynamically consistent 3-D numerical models of double subduction have yet to be explored, and so the physics of such double slab systems remain poorly understood. Here we build on the comparison of a fully numerical finite element model (CitcomCU) and a time-dependent semi-analytic subduction models (FAST) presented for single subduction systems (Royden et. al., 2015 AGU Fall Abstract) to explore how subducting slab kinematics, particularly trench and plate motions, can be affected by the presence of an additional slab, with all of the possible slab dip direction permutations. A second subducting slab gives rise to a more complex dynamic pressure and mantle flow fields, and an additional slab pull force that is transmitted across the subduction zone interface. While the general relationships among plate velocity, trench velocity, asthenospheric pressure drop, and plate coupling modes are similar to those observed for the single slab case, we find that multiple subducting slabs can interact with each other and indeed induce slab kinematics that deviate significantly from those observed for the equivalent single slab models. References Jagoutz, O., Royden, L. H., Holt, A. F. & Becker, T. W., 2015, Nature Geo., 8, 10.1038/NGEO2418. Moresi, L. N. & Gurnis, M., 1996, Earth Planet. Sci. Lett., 138, 15-28. Royden, L. H. & Husson, L., 2006, Geophys. J. Int. 167, 881-905. Zhong, S., 2006, J. Geophys. Res., 111, doi: 10.1029/2005JB003972.

  7. Bending and Shear Experimental Tests and Numerical Analysis of Composite Slabs Made Up of Lightweight Concrete

    OpenAIRE

    F. P. Alvarez Rabanal; J. Guerrero-Muñoz; Alonso-Martinez, M.; J. E. Martinez-Martinez

    2016-01-01

    The aim of this paper is to understand the structural behaviour of composite slabs. These composite slabs are made of steel and different kinds of concrete. The methodology used in this paper combines experimental studies with advanced techniques of numerical simulations. In this paper, four types of concrete were used in order to study their different structural strengths in composite slabs. The materials used were three lightweight concretes, a normal concrete, and a cold conformed steel de...

  8. Large negative Goos-Hänchen shift from a weakly absorbing dielectric slab.

    Science.gov (United States)

    Wang, Li-Gang; Chen, Hong; Zhu, Shi-Yao

    2005-11-01

    It is theoretically shown that the negative Goos-Hänchen shifts near resonance, Re[k(z)d] = m pi, can be an order of magnitude larger than the wavelength for both TE- and TM-polarized beams reflected from a weakly absorbing dielectric slab if the absorption of the slab is sufficiently weak, which is different from the case for a lossless dielectric slab [Phys. Rev. Lett. 91, 133903 (2003)].

  9. Penelitian pengaruh plasticizer DOP terhadap sifat fisis slab kompon PVC untuk acuan sepatu

    OpenAIRE

    Kelompok Peneliti Proses Produksi Barang Plastik

    1984-01-01

    Abstract DOP Plasticizer is a chemical substance which its function is to increase the plasticity of PVC compound slab. By adding DOP plasticizer can imporoves the impact resistance properties and decrease the hardness of slab. The utilization of 30% DOP results the greatest impact resistance (6,1016 kg/cm), and the hardness 55 shore A of PVC coumpund slab produced by this experiment.

  10. Penelitian pengaruh plasticizer DOP terhadap sifat fisis slab kompon PVC untuk acuan sepatu

    Directory of Open Access Journals (Sweden)

    Kelompok Peneliti Proses Produksi Barang Plastik

    1984-12-01

    Full Text Available Abstract DOP Plasticizer is a chemical substance which its function is to increase the plasticity of PVC compound slab. By adding DOP plasticizer can imporoves the impact resistance properties and decrease the hardness of slab. The utilization of 30% DOP results the greatest impact resistance (6,1016 kg/cm, and the hardness 55 shore A of PVC coumpund slab produced by this experiment.

  11. Physical activity and the pelvic floor.

    Science.gov (United States)

    Nygaard, Ingrid E; Shaw, Janet M

    2016-02-01

    Pelvic floor disorders are common, with 1 in 4 US women reporting moderate to severe symptoms of urinary incontinence, pelvic organ prolapse, or fecal incontinence. Given the high societal burden of these disorders, identifying potentially modifiable risk factors is crucial. Physical activity is one such potentially modifiable risk factor; the large number of girls and women participating in sport and strenuous training regimens increases the need to understand associated risks and benefits of these exposures. The aim of this review was to summarize studies reporting the association between physical activity and pelvic floor disorders. Most studies are cross-sectional and most include small numbers of participants. The primary findings of this review include that urinary incontinence during exercise is common and is more prevalent in women during high-impact sports. Mild to moderate physical activity, such as brisk walking, decreases both the odds of having and the risk of developing urinary incontinence. In older women, mild to moderate activity also decreases the odds of having fecal incontinence; however, young women participating in high-intensity activity are more likely to report anal incontinence than less active women. Scant data suggest that in middle-aged women, lifetime physical activity increases the odds of stress urinary incontinence slightly and does not increase the odds of pelvic organ prolapse. Women undergoing surgery for pelvic organ prolapse are more likely to report a history of heavy work than controls; however, women recruited from the community with pelvic organ prolapse on examination report similar lifetime levels of strenuous activity as women without this examination finding. Data are insufficient to determine whether strenuous activity while young predisposes to pelvic floor disorders later in life. The existing literature suggests that most physical activity does not harm the pelvic floor and does provide numerous health benefits for

  12. Ogive Nose Hard Missile Penetrating Concrete Slab Numerical Simulation Approach

    Directory of Open Access Journals (Sweden)

    Qadir Bux

    2011-01-01

    Full Text Available Great demand exists for more efficient design to protect delicate and serious structures such as nuclear plants, Power plants, Weapon Industries, weapons storage places, water retaining structures, & etc, against impact of kinetic missiles generated both accidentally and deliberately such as dynamic loading, incident occurs in nuclear plants, terrorist attack, Natural disasters like tsunami and etc., in various impact and blast scenarios for both civilian and military activities. In many cases, projectiles can be treated as rigid bodies when their damage and erosion are not severe. Due to the intricacy of the local impact damages, investigations are generally based on experimental data. Conclusions of the experimental observations are then used to guide engineering models. Local damages studies normally fall into three categories, i.e. empirical formulae based on data fitting, idealised analytical models based on physic laws and numerical simulations based on computational mechanics and material models. In the present study, 2D asymmetrical numerical simulation have done on concrete slab against the impact of  ogive nose hard missile of 26.90mm and 76.20mm diameter with CRH ratio 2.0 and 6.0 respectively, for penetration by using Concrete Damaged Plasticity Model, and ABAQUS/Explicit dynamic analysis in ABAQUS. It is found that the strains/stresses are induced in the concrete slab and a very nicely propagation of the stresses inside the  concrete slab in the form of waves, which is a clear indication for vibrations of the concrete. The lack of failure criterion in concrete damaged plasticity model does not allow the removal of elements during the analyses. This means that spalling, scabbing, and perforation cannot be modelled with the Concrete Damage Plasticity Model. The penetration depth results shows that the deeper penetration requires higher critical impact kinetic energies, and comparison shows the simulation results are more accurate

  13. The study of the transition regime between slab and mixed slab-toroidal electron temperature gradient modes in a basic experiment

    Energy Technology Data Exchange (ETDEWEB)

    Balbaky, Abed; Sokolov, Vladimir; Sen, Amiya K. [Plasma Research Laboratory, Columbia University, New York, New York 10027 (United States)

    2015-05-15

    Electron temperature gradient (ETG) modes are suspected sources of anomalous electron thermal transport in magnetically confined plasmas as in tokamaks. Prior work in the Columbia Linear Machine (CLM) has been able to produce and identify slab ETG modes in a slab geometry [Wei et al., Phys. Plasmas 17, 042108 (2010)]. Now by modifying CLM to introduce curvature to the confining axial magnetic field, we have excited mixed slab-toroidal modes. Linear theory predicts a transition between slab and toroidal ETG modes when (k{sub ∥}R{sub c})/(k{sub y}ρ) ∼1 [J. Kim and W. Horton, Phys. Fluids B 3, 1167 (1991)]. We observe changes in the mode amplitude for levels of curvature R{sub c}{sup −1}≪(k{sub ∥,slab})/(k{sub ⊥}ρ) , which may be explained by reductions in k{sub ∥} in the transition from slab to mixed slab-toroidal modes, as also predicted by theory. We present mode amplitude scaling as a function of magnetic field curvature. Over the range of curvature available in CLM experimentally we find a modest increase in saturated ETG potential fluctuations (∼1.5×), and a substantial increase in the power density of individual mode peaks (∼4–5×)

  14. Numerical Analysis of Secondary Cooling in Continuous Slab Casting

    Institute of Scientific and Technical Information of China (English)

    Kee-Hyeon Cho; Byung-Moon Kim

    2008-01-01

    In the present study, a numerical optimization program has been developed for predicting the optimal secondary cooling patterns in a continuous slab caster. Optimization strategy using Broydon-Fletcher-Goldfarb-Shanno (BFGS) method is carried out by determining the constant heat transfer coefficients in each spray zone, which could satisfy the casting conditions and metallurgical criteria specified by the engineer. From the present results, it is found that even a slight variation in the pouring temperature, allowable surface temperature, and casting speed could give rise to the changes in the cooling pattern throughout the spray zones.

  15. Effect of Rotation in an Orthotropic Elastic Slab

    Directory of Open Access Journals (Sweden)

    Santra S.

    2017-02-01

    Full Text Available The fundamental equations of the two dimensional generalized thermoelasticity (L-S model with one relaxation time parameter in orthotropic elastic slab has been considered under effect of rotation. The normal mode analysis is used to the basic equations of motion and heat conduction equation. Finally, the resulting equations are written in the form of a vector-matrix differential equation which is then solved by the eigenvalue approach. The field variables in the space time domain are obtained numerically. The results corresponding to the cases of conventional thermoelasticity CTE, extended thermoelasticity (ETE and temperature rate dependent thermoelasticity (TRDTE are compared by means of graphs.

  16. Second-harmonic generation from hyperbolic plasmonic nanorod metamaterial slab

    CERN Document Server

    Marino, Giuseppe; Krasavin, Alexey V; Ginzburg, Pavel; Olivier, Nicolas; Wurtz, Gregory A; Zayats, Anatoly V

    2015-01-01

    Hyperbolic plasmonic metamaterials provide numerous opportunities for designing unusual linear and nonlinear optical properties. We show that the modal overlap of fundamental and second-harmonic light in an anisotropic plasmonic metamaterial slab results in the broadband enhancement of radiated second-harmonic intensity by up to 2 and 11 orders of magnitudes for TM- and TE-polarized fundamental light, respectively, compared to a smooth Au film under TM-polarised illumination. The results open up possibilities to design tuneable frequency-doubling metamaterial with the goal to overcome limitations associated with classical phase matching conditions in thick nonlinear crystals.

  17. Development of Flexible Link Slabs using Ductile Fiber Reinforced Concrete

    DEFF Research Database (Denmark)

    Lárusson, Lárus Helgi

    emphasis oncrack formation and development at the rebar-matrix interface during direct tensile loading. Utilizing a high definition DIC technique in a novel approach, detailed measurements of the crack formation and debonding process are obtained. It is found that ductile ECC, in contrast to conventional...... two adjacent bridge deck segments. The link slab element, composed of GFRP reinforced ECC,exhibited the same tension stiffening and tension strengthening behavior with limited crack widths as was observed in the reinforced prisms under monotonic and cyclic loading. The combination of ductile ECC...

  18. Inverse Estimation of Transient Heat Flux to Slab Surface

    Institute of Scientific and Technical Information of China (English)

    CUI Miao; YANG Kai; LIU Yun-fei; GAO Xiao-wei

    2012-01-01

    The transient heat flux was calculated using a model for inverse heat conduction problems based on temper- ature measurements. The unknown heat flux was taken as an optimization variable and solved by minimizing the differences between the calculated temperatures and the measured ones. Several examples were given to show the ef- fectiveness and the accuracy of the inverse algorithm in estimating the transient heat flux to a slab surface. The re sults show that the inverse approach can be applied in the steel industry or in other areas where the target of investi- gation is inaccessible to direct measurements or difficult to be directly modeled.

  19. An Incursion on Punching of Reinforced Concrete Flat Slabs

    Directory of Open Access Journals (Sweden)

    Dan-Vasile Bompa

    2009-01-01

    Full Text Available Starting from the early 60s continuous studies have been made regarding punching of concrete flat slabs. The evolution of technology and calculus systems influenced this engineering branch. Nowadays is possible to account in structural analysis all the non-linear behaviour of reinforced and prestressed concrete and to get the most close structural response in comparison with the real behaviour. As a controversy matter, several tests and theories have been developed. Nowadays researchers try to find the most accurate and economic formula for punching. This paper purpose is to make a survey on punching classical model and related nonlinear concrete behaviour regarded to this issue.

  20. The Slab Method to Measure the Topological Susceptibility

    OpenAIRE

    2016-01-01

    In simulations of a model with topological sectors, algorithms which proceed in small update steps tend to get stuck in one sector, especially on fine lattices. This distorts the numerical results; in particular it is not straightforward to measure the topological susceptibility chi_t. We test a method to measure chi_t even if configurations from only one sector are available. It is based on the topological charges in sub-volumes, which we denote as "slab". This enables the evaluation of chi_...

  1. The Slab Method to Measure the Topological Susceptibility

    CERN Document Server

    Bietenholz, Wolfgang; de Forcrand, Philippe; Dromard, Arthur; Gerber, Urs

    2016-01-01

    In simulations of a model with topological sectors, algorithms which proceed in small update steps tend to get stuck in one sector, especially on fine lattices. This distorts the numerical results, in particular it is not straightforward to measure the topological susceptibility chi_t. We test a method to measure chi_t even if configurations from only one sector are available. It is based on the topological charges in sub-volumes, which we denote as "slabs". This enables the evaluation of chi_t, as we demonstrate with numerical results for non-linear sigma-models and for 2-flavour QCD.

  2. Subwavelength electromagnetic dynamics in stacked complementary plasmonic crystal slabs.

    Science.gov (United States)

    Iwanaga, Masanobu

    2010-07-19

    Resonant electromagnetic fields in stacked complementary plasmonic crystal slabs (sc-PlCSs) are numerically explored in subwavelength dimensions. It is found that the local plasmon resonances in the sc-PlCSs are composite states of locally enhanced electric and magnetic fields. Two sc-PlCSs are analyzed in this paper and it is shown that each sc-PlCS realizes a resonant electromagnetic state suggested by one of Maxwell equations. It is moreover clarified that the local plasmons open efficient paths of Poynting flux, those result in high-contrast polarized transmission.

  3. CONCRETE PROPERTIES IMPROVEMENT OF SLAB TRACKS USING CHEMICAL ADDITIVES

    Directory of Open Access Journals (Sweden)

    V. V. Pristinskaya

    2015-11-01

    Full Text Available Purpose. On the Railways of Ukraine a very large number of slab tracks are operated with cracks. Many scientific works of previous years are dedicated to improving the design of slab tracks. The main causes of defects are: poor exploitation of the track; insufficient physic-mechanical characteristics of concrete; poor quality of initial materials. It is therefore necessary to develop an optimum concrete mix for the manufacture of these concrete products. Methodology. To assess the impact of individual factors and effects of their interactions on properties of concrete mix and concrete method of experimental and statistical modeling was used. At this, methodological fundamentals of mathematical experiment planning in concrete technology and modern methods of optimization of composite materials were taking into account. Based on the obtained data during the planned experiment conducting, including15 studies and using the computer program MathCad, were obtained the regression equations, which describe the relevant physical and mechanical properties of concrete. On the basis of the equations with the help of computer program MATLAB R2012b the graphs were drawn, illustrating the dependences of system response from the changes of two factors at a fixed value of the third factor. Findings. Firstly was the analysis of cracks that occur in the process of operation in the constructions of slab tracks. Further reasons of possible occurrence of these cracks were presented. In the process of the conducted research the author has concluded that for rational concrete mix development it is necessary to conduct the planned experiment with the use of quality materials. It was established that to increase the strength, chemical additives should be added in to concrete mix, it will let reduce cement amount. Originality. Experiments proved the usage of modern chemical additives in order to improve the properties of concrete. Models were developed, reflecting

  4. Effects of Reinforcement Configuration on Reserve Capacity of Concrete Slabs

    Science.gov (United States)

    1985-08-01

    Reinforced concreted Tensile membrane,, Buried shelters/ Shelters/ ..i, Civil defense, Slab capacity, 120. A34TlRACT rCcnhma in~ r aidit noe..era aad...CHAPTER 1 I XTPODLCT, CI At the- iiti it io., of this Study civil d~efense plwlgcalled for the .;evacuation of nonessenrt*I51 pezrsonnel to safe (lower...lqbal and Derecho (Reference 10). The reinforcement ratio, p , was 0.0062 in "Christianscn’s te,;tts and varied from 0.0023 to 0.0093 in Roberts’ tests

  5. Structure-based coarse-graining in liquid slabs.

    Science.gov (United States)

    Jochum, Mara; Andrienko, Denis; Kremer, Kurt; Peter, Christine

    2012-08-14

    Structure-based coarse-graining relies on matching the pair correlation functions of a reference (atomistic) and a coarse-grained system. As such, it is designed for systems with uniform density distributions. Here, we demonstrate how it can be generalized for inhomogeneous systems by coarse-graining slabs of liquid water and methanol in vacuum, as well as a single benzene molecule at the water-vacuum interface. Our conclusion is that coarse-graining performed in inhomogeneous systems improves thermodynamic properties and the structure of interfaces without significant alterations to the local structure of the bulk liquid.

  6. Tomography of the subducting Pacific slab and the 2015 Bonin deepest earthquake (Mw 7.9)

    Science.gov (United States)

    Zhao, Dapeng; Fujisawa, Moeto; Toyokuni, Genti

    2017-01-01

    On 30 May 2015 an isolated deep earthquake (~670 km, Mw 7.9) occurred to the west of the Bonin Islands. To clarify its causal mechanism and its relationship to the subducting Pacific slab, we determined a detailed P-wave tomography of the deep earthquake source zone using a large number of arrival-time data. Our results show that this large deep event occurred within the subducting Pacific slab which is penetrating into the lower mantle. In the Izu-Bonin region, the Pacific slab is split at ~28° north latitude, i.e., slightly north of the 2015 deep event hypocenter. In the north the slab becomes stagnant in the mantle transition zone, whereas in the south the slab is directly penetrating into the lower mantle. This deep earthquake was caused by joint effects of several factors, including the Pacific slab’s fast deep subduction, slab tearing, slab thermal variation, stress changes and phase transformations in the slab, and complex interactions between the slab and the ambient mantle. PMID:28295018

  7. Cause Analysis on the Void under Slabs of Cement Concrete Pavement

    Science.gov (United States)

    Wen, Li; Zhu, Guo Xin; Baozhu

    2017-06-01

    This paper made a systematic analysis on the influence of the construction, environment, water and loads on the void beneath road slabs, and also introduced the formation process of structural void and pumping void, and summarizes the deep reasons for the bottom of the cement concrete pavement. Based on the analysis above, this paper has found out the evolution law of the void under slabs which claimed that the void usually appeared in the slab corners and then the cross joint, resulting void in the four sides with the void area under the front slab larger than the rear one.

  8. Displacement-based seismic design of flat slab-shear wall buildings

    Science.gov (United States)

    Sen, Subhajit; Singh, Yogendra

    2016-06-01

    Flat slab system is becoming widely popular for multistory buildings due to its several advantages. However, the performance of flat slab buildings under earthquake loading is unsatisfactory due to their vulnerability to punching shear failure. Several national design codes provide guidelines for designing flat slab system under gravity load only. Nevertheless, flat slab buildings are also being constructed in high seismicity regions. In this paper, performance of flat slab buildings of various heights, designed for gravity load alone according to code, is evaluated under earthquake loading as per ASCE/SEI 41 methodology. Continuity of slab bottom reinforcement through column cage improves the performance of flat slab buildings to some extent, but it is observed that these flat slab systems are not adequate in high seismicity areas and need additional primary lateral load resisting systems such as shear walls. A displacement-based method is proposed to proportion shear walls as primary lateral load resisting elements to ensure satisfactory performance. The methodology is validated using design examples of flat slab buildings with various heights.

  9. Flexural Strengthening of RC Slabs Using a Hybrid FRP-UHPC System Including Shear Connector

    Directory of Open Access Journals (Sweden)

    Jiho Moon

    2017-01-01

    Full Text Available A polymeric hybrid composite system made of UHPC and CFRP was proposed as a retrofit system to enhance flexural strength and ductility of RC slabs. While the effectiveness of the proposed system was confirmed previously through testing three full-scale one-way slabs having two continuous spans, the slabs retrofitted with the hybrid system failed in shear. This sudden shear failure would stem from the excessive enhancement of the flexural strength over the shear strength. In this study, shear connectors were installed between the hybrid system and a RC slab. Using simple beam, only positive moment section was examined. Two full-scale RC slabs were cast and tested to failure: the first as a control and the second using this new strengthening technique. The proposed strengthening system increased the ultimate load carrying capacity of the slab by 70%, the stiffness by 60%, and toughness by 128%. The efficiency of shear connectors on ductile behavior of the retrofitted slab was also confirmed. After the UHPC top is separated from the slab, the shear connector transfer shear load and the slab system were in force equilibrium by compression in UHPC and tension in CFRP.

  10. Abnormal seismological and magmatic processes controlled by the tearing South American flat slabs

    Science.gov (United States)

    Hu, Jiashun; Liu, Lijun

    2016-09-01

    The influence of flat slab subduction on the formation of intra-slab earthquakes, volcanic activities and mantle seismic velocity anomalies remains unclear. We attempt to better understand these processes by simulating the two flat slabs in Peru and Chile using data-orientated geodynamic models. Our results successfully reproduce the observed flat slabs as mainly due to two subducting aseismic ridges. In contrast to the traditional view of flat-slab subduction, we find that these slabs are internally torn, as is due to the 3D nature of the subducting buoyancy features. This broken slab configuration, confirmed by regional tomography, naturally explains the abnormal distribution of and stress regimes associated with the intermediate-depth earthquakes. We further show that the slab tearing process could also better explain the formation of adakitic and ore-forming magmatism, the evolution of the magmatic arc, and the enigmatic mantle seismic structures beneath these regions. We propose that slab tearing may represent a common result of buoyancy feature subduction and that the resulting mantle processes could affect the long-term geodynamic evolution of continents.

  11. Optimising the Slab Yard Planning and Crane Scheduling Problem using a two-stage heuristic

    DEFF Research Database (Denmark)

    Hansen, Anders Dohn; Clausen, Jens

    2010-01-01

    In this paper, we present the Slab Yard Planning and Crane Scheduling Problem. The problem has its origin in steel production facilities with a large throughput. A slab yard is used as a buffer for slabs that are needed in the upcoming production. Slabs are transported by cranes and the problem...... tests are run on a generic setup with simulated data. The test results are very promising. The production delays are reduced significantly in the new solutions compared with the corresponding delays observed in a simulation of manual planning....

  12. Tomography of the subducting Pacific slab and the 2015 Bonin deepest earthquake (Mw 7.9)

    Science.gov (United States)

    Zhao, Dapeng; Fujisawa, Moeto; Toyokuni, Genti

    2017-03-01

    On 30 May 2015 an isolated deep earthquake (~670 km, Mw 7.9) occurred to the west of the Bonin Islands. To clarify its causal mechanism and its relationship to the subducting Pacific slab, we determined a detailed P-wave tomography of the deep earthquake source zone using a large number of arrival-time data. Our results show that this large deep event occurred within the subducting Pacific slab which is penetrating into the lower mantle. In the Izu-Bonin region, the Pacific slab is split at ~28° north latitude, i.e., slightly north of the 2015 deep event hypocenter. In the north the slab becomes stagnant in the mantle transition zone, whereas in the south the slab is directly penetrating into the lower mantle. This deep earthquake was caused by joint effects of several factors, including the Pacific slab’s fast deep subduction, slab tearing, slab thermal variation, stress changes and phase transformations in the slab, and complex interactions between the slab and the ambient mantle.

  13. A Comparative Study of Strength of Two-Way Rectangular Slabs with and without Openings

    Science.gov (United States)

    Ravindra, M.; Rakesh, V.; Rambabu, K.

    2016-09-01

    The present work uses yield-line theory to find the strength of uniformly loaded rectangular reinforced concrete slabs with and without rectangular openings. Five positions of openings are considered, i.e. the slab centre, the slab corner, the centre of a short side, the centre of a long side and the opening eccentric to the slab centre. All possible admissible yield line patterns are considered for all given configurations of the slab subjected to uniformly distributed load keeping in view the basic principles of yield line theory. The ratios of the corresponding lengths of the sides of the opening and the slab are different and sizes of opening up to 0.4× the length of the slab sides are considered. Symmetric edge conditions like continuous slab, simply supported, two long sides continuous and two short sides continuous are considered for various sizes of openings in order to plot the design charts for isotropic reinforcement coefficients only. Affine transformation is also performed for slab with openings.

  14. A generalized slab-wise framework for parallel transmit multiband RF pulse design

    Science.gov (United States)

    Wu, Xiaoping; Schmitter, Sebastian; Auerbach, Edward J.; Uğurbil, Kâmil; de Moortele, Pierre-François Van

    2015-01-01

    Purpose We propose a new slab-wise framework to design parallel transmit multi-band pulses for volumetric simultaneous multi-slice imaging with a large field of view along the slice direction (FOVs). Theory and Methods The slab-wise framework divides FOVs into a few contiguous slabs and optimizes pulses for each slab. Effects of relevant design parameters including slab number and transmit B1 (B1+) mapping slice placement were investigated for human brain imaging by designing pulses with global or local SAR control based on electromagnetic simulations of a 7T head RF array. Pulse design using in-vivo B1+ maps was demonstrated and evaluated with Bloch simulations. Results RF performance with respect to SAR reduction or B1+ homogenization across the entire human brain improved with increasing slabs; however, this improvement was non-linear and leveled off at ~12 slabs when the slab thickness reduced to ~12 mm. The impact of using different slice placements for B1+ mapping was small. Conclusion Compared to slice-wise approaches where each of the many imaging slices requires both B1+ mapping and pulse optimization, the proposed slab-wise design framework is shown to attain comparable RF performance while drastically reducing the number of required pulses; therefore, it can be used to increase time efficiency for B1+ mapping, pulse calculation and sequence preparation. PMID:25994797

  15. General Assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : 1- Adoption de l’ordre du jour. 2- Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. 3- Présentation et approbation du rapport d’activités 2014. 4- Présentation et approbation du rapport financier 2014. 5- Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. 6- Programme 2015. 7- Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. 8- Pas de modifications aux Statuts de l'Association du personnel proposée. 9- Élections des membres de la Commission é...

  16. General Assembly

    CERN Multimedia

    Staff Association

    2016-01-01

    Mardi 5 avril à 11 h 00 BE Auditorium Meyrin (6-2-024) Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 mai 2015. Présentation et approbation du rapport d’activités 2015. Présentation et approbation du rapport financier 2015. Présentation et approbation du rapport des vérificateurs aux comptes pour 2015. Programme de travail 2016. Présentation et approbation du projet de budget 2016 Approbation du taux de cotisation pour 2017. Modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commissio...

  17. General assembly

    CERN Multimedia

    Staff Association

    2015-01-01

    Mardi 5 mai à 11 h 00 Salle 13-2-005 Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 22 mai 2014. Présentation et approbation du rapport d’activités 2014. Présentation et approbation du rapport financier 2014. Présentation et approbation du rapport des vérificateurs aux comptes pour 2014. Programme 2015. Présentation et approbation du projet de budget 2015 et taux de cotisation pour 2015. Pas de modifications aux Statuts de l'Association du personnel proposée. Élections des membres de la Commission électorale. &am...

  18. General Assembly

    CERN Multimedia

    Staff Association

    2017-01-01

    Conformément aux statuts de l’Association du personnel, une Assemblée générale ordinaire est organisée une fois par année (article IV.2.1). Projet d’ordre du jour : Adoption de l’ordre du jour. Approbation du procès-verbal de l’Assemblée générale ordinaire du 5 avril 2016. Présentation et approbation du rapport d’activités 2016. Présentation et approbation du rapport financier 2016. Présentation et approbation du rapport des vérificateurs aux comptes pour 2016. Programme de travail 2017. Présentation et approbation du projet de budget 2017 Approbation du taux de cotisation pour 2018. Modifications aux Statuts de l'Association du personnel proposées. Élections des membres de la Commission électorale. Élections des vérifica...

  19. Relations between pregnancy-related low back pain, pelvic floor activity and pelvic floor dysfunction.

    NARCIS (Netherlands)

    Pool-Goudzwaard, A.; Slieker ten Hove, M.C.; Vierhout, M.E.; Mulder, P.H.M. de; Pool, J.; Snijders, C.J.; Stoeckart, R.

    2005-01-01

    To assess the occurrence of pelvic floor dysfunction (PFD) in pregnancy- related low back and pelvic pain (PLBP) patients, a cross-sectional study was performed, comprising 77 subjects. Each subject underwent physical assessment, and filled in the Urogenital Distress Inventory completed with gynaeco

  20. Building concepts - Floor concepts. Towards more added value for precast concrete floors

    NARCIS (Netherlands)

    Donkervoort, D.R.; Kroon, J.C.A. de; Vullings, M.W.F.; Geurts, C.P.W.

    2005-01-01

    In the Netherlands, precast concrete are preffered for floors in residential buildings. Typical for the dutch building process is the labor intensive and time consuming character, which has considerable risks for building contractors, many parties are involved and, consequently, there are many

  1. Collection and Management of Shop-floor ControllerData

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper describes shop-floor data collection and management. An arc hitecture is presented for a shop-floor data collection and management system b a sed on the analysis of the features of these data. Two critical aspects of the s ystem are discussed in detail: the various communication protocols between compu ters and machines, and the real-time demands of the shop-floor controller.

  2. Tactile Imaging Markers to Characterize Female Pelvic Floor Conditions.

    Science.gov (United States)

    van Raalte, Heather; Egorov, Vladimir

    2015-08-01

    The Vaginal Tactile Imager (VTI) records pressure patterns from vaginal walls under an applied tissue deformation and during pelvic floor muscle contractions. The objective of this study is to validate tactile imaging and muscle contraction parameters (markers) sensitive to the female pelvic floor conditions. Twenty-two women with normal and prolapse conditions were examined by a vaginal tactile imaging probe. We identified 9 parameters which were sensitive to prolapse conditions (p pelvic floor prolapse.

  3. A Review on Forearc Ophiolite Obduction, Adakite-Like Generation, and Slab Window Development at the Chile Triple Junction Area: Uniformitarian Framework for Spreading-Ridge Subduction

    Science.gov (United States)

    Bourgois, Jacques; Lagabrielle, Yves; Martin, Hervé; Dyment, Jérôme; Frutos, Jose; Cisternas, Maria Eugenia

    2016-10-01

    This paper aggregates the main basic data acquired along the Chile Triple Junction (CTJ) area (45°-48°S), where an active spreading center is presently subducting beneath the Andean continental margin. Updated sea-floor kinematics associated with a comprehensive review of geologic, geochemical, and geophysical data provide new constraints on the geodynamics of this puzzling area. We discuss: (1) the emplacement mode for the Pleistocene Taitao Ridge and the Pliocene Taitao Peninsula ophiolite bodies. (2) The occurrence of these ophiolitic complexes in association with five adakite-like plutonic and volcanic centers of similar ages at the same restricted locations. (3) The inferences from the co-occurrence of these sub-coeval rocks originating from the same subducting oceanic lithosphere evolving through drastically different temperature-pressure ( P- T) path: low-grade greenschist facies overprint and amphibolite-eclogite transition, respectively. (4) The evidences that document ridge-jump events and associated microplate individualization during subduction of the SCR1 and SCR-1 segments: the Chonos and Cabo Elena microplates, respectively. The ridge-jump process associated with the occurrence of several closely spaced transform faults entering subduction is controlling slab fragmentation, ophiolite emplacement, and adakite-like production and location in the CTJ area. Kinematic inconsistencies in the development of the Patagonia slab window document an 11- km westward jump for the SCR-1 spreading segment at ~6.5-to-6.8 Ma. The SCR-1 spreading center is relocated beneath the North Patagonia Icefield (NPI). We argue that the deep-seated difference in the dynamically sustained origin of the high reliefs of the North and South Patagonia Icefield (NPI and SPI) is asthenospheric convection and slab melting, respectively. The Chile Triple Junction area provides the basic constraints to define the basic signatures for spreading-ridge subduction beneath an Andean

  4. A Review on Forearc Ophiolite Obduction, Adakite-Like Generation, and Slab Window Development at the Chile Triple Junction Area: Uniformitarian Framework for Spreading-Ridge Subduction

    Science.gov (United States)

    Bourgois, Jacques; Lagabrielle, Yves; Martin, Hervé; Dyment, Jérôme; Frutos, Jose; Cisternas, Maria Eugenia

    2016-05-01

    This paper aggregates the main basic data acquired along the Chile Triple Junction (CTJ) area (45°-48°S), where an active spreading center is presently subducting beneath the Andean continental margin. Updated sea-floor kinematics associated with a comprehensive review of geologic, geochemical, and geophysical data provide new constraints on the geodynamics of this puzzling area. We discuss: (1) the emplacement mode for the Pleistocene Taitao Ridge and the Pliocene Taitao Peninsula ophiolite bodies. (2) The occurrence of these ophiolitic complexes in association with five adakite-like plutonic and volcanic centers of similar ages at the same restricted locations. (3) The inferences from the co-occurrence of these sub-coeval rocks originating from the same subducting oceanic lithosphere evolving through drastically different temperature-pressure (P-T) path: low-grade greenschist facies overprint and amphibolite-eclogite transition, respectively. (4) The evidences that document ridge-jump events and associated microplate individualization during subduction of the SCR1 and SCR-1 segments: the Chonos and Cabo Elena microplates, respectively. The ridge-jump process associated with the occurrence of several closely spaced transform faults entering subduction is controlling slab fragmentation, ophiolite emplacement, and adakite-like production and location in the CTJ area. Kinematic inconsistencies in the development of the Patagonia slab window document an 11- km westward jump for the SCR-1 spreading segment at ~6.5-to-6.8 Ma. The SCR-1 spreading center is relocated beneath the North Patagonia Icefield (NPI). We argue that the deep-seated difference in the dynamically sustained origin of the high reliefs of the North and South Patagonia Icefield (NPI and SPI) is asthenospheric convection and slab melting, respectively. The Chile Triple Junction area provides the basic constraints to define the basic signatures for spreading-ridge subduction beneath an Andean

  5. FUEL ASSEMBLY SHAKER TEST SIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Klymyshyn, Nicholas A.; Sanborn, Scott E.; Adkins, Harold E.; Hanson, Brady D.

    2013-05-30

    direct comparison of model results to recorded test results. This does not offer validation for the fuel assembly model in all conceivable cases, such as high kinetic energy shock cases where the fuel assembly might lift off the basket floor to strike to basket ceiling. This type of nonlinear behavior was not witnessed in testing, so the model does not have test data to be validated against.a basis for validation in cases that substantially alter the fuel assembly response range. This leads to a gap in knowledge that is identified through this modeling study. The SNL shaker testing loaded a surrogate fuel assembly with a certain set of artificially-generated time histories. One thing all the shock cases had in common was an elimination of low frequency components, which reduces the rigid body dynamic response of the system. It is not known if the SNL test cases effectively bound all highway transportation scenarios, or if significantly greater rigid body motion than was tested is credible. This knowledge gap could be filled through modeling the vehicle dynamics of a used fuel conveyance, or by collecting acceleration time history data from an actual conveyance under highway conditions.

  6. Acoustics. Measurement of sound insulation in buildings and of building elements. Laboratory measurements of the reduction of transmitted impact noise by floor coverings on a heavyweight standard floor

    CERN Document Server

    British Standards Institution. London

    1998-01-01

    Acoustics. Measurement of sound insulation in buildings and of building elements. Laboratory measurements of the reduction of transmitted impact noise by floor coverings on a heavyweight standard floor

  7. Slab waveguide photobioreactors for microalgae based biofuel production.

    Science.gov (United States)

    Jung, Erica Eunjung; Kalontarov, Michael; Doud, Devin F R; Ooms, Matthew D; Angenent, Largus T; Sinton, David; Erickson, David

    2012-10-07

    Microalgae are a promising feedstock for sustainable biofuel production. At present, however, there are a number of challenges that limit the economic viability of the process. Two of the major challenges are the non-uniform distribution of light in photobioreactors and the inefficiencies associated with traditional biomass processing. To address the latter limitation, a number of studies have demonstrated organisms that directly secrete fuels without requiring organism harvesting. In this paper, we demonstrate a novel optofluidic photobioreactor that can help address the light distribution challenge while being compatible with these chemical secreting organisms. Our approach is based on light delivery to surface bound photosynthetic organisms through the evanescent field of an optically excited slab waveguide. In addition to characterizing organism growth-rates in the system, we also show here, for the first time, that the photon usage efficiency of evanescent field illumination is comparable to the direct illumination used in traditional photobioreactors. We also show that the stackable nature of the slab waveguide approach could yield a 12-fold improvement in the volumetric productivity.

  8. IMPROVING THE EFFICIENCY OF MINERAL WOOL SLABS TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Perfilov Vladimir Aleksandrovich

    2016-03-01

    Full Text Available The use of thermal insulation materials is an effective method to create an insulating envelope of a building, as well as to reduce energy costs and increase the durability of building structures. The properties of stone wool products and their operational durability is largely determined by the conditions of formation of the mineral wool carpet, uniform distribution of binder and its curing and the heat treatment conditions. Most domestic technologies are aimed at the production of mineral wool products with volume-oriented structure, which is formed using special units: spreader and corrugator placed in a production line. The next step to obtain the optimum structures is the production of dual density slabs. The denser upper layer receives mechanical loads caused by the operating conditions; the lower, less dense, but more thick layer performs the main function - insulation. The dual density slabs are produced on standard lines supplemented with a special unit, which is located in front of the heat treatment camera. Optimization of heat treatment parameters and prediction of the properties of materials is performed using software package.

  9. Trench migration, net rotation and slab mantle coupling

    Science.gov (United States)

    Funiciello, F.; Faccenna, C.; Heuret, A.; Lallemand, S.; Di Giuseppe, E.; Becker, T. W.

    2008-07-01

    Laboratory models have been conducted to improve our understanding of the role that the resistance of the slab to bending and its coupling to the ambient mantle play in subduction dynamics over geological time scales. Our models are set up with a viscous plate of silicone (lithosphere) subducting under negative buoyancy in a viscous layer of glucose syrup (mantle). For our study, the lithosphere/upper mantle viscosity contrast has been systematically varied, from ~ 10 to ~ 10 5 in order to explore the parameter space between weak and strong slab dynamics. We found that subduction is characterized by a retreating mode for viscosity ratios > 10 4, by the coexistence of a retreating mode and an advancing mode for viscosity ratios between ~ 10 4 and ~ 10 2, and quasi-stationary, Rayleigh-Taylor like behaviour for ratios < 10 2. By combining our experimental results and kinematic data from current subduction zones in four reference frames which differ in the amount of net rotation, we infer that a lithosphere/upper mantle viscosity contrast of 150-500 is necessary to obtain realistic trench/subducting plate velocity ratios as well as the variability of subduction styles observed in nature.

  10. Spike-and-Slab Sparse Coding for Unsupervised Feature Discovery

    CERN Document Server

    Goodfellow, Ian J; Bengio, Yoshua

    2012-01-01

    We consider the problem of using a factor model we call {\\em spike-and-slab sparse coding} (S3C) to learn features for a classification task. The S3C model resembles both the spike-and-slab RBM and sparse coding. Since exact inference in this model is intractable, we derive a structured variational inference procedure and employ a variational EM training algorithm. Prior work on approximate inference for this model has not prioritized the ability to exploit parallel architectures and scale to enormous problem sizes. We present an inference procedure appropriate for use with GPUs which allows us to dramatically increase both the training set size and the amount of latent factors. We demonstrate that this approach improves upon the supervised learning capabilities of both sparse coding and the ssRBM on the CIFAR-10 dataset. We evaluate our approach's potential for semi-supervised learning on subsets of CIFAR-10. We demonstrate state-of-the art self-taught learning performance on the STL-10 dataset and use our m...

  11. ROBUST RVM BASED ON SPIKE-SLAB PRIOR

    Institute of Scientific and Technical Information of China (English)

    Ding Xinghao; Mi Zengyuan; Huang Yue; Jin Wenbo

    2012-01-01

    Although Relevance Vector Machine (RVM) is the most popular algorithms in machine learning and computer vision,outliers in the training data make the estimation unreliable.In the paper,a robust RVM model under non-parametric Bayesian framework is proposed.We decompose the noise term in the RVM model into two components,a Gaussian noise term and a spiky noise term.Therefore the observed data is assumed represented as:y=Dw+s+e,where Dw is the relevance vector component,of which D is the kernel function matrix and w is the weight matrix,s is the spiky term and e is the Gaussian noise term.A spike-slab sparse prior is imposed on the weight vector w,which gives a more intuitive constraint on the sparsity than the Student's t-distribution described in the traditional RVM.For the spiky component s,a spike-slab sparse prior is also introduced to recognize outliers in the training data effectively.Several experiments demonstrate the better performance over the RVM regression.

  12. Oscillating Casimir force between two slabs in a Fermi sea

    Institute of Scientific and Technical Information of China (English)

    Chen Li-Weia; Su Guo-Zhen; Chen Jin-Can; Andresen Bjarne

    2012-01-01

    The Casimir effect for two parallel slabs immersed in an ideal Fermi sea is investigated at both zero and nonzero temperatures.It is found that the Casimir effect in a Fermi gas is distinctly different from that in an electromagnetic field or a massive Bose gas.In contrast to the familiar result that the Casimir force decreases monotonically with the increase of the separation L between two slabs in an electromagnetic field and a massive Bose gas,the Casimir force in a Fermi gas oscillates as a function of L.The Casimir force can be either attractive or repulsive,depending sensitively on the magnitude of L. In addition,it is found that the amplitude of the Casimir force in a Fermi gas decreases with the increase of the temperature,which also is contrary to the case in a Bose gas,since the bosonic Casimir force increases linearly with the increase of the temperature in the region T < Tc,where Tc is the critical temperature of the Bose-Einstein condensation.

  13. MODELING OF TRANSIENT HEAT TRANSFER IN FOAMED CONCRETE SLAB

    Directory of Open Access Journals (Sweden)

    MD AZREE OTHUMAN MYDIN

    2013-06-01

    Full Text Available This paper reports the basis of one-dimensional Finite Difference method to obtain thermal properties of foamed concrete in order to solve transient heat conduction problems in multi-layer panels. In addition, this paper also incorporates the implementation of the method and the validation of thermal properties model of foamed concrete. A one-dimensional finite difference heat conduction programme has been developed to envisage the temperature development through the thickness of the foamed concrete slab, based on an initial estimate of the thermal conductivity-temperature relationship as a function of porosity and radiation within the voids. The accuracy of the model was evaluated by comparing predicted and experimental temperature profiles obtained from small scale heat transfer test on foamed concrete slabs, so that the temperature history of the specimen calculated by the programme closely matches those recorded during the experiment. Using the thermal properties of foamed concrete, the validated heat transfer program predicts foamed concrete temperatures in close agreement with experimental results obtained from a number of high temperature tests. The proposed numerical and thermal properties are simple yet efficient and can be utilised to aid manufacturers to develop their products without having to conduct numerous large-scale fire tests.

  14. Magnetohydrodynamic stability of natural convection in a vertical porous slab

    Science.gov (United States)

    Shankar, B. M.; Kumar, Jai; Shivakumara, I. S.

    2017-01-01

    The stability of the conduction regime of natural convection in an electrically conducting fluid saturated porous vertical slab is investigated in the presence of a uniform external transverse magnetic field. The flow in the porous medium is described by modified Brinkman-extended Darcy equation with fluid viscosity different from effective viscosity. The boundaries of the vertical porous slab are assumed to be rigid-isothermal and electrically non-conducting. The resulting stability equations are solved numerically using Galerkin method. The critical Grashof number Gc, the critical wave number αc and the critical wave speed cc are computed for a wide range of porous parameter σp, the ratio of effective viscosity to the fluid viscosity Λ, the Prandtl number Pr and the Hartmann number M. Based on these parameters, the stability characteristics of the system are discussed in detail. The presence of advective inertia is to instill instability on the flow in a porous medium and found that the magnetic field, porous parameter and ratio of viscosities have a stabilizing effect on both stationary and oscillatory wave instabilities. Besides, the value of Pr at which transition occurs from stationary to oscillatory mode of instability decreases with increasing M ,σp and Λ .

  15. Effects of rubberized flooring on Asian elephant behavior in captivity.

    Science.gov (United States)

    Meller, Camie L; Croney, Candace C; Shepherdson, David

    2007-01-01

    Six Asian elephants at the Oregon Zoo were observed to determine the effects of a poured rubber flooring substrate on captive Asian elephant behavior. Room utilization also was evaluated in seven rooms used for indoor housing, including Front and Back observation areas. Data were collected in three phases. Phase I (Baseline Phase) examined elephant behavior on old concrete floors. In Phase II (Choice Phase), elephant behavior was observed in the Back observation area where room sizes were comparable and when a choice of flooring substrates was available. Phase III (Final Phase) examined elephant behavior when all rooms in both observation areas, Front and Back, were converted to rubberized flooring. Room use in both observation areas remained stable throughout the study, suggesting that flooring substrate did not affect room use choice. However, there was a clear pattern of decreased discomfort behaviors on the new rubber flooring. Normal locomotion as well as stereotypic locomotion increased on the new rubber flooring. In addition, resting behavior changed to more closely reflect the resting behavior of wild elephants, which typically sleep standing up, and spend very little time in lateral recumbence. Overall, these findings suggest that the rubber flooring may have provided a more comfortable surface for locomotion as well as standing resting behavior. It is suggested that poured rubber flooring may be a beneficial addition to similar animal facilities. Zoo Biol 0:1-11, 2007. (c) 2007 Wiley-Liss, Inc.

  16. Pelvic Organ Prolapse: New Concepts in Pelvic Floor Anatomy.

    Science.gov (United States)

    Maldonado, Pedro A; Wai, Clifford Y

    2016-03-01

    As the field of reconstructive pelvic surgery continues to evolve, with descriptions of new procedures to repair pelvic organ prolapse, it remains imperative to maintain a functional understanding of pelvic floor anatomy and support. The goal of this review was to provide a focused, conceptual approach to differentiating anatomic defects contributing to prolapse in the various compartments of the vagina. Rather than provide exhaustive descriptions of pelvic floor anatomy, basic pelvic floor anatomy is reviewed, new and historical concepts of pelvic floor support are discussed, and relevance to the surgical management of specific anatomic defects is addressed.

  17. Obtaining and Estimating Low Noise Floors in Vibration Sensors

    DEFF Research Database (Denmark)

    Brincker, Rune; Larsen, Jesper Abildgaard

    2007-01-01

    For some applications like seismic applications and measuring ambient vibrations in structures, it is essential that the noise floors of the sensors and other system components are low and known to the user. Some of the most important noise sources are reviewed and it is discussed how the sensor...... can be designed in order to obtain a low noise floor. Techniques to estimate the noise floors for sensors are reviewed and are demonstrated on a commercial commonly used sensor for vibration testing. It is illustrated how the noise floor can be calculated using the coherence between simultaneous...

  18. Analysis of Wood Floor Industry's Development in China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    As an emerging industry,China's wood floor industry dates back to the early 1980s. Despite a late start,it has developed rapidly during the last 20 years.The past decades have witnessed great changes in China's wood floor industry.With high quality,many products"made in China"are available widely abroad nowadays.Current global economic shocks,however,affect China's domestic real estate sector;hence the falling domestic sales of wood floor.The paper aims to identify the current situation of floor industry...

  19. Mantle flow and dynamic topography associated with slab window opening: Insights from laboratory models

    Science.gov (United States)

    Guillaume, Benjamin; Moroni, Monica; Funiciello, Francesca; Martinod, Joseph; Faccenna, Claudio

    2010-12-01

    We present dynamically self-consistent mantle-scale laboratory models that have been conducted to improve our understanding of the influence of slab window opening on subduction dynamics, mantle flow and associated dynamic topography over geological time scales. The adopted setup consists of a two-layer linearly viscous system simulating the subduction of a fixed plate of silicone (lithosphere) under negative buoyancy in a viscous layer of glucose syrup (mantle). Our experimental setting is also characterized by a constant-width rectangular window located at the center of a laterally confined slab, modeling the case of the interaction of a trench-parallel spreading ridge with a wide subduction zone. We found that the opening of a slab window does not produce consistent changes of the geometry and the kinematics of the slab. On the contrary, slab-induced mantle circulation, quantified both in the vertical and horizontal sections using the Feature Tracking image analysis technique, is strongly modified. In particular, rollback subduction and the opening of the slab window generate a complex mantle circulation pattern characterized by the presence of poloidal and toroidal components, with the importance of each evolving according to kinematic stages. Mantle coming from the oceanic domain floods through the slab window, indenting the supra-slab mantle zone and producing its deformation without any mixing between mantle portions. The opening of the slab window and the upwelling of sub-slab mantle produce a regional-scale non-isostatic topographic uplift of the overriding plate that would correspond to values ranging between ca. 1 and 5 km in nature. Assuming that our modeling results can be representative of the natural behavior of subduction zones, we compared them to the tectonics and volcanism of the Patagonian subduction zone. We found that the anomalous backarc volcanism that has been developing since the middle Miocene could result from the lateral flow of sub-slab

  20. The role of ridges in the formation and longevity of flat slabs.

    Science.gov (United States)

    Antonijevic, Sanja Knezevic; Wagner, Lara S; Kumar, Abhash; Beck, Susan L; Long, Maureen D; Zandt, George; Tavera, Hernando; Condori, Cristobal

    2015-08-13

    Flat-slab subduction occurs when the descending plate becomes horizontal at some depth before resuming its descent into the mantle. It is often proposed as a mechanism for the uplifting of deep crustal rocks ('thick-skinned' deformation) far from plate boundaries, and for causing unusual patterns of volcanism, as far back as the Proterozoic eon. For example, the formation of the expansive Rocky Mountains and the subsequent voluminous volcanism across much of the western USA has been attributed to a broad region of flat-slab subduction beneath North America that occurred during the Laramide orogeny (80-55 million years ago). Here we study the largest modern flat slab, located in Peru, to better understand the processes controlling the formation and extent of flat slabs. We present new data that indicate that the subducting Nazca Ridge is necessary for the development and continued support of the horizontal plate at a depth of about 90 kilometres. By combining constraints from Rayleigh wave phase velocities with improved earthquake locations, we find that the flat slab is shallowest along the ridge, while to the northwest of the ridge, the slab is sagging, tearing, and re-initiating normal subduction. On the basis of our observations, we propose a conceptual model for the temporal evolution of the Peruvian flat slab in which the flat slab forms because of the combined effects of trench retreat along the Peruvian plate boundary, suction, and ridge subduction. We find that while the ridge is necessary but not sufficient for the formation of the flat slab, its removal is sufficient for the flat slab to fail. This provides new constraints on our understanding of the processes controlling the beginning and end of the Laramide orogeny and other putative episodes of flat-slab subduction.

  1. Effects of human-structure interaction in slabs

    OpenAIRE

    Villamizar, Sandra; Gómez, Daniel; Thomson, Peter

    2014-01-01

    During the last several decades, stronger and lighter materials have been developed with the aim of optimizing performance and building costs. These technological advances have given rise to thin flexible flooring systems with natural frequencies that lie within the frequency range of vibrations produced by human activity. Human occupants can cause changes in the dynamic properties of the structure and structural vibrations can cause discomfort to the occupants, who not only perceive the vibr...

  2. Investigation of the Adsorption and Self Assembly of Isocyanide Derivatives on Au(111) Surface

    Institute of Scientific and Technical Information of China (English)

    ZHOU,Jun-Hong; SHI,Liang-Wei; ZHANG,Tao; CHEN,Min-Bo

    2007-01-01

    The adsorption and self-assembly of isocyanide derivatives on Au(111) surface were investigated by density functional theory (DFT) and molecular dynamics simulation. The calculation for phenyl isocyanide by DFT was based on cluster and slab models. The self-assembled monolayers of 2-isocyanoazulene and 1,3-diethoxycarbonyl2-isocyanoazulene on Au(111) were simulated using Au-C force field parameters developed by us. It was found that the top site was the most preferred position, and the isocyanoazulene and its derivatives could form the ordered face to edge self-assembled monolayer on gold surface indeed, and the molecules stood on the gold surface vertically.

  3. Ocean Floor Geomagnetic Data Collection System.

    Science.gov (United States)

    1982-12-01

    All sections of the spar buoy shall be assembled o)nboard the Acacia wi4th exceptio-n of the upper mast prior to deployment. Attach :he crane line...dual traze oszIlloscopes. AN/PRC 77 radio sets serve as a voice communications link. The squip- ment arrangement i-s as shown ina Figure= 2.13. The ant ...before. Lo not assemble the ant -enna 2ast (9) :)n the spa: buoy at this point. Step 3: Take the fiber optic transmitter, caceiver and storage reel

  4. Design of a Slab Waveguide Multiaperture Fourier Spectrometer for Water Vapor Measurements in Earth's Atmosphere

    Science.gov (United States)

    Sinclair, Kenneth; Florjańczyk, Mirosław; Solheim, Brian; Scott, Alan; Quine, Ben; Cheben, Pavel

    Concept, theory and design of a new type of waveguide device, a multiaperture Fourier-transform planar waveguide spectrometer[1], implemented as a prototype instrument is pre-sented. The spectrometer's objective is to demonstrate the ability of the new slab waveguide technology for application in remote sensing instruments[2]. The spectrometer will use a limb viewing configuration to detect the 1.36um waveband allowing concentrations of water vapor in earth's atmosphere to be measured[3]. The most challenging aspects of the design, assembly and calibration are presented. Focus will be given to the effects of packaging the spectrometer and interfacing to the detector array. Stress-induced birefringence will affect the performance of the waveguides, therefore the design of a stress-free mounting over a range of temperatures is important. Spectral retrieval algo-rithms will have to correct for expected fabrication errors in the waveguides. Data processing algorithms will also be developed to correct for non-uniformities of input brightness through the array, making use of MMI output couplers to capture both the in-phase and anti-phase interferometer outputs. A performance assessment of an existing breadboard spectrometer will demonstrate the capability of the instrument. REFERENCES 1. M. Florjáczyk, P. Cheben, S. Janz, A. Scott, B. Solheim, and D.-X. Xu, "Multiaper-n ture planar waveguide spectrometer formed by arrayed Mach-Zehnder interferometers," Opt. Expr. 15(26), 18176-18189 (2007). 2. M. Florjáczyk, P. Cheben, S. Janz, B. Lamontagne, J. n Lapointe, A. Scott, B. Solheim, and D.-X. Xu, "Slab waveguiode spatial heterodyne spectrom-eters for remote sensing from space," Optical sensors 2009. Proceedings of the SPIE, Volume 7356 (2009)., pp. 73560V-73560V-7 (2009). 3. A. Scott, M. Florjáczyk, P. Cheben, S. Janz, n B. Solheim, and D.-X. Xu, "Micro-interferometer with high throughput for remote sensing." MOEMS and Miniaturized Systems VIII. Proceedings of the SPIE

  5. The impact of slab dip variations, gaps and rollback on mantle wedge flow: insights from fluids experiments

    Science.gov (United States)

    MacDougall, Julia G.; Kincaid, Chris; Szwaja, Sara; Fischer, Karen M.

    2014-05-01

    Observed seismic anisotropy and geochemical anomalies indicate the presence of 3-D flow around and above subducting slabs. To investigate how slab geometry and velocity affect mantle flow, we conducted a set of experiments using a subduction apparatus in a fluid-filled tank. Our models comprise two independently adjustable, continuous belts to represent discrete sections of subducting slabs that kinematically drive flow in the surrounding glucose syrup that represents the upper mantle. We analyse how slab dip (ranging from 30° to 80°), slab dip difference between slab segments (ranging from 20° to 50°), rates of subduction (4-8 cm yr-1) and slab/trench rollback (0-3 cm yr-1) affect mantle flow. Whiskers were used to approximate mineral alignment induced by the flow, as well as to predict directions of seismic anisotropy. We find that dip variations between slab segments generate 3-D flow in the mantle wedge, where the path lines of trenchward moving mantle material above the slab are deflected towards the slab segment with the shallower dip. The degree of path line deflection increases as the difference in slab dip between the segments increases, and, for a fixed dip difference, as slab dip decreases. In cases of slab rollback and large slab dip differences, we observe intrusion of subslab material through the gap and into the wedge. Flow through the gap remains largely horizontal before eventual downward entrainment. Whisker alignment in the wedge flow is largely trench-normal, except near the lateral edges of the slab where toroidal flow dominates. In addition, whisker azimuths located above the slab gap deviate most strongly from trench-normal orientations when slab rollback does not occur. Such flow field complexities are likely sufficient to affect deep melt production and shallow melt delivery. However, none of the experiments produced flow fields that explain the trench-parallel shear wave splitting fast directions observed over broad arc and backarc

  6. Experimental validation of systematically designed acoustic hyperbolic meta material slab exhibiting negative refraction

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Sigmund, Ole

    2016-01-01

    This Letter reports on the experimental validation of a two-dimensional acoustic hyperbolic metamaterial slab optimized to exhibit negative refractive behavior. The slab was designed using a topology optimization based systematic design method allowing for tailoring the refractive behavior. The e...

  7. Internal deformation of the subducted Nazca slab inferred from seismic anisotropy

    Science.gov (United States)

    Eakin, Caroline M.; Long, Maureen D.; Scire, Alissa; Beck, Susan L.; Wagner, Lara S.; Zandt, George; Tavera, Hernando

    2016-01-01

    Within oceanic lithosphere a fossilized fabric is often preserved originating from the time of plate formation. Such fabric is thought to form at the mid-ocean ridge when olivine crystals align with the direction of plate spreading. It is unclear, however, whether this fossil fabric is preserved within slabs during subduction or overprinted by subduction-induced deformation. The alignment of olivine crystals, such as within fossil fabrics, can generate anisotropy that is sensed by passing seismic waves. Seismic anisotropy is therefore a useful tool for investigating the dynamics of subduction zones, but it has so far proved difficult to observe the anisotropic properties of the subducted slab itself. Here we analyse seismic anisotropy in the subducted Nazca slab beneath Peru and find that the fast direction of seismic wave propagation aligns with the contours of the slab. We use numerical modelling to simulate the olivine fabric created at the mid-ocean ridge, but find it is inconsistent with our observations of seismic anisotropy in the subducted Nazca slab. Instead we find that an orientation of the olivine crystal fast axes aligned parallel to the strike of the slab provides the best fit, consistent with along-strike extension induced by flattening of the slab during subduction (A. Kumar et al., manuscript in preparation). We conclude that the fossil fabric has been overprinted during subduction and that the Nazca slab must therefore be sufficiently weak to undergo internal deformation.

  8. Juan de Fuca slab geometry and its relation to Wadati-Benioff zone seismicity

    Science.gov (United States)

    McCrory, Patricia A.; Blair, J. Luke; Waldhause, Felix; Oppenheimer, David H.

    2012-01-01

    A new model of the subducted Juan de Fuca plate beneath western North America allows first-order correlations between the occurrence of Wadati-Benioff zone earthquakes and slab geometry, temperature, and hydration state. The geo-referenced 3D model, constructed from weighted control points, integrates depth information from earthquake locations and regional seismic velocity studies. We use the model to separate earthquakes that occur in the Cascadia forearc from those that occur within the underlying Juan de Fuca plate and thereby reveal previously obscured details regarding the spatial distribution of earthquakes. Seismicity within the slab is most prevalent where the slab is warped beneath northwestern California and western Washington suggesting that slab flexure, in addition to expected metamorphic dehydration processes, promotes earthquake occurrence within the subducted oceanic plate. Earthquake patterns beneath western Vancouver Island are consistent with slab dehydration processes. Conversely, the lack of slab earthquakes beneath western Oregon is consistent with an anhydrous slab. Double-differenced relocated seismicity resolves a double seismic zone within the slab beneath northwestern California that strongly constrains the location of the plate interface and delineates a cluster of seismicity 10 km above the surface that includes the 1992 M7.1 Mendocino earthquake. We infer that this earthquake ruptured a surface within the Cascadia accretionary margin above the Juan de Fuca plate. We further speculate that this earthquake is associated with a detached fragment of former Farallon plate. Other subsurface tectonic elements within the forearc may have the potential to generate similar damaging earthquakes.

  9. Calculation of shear strength of prestressed hollow core slabs by use of plastic theory

    DEFF Research Database (Denmark)

    Hoang, Linh Cao; Jørgensen, Henrik Brøner; Nielsen, Mogens Peter

    2014-01-01

    saw-cut into units with the desirable length. For this reason, hollow core slabs are usually not shear reinforced and anchorage of the prestressing strands has to be established by bond. Hollow core slabs may therefore be more critical to shear and Anchorage failure than ordinary two-way spanning...

  10. Calculation of shear strength of prestressed hollow core slabs by use of plastic theory

    DEFF Research Database (Denmark)

    Hoang, Linh Cao; Jørgensen, H.G.; Nielsen, Mogens Peter

    2014-01-01

    saw-cut into units with the desirable length. For this reason, hollow core slabs are usually not shear reinforced and anchorage of the prestressing strands has to be established by bond. Hollow core slabs may therefore be more critical to shear and anchorage failure than ordinary two-way spanning...

  11. Automated grading of wood-slabs. The development of a prototype system

    DEFF Research Database (Denmark)

    Ersbøll, Bjarne Kjær; Conradsen, Knut

    1992-01-01

    , etc. Based on the relative distribution of these detected defects on the surface of a given slab, the slab is further classified into 5 quality grades: prime, standard, flamy, extra flamy and rejects. As a result of this project, a prototype for the computer vision grading system has been built...

  12. Strong suppression of radiation states in a slab waveguide sandwiched between omnidirectional mirrors

    NARCIS (Netherlands)

    Hoekstra, H.J.W.M.; Yudistira, D.; Stoffer, R.

    2005-01-01

    Structures in channel or slab waveguides, applied deliberately or due to imperfections, may lead to strong modal losses, corresponding to the excitation of radiation modes. As an example, losses are generally very large in slab photonic crystal (PhC) impurity waveguides (WGs) due to the combined eff

  13. Evidence for slab material under Greenland and links to Cretaceous High Arctic magmatism

    NARCIS (Netherlands)

    Shephard, G. E.; Trønnes, R. G.; Spakman, W.; Panet, I.; Gaina, C.

    2016-01-01

    Understanding the evolution of extinct ocean basins through time and space demands the integration of surface kinematics and mantle dynamics. We explore the existence, origin, and implications of a proposed oceanic slab burial ground under Greenland through a comparison of seismic tomography, slab s

  14. Effect of CFRP strengthening on the response of RC slabs to hard projectile impact

    Energy Technology Data Exchange (ETDEWEB)

    Almusallam, Tarek; Al-Salloum, Yousef; Alsayed, Saleh; Iqbal, Rizwan; Abbas, Husain, E-mail: abbas_husain@hotmail.com

    2015-05-15

    Highlights: • Studied response of CFRP-strengthened RC slabs under the impact load. • Slabs were tested under the strike of hemispherical steel projectiles at varying impact. • The slabs were analyzed numerically using LS-DYNA. • Strengthening increased the ballistic limit velocity by 18% and perforation energy by 56.7%. • CFRP sheet reduced the crater damage and contained the flying concrete fragments. - Abstract: In this paper impact response of CFRP-strengthened RC panels under the impact of non-deformable projectiles has been presented. The control and CFRP-strengthened RC slab panels were tested under the strike of hemispherical nosed steel projectiles at varying impact velocities. The response of these panels was investigated experimentally as well as numerically. The damage of the slab panels was measured in terms of the penetration depth, formation of cracks, spalling and scabbing areas and fracture of CFRP sheet. This study presents a practical and efficient numerical method for analyzing the impact response of CFRP-strengthened RC structures using LS-DYNA. The CFRP strengthening was found to increase the ballistic limit velocity by 18%, perforation energy of RC slabs by 56.7%, reduce the front crater damage and contains the flying of concrete fragments from the rear face. The maximum impact force occurs at almost same penetration depth for the control and CFRP-strengthened slabs but the restraint provided by CFRP increased the penetration depth by about 1/19.3 of the thickness of slab.

  15. Effect of Oxide Scale on Interfacial Heat Transfer during Slab Hot Rolling

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The hot rolling of slab was studied with the aid of elastic-plastic and thermomechanical couple FEM. On the basis of experiment and numerical analysis, the physical models for interfacial heat transfer during hot rolling were established. The results indicated that the deformation, cracking and decohesion behavior of the oxide scale have considerable effects on temperature distribution of slab during hot rolling.

  16. Bending and Shear Experimental Tests and Numerical Analysis of Composite Slabs Made Up of Lightweight Concrete

    Directory of Open Access Journals (Sweden)

    F. P. Alvarez Rabanal

    2016-01-01

    Full Text Available The aim of this paper is to understand the structural behaviour of composite slabs. These composite slabs are made of steel and different kinds of concrete. The methodology used in this paper combines experimental studies with advanced techniques of numerical simulations. In this paper, four types of concrete were used in order to study their different structural strengths in composite slabs. The materials used were three lightweight concretes, a normal concrete, and a cold conformed steel deck which has embossments to increase the adherence between concrete and steel. Furthermore, two lengths of slabs were studied to compare structural behaviours between short and long slabs. m-k experimental tests were carried out to obtain the flexural behaviour of the composite slabs. These tests provide dimensionless coefficients to compare different sizes of slabs. Nonlinear numerical simulations were performed by means of the finite element method (FEM. Four different multilinear isotropic hardening laws were used to simulate the four concretes. Coulomb friction contact was used to model the coefficient of friction between steel and concrete. Finally, a chemical bond was included to consider sliding resistance in the contact surface between steel and concrete. Experimental and numerical results are in good agreement; therefore, numerical models can be used to improve and optimize lightweight composite slabs.

  17. Degradation and Mechanism of the Mechanics and Durability of Reinforced Concrete Slab in A Marine Environment

    Institute of Scientific and Technical Information of China (English)

    吴胜兴; 刘冠国; 卞汉兵; 吕维波; 蒋建华

    2016-01-01

    An experimental research was conducted to determine the corrosion and bearing capacity of a reinforced concrete (RC) slab at different ages in a marine environment. Results showthat the development of corrosion-induced cracks on a slab in a marine environment can be divided into three stages according to crack morphology at the bottom of the slab. In the first stage, cracks appear. In the second stage, cracks develop from the edges to the middle of the slab. In the third stage, longitudinal and transverse corrosion-induced cracks coexist. The corrosion ratio of reinforcements nonlinearly increases with theage, and the relationship between the corrosion ratio of the reinforcements and the corrosion-induced crack width of the concrete is established. The flexural capacity of the corroded RC slab nonlinearly decreases with the age, and the model for the bearing capacity factor of the corroded RC slab is established. The mid-span deflection of the corroded RC slab that corresponds to the yield of the reinforcements linearly increases with the increase in corrosion ratio. Finally, the mechanisms of corrosion morphology and the degradation of the mechanical properties of an RC slab in a marine environment are discussed on the basis of the basic theories of steel corrosion in concrete and concrete structure design.

  18. Study of stratified dielectric slab medium structures using pseudo-spectral time domain (PSTD) algorithm

    DEFF Research Database (Denmark)

    Tong, M.S.; Lu, Y.; Chen, Y.

    2005-01-01

    A planar stratified dielectric slab medium, which is an interesting problem in optics and geophysics, is studied using a pseudo-spectral time-domain (PSTD) algorithm. Time domain electric fields and frequency domain propagation characteristics of both single and periodic dielectric slab...

  19. Near-field imaging of out-of-plane light scattering in photonic crystal slabs

    DEFF Research Database (Denmark)

    Volkov, Valentyn; Bozhevolnyi, Sergey; Taillaert, Dirk

    2003-01-01

    A collection scanning near-field optical microscope (SNOM) is used to image the propagating of light at telecommunication wavelengths (1520-1570 nm) along photonic crystal (PC) slabs, which combine slab waveguides with in-plane PCs consisting of one- and two-dimensional gratings. The efficient out...

  20. Cohesive cracked-hinge model for simulation of fracture in one-way slabs on grade

    DEFF Research Database (Denmark)

    Skar, Asmus; Poulsen, Peter Noe; Olesen, John Forbes

    2017-01-01

    Numerical analysis of slab on grade structures subjected to mechanical loads is a complex matter often requiring computationally expensive models. In order to develop a simplified and general concept for non-linear analysis of slab on grade structures, this paper presents a cohesive cracked...