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Sample records for inclined plane model

  1. Inclined planes

    CERN Document Server

    Rivera, Andrea

    2016-01-01

    From moving ramps to playground slides, inclined planes are at work all over in our world today. Learn all about them in five easy-to-read chapters. Vibrant, full-color photos, bolded glossary words, and a key stats section let readers zoom in even deeper. Aligned to Common Core Standards and correlated to state standards. Abdo Zoom is a division of ABDO.

  2. Structural equation modeling for alteration of occlusal plane inclination.

    Science.gov (United States)

    Shigeta, Yuko; Ogawa, Takumi; Nakamura, Yoshiharu; Ando, Eriko; Hirabayashi, Rio; Ikawa, Tomoko

    2015-07-01

    Occlusal plane inclination is important to maintain a normal opening closing/biting function. However, there can be several causes that lead to alterations of the occlusal plane. The purpose of this study was to observe variations of occlusal plane inclination in adult patients, and to uncover the factors affecting changes in occlusal plane inclination with aging. Subjects were 143 patients. A cephalometric image was taken of these patients. In this study, our inquiry points were age, 3 variables on intra-oral findings, and 7 variables on cephalometric analysis. To evaluate the possible causes that affect occlusal plane inclination, factor analysis was carried out, and each component was treated as factors, which were then statistically applied to a structural equation model. Statistical analysis was carried out through the SPSS 20.0 (SPSS Inc., Chicago, USA). In all patients, Camper-occlusal plane angle (COA) ranged from -25.7 to -4.9° (Mean±SD: -6.4±5.36). In the 60 patients who had no missing teeth, COA ranged from -11.6 to -4.9° (Mean±SD: -3.3±3.31). From the results of the structural analysis, it was suggested that the occlusal plane changes to counter-clockwise (on the right lateral cephalograms) with aging. In this study, variations of occlusal plane inclination in adult patients were observed, and the factors affecting changes in occlusal plane inclination with aging were investigated via factor analysis. From our results, it was suggested that the mandibular morphology change and loss of teeth with aging influence occlusal plane inclination. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  3. Lateral dynamic flight stability of a model hoverfly in normal and inclined stroke-plane hovering

    International Nuclear Information System (INIS)

    Xu, Na; Sun, Mao

    2014-01-01

    Many insects hover with their wings beating in a horizontal plane (‘normal hovering’), while some insects, e.g., hoverflies and dragonflies, hover with inclined stroke-planes. Here, we investigate the lateral dynamic flight stability of a hovering model hoverfly. The aerodynamic derivatives are computed using the method of computational fluid dynamics, and the equations of motion are solved by the techniques of eigenvalue and eigenvector analysis. The following is shown: The flight of the insect is unstable at normal hovering (stroke-plane angle equals 0) and the instability becomes weaker as the stroke-plane angle increases; the flight becomes stable at a relatively large stroke-plane angle (larger than about 24°). As previously shown, the instability at normal hovering is due to a positive roll-moment/side-velocity derivative produced by the ‘changing-LEV-axial-velocity’ effect. When the stroke-plane angle increases, the wings bend toward the back of the body, and the ‘changing-LEV-axial-velocity’ effect decreases; in addition, another effect, called the ‘changing-relative-velocity’ effect (the ‘lateral wind’, which is due to the side motion of the insect, changes the relative velocity of its wings), becomes increasingly stronger. This causes the roll-moment/side-velocity derivative to first decrease and then become negative, resulting in the above change in stability as a function of the stroke-plane angle. (paper)

  4. Precession of a Spinning Ball Rolling down an Inclined Plane

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    Cross, Rod

    2015-01-01

    A routine problem in an introductory physics course considers a rectangular block at rest on a plane inclined at angle a to the horizontal. In order for the block not to slide down the incline, the coefficient of sliding friction, µ, must be at least tan a. The situation is similar for the case of a ball rolling down an inclined plane. In order…

  5. Granular flow down a flexible inclined plane

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    Sonar Prasad

    2017-01-01

    Full Text Available Discrete and continuous systems are commonly studied individually, but seldom together. Indeed, granular flows are typically studied through flows over a rigid base. Here, we investigate the behaviour of granular flows over an inclined, flexible base. The flexible base is modeled as a rigid platform mounted on springs and has one degree of freedom. The base vibrations are introduced by the flow. We simulate such flows through a discrete element method and compare with experiments. We find that a flexible base increased the upper limit of the inclination up to which a steady flow is possible by at least 3 degrees. This stabilized zone may have important implications in applications such as conveyor belts and chutes.

  6. Granular flow down a flexible inclined plane

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    Sonar, Prasad; Sharma, Ishan; Singh, Jayant

    2017-06-01

    Discrete and continuous systems are commonly studied individually, but seldom together. Indeed, granular flows are typically studied through flows over a rigid base. Here, we investigate the behaviour of granular flows over an inclined, flexible base. The flexible base is modeled as a rigid platform mounted on springs and has one degree of freedom. The base vibrations are introduced by the flow. We simulate such flows through a discrete element method and compare with experiments. We find that a flexible base increased the upper limit of the inclination up to which a steady flow is possible by at least 3 degrees. This stabilized zone may have important implications in applications such as conveyor belts and chutes.

  7. Influence of occlusal plane inclination and mandibular deviation on esthetics.

    Science.gov (United States)

    Corte, Cristiane Cherobini Dalla; Silveira, Bruno Lopes da; Marquezan, Mariana

    2015-10-01

    The aim of this study was to assess the degree of perception of occlusal plane inclination and mandibular deviation in facial esthetics, assessed by laypeople, dentists and orthodontists. A woman with 5.88° of inclination and 5.54 mm of mandibular deviation was selected and, based on her original photograph, four new images were created correcting the deviations and creating more symmetric faces and smiles. Examiners assessed the images by means of a questionnaire. Their opinions were compared by qualitative and quantitative analyses. A total of 45 laypeople, 27 dentists and 31 orthodontists filled out the questionnaires. All groups were able to perceive the asymmetry; however, orthodontists were more sensitive, identifying asymmetries as from 4.32° of occlusal plane inclination and 4.155 mm of mandibular deviation (pocclusal plane inclination and 5.54 mm of mandibular deviation (pOcclusal plane inclination and mandibular deviation were perceived by all groups, but orthodontists presented higher perception of deviations.

  8. Deformation Analysis of Fixed Bearing Inclined Plane Thrust Bearing

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    LI Yong--hai

    2017-02-01

    Full Text Available According to the theory of lubrication,Numerical simulation of the deformation of the thrust bearing of the fixed inclined plane was carried out,by finite element numerical analysis method and using the ANSYS software. The mathematical model of the oil film shape control equations about of the deformation and bearing is established. Analytical result showed that the force caused the tile surface generating concave deformation,and convex deformation increased with the height and the size of the load and bearing;Tile surface temperature generated convex deformation and increased with the height and the size of the temperature of bearing bush;The actual deformation of the tile surface is the superposition of the force and the thermal deformation. This conclusion can provide reference for the design and the application of thrust bearing,to reduce the tile surface,which is not conducive to the carrying capacity of the concave deformation.

  9. Motion on an Inclined Plane and the Nature of Science

    Science.gov (United States)

    Pendrill, Ann-Marie; Ekström, Peter; Hansson, Lena; Mars, Patrik; Ouattara, Lassana; Ryan, Ulrika

    2014-01-01

    Friction is an important phenomenon in everyday life. All children are familiar with playground slides, which may thus be a good starting point for investigating friction. Motion on an inclined plane is a standard physics example. This paper presents an investigation of friction by a group of 11-year olds. How did they plan their investigations?…

  10. Inclined Planes and Motion Detectors: A Study of Acceleration.

    Science.gov (United States)

    Tracy, Dyanne M.

    2001-01-01

    Presents an activity in which students work in cooperative groups and roll balls down inclined planes, collect data with the help of an electronic motion detector, and represent data with a graphing calculator to explore concepts such as mass, gravity, velocity, and acceleration. (Contains 12 references.) (Author/ASK)

  11. Reconstruction of Galileo Galilei's Experiment: The Inclined Plane

    Science.gov (United States)

    Straulino, S.

    2008-01-01

    In the "Third Day" of the "Discourses and Mathematical Demonstrations Concerning Two New Sciences" Galileo Galilei describes the famous experiment of the inclined plane and uses it to bring an experimental confirmation to the laws of uniformly accelerated motion. We describe a reconstruction of the experiment and how the results can be used for…

  12. Motion of a carrier with a mobile load along a rough inclined plane

    Science.gov (United States)

    Bilchenko, G. G.

    2018-03-01

    The mechanical system consisting of a carrier and a load is considered. The load can move respectively the carrier according to the preset given motion law. The carrier motion from rest caused the load motion is investigated. The carrier can move translationally along rectilinear trajectory along rough inclined plane. The trajectory is the line of the greatest descent. The axis of rectilinear channel along which the load moves is situated in vertical plane containing the carrier trajectory. The Coulomb model is taken to describe the friction forces on sloped plane. Differential equations of motion of carrier with load are obtained. The sufficient condition of the carrier motion without detachment from inclined plane is given. For two special cases of the channel installation angle and the plane inclination angle combination the motion types are described. The computation experiments results are presented: the carrier motions in the special cases are illustrated, the phase portraits for some types of motions are constructed.

  13. Fluorescence intensity dependence on the propagation plane inclination

    International Nuclear Information System (INIS)

    Fernandez, J.E.; Rubio, Marcelo; Sanchez, H.J.

    1987-01-01

    A Monte Carlo simulation of the primary and secondary X-ray fluorescent emission from an homogeneous and infinite thickness sample, irradiated under different inclination of the propagation plane, is carried out. An agreement with the predictions based on Sherman equations depending on the inclination angle α was found. The invariance of the primary fluorescence with respect to α and the decrease until evanescence of the secondary fluorescence for a α → π/2 are confirmed. A discussion about the physical basis of this dependence is carried out. Similar results are expected for tertiary fluorescence. (Author) [es

  14. Aerodynamics of flapping insect wing in inclined stroke plane hovering with ground effect

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    Gowda v, Krishne; Vengadesan, S.

    2014-11-01

    This work presents the time-varying aerodynamic forces and the unsteady flow structures of flapping insect wing in inclined stroke plane hovering with ground effect. Two-dimensional dragonfly model wing is chosen and the incompressible Navier-Stokes equations are solved numerically by using immersed boundary method. The main objective of the present work is to analyze the ground effect on the unsteady forces and vortical structures for the inclined stroke plane motions. We also investigate the influences of kinematics parameters such as Reynolds number (Re), stroke amplitude, wing rotational timing, for various distances between the airfoil and the ground. The effects of aforementioned parameters together with ground effect, on the stroke averaged force coefficients and regimes of force behavior are similar in both normal (horizontal) and inclined stroke plane motions. However, the evolution of the vortex structures which produces the effects are entirely different.

  15. Three-dimensional volumetric display by inclined-plane scanning

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    Miyazaki, Daisuke; Eto, Takuma; Nishimura, Yasuhiro; Matsushita, Kenji

    2003-05-01

    A volumetric display system based on three-dimensional (3-D) scanning that uses an inclined two-dimensional (2-D) image is described. In the volumetric display system a 2-D display unit is placed obliquely in an imaging system into which a rotating mirror is inserted. When the mirror is rotated, the inclined 2-D image is moved laterally. A locus of the moving image can be observed by persistence of vision as a result of the high-speed rotation of the mirror. Inclined cross-sectional images of an object are displayed on the display unit in accordance with the position of the image plane to observe a 3-D image of the object by persistence of vision. Three-dimensional images formed by this display system satisfy all the criteria for stereoscopic vision. We constructed the volumetric display systems using a galvanometer mirror and a vector-scan display unit. In addition, we constructed a real-time 3-D measurement system based on a light section method. Measured 3-D images can be reconstructed in the 3-D display system in real time.

  16. Rapid prototyping and inclined plane technique in the treatment of maxillofacial malformations in a fox

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    Freitas, Elisangela P.; Rahal, Sheila C.; Teixeira, Carlos R.; Silva, Jorge V.L.; Noritomi, Pedro Y.; Villela, Carlos H.S.; Yamashita, Seizo

    2010-01-01

    An approximately 9-month-old fox (Pseudalopex vetulus) was presented with malocclusion and deviation of the lower jaw to the right side. Orthodontic treatment was performed using the inclined plane technique. Virtual 3D models and prototypes of the head were based on computed tomography (CT) image data to assist in diagnosis and treatment. PMID:20514249

  17. Fluorescence intensity dependence on the propagation plane inclination

    International Nuclear Information System (INIS)

    Fernandez, J.E.; Rubio, Marcelo; Sanchez, H. J.

    1987-01-01

    An experimental confirmation of the fluorescence intensity behaviour with the inclination of the propagation plane (α angle) was carried out. A special angular sample-holder was developed and set up on our X-ray spectrometer. This sample-holder allows different positions of irradiation of the sample modifying the α angle until the maximum angle (α Μ ) is reached in the limit situation. In this work, this maximum angle was 86 deg and the incidence and take off angles were both 45 deg. The sample-holder and the collimation system were carefully lined up. The fluorescent spectra of three National Bureau of Standards (NBS) standard samples were taken for sixteen different α angle positions. The theoretical scheme for both enhanced fluorescent lines and nonenhanced fluorescent lines was confirmed, i.e. the invariance of the primary intensity with the α angle and the decline of the enhanced fluorescence intensities under the same conditions. This experimental confirmation agrees with theoretical prediction: the vanishing of the secondary fluorescence in the extreme case α = π/2. (Author) [es

  18. Determination of viscosity of fayalite slags for kv model and measurements by means of inclined plane; Estimacion de la viscosidad de escorias fayaliticas utilizando el modelo de calculo kv y el metodo experimental del plano inclinado

    Energy Technology Data Exchange (ETDEWEB)

    Bazan, V.; Goni, C.; Castella, L.; Brandaleze, E.; Verdeja, L. F.; Parra, R.

    2006-07-01

    The viscosity of the lands represents one of the most relevant variables of most of the processes metallurgical and kinetics of the refine operations, since it is one of the decisive factors of the efficiency in the reactions between metal and lag, as much as slag-refractory. In the last decades, the mathematical models of different metallurgical processes have established methods to predict viscosity of mixtures of oxides fused to high temperatures in function of the chemical composition. The model developed by Toguri, based on the data reported by Johasen and Winterhager et al has proposed the Kv model. The used index it is similar to the relationship used in the steel industry like the basicity index. It is presented in this work values determined of viscosity in experimental form by means of the technique of inclined plane. (Author)

  19. Motion of phospholipidic vesicles along an inclined plane: sliding and rolling.

    Science.gov (United States)

    Abkarian, M; Lartigue, C; Viallat, A

    2001-04-01

    The migration of giant phospholipidic vesicles along an inclined plane in a quiescent fluid was observed as a function of the mass and the radius R of the vesicles, and as a function of the angle of inclination of the plane. Vesicles were swollen, and did not adhere to the substrate surface. It was observed from a side-view chamber that they have quasispherical shapes. The vesicles mainly slide along the plane, but also roll. The ratio omegaR/v of rotational to translational velocities is of the order of 0.15 for vesicles of radius ranging from 10 to 30 microm. Values of this ratio, and variations of v versus R, are well described by Goldman et al.'s model developed for the motion of rigid spheres close to a wall [Chem. Eng. Sci. 22, 637 (1967)]. In this framework, the thickness of the fluid film between the vesicle and the substrate derived from fitting experimental data was found to be equal to 48 nm.

  20. Friction and drag forces on spheres propagating down inclined planes

    Science.gov (United States)

    Tee, Yi Hui; Longmire, Ellen

    2017-11-01

    When a submerged sphere propagates along an inclined wall at terminal velocity, it experiences gravity, drag, lift, and friction forces. In the related equations of motion, the drag, lift and friction coefficients are unknown. Experiments are conducted to determine the friction and drag coefficients of the sphere over a range of Reynolds numbers. Through high speed imaging, translational and rotational velocities of spheres propagating along a glass plate are determined in liquids with several viscosities. The onset of sliding motion is identified by computing the dimensionless rotation rate of the sphere. Using drag and lift coefficients for Re friction coefficients are calculated for several materials. The friction coefficients are then employed to estimate the drag coefficient for 350 frictional force over this Re range. Supported by NSF (CBET-1510154).

  1. An inclined plane system with microcontroller to determine limb motor function of laboratory animals.

    Science.gov (United States)

    Chang, Ming-Wen; Young, Ming-Shing; Lin, Mao-Tsun

    2008-02-15

    This study describes a high-accuracy inclined plane test system for quantitative measurement of the limb motor function of laboratory rats. The system is built around a microcontroller and uses a stepping motor to drive a ball screw, which changes the angle of the inclined plane. Any of the seven inclination speeds can be selected by the user. Two infrared (IR) LED/detector pairs function as interrupt sensors for objective determination of the moment that the rat loses its grip on the textured flooring of the starting area and slips down the plane. Inclination angle at the moment of IR interrupt (i.e. rat slip) is recorded. A liquid crystal display module shows the inclination speed and the inclination angle. The system can function as a stand alone device but a RS232 port allows connection to a personal computer (PC), so data can be sent directly to hard disk for storage and analysis. Experiments can be controlled by a local keypad or by the connected PC. Advantages of the presented system include easy operation, high accuracy, non-dependence on human observation for determination of slip angle, stand-alone capability, low cost and easy modification of the controlling software for different types of experiments. A fully functional prototype of the system is described. The prototype was used experimentally by a hospital group testing traumatic brain injury experiments, and some of their results are presented for system verification. It is found that the system is stable, accurate and easily used by investigators.

  2. Finding the Acceleration and Speed of a Light-Emitting Object on an Inclined Plane with a Smartphone Light Sensor

    Science.gov (United States)

    Kapucu, Serkan

    2017-01-01

    This study investigates how the acceleration and speed of a light-emitting object on an inclined plane may be determined using a smartphone's light sensor. A light-emitting object was released from the top of an inclined plane and its illuminance values were detected by a smartphone's light sensor during its subsequent motion down the plane. Using…

  3. DEM simulation of flow of dumbbells on a rough inclined plane

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    Mandal, Sandip; Khakhar, Devang

    2015-11-01

    The rheology of non-spherical granular materials such as food grains, sugar cubes, sand, pharmaceutical pills, among others, is not understood well. We study the flow of non-spherical dumbbells of different aspect ratios on a rough inclined plane by using soft sphere DEM simulations. The dumbbells are generated by fusing two spheres together and a linear spring dashpot model along with Coulombic friction is employed to calculate inter-particle forces. At steady state, a uni-directional shear flow is obtained which allows for a detailed study of the rheology. The effect of aspect ratio and inclination angle on mean velocity, volume fraction, shear rate, shear stress, pressure and viscosity profiles is examined. The effect of aspect ratio on probability distribution of angles, made by the major axes of the dumbbells with the flow direction, average angle and order parameter is analyzed. The dense flow rheology is well explained by Bagnold's law and the constitutive laws of JFP model. The dependencies of first and second normal stress differences on aspect ratio are studied. The probability distributions of translational and rotational velocity are analyzed.

  4. Hairpin packet structure of a turbulent boundary layer in inclined wall-normal/spanwise planes

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    Lee, Jae Hwa; Sung, Hyung Jin

    2009-11-01

    Turbulent coherent structures associated with hairpin packet motions have been scrutinized using the instantaneous flow fields obtained from the direct numerical simulation (DNS) of a turbulent boundary layer (TBL). The Reynolds number based on the momentum thickness was varied in the range Reθ=890˜2560. This study focused on the hairpin packet motions in inclined wall-normal/spanwise planes. The hairpin vortex signature associated with the hairpin leg components in the vertical inclined plane consists of a counter-rotating vortex pair, upward and downward motions and a stagnation point induced by the Q2 and Q4 events. These hairpin signatures were observed in the instantaneous flow field, in the two-point correlations and in the conditionally averaged flow fields, respectively. We considered three inclined planes (45^o, 90^o, and 135^o) to investigate the spatial characteristics of the hairpin packet motions in the log and wake regions. The statistical flow fields showed that significantly different flow patterns are induced by the intersections of the three inclined planes with the hairpin packet motions.

  5. Changes of occlusal plane inclination after orthodontic treatment in different dentoskeletal frames.

    Science.gov (United States)

    Li, Jin-le; Kau, Chung; Wang, Min

    2014-06-25

    The inclination of the occlusal plane (OP) is related to facial types and experiences physiological growth-related changes. The aims of this research were to determine if there were any differences in the inclination of OP in subjects with three types of skeletal malocclusion and to investigate the characteristics and differences of functional occlusal plane (FOP) compared to bisected occlusal plane (BOP). A sample of 90 Caucasians patients was skeletal-classified into three (n = 30), and pre- and post-treatment cephalograms were digitized. Six linear and 8 angular cephalometric measurements were selected. The changes of OP inclination within each group and the differences among the three groups pre- and post-treatment were compared with paired t test and ANOVA test, respectively. The comparison and correlation between BOP and FOP were analyzed with paired t test and coefficient of correlation, respectively. The BOP angle increased in all of the three groups but only had statistically significant differences in skeletal class II patients in a mean of 1.51° (p stability (p > 0.05) in all three groups. The inclination of FOP was closely related to that of BOP (p stability in orthodontically treated patients with all three skeletal patterns.

  6. PENGGUNAAN INCLINED BITE PLANE SEBAGAI ALAT BANTU UNTUK KOREKSI GIGITAN SILANG ANTERIOR PADA KASUS MALOKLUSI KLAS III SKELETAL

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    Amutavia P. Artsianti P.

    2015-08-01

    Full Text Available Anterior crossbite occurs in children and adult. This anterior crossbite could be a dental (pseudo class III or a skeletal class III malocclusions. A 15 year old young female came to orthodontic clinic RSGM FKGUI with maxillary dental crowding which canines were more protruded. The dental of mandible were more protruded than maxillary dental. The clinical examination, anamnesis, functional analyses and cephalometric evaluation and model study showed that it was a skeletal class III malocclusion with maxillary skeletal retrusion. To treat the anterior crossbite, the inclined bite plane is used for 2 weeks and followed by fixed appliance. After 2 month treatment, the anterior crossbite is resolved. The result of cephalometric evaluation showed that the use of inclined bite plane as a tool is quite effective to resolve this case.

  7. Valuation of coefficient of rolling friction by the inclined plane method

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    Ciornei, F. C.; Alaci, S.; Ciogole, V. I.; Ciornei, M. C.

    2017-05-01

    A major objective of tribological researches is characterisation of rolling friction, due to various cases encountered in classical engineering applications, like gear transmissions and cam mechanisms or more recent examples met in bioengineering and biomedical devices. A characteristic of these examples consists in reduced dimensions of the contact zones, theoretically zero, the relative motion occurring between the contact points being either sliding or rolling. A characteristic parameter for the rolling motion is the coefficient of rolling friction. The paper proposes a method for estimation of coefficient of rolling friction by studying the motion of a body of revolution on an inclined plane. Assuming the hypothesis that moment of rolling friction is proportional to the normal reaction force, the law of motion for the body on the inclined plane is found under the premise of pure rolling. It is reached the conclusion that there is an uniformly accelerated motion, and thus for a known plane slope, it is sufficient to find the time during which the body runs a certain distance, starting from motionless situation. To obtain accurate results assumes finding precisely the time of motion. The coefficient of rolling friction was estimated for several slopes of the inclined plane and it is concluded that with increased slope, the values of coefficient of rolling friction increase, fact that suggest that the proportionality between the rolling torque and normal load is valid only for domains of limited variations of normal load.

  8. Students’ understanding of forces: Force diagrams on horizontal and inclined plane

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    Sirait, J.; Hamdani; Mursyid, S.

    2018-03-01

    This study aims to analyse students’ difficulties in understanding force diagrams on horizontal surfaces and inclined planes. Physics education students (pre-service physics teachers) of Tanjungpura University, who had completed a Basic Physics course, took a Force concept test which has six questions covering three concepts: an object at rest, an object moving at constant speed, and an object moving at constant acceleration both on a horizontal surface and on an inclined plane. The test is in a multiple-choice format. It examines the ability of students to select appropriate force diagrams depending on the context. The results show that 44% of students have difficulties in solving the test (these students only could solve one or two items out of six items). About 50% of students faced difficulties finding the correct diagram of an object when it has constant speed and acceleration in both contexts. In general, students could only correctly identify 48% of the force diagrams on the test. The most difficult task for the students in terms was identifying the force diagram representing forces exerted on an object on in an inclined plane.

  9. Pemakaian Inclined Bite Plane untuk Koreksi Gigitan Terbalik Interior pada Anak

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    Debrania Santoso

    2012-12-01

    Full Text Available Latar Belakang. Anak dengan gigitan terbalik pada anterior pada umumnya mempunyai keluhan dalam hal estetik dan fungsi pengunyahan. Kondisi gigitan terbalik biasanya disebabkan oleh adanya kebiasaan buruk dan faktor keturunan yang semakin memperparah keadaan tersebut. Pada kasus ini ditampilkan dua anak dengan gigitan terbalik anterior yang disebabkan oleh adanya kebiasaan buruk bertopang dagu dan mendorong lidah ke gigi anterior bawah. Perawatan menggunakan inclined bite plane dapat mengkoreksi gigitan terbalik anterior. Tujuan. Laporan kasus ini adalah untuk melaporkan bahwa pemakaian alat inlined bite plane dapat mengkoreksi gigitan terbalik anterior pada anak. Kasus. Dua orang anak perempuan dengan kasus gigitan terbalik anterior dilakukan pemeriksaan di poli gigi anak RSGM. Dari anamnesa diketahui bahwa anak pertama memiliki kebiasaan buruk bertopang dagu dan anak kedua mendorong lidah ke gigi anterior bawah. Perawatan yang dipilih adalah menggunakan alat inlined bite plane yang harus digunakan setiap hari saat tidur kecuali waktu makan dan menggosok gigi. Perawatan lanjutan pasien pertama tetap menggunakan alat removable dan pasien kedua dengan fixed orthodonti. Kesimpulan. Pasien pertama setelah 7 minggu gigitan terbalik anterior terkoreksi dan kebiasaan buruk dapat dihentikan. Pada pasien kedua gigitan terbalik anterior terkoreksi setelah 5 minggu. Hubungan oklusi pada pasien kedua lebih baik dibandingkan pasien pertama.   Background. Children with anterior crossbite generally complaint about aesthetic and masticatory function. Anterior crossbite is usually caused by bad habits and hereditary factors that exacerbated this situation. In this case was displayed two children with anterior crossbite caused by a bad habit pushing the chin with one hand and pushing the tongue to the lower anterior teeth. Treatment approach using inclined bite plane correct the anterior crossbite. Purpose. The purpose of this case report is to report the use

  10. The effect of anterior inclined plane treatment on the dentoskeletal of Class II division 1 patients

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    Emami Meibodi

    2007-09-01

    Full Text Available Most of Class II malocclusions are due to underdeveloped mandible with increased overjet and overbite. Lack of incisal contact results in the extrusion of the upper and lower anterior dentoalveolar complex, which helps to lock the mandible and prevent its normal growth and development, and this abnormality is exaggerated by soft tissue imbalance. The purpose of this study was to evaluate the skeletal and dental changes in patients treated with anterior inclined plane appliance in growing patients with moderate Class II Division 1 having deep overbite. In this study, 25 patients, including 15 girls and 10 boys, with a mean age of 9 ±1.2 years were selected; all of them presented with moderate Class II deep bite with increased overjet and normal or horizontal growth pattern. Pre- and post-treatment X-rays and photos for an average of 8 months were taken. The statistical assessment of the data suggested that there were no significant changes in the vertical skeletal parameters. The mandibular incisors were protruded, whereas the maxillary incisors were retruded. Overbite and overjet were also reduced. There was significant increase in the mandibular length. The results revealed that in mixed dentition patients, the inclined plane corrected Class II discrepancies mostly through dentoskeletal changes.

  11. Numerical study of the flow of granular materials down an inclined plane. Quarterly report, October 1, 1993--February 28, 1994

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    Rajagopal, K.R.

    1994-05-01

    In the previous report the governing equations for the flow of granular materials down an inclined plane, modeled by the constitutive theory proposed by Boyle and Massoudi (1990) were derived. These equations are solved numerically subject to the appropriate boundary conditions. The effect of various non-dimensional parameters on the volume fraction and velocity are presented in the form of graphs. In this report we derive the governing equations for the flow of granular materials down an inclined plane using the continuum model proposed by Rajagopal and Massoudi [cf. Goodman and Cowin (1971, 1972), Rajagopal and Massoudi (1990)]. Here, we study the effect of the various forms of the materials parameters ({Beta}`s) as discussed in Case I, II, and III in the following sections. The numerical solutions for case I and case II were presented in the earlier reports and case III are presented in the form of graphs for various nondimensional parameters. Also, the solutions from Case I, II, and III are compared to see how the structure of the material parameters affect the velocity, volume fraction and temperature fields.

  12. Class II malocclusion with accentuated occlusal plane inclination corrected with miniplate: a case report

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    Farret, Marcel Marchiori; Farret, Milton M. Benitez

    2016-01-01

    ABSTRACT Introduction: A canted occlusal plane presents an unesthetic element of the smile. The correction of this asymmetry has been typically considered difficult by orthodontists, as it requires complex mechanics and may sometimes even require orthognathic surgery. Objective: This paper outlines the case of a 29-year-old woman with Class II malocclusion, pronounced midline deviation and accentuated occlusal plane inclination caused by mandibular deciduous molar ankylosis. Methods: The patient was treated with a miniplate used to provide anchorage in order to intrude maxillary teeth and extrude mandibular teeth on one side, thus eliminating asymmetry. Class II was corrected on the left side by means of distalization, anchored in the miniplate as well. On the right side, maxillary first premolar was extracted and molar relationship was kept in Class II, while canines were moved to Class I relationship. The patient received implant-prosthetic rehabilitation for maxillary left lateral incisor and mandibular left second premolar. Results: At the end of treatment, Class II was corrected, midlines were matched and the canted occlusal plane was totally corrected, thereby improving smile function and esthetics. PMID:27409658

  13. Rolling and sliding motion of spheres propagating down inclined planes in still water

    Science.gov (United States)

    Tee, Yi Hui; Longmire, Ellen

    2016-11-01

    In modelling the motion of spheres submerged in liquid, gravity, drag, lift, and added mass forces have to be taken into account. For spheres contacting bounding surfaces, friction coefficients due to rolling and sliding increase the complexity of the model. In this study, experiments are conducted to investigate the effects of particle density and diameter on the rolling and sliding motion of spheres. Spherical particles with marked surfaces are released from rest on an inclined glass plate in still water at various inclination angles and allowed to accelerate. A 45° mirror mounted beneath the plate allows simultaneous capture of both longitudinal and spanwise motions of the sphere. Based on sequences obtained by high speed imaging, the translational and rotational velocities are determined. Particle Reynolds numbers at terminal velocity range from 400 to 2500 corresponding with Galileo numbers of 800 to 2800. By comparing the translational and rotational velocities, the occurrence of sliding motion can be identified. The onset of sliding motion is then determined as a function of inclination angle and Galileo number for multiple particle materials. The experimental results are also compared against the existing models from the literature. Supported by NSF (CBET-1510154).

  14. Changes of occlusal plane inclination after orthodontic treatment with four premolars extraction in dento-alveolar bimaxillary protrusion cases

    Directory of Open Access Journals (Sweden)

    NR Yuliawati Zenab

    2009-07-01

    Full Text Available The purpose of this study was to find out whether there were changes in occlusal plane inclination after fixed orthodontic treatment of bimaxillary protrusion cases where extraction of four first premolars was needed using the standard Edgewise appliances. The sample was fourteen orthodontic patients, aged above sixteen years old, no sexual discrimination, treated with fixed appliances at Orthodontic Specialist Clinic Faculty of Dentistry Universitas Padjadjaran. The method was a pre-post design which compared occlusal plane inclination obtained from tracings of lateral cephalograms before and after orthodontic treatment. The results were calculated with the paired t-test analysis. The study revealed that there were no significant changes in occlusal plane inclination after the orthodontic treatment.

  15. Features in subjects with the frontal occlusal plane inclined toward the contralateral side of the mandibular deviation.

    Science.gov (United States)

    Uesugi, Shunsuke; Yonemitsu, Ikuo; Kokai, Satoshi; Takei, Maki; Omura, Susumu; Ono, Takashi

    2016-01-01

    The frontal occlusal plane of the maxilla generally inclines toward the ipsilateral side of the mandibular deviation in subjects with facial asymmetry; however, a few patients with facial asymmetry have their frontal occlusal planes inclined toward the contralateral side. We aimed to investigate the morphologic and functional features of such patients. The subjects were 40 patients with facial asymmetry divided into 2 groups based on the inclination of the frontal occlusal plane toward the ipsilateral or the contralateral side. We analyzed lateral and posteroanterior cephalometric radiographs and occlusal variables and evaluated temporomandibular joint symptoms. Statistical comparisons were performed between the 2 groups (P Occlusal force and occlusal contact area were significantly larger, and temporomandibular joint symptoms were more frequently found on the side of the upward-inclined frontal occlusal plane than on the opposite side in both groups. The features in the contralateral group in terms of occlusal force and temporomandibular disorders were clinically significant. Clinicians should note that the conditions associated with the contralateral group require less presurgical decompensation. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  16. Multi-layer film flow down an inclined plane: experimental investigation

    KAUST Repository

    Henry, Daniel

    2014-11-19

    We report the results from an experimental study of the flow of a film down an inclined plane where the film itself is comprised of up to three layers of different liquids. By measuring the total film thickness for a broad range of parameters including flow rates and liquid physical properties, we provide a thorough and systematic test of the single-layer approximation for multi-layer films for Reynolds numbers Re = ρQ/μ≈0.03-60. In addition, we also measure the change in film thickness of individual layers as a function of flow rates for a variety of experimental configurations. With the aid of high-speed particle tracking, we derive the velocity fields and free-surface velocities to compare to the single-layer approximation. Furthermore, we provide experimental evidence of small capillary ridge formations close to the point where two layers merge and compare our experimental parameter range for the occurrence of this phenomenon to those previously reported.

  17. A secular model for efficient exploration of mutually-inclined planetary systems

    Science.gov (United States)

    Deitrick, Russell; Barnes, Rory

    2015-01-01

    Dynamical studies of exoplanets largely assume coplanarity because of the lack of inclination information in many cases. However, the multiplanet system Upsilon Andromedae has orbital planes inclined by 30 degrees, models of planet-planet scattering predict large mutual inclinations, and astrometry missions such as Gaia have the power to reveal the 3 dimensional architecture of planetary systems. As the dynamics of systems with non-planar orbits will be key to understanding origins, and ultimately habitability where applicable, we present a computationally efficient model for the orbital evolution of planetary systems with modest inclinations and eccentricities which are not in a mean motion resonance. Specifically, our model is based on the disturbing function and extends to 4th order in eccentricity and inclination. We present comparisons to N-body models for known systems, such as the Solar System and Upsilon Andromedae, and hypothetical systems with a range of orbital configurations. We describe the eccentricity and inclination conditions under which the model is valid. We further calculate the rotational evolution of planets based on the orbital evolution and the stellar torque and find a wide range of obliquity evolution is possible. As obliquity is a key driver of planetary climate, Earth-like planets in non-planar systems may have climates dominated by their orbital evolution.

  18. Investigating the free-body diagram of a stationary object on an inclined plane using Apple Watch

    Science.gov (United States)

    Dilek, Ufuk; Çalışkan, Serap

    2017-11-01

    In this study, we present an activity in which the free-body diagram of a real stationary object on an inclined plane can be examined interactively. We use an Apple Watch and a few other materials that can be accessed easily. Instead of an Apple Watch, a mobile phone or a tablet could also be used. This activity may be employed to introduce the fundamental concepts associated with free-body diagrams in classroom settings, or adapted to physics labs.

  19. Investigating the Free-Body Diagram of a Stationary Object on an Inclined Plane Using Apple Watch

    Science.gov (United States)

    Dilek, Ufuk; Çaliskan, Serap

    2017-01-01

    In this study, we present an activity in which the free-body diagram of a real stationary object on an inclined plane can be examined interactively. We use an Apple Watch and a few other materials that can be accessed easily. Instead of an Apple Watch, a mobile phone or a tablet could also be used. This activity may be employed to introduce the…

  20. Theoretical study of moving magnetic beads on an inclined plane and its application in the ratchet separation technique

    Energy Technology Data Exchange (ETDEWEB)

    Rashidi, M.M., E-mail: mm_rashidi@tongji.edu.cn [Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems, Tongji University, 4800 Cao An Rd., Jiading, Shanghai, 201804 (China); ENN-Tongji Clean Energy Institute of Advanced Studies, Shanghai (China); ENN-Tongji Clean Energy Institute of Advanced Studies, Shanghai (China); Johnson, S., E-mail: mm_rashidi@sawtc.com [University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai (China); Yang, Z., E-mail: shane.johnson@sjtu.edu.cn [Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems, Tongji University, 4800 Cao An Rd., Jiading, Shanghai, 201804 (China); ENN-Tongji Clean Energy Institute of Advanced Studies, Shanghai (China)

    2016-01-15

    For first time, motion of a magnetic bead ascending an inclined surface is investigated. The translational and rotational velocities of magnetic beads traveling on an inclined plane in the creeping flow regime are studied. The governing equations considering lift force and magnetic torque are obtained. Rolling and slipping cases are studied in detail. It is shown that the lift force effect is critical for large values of sedimentation Reynolds number (Res) and negligible for small values of Res. This method is applicable for neutrally buoyant and heavy magnetic bead motion. Practical application of this study is implemented in the ratchet configuration for separation of magnetic beads with different sizes. This is applicable for novel applications such as drug delivery, magnetic tweezers, and magnetic actuated stiffness testing systems which require accurate magnetic bead sizes for accurate function. - Graphical abstract: Free body diagram for rolling/slipping motion a rough magnetic bead up a smooth plane. - Highlights: • For first time, motion of a magnetic bead ascending an inclined surface is investigated. • The governing equations considering lift force and magnetic torque are obtained. • Practical application of this study is implemented in the ratchet configuration for separation of magnetic beads with different sizes.

  1. Theoretical study of moving magnetic beads on an inclined plane and its application in the ratchet separation technique

    Science.gov (United States)

    Rashidi, M. M.; Johnson, S.; Yang, Z.

    2016-01-01

    For first time, motion of a magnetic bead ascending an inclined surface is investigated. The translational and rotational velocities of magnetic beads traveling on an inclined plane in the creeping flow regime are studied. The governing equations considering lift force and magnetic torque are obtained. Rolling and slipping cases are studied in detail. It is shown that the lift force effect is critical for large values of sedimentation Reynolds number (Res) and negligible for small values of Res. This method is applicable for neutrally buoyant and heavy magnetic bead motion. Practical application of this study is implemented in the ratchet configuration for separation of magnetic beads with different sizes. This is applicable for novel applications such as drug delivery, magnetic tweezers, and magnetic actuated stiffness testing systems which require accurate magnetic bead sizes for accurate function.

  2. Finding the acceleration and speed of a light-emitting object on an inclined plane with a smartphone light sensor

    Science.gov (United States)

    Kapucu, Serkan

    2017-09-01

    This study investigates how the acceleration and speed of a light-emitting object on an inclined plane may be determined using a smartphone’s light sensor. A light-emitting object was released from the top of an inclined plane and its illuminance values were detected by a smartphone’s light sensor during its subsequent motion down the plane. Using the illuminance and time values recorded by the smartphone, the distances between the sensor and the light-emitting object can be calculated. From these known distance and time values, the uniform acceleration and speed of the light-emitting object at any time could also be determined. A second method was also used to determine these values, i.e. the analysis of video-recordings of the light-emitting object during its motion. The values found by these two different methods were in good agreement. Thus, this experiment demonstrates that a smartphone’s light sensor can be used as a reliable instrument to determine the constant acceleration and speed of light-emitting objects.

  3. [Impact of the vertical dimension on the occlusal plane inclination in a Moroccan population].

    Science.gov (United States)

    Azaroual, Mohamed Faouzi; Halimi, Abdelalli; Benyahia, Hicham; Abouqal, Redouan; Zaoui, Fatima; Aalloula, Elhoucine

    2009-06-01

    This study was performed in order to investigate the influence of the vertical dimension on the occlusal plane angle. Cephalometric tracing were made from sideview headfilms from a sample of 150 patients consulting at the consultation and treatment center in Rabat, Morocco. This sample group included 60 males and 90 females. The aims of our research were to study statistically the impact of the vertical dimension on the occlusal plane angle and to check the validity of the Wits (Ao-Bo) by evaluating the impact of the vertical dimension on the Wits and by comparing it with the AF-BF value (Ao-Bo/Frankfurt) proposed by Chang.

  4. Ground plane detection for autonomous robots in complex environments inclined with flexed far-field terrains

    CSIR Research Space (South Africa)

    Osunmakind, IO

    2009-11-01

    Full Text Available In this paper, collective intelligence of the Emergent Situation Awareness (ESA) technology is proposed as a supportive strategy for autonomous robotic navigation. The ability to reveal uncertainties over time on flexed far-field is a ground plane...

  5. Aqua/Aura Updated Inclination Adjust Maneuver Performance Prediction Model

    Science.gov (United States)

    Boone, Spencer

    2017-01-01

    This presentation will discuss the updated Inclination Adjust Maneuver (IAM) performance prediction model that was developed for Aqua and Aura following the 2017 IAM series. This updated model uses statistical regression methods to identify potential long-term trends in maneuver parameters, yielding improved predictions when re-planning past maneuvers. The presentation has been reviewed and approved by Eric Moyer, ESMO Deputy Project Manager.

  6. Rolling stones: The motion of a sphere down an inclined plane coated with a thin liquid film

    Science.gov (United States)

    Bico, J.; Ashmore-Chakrabarty, J.; McKinley, G. H.; Stone, H. A.

    2009-08-01

    A spherical bead deposited on a smooth tilted dry plane wall rolls down the slope under the uniform acceleration of gravity. We describe an analogous experiment conducted using a plane wall that is coated with a thin layer (of order 50-100 μm) of a viscous liquid. The steady motion of the sphere under gravity involves a combination of rotation and sliding. We examine the dependence of the experimentally observed steady translational and rotational speeds on the physical parameters in the system. In particular, the interplay between viscous forces and interfacial forces leads to nontrivial exponents for the scaling of the speeds with the characteristics of the sphere and the viscous liquid. The overhang situation, in which the sphere rolls down the underside of an inclined lubricated plane, is also examined. In this case, the steady motion is still observed for a certain range of angles and bead sizes; that is, the sphere does not always detach from the surface. The adhesive force arises dynamically from the motion of the sphere and can exceed classical quasistatic capillary forces. Such a force should also play a role in other problems of lubrication mechanics such as humid granular flows.

  7. The effect of drainage channels on the hydrodynamic drag of non-colloidal spheres down an inclined plane

    Science.gov (United States)

    Ryu, Brian; Dhong, Charles; Frechette, Joelle

    While it is well known that surface asperities and roughness alter the hydrodynamic drag of a non-colloidal sphere down an inclined plane, less is known about how the hydrodynamic drag is modified if the asperities and roughness are connected through a network of drainage channels, which allows the movement of fluid between asperities. We investigate the rotational and translation motion of spheres on several pairs of surfaces that have the same porosity and asperity size, but one surface has interconnected drainage channels whereas the other does not. These can have direct relevance to lubricated surfaces such as ball bearings in industrial settings, or biological relevance of leucocyte movement across rough surfaces. Provost's Undergraduate Research Awards, Office of Naval Research, National Science Foundation.

  8. Flow of visco-elastic fluid of Rivlin-Ericksen type between two inclined parallel planes in presence of gravity and uniform transverse magnetic field

    International Nuclear Information System (INIS)

    Sengupta, P.R.; Sadat, Khondokar Anowarus; Kundu, Shyamal Kumar

    2003-01-01

    In this paper, an attempt has been made to study the flow of Rivlin-Ericksen visco-elastic fluid between two inclined parallel planes in presence of gravity and uniform transverse magnetic field. It has been assumed that the lower plane is at rest and the upper plane is moving with a transient velocity in the first case, while in the second case it is moving longitudinally with a periodic velocity. In both cases the fluid velocity and flux of fluid have been obtained by variable separation technique. These results are then deduced for the case of visco-elastic Maxwell fluid taking the fluid to be electrically conducting and placed in presence of a uniform transverse magnetic field. Further, when the magnetic field is absent the corresponding results are obtained by passing to the limit as uniform magnetic field tending to zero. Moreover, the titled problem has also been solved in case of inviscid fluid in both cases of hydromagnetic flow and flow in absence of magnetic field. Thus the present problem is focused to a wide range of flow problems of different types of fluid models. (author)

  9. A theoretical and numerical study of the flow of granular materials down an inclined plane. [Quarterly progress report, January--March 1995

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, K.R.

    1995-09-01

    The mechanics of the flowing granular materials such as coal, agricultural products, fertilizers, dry chemicals, metal ores, etc. have received a great deal of attention as it has relevance to several important technological problems. Despite wide interest and more than five decades of experimental and theoretical investigations, most aspects of the behavior of flowing granular materials are still not well understood. So Experiments have to be devised which quantify and describe the non-linear behavior of the granular materials, and theories developed which can explain the experimentally observed facts. Here we carry out a systematic numerical study of the flow of granular materials down an inclined plane using the models that stem from both the continuum theory approach and the kinetic theory approach. We also look at the existence of solutions, multiplicity and stability of solutions to the governing equations.

  10. Performance Analysis of Transposition Models Simulating Solar Radiation on Inclined Surfaces: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yu; Sengupta, Manajit

    2016-06-01

    Transposition models are widely used in the solar energy industry to simulate solar radiation on inclined photovoltaic (PV) panels. These transposition models have been developed using various assumptions about the distribution of the diffuse radiation, and most of the parameterizations in these models have been developed using hourly ground data sets. Numerous studies have compared the performance of transposition models, but this paper aims to understand the quantitative uncertainty in the state-of-the-art transposition models and the sources leading to the uncertainty using high-resolution ground measurements in the plane of array. Our results suggest that the amount of aerosol optical depth can affect the accuracy of isotropic models. The choice of empirical coefficients and the use of decomposition models can both result in uncertainty in the output from the transposition models. It is expected that the results of this study will ultimately lead to improvements of the parameterizations as well as the development of improved physical models.

  11. Bulbous head formation in bidisperse shallow granular flows over inclined planes

    Science.gov (United States)

    Denissen, I.; Thornton, A.; Weinhart, T.; Luding, S.

    2017-12-01

    Predicting the behaviour of hazardous natural granular flows (e.g. debris-flows and pyroclastic flows) is vital for an accurate assessment of the risks posed by such events. In these situations, an inversely graded vertical particle-size distribution develops, with larger particles on top of smaller particles. As the surface velocity of such flows is larger than the mean velocity, the larger material is then transported to the flow front. This creates a downstream size-segregation structure, resulting in a flow front composed purely of large particles, that are generally more frictional in geophysical flows. Thus, this segregation process reduces the mobility of the flow front, resulting in the formation of, a so-called, bulbous head. One of the main challenges of simulating these hazardous natural granular flows is the enormous number of particles they contain, which makes discrete particle simulations too computationally expensive to be practically useful. Continuum methods are able to simulate the bulk flow- and segregation behaviour of such flows, but have to make averaging approximations that reduce the huge number of degrees of freedom to a few continuum fields. Small-scale periodic discrete particle simulations can be used to determine the material parameters needed for the continuum model. In this presentation, we use a depth-averaged model to predict the flow profile for particulate chute flows, based on flow height, depth-averaged velocity and particle-size distribution [1], and show that the bulbous head structure naturally emerges from this model. The long-time behaviour of this solution of the depth-averaged continuum model converges to a novel travelling wave solution [2]. Furthermore, we validate this framework against computationally expensive 3D particle simulations, where we see surprisingly good agreement between both approaches, considering the approximations made in the continuum model. We conclude by showing that the travelling distance and

  12. An Experimental Study of the Thermal Performance of Solar Air Collector Inclined (75o on the Horizontal Plane

    Directory of Open Access Journals (Sweden)

    Hasasn Ali Jurmut

    2018-02-01

    Full Text Available In this paper, an experimental study of the thermal performance of the solar air collector manufactured of galvanized iron sheet with dimension 100×120cm, frame width 20cm, has holes 0.5cm arrangement on horizontal and vertical, the collector inclined at an angle (75o on the horizontal plane. All author faces of the collector (four sides and background are insulations in order to minimize the thermal losses .All the result recorded in winter season for two different days one of them sunny and the other was cloudy. The result shows the effect of the angle of collector gives more heat to the collector, hence higher outlet temperature, especially in sunny day. Maximum outlet temperature  of the collector (35.5o when inlet temperature 18o and maximum Nusselt  number(Nu at twelve o’clock of the sunny day more than the cloudy day.  At the end its high system efficiency and good collector effectiveness.

  13. Diagnosing Model Errors in Simulations of Solar Radiation on Inclined Surfaces: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yu; Sengupta, Manajit

    2016-06-01

    Transposition models have been widely used in the solar energy industry to simulate solar radiation on inclined PV panels. Following numerous studies comparing the performance of transposition models, this paper aims to understand the quantitative uncertainty in the state-of-the-art transposition models and the sources leading to the uncertainty. Our results suggest that an isotropic transposition model developed by Badescu substantially underestimates diffuse plane-of-array (POA) irradiances when diffuse radiation is perfectly isotropic. In the empirical transposition models, the selection of empirical coefficients and land surface albedo can both result in uncertainty in the output. This study can be used as a guide for future development of physics-based transposition models.

  14. The effect of model inclination during fabrication on mouthguard calliper-measured and CT scan-assessed thickness.

    Science.gov (United States)

    Farrington, Timothy; Coward, Trevor; Onambele-Pearson, Gladys; Taylor, Rebecca L; Earl, Philip; Winwood, Keith

    2016-06-01

    Excessive material thinning has been observed in the production of custom-made mouthguards in a number of studies, due to production anomalies that may lead to such thinning. This study investigated thinning material patterns of custom-made mouthguards when the anterior angulation of dental model was increased during the thermoforming process. A total of 60 samples of mouthguard blanks were thermoformed on identical maxillary models under four anterior inclination conditions (n = 4 × 15): control 0, 15, 30 and 45°. Each mouthguard sample was measured, using an electronic calliper gauge at three anatomical points (anterior labial sulcus, posterior occlusion and posterior lingual). Mouthguards were then CT scanned to give a visual representation of the surface thickness. Data showed a significant difference (P < 0.005) in the anterior mouthguard thickness between the four levels of anterior inclination, with the 45° inclination producing the thickest mouthguards, increasing the mean anterior thickness by 75% (2.8 mm, SD: 0.16) from the model on a flat plane (1.6 mm, SD: 0.34). Anterior model inclination of 30 and 45° inclinations increased consistencies between the thickest and thinnest mouthguards in the anterior region of these sample groups. This study highlights the importance of standardizing the thermoforming process, as this has a significant effect on the quality and material distribution of the resultant product. In particular, greater model inclination is advised as this optimizes the thickness of the anterior sulcus of the mouthguard which may be more prominently at risk from sport-related impact. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Direct spontaneous growth and interfacial structural properties of inclined GaN nanopillars on r-plane sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Adikimenakis, A.; Aretouli, K. E.; Tsagaraki, K.; Androulidaki, M.; Georgakilas, A. [Microelectronics Research Group (MRG), IESL, FORTH, P.O. Box 1385, GR 711 10 Heraklion Crete, Greece and Physics Department, University of Crete, GR 710 03 Heraklion Crete (Greece); Lotsari, A.; Dimitrakopulos, G. P., E-mail: gdim@auth.gr; Kehagias, Th.; Komninou, Ph. [Physics Department, Aristotle University of Thessaloniki, GR 541 24, Thessaloniki (Greece)

    2015-06-28

    The spontaneous growth of GaN nanopillars (NPs) by direct plasma-assisted molecular beam epitaxy on nitridated r-plane sapphire substrates has been studied. The emanation of metal-polarity NPs from inside an a-plane nonpolar GaN film was found to depend on both the substrate nitridation and the growth conditions. The density of NPs increased with increasing the duration of the nitridation process and the power applied on the radio-frequency plasma source, as well as the III/V flux ratio, while variation of the first two parameters enhanced the roughness of the substrate's surface. Transmission electron microscopy (TEM) techniques were employed to reveal the structural characteristics of the NPs and their nucleation mechanism from steps on the sapphire surface and/or interfacial semipolar GaN nanocrystals. Lattice strain measurements showed a possible Al enrichment of the first 5–6 monolayers of the NPs. By combining cross-sectional and plan-view TEM observations, the three-dimensional model of the NPs was constructed. The orientation relationship and interfacial accommodation between the NPs and the nonpolar a-plane GaN film were also elucidated. The NPs exhibited strong and narrow excitonic emission, suggesting an excellent structural quality.

  16. A layered model for inclined pipe flow of settling slurry

    Czech Academy of Sciences Publication Activity Database

    Matoušek, Václav; Krupička, Jan; Kesely, Mikoláš

    2018-01-01

    Roč. 333, June (2018), s. 317-326 ISSN 0032-5910 R&D Projects: GA ČR GA17-14271S Institutional support: RVO:67985874 Keywords : inclined pipe * settling slurry * pressure drop * flow stratification * laboratory loop Impact factor: 2.942, year: 2016

  17. [Reliability study in the measurement of the cusp inclination angle of a chairside digital model].

    Science.gov (United States)

    Xinggang, Liu; Xiaoxian, Chen

    2018-02-01

    This study aims to evaluate the reliability of the software Picpick in the measurement of the cusp inclination angle of a digital model. Twenty-one trimmed models were used as experimental objects. The chairside digital impression was then used for the acquisition of 3D digital models, and the software Picpick was employed for the measurement of the cusp inclination of these models. The measurements were repeated three times, and the results were compared with a gold standard, which was a manually measured experimental model cusp angle. The intraclass correlation coefficient (ICC) was calculated. The paired t test value of the two measurement methods was 0.91. The ICCs between the two measurement methods and three repeated measurements were greater than 0.9. The digital model achieved a smaller coefficient of variation (9.9%). The software Picpick is reliable in measuring the cusp inclination of a digital model.

  18. Model and experimental vizualisation of a bubble interacting with an inclined wall

    Science.gov (United States)

    Podvin, Berengere; Khoja, Suleman; Attinger, Daniel; Moraga, Francisco

    2006-11-01

    We describe the motion of an air bubble rising through water as it interacts with a wall of variable inclination. The bubble diameter varies about O(1) mm. We use lubrication theory to determine the modification of the bubble interface and compute the hydrodynamic force exerted by the wall. The present work is an extension of Moraga et al's model [Computers and Fluids 2006], which was devised for a horizontal wall. The predictions of the model are checked against experimental visualizations. The influence of the Weber number, Reynolds number and wall inclination is examined

  19. An analytical model for force prediction in ball nose micro milling of inclined surfaces

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2010-01-01

    Ball nose micro milling is a key process for the generation of free form surfaces and inclined surfaces often present in mould inserts for micro replication. This paper presents a new cutting force model for ball nose micro milling that is capable of taking into account the effect of the edge rad...... radius and the effect of the surface topography due to the previous milling passes. The model is completely analytical can be applied to ball end micro milling of slanted surfaces for any value of the surface inclination angle relative to the tool axis....

  20. Clinically acceptable agreement between the ViMove wireless motion sensor system and the Vicon motion capture system when measuring lumbar region inclination motion in the sagittal and coronal planes

    DEFF Research Database (Denmark)

    Mjøsund, Hanne Leirbekk; Boyle, Eleanor; Kjær, Per

    2017-01-01

    . CONCLUSIONS: We found a clinically acceptable level of agreement between these two methods for measuring standing lumbar inclination motion in these two cardinal movement planes. Further research should investigate the ViMove system's ability to measure lumbar motion in more complex 3D functional movements...

  1. Mi Quinto Libro de Maquinas Simples: El Plano Inclinado. Escuela Intermedia Grados 7, 8 y 9 (My Fifth Book of Simple Machines: The Inclined Plane. Intermediate School Grades 7, 8, and 9).

    Science.gov (United States)

    Alvarado, Patricio R.; Montalvo, Luis

    This is the fifth book in a five-book physical science series on simple machines. The books are designed for Spanish-speaking junior high school students. This volume explains the principles and some of the uses of inclined planes, as they appear in simple machines, by suggesting experiments and posing questions concerning drawings in the book…

  2. A theoretical and numerical study of the flow of granular materials down an inclined plane. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, K.R.

    1995-12-31

    The mechanics of the flowing granular materials such as coal, agricultural products, at deal of attention as it has fertilizers, dry chemicals, metal ores, etc. have received a great deal of attention as it has relevance to several important technological problems. Despite wide interest and more than five decades of experimental and theoretical investigations, most aspects of the behavior of flowing granular materials are still not well understood. So Experiments have to be devised which quantify and describe the non-linear behavior of the modular materials, and theories developed which can explain the experimentally observed facts. As many models have been suggested for describing the behavior of granular materials, from both continuum and kinetic theory viewpoints, we proposed to investigate the validity and usefulness of representative models from both the continuum and kinetic theory points of view, by determining the prediction of such a theory, in a representative flow, with respect to existence, non-existence, multiplicity and stability of solutions. The continuum model to be investigated is an outgrowth of a model due to Goodman and Cowin (1971, 1972) and the kinetic theory models being those due to Jenkins and Richman (1985) and Boyle and Massoudi (1989). In this report we present detailed results regarding the same. Interestingly, we find that the predictions of all the theories, in certain parameter space associated with these models, are qualitatively similar. This ofcourse depends on the values assumed for various material parameters in the models, which as yet are unknown, as reliable experiments have not been carried out as yet for their determination.

  3. Impact of cusp inclinations on dental fractures in cracked tooth syndrome model and relevant risk evaluation.

    Science.gov (United States)

    Xie, Nina; Wang, Penglai; Wu, Cui; Song, Wenting; Wang, Wen; Liu, Zongxiang

    2017-12-01

    We explored the impact of cusp inclinations on dental fractures in cracked tooth syndrome model and formulated corresponding risk scale. Forty maxillary premolars were randomized into four groups for cusp inclination measurements by digital radiovisiography (RVG). For cracked tooth models, buccal and palatal cusp inclinations were achieved by grinding in groups I (59°-50°), II (64°-55°) and III (69°-60°), with group IV as blank control. All groups underwent compression loading test, with fracture levels recorded for statistical analysis. The fracture modes included a majority of crown root fractures and a minority of crown fractures in groups I and II, exclusive crown root fractures in group III, and exclusive crown fractures in group IV. Overall, palatal fractures were predominant versus buccal fractures, with exclusive palatal fractures in group IV, and oblique fractures were overwhelming versus the scanty vertical fractures. Fracture risk classification: grade III was prevalent in groups I and II, grade IV in group III, and grades I and II in group IV only. The fracture risk scores in groups III and IV had significant statistical differences versus groups I and II (P0.05). Cracked teeth are more vulnerable to complex fractures, with increment of cusp inclinations contributable to complex fracture modes, involving deep roots and high risk scores.

  4. In vitro comparative study on the friction of stainless steel wires with and without Orthospeed® (JAL 90458) on an inclined plane.

    Science.gov (United States)

    Alió-Sanz, Juan J; Claros-Stucchi, Miguel; Albaladejo, Alberto; Iglesias-Conde, Carmen; Alvarado-Lorenzo, Alfonso

    2016-04-01

    During the treatment of orthodontics, in the mechanics of slide, there takes place friction, which they reduce the slide of the arch across bracket. Therefore, clinical there takes place an increase of the time of treatment. There are different the technologies that try to reduce this friction, as the self-ligating braces. The purpose of this study was to research the in vitro behavior of JAL 90458 as a buffering agent which reduces friction between brackets and stainless steel arch wires of different cross sections and sizes. Three types of stainless steel wires with different cross sections and three types of ligatures were used with and without JAL 90458 to measure the friction according to the time and distance traveled by the brackets on an inclined plane with two angulations. The Kruskal-Wallis one-way analysis of variance by ranks was applied to determine the degree of friction between the group using and the group not using the product (P ≤ .05). Separate analysis of the arch wires, ligatures and angulation with and without the compound revealed statistically significant differences between the groups, showing that friction was reduced significantly when JAL 90458 was used (P ≤ .01). The 0.021x0.025" arch wires and the arch wires attached using elastic ligatures produce the least resistance to sliding among all of those analyzed when the product was not used (P ≤ .05). The results show that JAL 90458 reduces friction independently of arch wire cross section, type of ligature and angulation of the measuring instrument. Friction, JAL 90458, arch wires, ligatures, in vitro.

  5. Modelling and Simulation of Free Floating Pig for Different Pipeline Inclination Angles

    Directory of Open Access Journals (Sweden)

    Woldemichael Dereje Engida

    2016-01-01

    Full Text Available This paper presents a modelling and simulation of free floating pig to determine the flow parameters to avoid pig stalling in pigging operation. A free floating spherical shaped pig was design and equipped with necessary sensors to detect leak along the pipeline. The free floating pig does not have internal or external power supply to navigate through the pipeline. Instead, it is being driven by the flowing medium. In order to avoid stalling of the pig, it is essential to conduct simulation to determine the necessary flow parameters for different inclination angles. Accordingly, a pipeline section with inclination of 0°, 15°, 30°, 45°, 60°, 75°, and 90° were modelled and simulated using ANSYS FLUENT 15.0 with water and oil as working medium. For each case, the minimum velocity required to propel the free floating pig through the inclination were determined. In addition, the trajectory of the free floating pig has been visualized in the simulation.

  6. A Comprehensive Comparison Study of Empirical Cutting Transport Models in Inclined and Horizontal Wells

    Directory of Open Access Journals (Sweden)

    Asep Mohamad Ishaq Shiddiq

    2017-07-01

    Full Text Available In deviated and horizontal drilling, hole-cleaning issues are a common and complex problem. This study explored the effect of various parameters in drilling operations and how they affect the flow rate required for effective cutting transport. Three models, developed following an empirical approach, were employed: Rudi-Shindu’s model, Hopkins’, and Tobenna’s model. Rudi-Shindu’s model needs iteration in the calculation. Firstly, the three models were compared using a sensitivity analysis of drilling parameters affecting cutting transport. The result shows that the models have similar trends but different values for minimum flow velocity. Analysis was conducted to examine the feasibility of using Rudi-Shindu’s, Hopkins’, and Tobenna’s models. The result showed that Hopkins’ model is limited by cutting size and revolution per minute (RPM. The minimum flow rate from Tobenna’s model is affected only by well inclination, drilling fluid weight and drilling fluid rheological property. Meanwhile, Rudi-Shindu’s model is limited by inclinations above 45°. The study showed that the investigated models are not suitable for horizontal wells because they do not include the effect of lateral section.

  7. New plastic plane stress model for concrete

    International Nuclear Information System (INIS)

    Winnicki, A.; Cichon, Cz.

    1993-01-01

    In the paper a description of concrete behaviour in the plane stress case is given on the basis of the modified bounding surface plasticity theory. Three independent plastic mechanisms have been introduced describing axiatoric and deviatoric plastic strains and their coupling. All the new analytical formulae for material functions being in agreement with experiments and loading/unloading criteria have been proposed. In addition, for the proper description of concrete behaviour in tension a new, separate function of bounding surface shrinkage has been introduced. (author)

  8. Lower bound plane stress element for modelling 3D structures

    DEFF Research Database (Denmark)

    Herfelt, Morten Andersen; Poulsen, Peter Noe; Hoang, Linh Cao

    2017-01-01

    In-plane action is often the primary load-carrying mechanism of reinforced concrete structures. The plate bending action will be secondary, and the behaviour of the structure can be modelled with a reasonable accuracy using a generalised three-dimensional plane stress element. In this paper...

  9. Variation of the Friction Coefficient for a Cylinder Rolling down an Inclined Board

    Science.gov (United States)

    Yan, Zixiang; Xia, Heming; Lan, Yueheng; Xiao, Jinghua

    2018-01-01

    A cylinder rolling down an inclined board is a commonly seen and interesting object to study and it is also easy to experiment with and model. Following what has become a popular practice, we use smartphones to measure the angular acceleration of a cylinder rolling down a plane of different inclining angles. The friction force deviates from the…

  10. Evaluation of different models to estimate the global solar radiation on inclined surface

    Science.gov (United States)

    Demain, C.; Journée, M.; Bertrand, C.

    2012-04-01

    Global and diffuse solar radiation intensities are, in general, measured on horizontal surfaces, whereas stationary solar conversion systems (both flat plate solar collector and solar photovoltaic) are mounted on inclined surface to maximize the amount of solar radiation incident on the collector surface. Consequently, the solar radiation incident measured on a tilted surface has to be determined by converting solar radiation from horizontal surface to tilted surface of interest. This study evaluates the performance of 14 models transposing 10 minutes, hourly and daily diffuse solar irradiation from horizontal to inclined surface. Solar radiation data from 8 months (April to November 2011) which include diverse atmospheric conditions and solar altitudes, measured on the roof of the radiation tower of the Royal Meteorological Institute of Belgium in Uccle (Longitude 4.35°, Latitude 50.79°) were used for validation purposes. The individual model performance is assessed by an inter-comparison between the calculated and measured solar global radiation on the south-oriented surface tilted at 50.79° using statistical methods. The relative performance of the different models under different sky conditions has been studied. Comparison of the statistical errors between the different radiation models in function of the clearness index shows that some models perform better under one type of sky condition. Putting together different models acting under different sky conditions can lead to a diminution of the statistical error between global measured solar radiation and global estimated solar radiation. As models described in this paper have been developed for hourly data inputs, statistical error indexes are minimum for hourly data and increase for 10 minutes and one day frequency data.

  11. A couple stress fluid modeling on free convection oscillatory hydromagnetic flow in an inclined rotating channel

    Directory of Open Access Journals (Sweden)

    Sahin Ahmed

    2014-12-01

    Full Text Available This study focuses analytically on the oscillatory hydromagnetic flow of a viscous, incompressible, electrically-conducting, non-Newtonian fluid in an inclined, rotating channel with non-conducting walls, incorporating couple stress effects. The model is then non-dimensionalized with appropriate variables and shown to be controlled by the inverse Ekman number (K2 = 1/Ek, the hydromagnetic body force parameter (M, channel inclination (α, Grashof number (Gr, Prandtl number (Pr, oscillation frequency (ω and time variable (ωT. Analytical solutions are derived using complex variables. Excellent agreement is obtained between both previous and present work. The influence of the governing parameters on the primary velocity, secondary velocity, temperature (θ, primary and secondary flow discharges per unit depth in the channel, and frictional shear stresses due to primary and secondary flow, is studied graphically and using tables. Applications of the study arise in the simulation of the manufacture of electrically-conducting polymeric liquids and hydromagnetic energy systems exploiting rheological working fluids.

  12. Can plane wave modes be physical modes in soliton models?

    International Nuclear Information System (INIS)

    Aldabe, F.

    1995-08-01

    I show that plane waves may not be used as asymptotic states in soliton models because they describe unphysical states. When asymptotic states are taken to the physical there is not T-matrix of O(1). (author). 9 refs

  13. Sexual dimorphism and regional variation in human frontal bone inclination measured via digital 3D models.

    Science.gov (United States)

    Petaros, Anja; Garvin, Heather M; Sholts, Sabrina B; Schlager, Stefan; Wärmländer, Sebastian K T S

    2017-11-01

    The frontal bone is one of the most sexually dimorphic elements of the human skull, due to features such as the glabella, frontal eminences, and frontal inclination. While glabella is frequently evaluated in procedures to estimate sex in unknown human skeletal remains, frontal inclination has received less attention. In this study we present a straightforward, quick, and reproducible method for measuring frontal inclination angles from glabella and supraglabella. Using a sample of 413 human crania from four different populations (U.S. Whites, U.S. Blacks, Portuguese, and Chinese), we test the usefulness of the inclination angles for sex estimation and compare their performance to traditional methods of frontal inclination assessment. Accuracy rates in the range 75-81% were achieved for the U.S. White, U.S. Black, and Portuguese groups. For Chinese the overall accuracy was lower, i.e. 66%. Although some regional variation was observed, a cut-off value of 78.2° for glabellar inclination angles separates female and male crania from all studied populations with good accuracy. As inclination angles measured from glabella captures two sexually dimorphic features (i.e. glabellar prominence and frontal inclination) in a single measure, the observed clear male/female difference is not unexpected. Being continuous variables, inclination angles are suitable for use in statistical methods for sex estimations. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. DLCQ and plane wave matrix Big Bang models

    Science.gov (United States)

    Blau, Matthias; O'Loughlin, Martin

    2008-09-01

    We study the generalisations of the Craps-Sethi-Verlinde matrix big bang model to curved, in particular plane wave, space-times, beginning with a careful discussion of the DLCQ procedure. Singular homogeneous plane waves are ideal toy-models of realistic space-time singularities since they have been shown to arise universally as their Penrose limits, and we emphasise the role played by the symmetries of these plane waves in implementing the flat space Seiberg-Sen DLCQ prescription for these curved backgrounds. We then analyse various aspects of the resulting matrix string Yang-Mills theories, such as the relation between strong coupling space-time singularities and world-sheet tachyonic mass terms. In order to have concrete examples at hand, in an appendix we determine and analyse the IIA singular homogeneous plane wave - null dilaton backgrounds.

  15. DLCQ and plane wave matrix Big Bang models

    International Nuclear Information System (INIS)

    Blau, Matthias; O'Loughlin, Martin

    2008-01-01

    We study the generalisations of the Craps-Sethi-Verlinde matrix big bang model to curved, in particular plane wave, space-times, beginning with a careful discussion of the DLCQ procedure. Singular homogeneous plane waves are ideal toy-models of realistic space-time singularities since they have been shown to arise universally as their Penrose limits, and we emphasise the role played by the symmetries of these plane waves in implementing the flat space Seiberg-Sen DLCQ prescription for these curved backgrounds. We then analyse various aspects of the resulting matrix string Yang-Mills theories, such as the relation between strong coupling space-time singularities and world-sheet tachyonic mass terms. In order to have concrete examples at hand, in an appendix we determine and analyse the IIA singular homogeneous plane wave - null dilaton backgrounds.

  16. Evaluation of the inclination of maxillary occlusal plane on mounted casts using a fixed value and customized nasion indicator in artex articulator: Facebow system - An in-vivo comparative study

    Directory of Open Access Journals (Sweden)

    Manikandan Ramasamy

    2013-01-01

    Full Text Available Aim: To evaluate and compare the variations in the inclination of occlusal plane of casts mounted on Artex articulator using a facebow with a fixed value and customized nasion indicator. Materials and Methods: Twenty two subjects were selected for this investigation. Two maxillary impressions were made, and casts poured. For each of the twenty two subjects, the facebow records were made with, Artex face-bow using a fixed value nasion indicator and customized nasion indicator and mounted. The angle between the occlusal plane of upper cast and the upper articulator arm was measured with a Universal bevel protractor and compared with the gold standard cephalometric value. Results: It shows that, when angle was measured between maxillary occlusal plane and upper member of the articulator, on the mounted cast using a customized nasion indicator and fixed value nasion indicator against the gold standard cephalometric value as a whole, it was found to be not significant. But, if each patient were evaluated individually, there found to be the difference in the angle. Discussion and Conclusion: Variation in occlusal plane was very minimal and close to the cephalometric value when using customized nasion indicator compared to fixed value nasion indicator on the Artex.

  17. Multi-lane Changing Model with Coupling Driving Intention and Inclination

    Directory of Open Access Journals (Sweden)

    Jiangfeng Wang

    2017-04-01

    Full Text Available Considering the impact of drivers’ psychology and behaviour, a multi-lane changing model coupling driving intention and inclination is proposed by introducing two quantitative indices of intention: strength of lane changing and risk factor. According to the psychological and behavioural characteristics of aggressive drivers and conservative drivers, the safety conditions for lane changing are designed respectively. The numerical simulations show that the proposed model is suitable for describing the traffic flow with frequent lane changing, which is more consistent with the driving behaviour of drivers in China. Compared with symmetric two-lane cellular automata (STCA model, the proposed model can improve the average speed of vehicles by 1.04% under different traffic demands when aggressive drivers are in a higher proportion (the threshold of risk factor is 0.4. When the risk factor increases, the average speed shows the polarization phenomenon with the average speed slowing down in big traffic demand. The proposed model can reflect the relationship among density, flow, and speed, and the risk factor has a significant impact on density and flow.

  18. Modelling the Landing of a Plane in a Calculus Lab

    Science.gov (United States)

    Morante, Antonio; Vallejo, Jose A.

    2012-01-01

    We exhibit a simple model of a plane landing that involves only basic concepts of differential calculus, so it is suitable for a first-year calculus lab. We use the computer algebra system Maxima and the interactive geometry software GeoGebra to do the computations and graphics. (Contains 5 figures and 1 note.)

  19. Plane Symmetric Cosmological Model with Quark and Strange ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Astrophysics and Astronomy; Volume 38; Issue 1. Plane Symmetric Cosmological Model with Quark and Strange Quark Matter in f ( R , T ) Theory of Gravity. P. K. AGRAWAL D. D. PAWAR. Research Article Volume 38 Issue 1 March 2017 Article ID 2 ...

  20. Transient laminar opposing mixed convection in a symmetrically heated duct with a plane symmetric sudden contraction-expansion: Buoyancy an inclination effects

    Science.gov (United States)

    Martínez-Suástegui, Lorenzo; Barreto, Enrique; Treviño, César

    2015-11-01

    Transient laminar opposing mixed convection is studied experimentally in an open vertical rectangular channel with two discrete protruded heat sources subjected to uniform heat flux simulating electronic components. Experiments are performed for a Reynolds number of Re = 700, Prandtl number of Pr = 7, inclination angles with respect to the horizontal of γ =0o , 45o and 90o, and different values of buoyancy strength or modified Richardson number, Ri* =Gr* /Re2 . From the experimental measurements, the space averaged surface temperatures, overall Nusselt number of each simulated electronic chip, phase-space plots of the self-oscillatory system, characteristic times of temperature oscillations and spectral distribution of the fluctuating energy have been obtained. Results show that when a threshold in the buoyancy parameter is reached, strong three-dimensional secondary flow oscillations develop in the axial and spanwise directions. This research was supported by the Consejo Nacional de Ciencia y Tecnología (CONACYT), Grant number 167474 and by the Secretaría de Investigación y Posgrado del IPN, Grant number SIP 20141309.

  1. Hydrodynamic modeling of semi-planing hulls with air cavities

    Directory of Open Access Journals (Sweden)

    Konstantin I. Matveev

    2015-05-01

    Full Text Available High-speed heavy loaded monohull ships can benefit from application of drag-reducing air cavities under stepped hull bottoms. The subject of this paper is the steady hydrodynamic modeling of semi-planing air-cavity hulls. The current method is based on a linearized potential-flow theory for surface flows. The mathematical model description and parametric calculation results for a selected configuration with pressurized and open air cavities are presented.

  2. Modelling of subcritical free-surface flow over an inclined backward-facing step in a water channel

    Directory of Open Access Journals (Sweden)

    Šulc Jan

    2012-04-01

    Full Text Available The contribution deals with the experimental and numerical modelling of subcritical turbulent flow in an open channel with an inclined backward-facing step. The step with the inclination angle α = 20° was placed in the water channel of the cross-section 200×200 mm. Experiments were carried out by means of the PIV and LDA measuring techniques. Numerical simulations were executed by means of the commercial software ANSYS CFX 12.0. Numerical results obtained for twoequation models and EARSM turbulence model completed by transport equations for turbulent energy and specific dissipation rate were compared with experimental data. The modelling was concentrated particularly on the development of the flow separation and on the corresponding changes of free surface.

  3. Roof planes detection via a second-order variational model

    Science.gov (United States)

    Benciolini, Battista; Ruggiero, Valeria; Vitti, Alfonso; Zanetti, Massimo

    2018-04-01

    The paper describes a unified automatic procedure for the detection of roof planes in gridded height data. The procedure exploits the Blake-Zisserman (BZ) model for segmentation in both 2D and 1D, and aims to detect, to model and to label roof planes. The BZ model relies on the minimization of a functional that depends on first- and second-order derivatives, free discontinuities and free gradient discontinuities. During the minimization, the relative strength of each competitor is controlled by a set of weight parameters. By finding the minimum of the approximated BZ functional, one obtains: (1) an approximation of the data that is smoothed solely within regions of homogeneous gradient, and (2) an explicit detection of the discontinuities and gradient discontinuities of the approximation. Firstly, input data is segmented using the 2D BZ. The maps of data and gradient discontinuities are used to isolate building candidates and planar patches (i.e. regions with homogeneous gradient) that correspond to roof planes. Connected regions that can not be considered as buildings are filtered according to both patch dimension and distribution of the directions of the normals to the boundary. The 1D BZ model is applied to the curvilinear coordinates of boundary points of building candidates in order to reduce the effect of data granularity when the normals are evaluated. In particular, corners are preserved and can be detected by means of gradient discontinuity. Lastly, a total least squares model is applied to estimate the parameters of the plane that best fits the points of each planar patch (orthogonal regression with planar model). Refinement of planar patches is performed by assigning those points that are close to the boundaries to the planar patch for which a given proximity measure assumes the smallest value. The proximity measure is defined to account for the variance of a fitting plane and a weighted distance of a point from the plane. The effectiveness of the

  4. Mobility-Aware Modeling and Analysis of Dense Cellular Networks With $C$ -Plane/ $U$ -Plane Split Architecture

    KAUST Repository

    Ibrahim, Hazem

    2016-09-19

    The unrelenting increase in the population of mobile users and their traffic demands drive cellular network operators to densify their network infrastructure. Network densification shrinks the footprint of base stations (BSs) and reduces the number of users associated with each BS, leading to an improved spatial frequency reuse and spectral efficiency, and thus, higher network capacity. However, the densification gain comes at the expense of higher handover rates and network control overhead. Hence, user’s mobility can diminish or even nullifies the foreseen densification gain. In this context, splitting the control plane ( C -plane) and user plane ( U -plane) is proposed as a potential solution to harvest densification gain with reduced cost in terms of handover rate and network control overhead. In this paper, we use stochastic geometry to develop a tractable mobility-aware model for a two-tier downlink cellular network with ultra-dense small cells and C -plane/ U -plane split architecture. The developed model is then used to quantify the effect of mobility on the foreseen densification gain with and without C -plane/ U -plane split. To this end, we shed light on the handover problem in dense cellular environments, show scenarios where the network fails to support certain mobility profiles, and obtain network design insights.

  5. Non-static plane symmetric cosmological model in Wesson's theory

    Indian Academy of Sciences (India)

    geodesic path in this theory. Further, it is observed that ρm →∞ as t →0 and ρm →0 as t →∞, which indicates that there is a Big Bang-like singularity at the initial epoch. 5. Conclusions. The non-static plane symmetric cosmological model constructed here expands with increase of time and the rate of expansion is slow with ...

  6. Two-Dimensional Computational Flow Analysis and Frictional Characteristics Model for Red Blood Cell under Inclined Centrifuge Microscopy

    Science.gov (United States)

    Funamoto, Kenichi; Hayase, Toshiyuki; Shirai, Atsushi

    Simplified two-dimensional flow analysis is performed in order to simulate frictional characteristics measurement of red blood cells moving on a glass plate in a medium with an inclined centrifuge microscope. Computation under various conditions reveals the influences of parameters on lift, drag, and moment acting on a red blood cell. Among these forces, lift appears only when the cell is longitudinally asymmetric. By considering the balance of forces, the frictional characteristics of the red blood cell are modeled as the sum of Coulomb friction and viscous drag. The model describes the possibility that the red blood cell deforms to expand in the front side in response to the inclined centrifugal force. When velocity exceeds some critical value, the lift overcomes the normal centrifugal force component, and the thickness of the plasma layer between the cell and the glass plate increases from the initial value of the plasma protein thickness.

  7. Self-similar decay to the marginally stable ground state in a model for film flow over inclined wavy bottoms

    Directory of Open Access Journals (Sweden)

    Tobias Hacker

    2012-04-01

    Full Text Available The integral boundary layer system (IBL with spatially periodic coefficients arises as a long wave approximation for the flow of a viscous incompressible fluid down a wavy inclined plane. The Nusselt-like stationary solution of the IBL is linearly at best marginally stable; i.e., it has essential spectrum at least up to the imaginary axis. Nevertheless, in this stable case we show that localized perturbations of the ground state decay in a self-similar way. The proof uses the renormalization group method in Bloch variables and the fact that in the stable case the Burgers equation is the amplitude equation for long waves of small amplitude in the IBL. It is the first time that such a proof is given for a quasilinear PDE with spatially periodic coefficients.

  8. A comprehensive model for in-plane and out-of-plane vibration of CANDU fuel endplate rings

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.D., E-mail: syu@ryerson.ca; Fadaee, M.

    2016-08-01

    Highlights: • Proposed an effective method for modelling bending and torsional vibration of CANDU fuel endplate rings. • Applied successfully the thick plate theory to curved structural members by accounting for the transverse shear effect. • The proposed method is computationally more efficient compared to the 3D finite element. - Abstract: In this paper, a comprehensive vibration model is developed for analysing in-plane and out-of-plane vibration of CANDU fuel endplate rings by taking into consideration the effects of in-plane extension in the circumferential and radial directions, shear, and rotatory inertia. The model is based on Reddy’s thick plate theory and the nine-node isoparametric Lagrangian plate finite elements. Natural frequencies of various modes of vibration of circular rings obtained using the proposed method are compared with 3D finite element results, experimental data and results available in the literature. Excellent agreement was achieved.

  9. Natural Frequencies and Mode Shapes of Statically Deformed Inclined Risers

    KAUST Repository

    Alfosail, Feras

    2016-10-15

    We investigate numerically the linear vibrations of inclined risers using the Galerkin approach. The riser is modeled as an Euler-Bernoulli beam accounting for the nonlinear mid-plane stretching and self-weight. After solving for the initial deflection of the riser due to self-weight, we use a Galerkin expansion employing 15 axially loaded beam mode shapes to solve the eigenvalue problem of the riser around the static equilibrium configuration. This yields the riser natural frequencies and corresponding exact mode shapes for various values of inclination angles and tension. The obtained results are validated against a boundary-layer analytical solution and are found to be in good agreement. This constitutes a basis to study the nonlinear forced vibrations of inclined risers.

  10. Kinetic models of two-dimensional plane and axially symmetric current sheets: Group theory approach

    Energy Technology Data Exchange (ETDEWEB)

    Vasko, I. Y.; Artemyev, A. V. [Space Research Institute, RAS, Moscow (Russian Federation); Popov, V. Y. [Space Research Institute, RAS, Moscow (Russian Federation); Department of Physics, Moscow State University, Moscow (Russian Federation); Malova, H. V. [Space Research Institute, RAS, Moscow (Russian Federation); Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow (Russian Federation)

    2013-02-15

    In this paper, we present new class of solutions of Grad-Shafranov-like (GS-like) equations, describing kinetic plane and axially symmetric 2D current sheets. We show that these equations admit symmetry groups only for Maxwellian and {kappa}-distributions of charged particles. The admissible symmetry groups are used to reduce GS-like equations to ordinary differential equations for invariant solutions. We derive asymptotes of invariant solutions, while invariant solutions are found analytically for the {kappa}-distribution with {kappa}=7/2. We discuss the difference of obtained solutions from equilibria widely used in other studies. We show that {kappa} regulates the decrease rate of plasma characteristics along the current sheet and determines the spatial distribution of magnetic field components. The presented class of plane and axially symmetric (disk-like) current sheets includes solutions with the inclined neutral plane.

  11. Models of Quantum Space Time: Quantum Field Planes

    OpenAIRE

    Mack, G.; Schomerus, V.

    1994-01-01

    Quantum field planes furnish a noncommutative differential algebra $\\Omega$ which substitutes for the commutative algebra of functions and forms on a contractible manifold. The data required in their construction come from a quantum field theory. The basic idea is to replace the ground field ${\\bf C}$ of quantum planes by the noncommutative algebra ${\\cal A}$ of observables of the quantum field theory.

  12. Incisor inclination and perceived tooth colour changes.

    Science.gov (United States)

    Ciucchi, Philip; Kiliaridis, Stavros

    2017-10-01

    Social attractiveness is influenced by a variety of different smile-related factors. We evaluated whether the degree of upper central incisor proclination can result in tooth colour change. Forty young adult subjects (20-25 years) in good health with a complete sound dentition were selected. The subjects were seated in standardized light conditions with an above-directed light source. Their natural head position was stated as 0 degrees. To mimic the range of possible anterior torque movements they were asked to tilt their heads upward +15 degrees (upward tilting) and downward -15 degrees (downward tilting). Frontal macro photographs, parallel to the Frankfort plane of the patient's natural head position were taken at the three head angulations (+15, 0, and -15 degrees ). Photographs were analysed for colour differences at the centre of the incisor clinical crowns with a CIE L*a*b* colour model based software. A paired t-test was used to test for significance between each value for each inclination. Differences were found between the CIE L*a*b* colour values for: upward tilting, downward tilting, and -15 to +15 degrees (total tilting) except for b* values for downward tilting. As the inclination of the subject's head changed downward, the upper incisors were retroclined and the CIE L*a*b* values indicated a darker and less green but redder colour component. As the inclination of the subject's head changed upwards the upper incisors were proclined and the L*a*b* values indicated a lighter and less green and yellow but redder and bluer colour component. Proclination of upper incisors caused lighter tooth colour parameters compared to retroclined incisors and colour changes. Orthodontic change of upper incisor inclination may induce alterations on how tooth colour is perceived.

  13. Dissipative N-point-vortex Models in the Plane

    Science.gov (United States)

    Shashikanth, Banavara N.

    2010-02-01

    A method is presented for constructing point vortex models in the plane that dissipate the Hamiltonian function at any prescribed rate and yet conserve the level sets of the invariants of the Hamiltonian model arising from the SE (2) symmetries. The method is purely geometric in that it uses the level sets of the Hamiltonian and the invariants to construct the dissipative field and is based on elementary classical geometry in ℝ3. Extension to higher-dimensional spaces, such as the point vortex phase space, is done using exterior algebra. The method is in fact general enough to apply to any smooth finite-dimensional system with conserved quantities, and, for certain special cases, the dissipative vector field constructed can be associated with an appropriately defined double Nambu-Poisson bracket. The most interesting feature of this method is that it allows for an infinite sequence of such dissipative vector fields to be constructed by repeated application of a symmetric linear operator (matrix) at each point of the intersection of the level sets.

  14. Bidispersive-inclined convection

    Science.gov (United States)

    Mulone, Giuseppe; Straughan, Brian

    2016-01-01

    A model is presented for thermal convection in an inclined layer of porous material when the medium has a bidispersive structure. Thus, there are the usual macropores which are full of a fluid, but there are also a system of micropores full of the same fluid. The model we employ is a modification of the one proposed by Nield & Kuznetsov (2006 Int. J. Heat Mass Transf. 49, 3068–3074. (doi:10.1016/j.ijheatmasstransfer.2006.02.008)), although we consider a single temperature field only. PMID:27616934

  15. [Reproducibility and repeatability of the determination of occlusal plane on digital dental models].

    Science.gov (United States)

    Qin, Yi-fei; Xu, Tian-min

    2015-06-18

    To assess the repeatability(intraobserver comparison)and reproducibility(interobserver comparison)of two different methods for establishing the occlusal plane on digital dental models. With Angle's classification as a stratification factor,48 cases were randomly extracted from 806 ones which had integrated clinical data and had their orthodontic treatment from July 2004 to August 2008 in Department of Orthodontics ,Peking University School and Hospital of Stomatology.Post-treatment plaster casts of 48 cases were scanned by Roland LPX-1200 3D laser scanner to generate geometry data as research subjects.In a locally developed software package,one observer repeated 5 times at intervals of at least one week to localize prescriptive landmarks on each digital model to establish a group of functional occlusal planes and a group of anatomic occlusal planes, while 6 observers established two other groups of functional and anatomic occlusal planes independently.Standard deviations of dihedral angles of each group on each model were calculated and compared between the related groups.The models with the five largest standard deviations of each group were studied to explore possible factors that might influence the identification of the landmarks on the digital models. Significant difference of intraobserver variability was not detected between the functional occlusal plane and the anatomic occlusal plane (P>0.1), while that of interobserver variability was detected (Pocclusal plane was 0.2° smaller than that of the anatomic occlusal plane.The functional occlusal plane's variability of intraobserver and interobsever did not differ significantly (P>0.1), while the anatomic occlusal plane's variability of the intraobserver was significantly smaller than that of the interobserver (Pocclusal planes are suitable as a conference plane with equal repeatability. When several observers measure a large number of digital models,the functional occlusal plane is more reproducible than the

  16. Plane Symmetric Cosmological Model with Quark and Strange ...

    Indian Academy of Sciences (India)

    parameter. We also discussed the physical behavior of the solutions by using some physical parameters. Keywords. f(R,T) theory of gravity—plane symmetric space-time—quark and strange quark matter—constant deceleration parameter. 1. Introduction. Modern astrophysical observations point out that present expansion ...

  17. Modeling pressure drop of inclined flow through a heat exchanger for aero-engine applications

    International Nuclear Information System (INIS)

    Missirlis, D.; Yakinthos, K.; Storm, P.; Goulas, A.

    2007-01-01

    In the present work further numerical predictions for the flow field through a specific type of a heat exchanger, which is planned to be used in the exhaust nozzle of aircraft engines. In order to model the flow field through the heat exchanger, a porous medium model is used based on a simple quadratic relation, which connects the pressure drop with the inlet air velocity in the external part of the heat exchanger. The aim of this work is to check the applicability of the quadratic law in a variety of velocity inlet conditions configured by different angles of attack. The check is performed with CFD and the results are compared with new available experimental data for these inlet conditions. A detailed qualitative analysis shows that although the quadratic law has been derived for a zero angle of attack, it performs very well for alternative non-zero angles. These observations are very helpful since this simple pressure drop law can be used for advanced computations where the whole system of the exhaust nozzle together with the heat exchangers can be modeled within a holistic approach

  18. Bound states in a model of interaction of Dirac field with material plane

    Directory of Open Access Journals (Sweden)

    Pismak Yu. M.

    2016-01-01

    Full Text Available In the framework of the Symanzik approach model of the interaction of the Dirac spinor field with the material plane in the 3 + 1-dimensional space is constructed. The model contains eight real parameters characterizing the properties of the material plane. The general solution of the Euler-Lagrange equations of the model and dispersion equations for bound states are analyzed. It is shown that there is a choice of parameters of the model in which the connected states are characterized by dispersion law of a mass-less particle moving along the material plane with the dimensionless Fermi velocity not exceeding one.

  19. Modelling the Impact of Ground Planes on Antenna Radiation Using the Method of Auxiliary Sources

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal; Breinbjerg, Olav

    2007-01-01

    The Method of Auxiliary Sources is employed to model the impact of finite ground planes on the radiation from antennas. In many cases the computational cost of available commercial tools restricts the simulations to include only a small ground plane or, by use of the image principle, the infinitely...

  20. Dynamic Fracturing Behavior of Layered Rock with Different Inclination Angles in SHPB Tests

    Directory of Open Access Journals (Sweden)

    Jiadong Qiu

    2017-01-01

    Full Text Available The fracturing behavior of layered rocks is usually influenced by bedding planes. In this paper, five groups of bedded sandstones with different bedding inclination angles θ are used to carry out impact compression tests by split Hopkinson pressure bar. A high-speed camera is used to capture the fracturing process of specimens. Based on testing results, three failure patterns are identified and classified, including (A splitting along bedding planes; (B sliding failure along bedding planes; (C fracturing across bedding planes. The failure pattern (C can be further classified into three subcategories: (C1 fracturing oblique to loading direction; (C2 fracturing parallel to loading direction; (C3 mixed fracturing across bedding planes. Meanwhile, a numerical model of layered rock and SHPB system are established by particle flow code (PFC. The numerical results show that the shear stress is the main reason for inducing the damage along bedding plane at θ = 0°~75°. Both tensile stress and shear stress on bedding planes contribute to the splitting failure along bedding planes when the inclination angle is 90°. Besides, tensile stress is the main reason that leads to the damage in rock matrixes at θ = 0°~90°.

  1. Lost of solar energy by not optimized guidance and inclination of the planes, in Galicia; Perdidas de energia solar por orientacion e inclinacion no optimizadas de los planos, en Galicia

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez, M.; Pose, M.; Izquierdo, P.; Prado, T.

    2008-07-01

    Graphs of percentages of solar energy received in planes with different orientations and tilts, with respect to the maximum solar energy received on the plane with optimum orientation and tilt, are obtained for Galicia. The graphs are needed to calculate the losses because orientation and tilt that the Spanish Technical Building Code (TBC) limits. (Author)

  2. Development of a new mathematical model for prediction of surface subsidence due to inclined coal-seam mining

    Energy Technology Data Exchange (ETDEWEB)

    Asadi, A.; Shahriar, K.; Goshtasbi, K.; Najm, K. [Islam Azad University, Tehran (Iran). Dept. of Mining Engineering

    2005-01-01

    Subsidence phenomenon as an unwanted consequence of underground mining can cause problems for environment and surface structures in mine area. Surface subsidence prediction for inclined and steep seams has been given less attention than horizontal seams due to the difficulties involved in the extraction of such coal-seams. This paper introduces a new profile function method for prediction of surface subsidence due to inclined coal-seam mining. The results of calculation with the new function indicate that the predicted value has good agreement with the measured data.

  3. Current perpendicular to plane giant magnetoresistance and tunneling magnetoresistance treated with unified model

    NARCIS (Netherlands)

    Jonkers, PAE

    2002-01-01

    The conceptual similarity between current perpendicular to plane giant magnetoresistance (CPP-GMR) and tunneling magnetoresistance (TMR) is exploited by utilizing a unified single-particle model accounting for both types of magnetoresistance. By defining structures composed of ferromagnetic,

  4. Experimental and numerical modelling of turbulent flow over an inclined backward-facing step in an open channel

    Czech Academy of Sciences Publication Activity Database

    Příhoda, Jaromír; Zubík, P.; Šulc, J.; Sedlář, M.

    2012-01-01

    Roč. 14, 4a (2012), s. 6-12 ISSN 1335-4205 R&D Projects: GA ČR GA103/09/0977 Institutional support: RVO:61388998 Keywords : open channel flow * inclined backward-facing step Subject RIV: BK - Fluid Dynamics

  5. Non-static plane symmetric cosmological model in Wesson's theory

    Indian Academy of Sciences (India)

    ] scale invariant theory of gravitation with a time-dependent gauge function is investigated. The false vacuum model of the universe is constructed and some physical properties of the model are discussed.

  6. Impact of flow inclination on downwind turbine loads and power

    Science.gov (United States)

    Kress, C.; Chokani, N.; Abhari, R. S.; Hashimoto, T.; Watanabe, M.; Sano, T.; Saeki, M.

    2016-09-01

    Wind turbines frequently operate under situations of pronounced flow inclinations, such as in complex terrain. In the present work the performance and rotor thrust of downwind and upwind turbines in upward and downward flow inclinations are experimentally investigated. In an upward flow inclination of +13°, downwind turbines are shown to have a 29% larger power output than a corresponding upwind turbine, whereas the relative increase in rotor thrust is only 9%. Furthermore, it is also shown that the performance of downwind turbines is less sensitive to changes in the flow inclination, as the upstream nacelle on downwind turbines beneficially redirects and accelerates the flow around the nacelle into the rotor plane.

  7. Vehicle with inclinable caterpillars

    International Nuclear Information System (INIS)

    Carra, O.; Delevallee, A.

    1991-01-01

    Vehicle has a body with propulsion assemblies that drive caterpillar tracks. When a propulsion unit inclines about its articulation axis it is aided by an advance movement of the caterpillar track in the opposite direction of rotation [fr

  8. Analyses and testing of model prestressed concrete reactor vessels with built-in planes of weakness

    International Nuclear Information System (INIS)

    Dawson, P.; Paton, A.A.; Fleischer, C.C.

    1990-01-01

    This paper describes the design, construction, analyses and testing of two small scale, single cavity prestressed concrete reactor vessel models, one without planes of weakness and one with planes of weakness immediately behind the cavity liner. This work was carried out to extend a previous study which had suggested the likely feasibility of constructing regions of prestressed concrete reactor vessels and biological shields, which become activated, using easily removable blocks, separated by a suitable membrane. The paper describes the results obtained and concludes that the planes of weakness concept could offer a means of facilitating the dismantling of activated regions of prestressed concrete reactor vessels, biological shields and similar types of structure. (author)

  9. Plane answers to complex questions the theory of linear models

    CERN Document Server

    Christensen, Ronald

    1987-01-01

    This book was written to rigorously illustrate the practical application of the projective approach to linear models. To some, this may seem contradictory. I contend that it is possible to be both rigorous and illustrative and that it is possible to use the projective approach in practical applications. Therefore, unlike many other books on linear models, the use of projections and sub­ spaces does not stop after the general theory. They are used wherever I could figure out how to do it. Solving normal equations and using calculus (outside of maximum likelihood theory) are anathema to me. This is because I do not believe that they contribute to the understanding of linear models. I have similar feelings about the use of side conditions. Such topics are mentioned when appropriate and thenceforward avoided like the plague. On the other side of the coin, I just as strenuously reject teaching linear models with a coordinate free approach. Although Joe Eaton assures me that the issues in complicated problems freq...

  10. Modeling posture-dependent leg actuation in sagittal plane locomotion

    International Nuclear Information System (INIS)

    Schmitt, J; Clark, J

    2009-01-01

    The spring loaded inverted pendulum template has been shown to accurately model the steady locomotion dynamics of a variety of running animals, and has served as the inspiration for an entire class of dynamic running robots. While the template models the leg dynamics by an energy-conserving spring, insects and animals have structures that dissipate, store and produce energy during a stance phase. Recent investigations into the spring-like properties of limbs, as well as animal response to drop-step perturbations, suggest that animals use their legs to manage energy storage and dissipation, and that this management is important for gait stability. In this paper, we extend our previous analysis of control of the spring loaded inverted pendulum template via changes in the leg touch-down angle to include energy variations during the stance phase. Energy variations are incorporated through leg actuation that varies the force-free leg length during the stance phase, yet maintains qualitatively correct force and velocity profiles. In contrast to the partially asymptotically stable gaits identified in previous analyses, incorporating energy and leg angle variations in this manner produces complete asymptotic stability. Drop-step perturbation simulations reveal that the control strategy is rather robust, with gaits recovering from drops of up to 30% of the nominal hip height.

  11. Snakes on a plane: modeling flexible active nematics

    Science.gov (United States)

    Selinger, Robin

    Active soft matter systems of self-propelled rod-shaped particles exhibit ordered phases and collective behavior that are remarkably different from their passive analogs. In nature, many self-propelled rod-shaped particles, such as gliding bacteria and kinesin-driven microtubules, are flexible and can bend. We model these ``living liquid crystals'' to explore their phase behavior, dynamics, and pattern formation. We model particles as short polymers via molecular dynamics with a Langevin thermostat and various types of activity, substrate, and environments. For self-propelled polar particles gliding on a solid substrate, we map out the phase diagram as a function of particle density and flexibility. We compare simulated defect structures to those observed in colonies of gliding myxobacteria; compare spooling behavior to that observed in microtubule gliding assays; and analyze emergence of nematic and polar order. Next we explore pattern formation of self-propelled polar particles under flexible encapsulation, and on substrates with non-uniform Gaussian curvature. Lastly, we impose an activity mechanism that mimics extensile shear, study flexible particles both on solid substrates and coupled to a lipid membrane, and discuss comparisons to relevant experiments. Work performed in collaboration with Michael Varga (Kent State) and Luca Giomi (Universiteit Leiden.) Work supported by NSF DMR-1409658.

  12. Modeling posture-dependent leg actuation in sagittal plane locomotion

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, J [Department of Mechanical Engineering, Oregon State University, Corvallis, OR 97331 (United States); Clark, J, E-mail: schmitjo@engr.orst.ed [Department of Mechanical Engineering, Florida State University, Tallahassee, FL 32310 (United States)

    2009-12-15

    The spring loaded inverted pendulum template has been shown to accurately model the steady locomotion dynamics of a variety of running animals, and has served as the inspiration for an entire class of dynamic running robots. While the template models the leg dynamics by an energy-conserving spring, insects and animals have structures that dissipate, store and produce energy during a stance phase. Recent investigations into the spring-like properties of limbs, as well as animal response to drop-step perturbations, suggest that animals use their legs to manage energy storage and dissipation, and that this management is important for gait stability. In this paper, we extend our previous analysis of control of the spring loaded inverted pendulum template via changes in the leg touch-down angle to include energy variations during the stance phase. Energy variations are incorporated through leg actuation that varies the force-free leg length during the stance phase, yet maintains qualitatively correct force and velocity profiles. In contrast to the partially asymptotically stable gaits identified in previous analyses, incorporating energy and leg angle variations in this manner produces complete asymptotic stability. Drop-step perturbation simulations reveal that the control strategy is rather robust, with gaits recovering from drops of up to 30% of the nominal hip height.

  13. Geosynchronous inclined orbits for high-latitude communications

    Science.gov (United States)

    Fantino, E.; Flores, R. M.; Di Carlo, M.; Di Salvo, A.; Cabot, E.

    2017-11-01

    We present and discuss a solution to the growing demand for satellite telecommunication coverage in the high-latitude geographical regions (beyond 55°N), where the signal from geostationary satellites is limited or unavailable. We focus on the dynamical issues associated to the design, the coverage, the maintenance and the disposal of a set of orbits selected for the purpose. Specifically, we identify a group of highly inclined, moderately eccentric geosynchronous orbits derived from the Tundra orbit (geosynchronous, eccentric and critically inclined). Continuous coverage can be guaranteed by a constellation of three satellites in equally spaced planes and suitably phased. By means of a high-precision model of the terrestrial gravity field and the relevant environmental perturbations, we study the evolution of these orbits. The effects of the different perturbations on the ground track (which is more important for coverage than the orbital elements themselves) are isolated and analyzed. The physical model and the numerical setup are optimized with respect to computing time and accuracy. We show that, in order to maintain the ground track unchanged, the key parameters are the orbital period and the argument of perigee. Furthermore, corrections to the right ascension of the ascending node are needed in order to preserve the relative orientation of the orbital planes. A station-keeping strategy that minimizes propellant consumption is then devised, and comparisons are made between the cost of a solution based on impulsive maneuvers and one with continuous thrust. Finally, the issue of end-of-life disposal is discussed.

  14. The finite element modeling and thermal analysis of the special focal plane of LAMOST

    Science.gov (United States)

    Zuo, Heng; Yang, Dehua; Li, Guoping

    2010-07-01

    The Large Area Multi-Object Spectroscopic Telescope (LAMOST) is a meridian reflecting Schmidt telescope with a 40m optical axis between the reflecting Schmidt plate and the spherical primary mirror. In the middle is located the spherical focal plane, through which there are corresponding 4000+ unit mounting holes for the fibers, and on its back, there attached a support truss adapted from Serrurier concept. The mechanical stabilization of the focal plane system naturally has magnificent impact on the observation efficiency of the LAMOST. A comprehensive Finite Element Model of the focal plane system has been built to evaluate thermally induced degradation of its mechanical accuracy using the nodal modification technique within ANSYS, and diverse temperature load cases have been considered on the Finite Element model and related thermal analyses have been carried out to investigate thermal deformation of the focal plane. Subsequently the calculated deflection of the working surface has been extracted and reconstructed with least square fitting in MATLAB. The results show that temperature change around the telescope has little effect on the performance of the focal plane within temperature variation requirements of the LAMOST. The methods of modeling and analyzing used in this research are informative for future large telescope projects.

  15. A superellipsoid-plane model for simulating foot-ground contact during human gait.

    Science.gov (United States)

    Lopes, D S; Neptune, R R; Ambrósio, J A; Silva, M T

    2016-01-01

    Musculoskeletal models and forward dynamics simulations of human movement often include foot-ground interactions, with the foot-ground contact forces often determined using a constitutive model that depends on material properties and contact kinematics. When using soft constraints to model the foot-ground interactions, the kinematics of the minimum distance between the foot and planar ground needs to be computed. Due to their geometric simplicity, a considerable number of studies have used point-plane elements to represent these interacting bodies, but few studies have provided comparisons between point contact elements and other geometrically based analytical solutions. The objective of this work was to develop a more general-purpose superellipsoid-plane contact model that can be used to determine the three-dimensional foot-ground contact forces. As an example application, the model was used in a forward dynamics simulation of human walking. Simulation results and execution times were compared with a point-like viscoelastic contact model. Both models produced realistic ground reaction forces and kinematics with similar computational efficiency. However, solving the equations of motion with the surface contact model was found to be more efficient (~18% faster), and on average numerically ~37% less stiff. The superellipsoid-plane elements are also more versatile than point-like elements in that they allow for volumetric contact during three-dimensional motions (e.g. rotating, rolling, and sliding). In addition, the superellipsoid-plane element is geometrically accurate and easily integrated within multibody simulation code. These advantages make the use of superellipsoid-plane contact models in musculoskeletal simulations an appealing alternative to point-like elements.

  16. Granular flow over inclined channels with constrictions

    Science.gov (United States)

    Tunuguntla, Deepak; Weinhart, Thomas; Thornton, Anthony; Bokhove, Onno

    2013-04-01

    Study of granular flows down inclined channels is essential in understanding the dynamics of natural grain flows like landslides and snow avalanches. As a stepping stone, dry granular flow over an inclined channel with a localised constriction is investigated using both continuum methods and particle simulations. Initially, depth-averaged equations of motion (Savage & Hutter 1989) containing an unknown friction law are considered. The shallow-layer model for granular flows is closed with a friction law obtained from particle simulations of steady flows (Weinhart et al. 2012) undertaken in the open source package Mercury DPM (Mercury 2010). The closed two-dimensional (2D) shallow-layer model is then width-averaged to obtain a novel one-dimensional (1D) model which is an extension of the one for water flows through contraction (Akers & Bokhove 2008). Different flow states are predicted by this novel one-dimensional theory. Flow regimes with distinct flow states are determined as a function of upstream channel Froude number, F, and channel width ratio, Bc. The latter being the ratio of the channel exit width and upstream channel width. Existence of multiple steady states is predicted in a certain regime of F - Bc parameter plane which is in agreement with experiments previously undertaken by (Akers & Bokhove 2008) and for granular flows (Vreman et al. 2007). Furthermore, the 1D model is verified by solving the 2D shallow granular equations using an open source discontinuous Galerkin finite element package hpGEM (Pesch et al. 2007). For supercritical flows i.e. F > 1 the 1D asymptotics holds although the two-dimensional oblique granular jumps largely vary across the converging channel. This computationally efficient closed 1D model is validated by comparing it to the computationally more expensiveaa three-dimensional particle simulations. Finally, we aim to present a quasi-steady particle simulation of inclined flow through two rectangular blocks separated by a gap

  17. Seismicity Induced by Hydraulic Fracturing in Shales: A Bedding Plane Slip Model

    Science.gov (United States)

    Staněk, František; Eisner, Leo

    2017-10-01

    Passive seismic monitoring of microseismic events induced in oil or gas reservoirs is known as microseismic monitoring. Microseismic monitoring is used to understand the process of hydraulic fracturing, which is a reservoir stimulation technique. We use a new geomechanical model with bedding plane slippage induced by hydraulic fractures within shale reservoirs to explain seismicity observed in a typical case study of hydraulic fracturing of a shale gas play in North America. Microseismic events propagating from the injection point are located at similar depths (within the uncertainty of their locations), and their source mechanisms are dominated by shear failure with both dip-slip and strike-slip senses of motion. The prevailing dip-slip mechanisms have one nearly vertical nodal plane perpendicular to the minimum horizontal stress axis, while the other nodal plane is nearly horizontal. Such dip-slip mechanisms can be explained by slippage along bedding planes activated by the aseismic opening of vertical hydraulic fractures. The model explains the observed prevailing orientation of the shear planes of the microseismic events, as well as the large difference between seismic and hydraulic energy.

  18. Effect of simplifications of bone and components inclination on the elastohydrodynamic lubrication modeling of metal-on-metal hip resurfacing prosthesis.

    Science.gov (United States)

    Meng, Qingen; Liu, Feng; Fisher, John; Jin, Zhongmin

    2013-05-01

    It is important to study the lubrication mechanism of metal-on-metal hip resurfacing prosthesis in order to understand its overall tribological performance, thereby minimize the wear particles. Previous elastohydrodynamic lubrication studies of metal-on-metal hip resurfacing prosthesis neglected the effects of the orientations of the cup and head. Simplified pelvic and femoral bone models were also adopted for the previous studies. These simplifications may lead to unrealistic predictions. For the first time, an elastohydrodynamic lubrication model was developed and solved for a full metal-on-metal hip resurfacing arthroplasty. The effects of the orientations of components and the realistic bones on the lubrication performance of metal-on-metal hip resurfacing prosthesis were investigated by comparing the full model with simplified models. It was found that the orientation of the head played a very important role in the prediction of pressure distributions and film profiles of the metal-on-metal hip resurfacing prosthesis. The inclination of the hemispherical cup up to 45° had no appreciable effect on the lubrication performance of the metal-on-metal hip resurfacing prosthesis. Moreover, the combined effect of material properties and structures of bones was negligible. Future studies should focus on higher inclination angles, smaller coverage angle and microseparation related to the occurrences of edge loading.

  19. Reaction plane angle dependence of dihadron azimuthal correlations from a multiphase transport model calculation

    International Nuclear Information System (INIS)

    Li, W.; Zhang, S.; Ma, Y. G.; Cai, X. Z.; Chen, J. H.; Ma, G. L.; Zhong, C.; Huang, H. Z.

    2009-01-01

    Dihadron azimuthal angle correlations relative to the reaction plane have been investigated in Au+Au collisions at √(s NN )=200 GeV using a multiphase transport model (AMPT). Such reaction plane azimuthal-angle-dependent correlations can shed light on the path-length effect of energy loss of high-transverse-momentum particles propagating through a hot dense medium. The correlations vary with the trigger particle azimuthal angle with respect to the reaction plane direction, φ s =φ T -Ψ EP , which is consistent with the experimental observation by the STAR Collaboration. The dihadron azimuthal angle correlation functions on the away side of the trigger particle present a distinct evolution from a single-peak to a broad, possibly double-peak structure when the trigger particle direction goes from in-plane to out-of-plane with the reaction plane. The away-side angular correlation functions are asymmetric with respect to the back-to-back direction in some regions of φ s , which could provide insight into the testing v 1 method for reconstructing the reaction plane. In addition, both the root-mean-square width (W rms ) of the away-side correlation distribution and the splitting parameter (D) between the away-side double peaks increase slightly with φ s , and the average transverse momentum of away-side-associated hadrons shows a strong φ s dependence. Our results indicate that a strong parton cascade and resultant energy loss could play an important role in the appearance of a double-peak structure in the dihadron azimuthal angular correlation function on the away side of the trigger particle.

  20. Study of size effects in the Dugdale model through the case of a crack in a semi-infinite plane under anti-plane shear loading

    Science.gov (United States)

    Ferdjani, H.; Abdelmoula, R.; Marigo, J.-J.; El Borgi, S.

    2009-06-01

    The main objective of this work is to prove that, with the Dugdale model, the small size defects, comparatively to the material characteristic length, are practically without influence on the limit load of structures. For that, we treat the case of a crack in a semi-infinite plane under anti-plane shear loading. Using integral transforms, the elasticity equations are converted analytically into a singular integral equation. The singular integral equation is solved numerically using Chebychev polynomials. Special care is needed to take into account the presence of jump discontinuities in the loading distribution along the crack lips.

  1. Revealing the inclined circumstellar disk in the UX Ori system KK Ophiuchi

    Science.gov (United States)

    Kreplin, A.; Weigelt, G.; Kraus, S.; Grinin, V.; Hofmann, K.-H.; Kishimoto, M.; Schertl, D.; Tambovtseva, L.; Clausse, J.-M.; Massi, F.; Perraut, K.; Stee, Ph.

    2013-07-01

    We study the inner sub-AU region of the circumstellar environment of the UX Ori type star KK Oph with near-infrared VLTI/AMBER interferometry. We are particularly interested in the inclination of the star-disk system, and we will use this information to test the current standard picture for UX Ori stars. We recorded spectrally dispersed (R˜35) interferograms in the near-infrared H and K bands with the VLTI/AMBER instrument. The derived visibilities, closure phases and the SED of KK Oph were compared with two-dimensional geometric and radiative transfer models (RADMC). We obtained visibilities at four different position angles. Using two-dimensional geometric models, we derive an axis ratio ˜3.0 corresponding to an inclination of ˜70 degree. A fitted inclined ring model leads to a ring radius of 2.8 ± 0.2 mas, corresponding to 0.44 ± 0.03 AU at a distance of 160 pc, which is larger than the dust sublimation radius of ˜0.1 AU predicted for a dust sublimation temperature of 1500 K. Our derived two-dimensional RADMC model consists of a circumstellar disk with an inclination angle of ˜70 degree and an additional dust envelope. The finding of an ˜70 degree inclined disk around KK Oph is consistent with the prediction that UX Ori objects are seen under large inclination angles, and orbiting clouds in the line of sight cause the observed variability. Furthermore, our results suggest that the orbit of the companion KK Oph B and the disk plane are coplanar.

  2. Revealing the inclined circumstellar disk in the UX Orionis system KK Ophiuchi

    Science.gov (United States)

    Kreplin, A.; Weigelt, G.; Kraus, S.; Grinin, V.; Hofmann, K.-H.; Kishimoto, M.; Schertl, D.; Tambovtseva, L.; Clausse, J.-M.; Massi, F.; Perraut, K.; Stee, Ph.

    2013-03-01

    Aims: We study the inner sub-AU region of the circumstellar environment of the UX Ori-type star KK Oph with near-infrared VLTI/AMBER interferometry. We are particularly interested in the inclination of the star-disk system, and we use this information to test the current standard picture for UX Ori stars. Methods: We recorded spectrally dispersed (R ~ 35) interferograms in the near-infrared H and K bands with the VLTI/AMBER instrument. The derived visibilities, closure phases, and the spectral energy distribution of KK Oph were compared with two-dimensional geometric and radiative transfer models (RADMC). Results: We obtained visibilities at four different position angles. Using two-dimensional geometric models, we derive an axis ratio ~3.0 corresponding to an inclination of ~70°. A fitted inclined ring model leads to a ring radius of 2.8 ± 0.2 mas, corresponding to 0.44 ± 0.03 AU at a distance of 160 pc, which is larger than the dust sublimation radius of ~0.1 AU predicted for a dust sublimation temperature of 1500 K. Our derived two-dimensional RADMC model consists of a circumstellar disk with an inclination angle of ~70° and an additional dust envelope. Conclusions: The finding of an ~70° inclined disk around KK Oph is consistent with the prediction that UX Ori objects are seen under large inclination angles, and orbiting clouds in the line of sight cause the observed variability. Furthermore, our results suggest that the orbit of the companion KK Oph B and the disk plane are coplanar. Based on observations made with ESO telescopes at Paranal Observatory under program ID: 083.D-0224(C) and 088.C-0575(A).

  3. Benchmark models, planes lines and points for future SUSY searches at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    AbdusSalam, S.S. [The Abdus Salam International Centre for Theoretical Physics, Trieste (Italy); Allanach, B.C. [Cambridge Univ. (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics; Dreiner, H.K. [Bonn Univ. (DE). Bethe Center for Theoretical Physics and Physikalisches Inst.] (and others)

    2012-03-15

    We define benchmark models for SUSY searches at the LHC, including the CMSSM, NUHM, mGMSB, mAMSB, MM-AMSB and p19MSSM, as well as models with R-parity violation and the NMSSM. Within the parameter spaces of these models, we propose benchmark subspaces, including planes, lines and points along them. The planes may be useful for presenting results of the experimental searches in different SUSY scenarios, while the specific benchmark points may serve for more detailed detector performance tests and comparisons. We also describe algorithms for defining suitable benchmark points along the proposed lines in the parameter spaces, and we define a few benchmark points motivated by recent fits to existing experimental data.

  4. Polarimetry of transiting planets: Differences between plane-parallel and spherical host star atmosphere models

    Science.gov (United States)

    Kostogryz, N. M.; Yakobchuk, T. M.; Berdyugina, S. V.; Milic, I.

    2017-05-01

    Context. To properly interpret photometric and polarimetric observations of exoplanetary transits, accurate calculations of center-to-limb variations of intensity and linear polarization of the host star are needed. These variations, in turn, depend on the choice of geometry of stellar atmosphere. Aims: We want to understand the dependence of the flux and the polarization curves during a transit on the choice of the applied approximation for the stellar atmosphere: spherical and plane-parallel. We examine whether simpler plane-parallel models of stellar atmospheres are good enough to interpret the flux and the polarization light curves during planetary transits, or whether more complicated spherical models should be used. Methods: Linear polarization during a transit appears because a planet eclipses a stellar disk and thus breaks left-right symmetry. We calculate the flux and the polarization variations during a transit with given center-to-limb variations of intensity and polarization. Results: We calculate the flux and the polarization variations during transit for a sample of 405 extrasolar systems. Most of them show higher transit polarization for the spherical stellar atmosphere. Our calculations reveal a group of exoplanetary systems that demonstrates lower maximum polarization during the transits with spherical model atmospheres of host stars with effective temperatures of Teff = 4400-5400 K and surface gravity of log g = 4.45-4.65 than that obtained with plane-parallel atmospheres. Moreover, we have found two trends of the transit polarization. The first trend is a decrease in the polarization calculated with spherical model atmosphere of host stars with effective temperatures Teff = 3500-5100 K, and the second shows an increase in the polarization for host stars with Teff = 5100-7000 K. These trends can be explained by the relative variation of temperature and pressure dependences in the plane-parallel and spherical model atmospheres. Conclusions: For

  5. Evaporation of inclined water droplets

    Science.gov (United States)

    Kim, Jin Young; Hwang, In Gyu; Weon, Byung Mook

    2017-01-01

    When a drop is placed on a flat substrate tilted at an inclined angle, it can be deformed by gravity and its initial contact angle divides into front and rear contact angles by inclination. Here we study on evaporation dynamics of a pure water droplet on a flat solid substrate by controlling substrate inclination and measuring mass and volume changes of an evaporating droplet with time. We find that complete evaporation time of an inclined droplet becomes longer as gravitational influence by inclination becomes stronger. The gravity itself does not change the evaporation dynamics directly, whereas the gravity-induced droplet deformation increases the difference between front and rear angles, which quickens the onset of depinning and consequently reduces the contact radius. This result makes the evaporation rate of an inclined droplet to be slow. This finding would be important to improve understanding on evaporation dynamics of inclined droplets. PMID:28205642

  6. Magnetohydrdodynamic models of coronal transients in the meridional plane. IV. effect of the solar wind

    International Nuclear Information System (INIS)

    Wu, S.T.; Steinolfson, R.S.; Dryer, M.; Tandberg-Hanssen, E.

    1981-01-01

    A two-dimensional, time-dependenct magnetohydrodynamic model in the meridional plane with and without an ambient solar wind in an ambient radial magnetic field has been used to investigate mass motions associated with coronal transients. We show that that solar wind does not significantly affect the general dynamic characteristics of the mass motion. The ambient solar wind, however, increases the velocity of the mass motion and produces a moderate change in the thermodynamic properties of the coronal plasma

  7. A 4-Mid-Node Plane Model of Base Force Element Method on Complementary Energy Principle

    Directory of Open Access Journals (Sweden)

    Yinghua Liu

    2013-01-01

    Full Text Available Using the base forces as fundamental variables to describe the stress state and the displacement gradients that are the conjugate variables of the base forces to describe the deformation state for the two-dimensional elasticity problems, a 4-mid-node plane model of base force element method (BFEM based on complementary energy principle is proposed. In this paper, the complementary energy of an element of the BFEM is constructed by using the base forces. The equilibrium conditions are released by the Lagrange multiplier method, and a modified complementary energy principle described by the base forces is obtained. The formulation of the 4-mid-node plane element of the BFEM is derived by assuming that the stress is uniformly distributed on each edge of the plane elements. A procedure of the BFEM on complementary energy principle is developed using MATLAB language. The numerical results of examples show that this model of the BFEM has high precision and is free from mesh sensitivity. This model shows good performances.

  8. Plane symmetric cosmological micro model in modified theory of Einstein’s general relativity

    Directory of Open Access Journals (Sweden)

    Panigrahi U.K.

    2003-01-01

    Full Text Available In this paper, we have investigated an anisotropic homogeneous plane symmetric cosmological micro-model in the presence of massless scalar field in modified theory of Einstein's general relativity. Some interesting physical and geometrical aspects of the model together with singularity in the model are discussed. Further, it is shown that this theory is valid and leads to Ein­stein's theory as the coupling parameter λ →>• 0 in micro (i.e. quantum level in general.

  9. Influence of thread shape and inclination on the biomechanical behaviour of plateau implant systems.

    Science.gov (United States)

    Calì, Michele; Zanetti, Elisabetta Maria; Oliveri, Salvatore Massimo; Asero, Riccardo; Ciaramella, Stefano; Martorelli, Massimo; Bignardi, Cristina

    2018-03-01

    To assess the influence of implant thread shape and inclination on the mechanical behaviour of bone-implant systems. The study assesses which factors influence the initial and full osseointegration stages. Point clouds of the original implant were created using a non-contact reverse engineering technique. A 3D tessellated surface was created using Geomagic Studio ® software. From cross-section curves, generated by intersecting the tessellated model and cutting-planes, a 3D parametric CAD model was created using SolidWorks ® 2017. By the permutation of three thread shapes (rectangular, 30° trapezoidal, 45° trapezoidal) and three thread inclinations (0°, 3° or 6°), nine geometric configurations were obtained. Two different osseointegration stages were analysed: the initial osseointegration and a full osseointegration. In total, 18 different FE models were analysed and two load conditions were applied to each model. The mechanical behaviour of the models was analysed by Finite Element (FE) Analysis using ANSYS ® v. 17.0. Static linear analyses were also carried out. ANOVA was used to assess the influence of each factor. Models with a rectangular thread and 6° inclination provided the best results and reduced displacement in the initial osseointegration stages up to 4.58%. This configuration also reduced equivalent VM stress peaks up to 54%. The same effect was confirmed for the full osseointegration stage, where 6° inclination reduced stress peaks by up to 62%. The FE analysis confirmed the beneficial effect of thread inclination, reducing the displacement in immediate post-operative conditions and equivalent VM stress peaks. Thread shape does not significantly influence the mechanical behaviour of bone-implant systems but contributes to reducing stress peaks in the trabecular bone in both the initial and full osseointegration stages. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. A Plane-Symmetric Inhomogeneous Cosmological Model of Perfect Fluid Distribution with Electromagnetic Field I

    OpenAIRE

    Pradhan, Anirudh; Singh, P. K.; Yadav, A. K.

    2007-01-01

    A plane-symmetric inhomogeneous cosmological model of perfect fluid distribution with electro-magnetic field is obtained. The source of the magnetic field is due to an electric current produced along the z-axis. $F_{12}$ is the non-vanishing component of electromagnetic field tensor. To get a deterministic solution, we assume the free gravitational field is Petrov type-II non-degenerate. The behaviour of the electro-magnetic field tensor together with some physical aspects of the model are al...

  11. How do ants make sense of gravity? A Boltzmann Walker analysis of Lasius niger trajectories on various inclines.

    Directory of Open Access Journals (Sweden)

    Anaïs Khuong

    Full Text Available The goal of this study is to describe accurately how the directional information given by support inclinations affects the ant Lasius niger motion in terms of a behavioral decision. To this end, we have tracked the spontaneous motion of 345 ants walking on a 0.5×0.5 m plane canvas, which was tilted with 5 various inclinations by [Formula: see text] rad ([Formula: see text] data points. At the population scale, support inclination favors dispersal along uphill and downhill directions. An ant's decision making process is modeled using a version of the Boltzmann Walker model, which describes an ant's random walk as a series of straight segments separated by reorientation events, and was extended to take directional influence into account. From the data segmented accordingly ([Formula: see text] segments, this extension allows us to test separately how average speed, segments lengths and reorientation decisions are affected by support inclination and current walking direction of the ant. We found that support inclination had a major effect on average speed, which appeared approximately three times slower on the [Formula: see text] incline. However, we found no effect of the walking direction on speed. Contrastingly, we found that ants tend to walk longer in the same direction when they move uphill or downhill, and also that they preferentially adopt new uphill or downhill headings at turning points. We conclude that ants continuously adapt their decision making about where to go, and how long to persist in the same direction, depending on how they are aligned with the line of maximum declivity gradient. Hence, their behavioral decision process appears to combine klinokinesis with geomenotaxis. The extended Boltzmann Walker model parameterized by these effects gives a fair account of the directional dispersal of ants on inclines.

  12. Stability analysis of a nonlinear vehicle model in plane motion using the concept of Lyapunov exponents

    Science.gov (United States)

    Sadri, Sobhan; Wu, Christine

    2013-06-01

    For the first time, this paper investigates the application of the concept of Lyapunov exponents to the stability analysis of the nonlinear vehicle model in plane motion with two degrees of freedom. The nonlinearity of the model comes from the third-order polynomial expression between the lateral forces on the tyres and the tyre slip angles. Comprehensive studies on both system and structural stability analyses of the vehicle model are presented. The system stability analysis includes the stability, lateral stability region, and effects of driving conditions on the lateral stability region of the vehicle model in the state space. In the structural stability analysis, the ranges of driving conditions in which the stability of the vehicle model is guaranteed are given. Moreover, through examples, the largest Lyapunov exponent is suggested as an indicator of the convergence rate in which the disturbed vehicle model returns to its stable fixed point.

  13. Using Measured Plane-of-Array Data Directly in Photovoltaic Modeling: Methodology and Validation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Janine; Freestate, David; Riley, Cameron; Hobbs, William

    2016-11-01

    Measured plane-of-array (POA) irradiance may provide a lower-cost alternative to standard irradiance component data for photovoltaic (PV) system performance modeling without loss of accuracy. Previous work has shown that transposition models typically used by PV models to calculate POA irradiance from horizontal data introduce error into the POA irradiance estimates, and that measured POA data can correlate better to measured performance data. However, popular PV modeling tools historically have not directly used input POA data. This paper introduces a new capability in NREL's System Advisor Model (SAM) to directly use POA data in PV modeling, and compares SAM results from both POA irradiance and irradiance components inputs against measured performance data for eight operating PV systems.

  14. Using Measured Plane-of-Array Data Directly in Photovoltaic Modeling: Methodology and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Janine; Freestate, David; Hobbs, William; Riley, Cameron

    2016-11-21

    Measured plane-of-array (POA) irradiance may provide a lower-cost alternative to standard irradiance component data for photovoltaic (PV) system performance modeling without loss of accuracy. Previous work has shown that transposition models typically used by PV models to calculate POA irradiance from horizontal data introduce error into the POA irradiance estimates, and that measured POA data can correlate better to measured performance data. However, popular PV modeling tools historically have not directly used input POA data. This paper introduces a new capability in NREL's System Advisor Model (SAM) to directly use POA data in PV modeling, and compares SAM results from both POA irradiance and irradiance components inputs against measured performance data for eight operating PV systems.

  15. Using Measured Plane-of-Array Data Directly in Photovoltaic Modeling: Methodology and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Janine; Freestate, David; Hobbs, William; Riley, Cameron

    2016-06-05

    Measured plane-of-array (POA) irradiance may provide a lower-cost alternative to standard irradiance component data for photovoltaic (PV) system performance modeling without loss of accuracy. Previous work has shown that transposition models typically used by PV models to calculate POA irradiance from horizontal data introduce error into the POA irradiance estimates, and that measured POA data can correlate better to measured performance data. However, popular PV modeling tools historically have not directly used input POA data. This paper introduces a new capability in NREL's System Advisor Model (SAM) to directly use POA data in PV modeling, and compares SAM results from both POA irradiance and irradiance components inputs against measured performance data for eight operating PV systems.

  16. Dissipative descent: rocking and rolling down an incline

    Science.gov (United States)

    Balmforth, N. J.; Bush, J. W. M.; Vener, D.; Young, W. R.

    We consider the dynamics of a hollow cylindrical shell that is filled with viscous fluid and another, nested solid cylinder, and allowed to roll down an inclined plane. A mathematical model is compared to simple experiments. Two types of behaviour are observed experimentally: on steeper slopes, the device accelerates; on shallower inclines, the cylinders rock and roll unsteadily downhill, with a speed that is constant on average. The theory also predicts runaway and unsteady rolling motions. For the rolling solutions, however, the inner cylinder cannot be suspended in the fluid by the motion of the outer cylinder, and instead falls inexorably toward the outer cylinder. Whilst only occurs after an infinite time, the system slows progressively as the gap between the cylinders narrows, owing to heightened viscous dissipation. Such a deceleration is not observed in the experiments, suggesting that some mechanism limits the approach to contact. Coating the surface of the inner cylinder with sandpaper of different grades changes the rolling speed, consistent with the notion that surface roughness is responsible for limiting the acceleration.

  17. Finite Element Model for Nonlinear Analysis of Reinforced Concrete Beams and Plane Frames

    Directory of Open Access Journals (Sweden)

    R.S.B. STRAMANDINOLI

    Full Text Available Abstract In this work, a two-dimensional finite element (FE model for physical and geometric nonlinear analysis of reinforced concrete beams and plane frames, developed by the authors, is presented. The FE model is based on the Euler-Bernoulli Beam Theory, in which shear deformations are neglected. The bar elements have three nodes with a total of seven degrees of freedom. Three Gauss-points are utilized for the element integration, with the element section discretized into layers at each Gauss point (Fiber Model. It is assumed that concrete and reinforcing bars are perfectly bonded, and each section layer is assumed to be under a uniaxial stress-state. Nonlinear constitutive laws are utilized for both concrete and reinforcing steel layers, and a refined tension-stiffening model, developed by the authors, is included. The Total Lagrangean Formulation is adopted for geometric nonlinear consideration and several methods can be utilized to achieve equilibrium convergence of the nonlinear equations. The developed model is implemented into a computer program named ANEST/CA, which is validated by comparison with some tests on RC beams and plane frames, showing an excellent correlation between numerical and experimental results.

  18. Submarine granular flow down a rough plane

    Science.gov (United States)

    Nicolas, Maxime; Cassar, Cyril; Pouliquen, Olivier

    2003-11-01

    We lead experiments of submarine granular flows in a water tank. The particles are spherical 100 microns glass beads and flow down a rough inclined plane from a reservoir with a controlled opening. Different flow regimes are observed, the flow velocity and thickness are measured. The basal water pressure is also measured and give information on the suspension rate of the flow. No flow was observed for an angle below 24 degrees. The flow velocity increases smoothly for a [24-36] degrees inclination range, and a strong velocity increase occurs for inclination over 36 degrees. The thickness of the flow decreases when inclination increases but no abrupt change of thickness is observed around 36 degrees. That suggests that a transition exists between a granular regime, where friction on the rough plane and particle contacts are dominant, and a suspension regime where basal friction vanishes. A thin film ripple instability is also observed for large inclination angles.

  19. Frontal Plane Modelling of Human Dynamics during Standing in Narrow-Stance

    Science.gov (United States)

    Sonobe, M.; Yamaguchi, H.; Hino, J.

    2016-09-01

    Standing ride type vehicles like electric skateboards have been developed in recent years. Although these vehicles have advantages as being compact and low cost due to their simple structure, it is necessary to improve the riding quality. Therefore, the system aiding riders to keep their balance on a skateboard by feedback control or feedforward control has been required. To achieve it, a human balance model should be built as simple as possible. In this study, we focus on the human balance modelling during standing when the support surface moves largely. We restricted the model on frontal plane and narrow stance because the restrictions allow us to assume single-degree-of-freedom model. The balance control system is generally assumed as a delayed feedback control system. The model was identified through impulse response test and frequency response test. As a result, we found the phase between acceleration of the skateboard and posture angle become opposite phase in low frequency range.

  20. Evaluation of the crack plane equilibrium model for predicting plastic fracture

    International Nuclear Information System (INIS)

    Butler, T.A.; Smith, F.W.

    1985-01-01

    The Crack Plane Equilibium (CPE) model is a simple model for predicting the initiation of crack growth in ductile materials. The CPE model is evaluated for center-crack tension specimens and for pipe specimens containing part-through circumferential cracks emanating from the inside surface of the pipe. The model is based upon requiring equilibrium between the applied loads and an assumed stress distribution in the uncracked ligament near the crack tip. Required fracture parameters are the ultimate tensile strength and a process zone size at the crack tip that is determined from simple fracture tests. Crack growth initiation for the crack and specimen geometries studied is predicted with sufficient accuracy to warrant extending the CPE model for investigating other geometries and for predicting stable crack growth and the onset of unstable crack growth

  1. Evidences of inclined transpression at the contact between ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 125; Issue 5. Evidences of inclined ... a right lateral strike-slip component. As a whole, it is suggested that Udayagiri group is thrusted over Vinjamuru group along a westerly dipping thrust plane with a right lateral strike-slip motion and simultaneous E–W contraction.

  2. Measurement, characterization, and modeling of noise in staring infrared focal plane arrays

    International Nuclear Information System (INIS)

    Scribner, D.A.; Kruer, M.R.; Gridley, C.J.; Sarkady, K.

    1987-01-01

    An account is given of selected methods for the measurement and characterization of spatial and temporal noise in staring focal plane arrays (FPAs), in order to demonstrate how these results can be used in simulations and analytic models to predict the performance of selected staring sensors. Attention is given to MIR FPAs applicable to the detection and tracking of point sources, and to the ways in which these spatial and temporal noise measurements can be incorporated into simulations and sensors having staring FPAs. Methods for predicting the performance of selected staring sensor systems are derivable from spatial and temporal noise values. 13 references

  3. Analysis of TLM Air-vent Model Applicability to EMC Problems for Normal Incident Plane Wave

    Directory of Open Access Journals (Sweden)

    N. J. Nešić

    2016-11-01

    Full Text Available In this paper, the shielding properties related to a protective metal enclosure with airflow aperture arrays are numerically analyzed. As a numerical model, a TLM method, either in a conventional form based on fine mesh to describe apertures presence or enhanced with the compact air-vent model is employed. The main focus in the paper is on examining the limits of applying the compact air-vent model for EMC problems solving. Namely, various values for the distance between neighboring apertures in the TLM air-vent models as well as the air-vent thicknesses are analyzed. Specifically, the analyses are conducted for a normal incident plane wave, vertically and horizontally polarized.

  4. Psychosocial Determinants of Romantic Inclination Among Indian Youth

    Directory of Open Access Journals (Sweden)

    D. Barani Ganth

    2017-10-01

    Full Text Available The present study was conducted with the aim of understanding the psychosocial determinants of romantic inclination among youth in India. We involved 779 student participants from a large central university in south India in the age range of 18-24 years. The participants filled measures on romantic inclination, personality, attachment style, interpersonal attraction, and social influence on romantic relationship in addition to a questionnaire on demographic information and relationship history. Analysis of the data revealed that males showed higher level of romantic inclination than females. Those who had current/past involvement in a romantic relationship (Lovers showed higher levels of romantic inclination than those who had never involved in a romantic relationship (Non-lovers. Parents’ type of marriage (Love/arranged, close fiends’ involvement in romantic relationship too had a discriminatory role in romantic inclination. Romantic inclination was significantly related to personality factors, attachment style, media and peer influences on romantic relationships and interpersonal attraction. Extraversion, openness to experience, agreeableness, media influence, peer influence, secure attachment and physical attraction emerged as significant predictors of romantic inclination in a regression model. Structural Equations Modeling (SEM indicated that personality, attachment style and interpersonal attraction had a significant influence on romantic inclination mediated by both media and peer influences. Romantic inclination in turn significantly predicted romantic relationship status.

  5. Estudo da inclinação do plano palatino em relação à base posterior do crânio em indivíduos portadores de oclusão normal Study of palatal plane inclination related to the posterior cranial base in subjects with normal occlusion

    Directory of Open Access Journals (Sweden)

    Cássia T. Lopes de Alcântara Gil

    2006-10-01

    Full Text Available OBJETIVO: estudar a relação entre o plano palatino e a região posterior da base do crânio, em indivíduos portadores de oclusão normal. METODOLOGIA: a amostra foi constituída por telerradiografias em norma lateral de 95 indivíduos portadores de oclusão normal natural. O plano palatino foi determinado pelos pontos Ena e Enp (Espinha Nasal Anterior e Posterior. Utilizou-se o ponto mais posterior e inferior do osso occipital (OPI, para definição da região póstero-inferior da base do crânio. Avaliou-se o comportamento do ângulo formado pelos planos OPI-Ena e Ena-Enp, denominado ângulo OPI.Ena.Enp, tendo como vértice o ponto Ena. Desta forma, valores angulares próximos a 0º indicaram tendência à coincidência entre os planos OPI-Ena e Ena-Enp, o que equivale a dizer que, nestes casos, a extensão do plano palatino tangencia a base posterior do crânio, representada pelo Ponto OPI. RESULTADOS: a média de valor encontrada em relação ao ângulo OPI.Ena.Enp na referida amostra foi de -0,13º, valor próximo a zero, indicando tendência à coincidência entre os planos OPI-Ena e Ena-Enp. CONCLUSÃO: os resultados indicam que em pacientes portadores de oclusão normal natural, o prolongamento do plano palatino tende a tangenciar a região posterior da base do crânio, o que se revela uma característica estrutural em crânios de indivíduos portadores de oclusão equilibrada.AIM: to study the inclination of the palatal plane in 95 subjects with clinically normal occlusion. METHODS: the study was made using lateral headfilms and the results showed that in normal occlusion the extension of the palatal plane (ANS-PNS passes trough the most posterior and inferior region of the skull, defined as Point "OPI". RESULTS: OPI.Ena.Enp mean value was -0.13º, close to zero. CONCLUSION: the results indicated that in normal occlusion patients the palatal plane presents a tendency to be tangent with posterior cranial base.

  6. Monte Carlo simulation of irradiation of MTR fuel plates in the BR2 reactor using a full-scale 3-d model with inclined channels

    International Nuclear Information System (INIS)

    Kuzminov, V. V; Koonen, E.; Ponsard, B.

    2002-01-01

    A three-dimensional full-scale Monte Carlo model of the BR2 reactor has been developed for simulation of irradiation conditions of materials and fuel loaded in various irradiation devices. This new reactor model includes a detailed geometrical description of the inclined reactor channels, the irradiation devices loaded in these channels including the materials to be tested/loaded in these devices, the burn-up of the BR2 fuel elements and the poisoning of the beryllium matrix. Recently a benchmark irradiation of new irradiation device for testing and qualification of MTR fuel plates has been performed. For this purpose the detailed irradiation conditions of fuel plates had to be predetermined. Monte Carlo calculations of neutron fluxes and heat load distributions in irradiated MTR fuel plates were performed taking into account the contents of all loaded experimental devices in the reactor channels. A comparison of the calculated and measured values of neutron fluxes and of heat loads in the BR2 reactor is presented in this paper. The comparison is part of the validation process of the new reactor model. It also serves to establish the capability to conduct a fuel plate irradiation program under requested and well- known irradiation conditions. (author)

  7. Monte Carlo simulation of irradiation of MTR fuel plates in the BR2 reactor using a full-scale 3-d model with inclined channels

    Energy Technology Data Exchange (ETDEWEB)

    Kuzminov, V. V [On leave from Petersburg Nuclear Physics Institute, Gatchina, 188300 St.Petersburg (Russian Federation); Koonen, E.; Ponsard, B. [BR2 Department SCK CEN, Belgian Nuclear Research Centre, Boeretang 200, B-2400 Mol (Belgium)

    2002-07-01

    A three-dimensional full-scale Monte Carlo model of the BR2 reactor has been developed for simulation of irradiation conditions of materials and fuel loaded in various irradiation devices. This new reactor model includes a detailed geometrical description of the inclined reactor channels, the irradiation devices loaded in these channels including the materials to be tested/loaded in these devices, the burn-up of the BR2 fuel elements and the poisoning of the beryllium matrix. Recently a benchmark irradiation of new irradiation device for testing and qualification of MTR fuel plates has been performed. For this purpose the detailed irradiation conditions of fuel plates had to be predetermined. Monte Carlo calculations of neutron fluxes and heat load distributions in irradiated MTR fuel plates were performed taking into account the contents of all loaded experimental devices in the reactor channels. A comparison of the calculated and measured values of neutron fluxes and of heat loads in the BR2 reactor is presented in this paper. The comparison is part of the validation process of the new reactor model. It also serves to establish the capability to conduct a fuel plate irradiation program under requested and well- known irradiation conditions. (author)

  8. A constitutive framework for modelling thin incompressible viscoelastic materials under plane stress in the finite strain regime

    Science.gov (United States)

    Kroon, M.

    2011-11-01

    Rubbers and soft biological tissues may undergo large deformations and are also viscoelastic. The formulation of constitutive models for these materials poses special challenges. In several applications, especially in biomechanics, these materials are also relatively thin, implying that in-plane stresses dominate and that plane stress may therefore be assumed. In the present paper, a constitutive model for viscoelastic materials in the finite strain regime and under the assumption of plane stress is proposed. It is assumed that the relaxation behaviour in the direction of plane stress can be treated separately, which makes it possible to formulate evolution laws for the plastic strains on explicit form at the same time as incompressibility is fulfilled. Experimental results from biomechanics (dynamic inflation of dog aorta) and rubber mechanics (biaxial stretching of rubber sheets) were used to assess the proposed model. The assessment clearly indicates that the model is fully able to predict the experimental outcome for these types of material.

  9. Minimum descent time along a set of connected inclined planes

    Science.gov (United States)

    Mungan, Carl E.; Lipscombe, Trevor C.

    2017-07-01

    The time required for a particle to slide frictionlessly down a set of ramps connected end to end can be minimized numerically as a function of the coordinates of the connection points between ramps and compared to the exact cycloidal solution of the brachistochrone problem. It is found that a set of just three joined ramps over a large range of geometrical aspect ratios has a descent time within 5% of the optimal cycloid. The special case where the particle starts and ends at the same height has sufficient symmetry that it can be analyzed analytically using algebra alone. The level of analysis is appropriate to an undergraduate classical mechanics course.

  10. Fluorescence intensity dependence on the propagation plane inclination

    International Nuclear Information System (INIS)

    Fernandez, J.E.; Rubio, Marcelo; Sanchez, H.J.

    1987-01-01

    A theoretical study of the emission from layers of primary and secondary fluorescent components for a sample of infinite thickness was made, finding out that this emission depends mainly on the α angle as a maximum emission selector of a certain layer, which means 'tuning' the fluorescent radiation that comes primarily from a certain depth. These results can be applied to the study of both selective emission by layers and to the selection of superficial fluorescence. The analytical results have been confirmed by a Monte Carlo simulation. (Author) [es

  11. A semi-analytical stationary model of a point-to-plane corona discharge

    International Nuclear Information System (INIS)

    Yanallah, K; Pontiga, F

    2012-01-01

    A semi-analytical model of a dc corona discharge is formulated to determine the spatial distribution of charged particles (electrons, negative ions and positive ions) and the electric field in pure oxygen using a point-to-plane electrode system. A key point in the modeling is the integration of Gauss' law and the continuity equation of charged species along the electric field lines, and the use of Warburg's law and the corona current–voltage characteristics as input data in the boundary conditions. The electric field distribution predicted by the model is compared with the numerical solution obtained using a finite-element technique. The semi-analytical solutions are obtained at a negligible computational cost, and provide useful information to characterize and control the corona discharge in different technological applications. (paper)

  12. Simulation of Canopy Leaf Inclination Angle in Rice

    Directory of Open Access Journals (Sweden)

    Xiao-cui ZHANG

    2013-11-01

    Full Text Available A leaf inclination angle distribution model, which is applicable to simulate leaf inclination angle distribution in six heights of layered canopy at different growth stages, was established by component factors affecting plant type in rice. The accuracy of the simulation results was validated by measured values from a field experiment. The coefficient of determination (R2 and the root mean square error (RMSE between the simulated and measured values were 0.9472 and 3.93%, respectively. The simulation results showed that the distribution of leaf inclination angles differed among the three plant types. The leaf inclination angles were larger in the compact variety Liangyoupeijiu with erect leaves than in the loose variety Shanyou 63 with droopy leaves and the intermediate variety Liangyou Y06. The leaf inclination angles were distributed in the lower range in Shanyou 63, which matched up with field measurements. The distribution of leaf inclination angles in the same variety changed throughout the seven growth stages. The leaf inclination angles enlarged gradually from transplanting to booting. During the post-booting period, the leaf inclination angle increased in Shanyou 63 and Liangyou Y06, but changed little in Liangyoupeijiu. At every growth stage of each variety, canopy leaf inclination angle distribution on the six heights of canopy layers was variable. As canopy height increased, the layered leaf area index (LAI decreased in all the three plant types. However, while the leaf inclination angles showed little change in Liangyoupeijiu, they became larger in Shanyou 63 but smaller in Liangyou Y06. The simulation results used in the constructed model were very similar to the actual measurement values. The model provides a method for estimating canopy leaf inclination angle distribution in rice production.

  13. Temperature elevation in the eye of anatomically based human head models for plane-wave exposures

    International Nuclear Information System (INIS)

    Hirata, A; Watanabe, S; Fujiwara, O; Kojima, M; Sasaki, K; Shiozawa, T

    2007-01-01

    This study investigated the temperature elevation in the eye of anatomically based human head models for plane-wave exposures. The finite-difference time-domain method is used for analyzing electromagnetic absorption and temperature elevation. The eyes in the anatomic models have average dimensions and weight. Computational results show that the ratio of maximum temperature in the lens to the eye-average SAR (named 'heating factor for the lens') is almost uniform (0.112-0.147 deg. C kg W -1 ) in the frequency region below 3 GHz. Above 3 GHz, this ratio increases gradually with an increase of frequency, which is attributed to the penetration depth of an electromagnetic wave. Particular attention is paid to the difference in the heating factor for the lens between this study and earlier works. Considering causes clarified in this study, compensated heating factors in all these studies are found to be in good agreement

  14. Modeling of steady motion and vertical-plane dynamics of a tunnel hull

    Directory of Open Access Journals (Sweden)

    Chaney Christopher S.

    2014-06-01

    Full Text Available High-speed marine vehicles can take advantage of aerodynamically supported platforms or air wings to increase maximum speed or transportation efficiency. However, this also results in increased complexity of boat dynamics, especially in the presence of waves and wind gusts. In this study, a mathematical model based on the fully unsteady aerodynamic extreme-ground-effect theory and the hydrodynamic added-mass strip theory is applied for simulating vertical-plane motions of a tunnel hull in a disturbed environment, as well as determining its steady states in calm conditions. Calculated responses of the boat to wind gusts and surface waves are demonstrated. The present model can be used as a supplementary method for preliminary estimations of performance of aerodynamically assisted marine craft.

  15. Numerical modeling of normal turbulent plane jet impingement on solid wall

    Energy Technology Data Exchange (ETDEWEB)

    Guo, C.Y.; Maxwell, W.H.C.

    1984-10-01

    Attention is given to a numerical turbulence model for the impingement of a well developed normal plane jet on a solid wall, by means of which it is possible to express different jet impingement geometries in terms of different boundary conditions. Examples of these jets include those issuing from VTOL aircraft, chemical combustors, etc. The two-equation, turbulent kinetic energy-turbulent dissipation rate model is combined with the continuity equation and the transport equation of vorticity, using an iterative finite difference technique in the computations. Peak levels of turbulent kinetic energy occur not only in the impingement zone, but also in the intermingling zone between the edges of the free jet and the wall jet. 20 references.

  16. Two-dimensional modeling of stepped planing hulls with open and pressurized air cavities

    Directory of Open Access Journals (Sweden)

    Konstantin I. Matveev

    2012-06-01

    Full Text Available A method of hydrodynamic discrete sources is applied for two-dimensional modeling of stepped planing surfaces. The water surface deformations, wetted hull lengths, and pressure distribution are calculated at given hull attitude and Froude number. Pressurized air cavities that improve hydrodynamic performance can also be modeled with the current method. Presented results include validation examples, parametric calculations of a single-step hull, effect of trim tabs, and performance of an infinite series of periodic stepped surfaces. It is shown that transverse steps can lead to higher lift-drag ratio, although at reduced lift capability, in comparison with a stepless hull. Performance of a multi-step configuration is sensitive to the wave pattern between hulls, which depends on Froude number and relative hull spacing.

  17. Development of a new dynamic turbulent model, applications to two-dimensional and plane parallel flows

    International Nuclear Information System (INIS)

    Laval, Jean Philippe

    1999-01-01

    We developed a turbulent model based on asymptotic development of the Navier-Stokes equations within the hypothesis of non-local interactions at small scales. This model provides expressions of the turbulent Reynolds sub-grid stresses via estimates of the sub-grid velocities rather than velocities correlations as is usually done. The model involves the coupling of two dynamical equations: one for the resolved scales of motions, which depends upon the Reynolds stresses generated by the sub-grid motions, and one for the sub-grid scales of motions, which can be used to compute the sub-grid Reynolds stresses. The non-locality of interaction at sub-grid scales allows to model their evolution with a linear inhomogeneous equation where the forcing occurs via the energy cascade from resolved to sub-grid scales. This model was solved using a decomposition of sub-grid scales on Gabor's modes and implemented numerically in 2D with periodic boundary conditions. A particles method (PIC) was used to compute the sub-grid scales. The results were compared with results of direct simulations for several typical flows. The model was also applied to plane parallel flows. An analytical study of the equations allows a description of mean velocity profiles in agreement with experimental results and theoretical results based on the symmetries of the Navier-Stokes equation. Possible applications and improvements of the model are discussed in the conclusion. (author) [fr

  18. Inclination evolution of protoplanetary discs around eccentric binaries

    Science.gov (United States)

    Zanazzi, J. J.; Lai, Dong

    2018-01-01

    It is usually thought that viscous torque works to align a circumbinary disc with the binary's orbital plane. However, recent numerical simulations suggest that the disc may evolve to a configuration perpendicular to the binary orbit ('polar alignment) if the binary is eccentric and the initial disc-binary inclination is sufficiently large. We carry out a theoretical study on the long-term evolution of inclined discs around eccentric binaries, calculating the disc warp profile and dissipative torque acting on the disc. For discs with aspect ratio H/r larger than the viscosity parameter α, bending wave propagation effectively makes the disc precess as a quasi-rigid body, while viscosity acts on the disc warp and twist to drive secular evolution of the disc-binary inclination. We derive a simple analytic criterion (in terms of the binary eccentricity and initial disc orientation) for the disc to evolve towards polar alignment with the eccentric binary. When the disc has a non-negligible angular momentum compared to the binary, the final 'polar alignment' inclination angle is reduced from 90°. For typical protoplanetary disc parameters, the time-scale of the inclination evolution is shorter than the disc lifetime, suggesting that highly inclined discs and planets may exist orbiting eccentric binaries.

  19. Three-dimensional Subsurface Geological Modeling of the Western Osaka Plane based on Borehole Data

    Science.gov (United States)

    Nonogaki, S.; Masumoto, S.; Nemoto, T.

    2012-12-01

    Three-dimensional (3D) geological model of subsurface structure plays an important role in developing infrastructures. In particular, the 3D geological model in urban area is quite helpful to solve social problems such as underground utilization, environmental preservation, and disaster assessment. Over the past few years, many studies have been made on algorithms for 3D geological modeling. However, most of them have given little attention to objectivity of the model and traceability of modeling procedures. The purpose of this study is to develop an algorithm for constructing a 3D geological model objectively and for maintaining high-traceability of modeling procedures. For the purpose of our work, we proposed a new algorithm for 3D geological modeling using gridded geological boundary surfaces and the "logical model of geologic structure". The geological boundary surface is given by a form of Digital Elevation Model (DEM). The DEM is generated based on geological information such as elevation, strike and dip by using a unique spline-fitting method. The logical model of geological structure is a mathematical model that defines a positional relation between geological boundary surfaces and geological units. The model is objectively given by recurrence formula derived from a sequence of geological events arranged in chronological order. We applied the proposed algorithm into constructing a 3D subsurface geological model of the western Osaka Plane, southwest Japan. The data used for 3D geological modeling is a set of borehole data provided by Osaka City and Kansai Geoinformatics Agency. As a result, we constructed a 3D model consistent with the subjective model reported in other studies. In addition, all information necessary for modeling, such as the used geological information, the parameters of surface fitting, and the logical model, was stored in text files. In conclusion, we can not only construct 3D geological model objectively but also maintain high

  20. Centrifuge model test of rock slope failure caused by seismic excitation. Plane failure of dip slope

    International Nuclear Information System (INIS)

    Ishimaru, Makoto; Kawai, Tadashi

    2008-01-01

    Recently, it is necessary to assess quantitatively seismic safety of critical facilities against the earthquake induced rock slope failure from the viewpoint of seismic PSA. Under these circumstances, it is essential to evaluate more accurately the possibilities of rock slope failure and the potential failure boundary, which are triggered by earthquake ground motions. The purpose of this study is to analyze dynamic failure characteristics of rock slopes by centrifuge model tests for verification and improvement of the analytical methods. We conducted a centrifuge model test using a dip slope model with discontinuities limitated by Teflon sheets. The centrifugal acceleration was 50G, and the acceleration amplitude of input sin waves increased gradually at every step. The test results were compared with safety factors of the stability analysis based on the limit equilibrium concept. Resultant conclusions are mainly as follows: (1) The slope model collapsed when it was excited by the sine wave of 400gal, which was converted to real field scale, (2) Artificial discontinuities were considerably concerned in the collapse, and the type of collapse was plane failure, (3) From response acceleration records observed at the slope model, we can say that tension cracks were generated near the top of the slope model during excitation, and that might be cause of the collapse, (4) By considering generation of the tension cracks in the stability analysis, correspondence of the analytical results and the experimental results improved. From the obtained results, we need to consider progressive failure in evaluating earthquake induced rock slope failure. (author)

  1. Approaching the brachistochrone using inclined planes—striving for shortest or equal travelling times

    Science.gov (United States)

    Theilmann, Florian

    2017-01-01

    The classical brachistochrone problem asks for the path on which a mobile point M just driven by its own gravity will travel in the shortest possible time between two given points A and B. The resulting curve, the cycloid, will also be the tautochrone curve, i.e. the travelling time of the mobile point will not depend on its starting position. We discuss three similar problems of increasing complexity that restrict the motion to inclined planes. Without using calculus we derive the respective optimal geometry and compare the theoretical values to measured travelling times. The observed discrepancies are quantitatively modelled by including angular motion and friction. We also investigate the correspondence between the original problem and our setups. The topic provides a conceptually simple yet non-trivial problem setting inviting for problem based learning and complex learning activities such as planing suitable experiments or modelling the relevant kinematics.

  2. Assessment of uncertainty in the numerical simulation of solar irradiance over inclined PV panels: New algorithms using measurements and modeling tools

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yu; Sengupta, Manajit; Dooraghi, Mike

    2018-05-01

    Development of accurate transposition models to simulate plane-of-array (POA) irradiance from horizontal measurements or simulations is a complex process mainly because of the anisotropic distribution of diffuse solar radiation in the atmosphere. The limited availability of reliable POA measurements at large temporal and spatial scales leads to difficulties in the comprehensive evaluation of transposition models. This paper proposes new algorithms to assess the uncertainty of transposition models using both surface-based observations and modeling tools. We reviewed the analytical derivation of POA irradiance and the approximation of isotropic diffuse radiation that simplifies the computation. Two transposition models are evaluated against the computation by the rigorous analytical solution. We proposed a new algorithm to evaluate transposition models using the clear-sky measurements at the National Renewable Energy Laboratory's (NREL's) Solar Radiation Research Laboratory (SRRL) and a radiative transfer model that integrates diffuse radiances of various sky-viewing angles. We found that the radiative transfer model and a transposition model based on empirical regressions are superior to the isotropic models when compared to measurements. We further compared the radiative transfer model to the transposition models under an extensive range of idealized conditions. Our results suggest that the empirical transposition model has slightly higher cloudy-sky POA irradiance than the radiative transfer model, but performs better than the isotropic models under clear-sky conditions. Significantly smaller POA irradiances computed by the transposition models are observed when the photovoltaics (PV) panel deviates from the azimuthal direction of the sun. The new algorithms developed in the current study have opened the door to a more comprehensive evaluation of transposition models for various atmospheric conditions and solar and PV orientations.

  3. Singular solutions for the rigid plastic double slip and rotation model under plane strain

    Science.gov (United States)

    Alexandrov, S.; Lyamina, E.

    2018-02-01

    In the mechanics of granular and other materials the system of equations comprising the rigid plastic double slip and rotation model together with the stress equilibrium equations under plane strain conditions forms a hyperbolic system. Boundary value problems for this system of equations can involve a frictional interface. An envelope of characteristics may coincide with this interface. In this case, the solution is singular. In particular, some components of the strain rate tensor approach infinity in the vicinity of the frictional interface. Such behavior of solutions is in qualitative agreement with experimental data that show that a narrow layer of localized plastic deformation is often generated near frictional interfaces. The present paper deals with asymptotic analysis of the aforementioned system of equations in the vicinity of an envelope of characteristics. It is shown that the shear strain rate and the spin component in a local coordinate system connected to the envelope follow an inverse square root rule in its vicinity.

  4. Event-plane dependent di-hadron correlations with harmonic vn subtraction in a hydrodynamic model

    Science.gov (United States)

    Castilho, Wagner M.; Qian, Wei-Liang; Hama, Yogiro; Kodama, Takeshi

    2018-02-01

    In this work, a hydrodynamic study of the di-hadron azimuthal correlations for the Au+Au collisions at 200 GeV is carried out. The correlations are evaluated using the ZYAM method for the centrality windows as well as the transverse momentum range in accordance with the existing data. Event-plane dependence of the correlation is obtained after the subtraction of contributions from the most dominant harmonic coefficients. In particular, the contribution from the triangular flow, v3, is removed from the proper correlations following the procedure implemented by the STAR collaboration. The resultant structure observed in the correlations was sometimes attributed to the mini-jet dynamics, but the present calculations show that a pure hydrodynamic model gives a reasonable agreement with the main feature of the published data. A brief discussion on the physical content of the present findings is presented.

  5. Comparison of normal permanent and primary dentition sagittal tooth-crown inclinations of Japanese females.

    Science.gov (United States)

    Inada, Emi; Saitoh, Issei; Hayasaki, Haruaki; Iwase, Yoko; Kubota, Naoko; Takemoto, Yoshihiko; Yamasaki, Youichi

    2012-01-01

    The purpose of this study was to clarify the characteristics of permanent and primary tooth-crown inclinations. Landmark points from cephalograms and dental casts of two groups; 23 women (mean 20.3 +/- 3.3 years) and 11 girls (mean 5.2 +/- 0.1 years) were digitized, and the coordinates were integrated and transformed to a standardized plane. The 3-dimensional crown inclinations were projected on the sagittal plane, and the angles between the tooth vectors and the FH plane were calculated. An independent-group t-test was used to test for group differences of each tooth inclination, and correlation coefficients were generated for the inclination angles among the permanent and primary teeth. Most maxillary tooth-crown inclinations showed significant age-related differences, while only the second premolar and primary second molar differed significantly in the mandible. The maxillary molars were parallel to the corresponding mandibular molars and correlated with each other, but the primary molars were not. Significant correlations were found between inclinations of most permanent teeth, but not the primary teeth. Maxillary tooth-crown inclinations change during growth, but tooth-crown inclinations of the mandibular teeth do not.

  6. Modeling And Simulation Of Prolate Dual-Spin Satellite Dynamics In An Inclined Elliptical Orbit: Case Study Of Palapa B2R Satellite

    OpenAIRE

    Muliadi, J.; Jenie, S. D.; Budiyono, A.

    2008-01-01

    In response to the interest to re-use Palapa B2R satellite nearing its End of Life (EOL) time, an idea to incline the satellite orbit in order to cover a new region has emerged in the recent years. As a prolate dual-spin vehicle, Palapa B2R has to be stabilized against its internal energy dissipation effect. This work is focused on analyzing the dynamics of the reusable satellite in its inclined orbit. The study discusses in particular the stability of the prolate dual-spin satellite under th...

  7. MATHEMATICAL MODELING OF PLANE IL-76TD-90VD LANDING IN ANTARCTICA

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available Based on the information from the Internet the authors decided to reproduce the possible conditions of landing the plane IL-76TD-90VD in Antarctica in their computer experiment using the mathematical modeling system of aircraft flight dynamics (MMS AFD, which is developed and continuously improved in MSTUCA. MMS AFD has already shown its ability to complete such tasks for different aircraft types in various conditions, including IL-76TD, IL-96-300, IL-96T and also slippery runways.For the computational experiments the information from the web sources was used. The authors did not aim to pro- duce a final numerical results, which describe the possible operating conditions. It was expected only to get accurate qualita- tive results, which can adequately describe the behavior of the airplane IL-76TD-90VD when landing on the slippery runway.So, the authors were able to obtain a typical turn of plane at the end of run and show that the pilot style in these conditions has little effect on the qualitative behavior of the aircraft. The most important factor leading to such maneuvers, lies in the special connection of longitudinal and lateral friction of gear wheels with runway.The authors managed to identify the minimum allowed value of standard friction coefficient of the runway (0,42 which allows a safe landing under crosswind 15 m/s.The results that agree qualitatively with the known situations indicate the possibility for MMS AFD to properly reproduce various cases of aircraft IL-76TD-90VD landing to Antarctica ice airfield and identify any inaccurately knownparameters.

  8. Continuum modelling of pantographic sheets for out-of-plane bifurcation and vibrational analysis

    Science.gov (United States)

    Giorgio, I.; Rizzi, N. L.; Turco, E.

    2017-11-01

    A nonlinear two-dimensional (2D) continuum with a latent internal structure is introduced as a coarse model of a plane network of beams which, in turn, is assumed as a model of a pantographic structure made up by two families of equispaced beams, superimposed and connected by pivots. The deformation measures of the beams of the network and that of the 2D body are introduced and the former are expressed in terms of the latter by making some kinematical assumptions. The expressions for the strain and kinetic energy densities of the network are then introduced and given in terms of the kinematic quantities of the 2D continuum. To account for the modelling abilities of the 2D continuum in the linear range, the eigenmode and eigenfrequencies of a given specimen are determined. The buckling and post-buckling behaviour of the same specimen, subjected to two different loading conditions are analysed as tests in the nonlinear range. The problems have been solved numerically by means of the COMSOL Multiphysics finite element software.

  9. Determining The Plane of The Kuiper Belt with OSSOS

    Science.gov (United States)

    Van Laerhoven, Christa; Kavelaars, J. J.; Volk, Kathryn; Gladman, Brett; Petit, Jean-Marc

    2018-04-01

    We present the OSSOS-based measurement of the semi-major axes dependent orientation of the Kuiper Belt plane. A Kuiper Belt object's (KBO's) inclination can be broken down into a forced component and a free component. The inclination and longitude of ascending node of the forced inclination define the 'forced plane,' the plane about which the KBO's inclination will precess. Secular theory predicts that this forced plane should depend on semi-major axis. For example, the nu18 secular resonance should create a significant warp in the forced planet near 40.5 au (Chiang and Choi 2008). Not predicted by secular theory is a warp in the distant Kuiper Belt (semi-major axes greater than 50 au) seen by Volk and Malhotra 2016 using KBOs from the Minor Planet Catalog. We investigate what the inclination distribution is for objects beyond Neptune as a function of semi-major axis using the OSSOS characterized sample. Through use of the OSSOS survey simulator we test various underlying orbital distributions and compare how the survey would have observed those populations to the actual observed sample. In particular, we test various widths for the inclination distribution about various local forcing planes for the kernel, stirred, and hot classical Kuiper Belt. We find that the forced plane in matches well with the expected forced plane from secular theory. Through most of the main Kuiper Belt (between the 3:2 and 2:1 resonances), we can reject both the ecliptic plane and the invariable plane as the true forced plane. Only as the expected secularly forced plane approaches the invariable plane does the invariable plane become non-rejectable. In the outer Kuiper Belt we reject the nominal mean-plane measured by Volk and Malhotra, but smaller warps are still allowed by the data.

  10. Study and modeling of changes in volumetric efficiency of helix conveyors at different rotational speeds and inclination angels by ANFIS and statistical methods

    Directory of Open Access Journals (Sweden)

    A Zareei

    2017-05-01

    Full Text Available Introduction Spiral conveyors effectively carry solid masses as free or partly free flow of materials. They create good throughput and they are the perfect solution to solve the problems of transport, due to their simple structure, high efficiency and low maintenance costs. This study aims to investigate the performance characteristics of conveyors as function of auger diameter, rotational speed and handling inclination angle. The performance characteristic was investigated according to volumetric efficiency. In another words, the purpose of this study was obtaining a suitable model for volumetric efficiency changes of steep auger to transfer agricultural products. Three different diameters of auger, five levels of rotational speed and three slope angles were used to investigate the effects of changes in these parameters on volumetric efficiency of auger. The used method is novel in this area and the results show that performance by ANFIS models is much better than common statistical models. Materials and Methods The experiments were conducted in Department of Mechanical Engineering of Agricultural Machinery in Urmia University. In this study, SAYOS cultivar of wheat was used. This cultivar of wheat had hard seeds and the humidity was 12% (based on wet. Before testing, all foreign material was separated from the wheat such as stone, dust, plant residues and green seeds. Bulk density of wheat was 790 kg m-3. The auger shaft of the spiral conveyor was received its rotational force through belt and electric motor and its rotation leading to transfer the product to the output. In this study, three conveyors at diameters of 13, 17.5, and 22.5 cm, five levels of rotational speed at 100, 200, 300, 400, and 500 rpm and three handling angles of 10, 20, and 30º were tested. Adaptive Nero-fuzzy inference system (ANFIS is the combination of fuzzy systems and artificial neural network, so it has both benefits. This system is useful to solve the complex non

  11. A simple model for normal state in- and out-of-plane resistivities of hole doped cuprates

    Science.gov (United States)

    Naqib, S. H.; Azam, M. Afsana; Uddin, M. Borhan; Cole, J. R.

    2016-05-01

    The highly anisotropic and qualitatively different nature of the normal state in- and out-of-plane charge dynamics in high-Tc cuprates cannot be accommodated within the conventional Boltzmann transport theory. The variation of in-plane and out-of-plane resistivities with temperature and hole content are anomalous and cannot be explained by Fermi-liquid theory. In this study, we have proposed a simple phenomenological model for the dc resistivity of cuprates by incorporating two firmly established generic features of all hole doped cuprate superconductors-(i) the pseudogap in the quasiparticle energy spectrum and (ii) the T-linear resistivity at high temperatures. This T-linear behavior over an extended temperature range can be attributed to a quantum criticality, affecting the electronic phase diagram of cuprates. Experimental in-plane and out-of-plane resistivities (ρp(T) and ρc(T), respectively) of double-layer Y(Ca)123 have been analyzed using the proposed model. This phenomenological model describes the temperature and the hole content dependent resistivity over a wide range of temperature and hole content, p. The characteristic PG energy scale, εg(p), extracted from the analysis of the resistivity data, agrees quite well with those found in variety of other experiments. Various other extracted parameters from the analysis of ρp(T) and ρc(T) data showed systematic trends with changing hole concentration. We have discussed important features found from the analysis in detail in this paper.

  12. Development of a,b-plane-oriented hydroxyapatite ceramics as models for living bones and their cell adhesion behavior.

    Science.gov (United States)

    Zhuang, Zhi; Fujimi, Takahiko J; Nakamura, Mariko; Konishi, Toshiisa; Yoshimura, Hideyuki; Aizawa, Mamoru

    2013-05-01

    In vertebrate bones and tooth enamel surfaces, the respective a,b-planes and c-planes of hydroxyapatite (HAp) crystals are preferentially exposed. However, the reason why the HAp crystals show different orientations depending on the type of hard tissues is not yet understood. To clarify this question, appropriate ceramic models with highly preferred orientation are necessary. In the present study, dense HAp ceramic models which have the same orientation as living bones were fabricated using composite powders of c-axis-oriented single-crystal apatite fibers (AF) and wet-synthesized apatite gels (AG). The results of crystalline identification and ultrastructural observation showed that the resulting HAp ceramics maintained the c-axis orientation of the AF particles, and their high a,b-plane orientation degrees could be maintained with small additive amounts of AG; however, when the AG content was over 30 mass%, this value decreased. The influence of orientation degree on the surface characteristics was investigated by evaluating the surface zeta-potential and wettability. These results show that increasing the a,b-plane orientation degree shifted the surface charge from negative to positive, and decreased the surface wettability. Initial cell-attachment assays were performed on these resulting ceramics using MC3T3-E1 cells as models of osteoblasts. The results show that the cell-attachment efficiency decreased with increasing a,b-plane orientation degree. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. Modeling the Test-Retest Statistics of a Localization Experiment in the Full Horizontal Plane.

    Science.gov (United States)

    Morsnowski, André; Maune, Steffen

    2016-10-01

    Two approaches to model the test-retest statistics of a localization experiment basing on Gaussian distribution and on surrogate data are introduced. Their efficiency is investigated using different measures describing directional hearing ability. A localization experiment in the full horizontal plane is a challenging task for hearing impaired patients. In clinical routine, we use this experiment to evaluate the progress of our cochlear implant (CI) recipients. Listening and time effort limit the reproducibility. The localization experiment consists of a 12 loudspeaker circle, placed in an anechoic room, a "camera silens". In darkness, HSM sentences are presented at 65 dB pseudo-erratically from all 12 directions with five repetitions. This experiment is modeled by a set of Gaussian distributions with different standard deviations added to a perfect estimator, as well as by surrogate data. Five repetitions per direction are used to produce surrogate data distributions for the sensation directions. To investigate the statistics, we retrospectively use the data of 33 CI patients with 92 pairs of test-retest-measurements from the same day. The first model does not take inversions into account, (i.e., permutations of the direction from back to front and vice versa are not considered), although they are common for hearing impaired persons particularly in the rear hemisphere. The second model considers these inversions but does not work with all measures. The introduced models successfully describe test-retest statistics of directional hearing. However, since their applications on the investigated measures perform differently no general recommendation can be provided. The presented test-retest statistics enable pair test comparisons for localization experiments.

  14. Finite-size behaviour of generalized susceptibilities in the whole phase plane of the Potts model

    Science.gov (United States)

    Pan, Xue; Zhang, Yanhua; Chen, Lizhu; Xu, Mingmei; Wu, Yuanfang

    2018-01-01

    We study the sign distribution of generalized magnetic susceptibilities in the temperature-external magnetic field plane using the three-dimensional three-state Potts model. We find that the sign of odd-order susceptibility is opposite in the symmetric (disorder) and broken (order) phases, but that of the even-order one remains positive when it is far away from the phase boundary. When the critical point is approached from the crossover side, negative fourth-order magnetic susceptibility is observable. It is also demonstrated that non-monotonic behavior occurs in the temperature dependence of the generalized susceptibilities of the energy. The finite-size scaling behavior of the specific heat in this model is mainly controlled by the critical exponent of the magnetic susceptibility in the three-dimensional Ising universality class. Supported by Fund Project of National Natural Science Foundation of China (11647093, 11405088, 11521064), Fund Project of Sichuan Provincial Department of Education (16ZB0339), Fund Project of Chengdu Technological University (2016RC004) and the Major State Basic Research Development Program of China (2014CB845402)

  15. Modelling bacterial behaviour close to a no-slip plane boundary: the influence of bacterial geometry

    KAUST Repository

    Shum, H.

    2010-01-13

    We describe a boundary-element method used to model the hydrodynamics of a bacterium propelled by a single helical flagellum. Using this model, we optimize the power efficiency of swimming with respect to cell body and flagellum geometrical parameters, and find that optima for swimming in unbounded fluid and near a no-slip plane boundary are nearly indistinguishable. We also consider the novel optimization objective of torque efficiency and find a very different optimal shape. Excluding effects such as Brownian motion and electrostatic interactions, it is demonstrated that hydrodynamic forces may trap the bacterium in a stable, circular orbit near the boundary, leading to the empirically observable surface accumulation of bacteria. Furthermore, the details and even the existence of this stable orbit depend on geometrical parameters of the bacterium, as described in this article. These results shed some light on the phenomenon of surface accumulation of micro-organisms and offer hydrodynamic explanations as to why some bacteria may accumulate more readily than others based on morphology. © 2010 The Royal Society.

  16. Collective noise model for focal plane modulated single-pixel imaging

    Science.gov (United States)

    Sun, Ming-Jie; Xu, Zi-Hao; Wu, Ling-An

    2018-01-01

    Single-pixel imaging, also known as computational ghost imaging, provides an alternative method to perform imaging in various applications which are difficult for conventional cameras with pixelated detectors, such as multi-wavelength imaging, three-dimensional imaging, and imaging through turbulence. In recent years, many improvements have successfully increased the signal-to-noise ratio of single-pixel imaging systems, showing promise for the engineering feasibility of this technique. However, many of these improvements are based on empirical findings. In this work we perform an investigation of the noise from each system component that affects the quality of the reconstructed image in a single-pixel imaging system based on focal plane modulation. A collective noise model is built to describe the resultant influence of these different noise sources, and numerical simulations are performed to quantify the effect. Experiments have been conducted to verify the model, and the results agree well with the simulations. This work provides a simple yet accurate method for evaluating the performance of a single-pixel imaging system, without having to carry out actual experimental tests.

  17. A new model to produce sagittal plane rotational induced diffuse axonal injuries

    Directory of Open Access Journals (Sweden)

    Johan eDavidsson

    2011-06-01

    Full Text Available A new in vivo animal model that produces diffuse brain injuries (DBI in sagittal plane rearward rotational acceleration has been developed. In this model, the skull of an anesthetized adult rat is tightly secured to a rotating bar. During trauma, the bar is impacted by a striker that causes the bar and the animal head to rotate rearward; the acceleration phase last 0.4 ms and is followed by a rotation at constant speed and a gentle deceleration when the bar makes contact with a padded stop. The total head angle change is less than 30 degrees. By adjusting the air pressure in the rifle used to accelerate the striker, resulting rotational acceleration between 0.3 and 2.1 Mrad/s2 can be produced.Numerous combinations of trauma levels, post-trauma survival times, brain and serum retrieval and tissue preparation techniques were adopted to characterise this new model. The trauma caused subdural bleedings in animals exposed to severe trauma. Staining brain tissue with β-Amyloid Precursor Protein antibodies and FD Neurosilver that detect degenerating axons revealed wide spread axonal injuries (AI in the corpus callosum, the border between the corpus callosum and cortex and in tracts in the brain stem. The observed AI:s were apparent only when the rotational acceleration level was moderate and above. On the contrary, only limited signs of contusion injuries were observed following trauma. S100 serum analyses indicate that blood vessel and glia cell injuries occur following moderate levels of trauma despite the absence of obvious BBB injuries. We conclude that this rotational trauma model is capable of producing graded axonal injury, is repeatable and produces limited other types of traumatic brain injuries (TBI and as such is useful in the study of injury biomechanics, diagnostics and treatment strategies following diffuse axonal injury (DAI.

  18. A new model to produce sagittal plane rotational induced diffuse axonal injuries.

    Science.gov (United States)

    Davidsson, Johan; Risling, Marten

    2011-01-01

    A new in vivo animal model that produces diffuse brain injuries in sagittal plane rearward rotational acceleration has been developed. In this model, the skull of an anesthetized adult rat is tightly secured to a rotating bar. During trauma, the bar is impacted by a striker that causes the bar and the animal head to rotate rearward; the acceleration phase last 0.4 ms and is followed by a rotation at constant speed and a gentle deceleration when the bar makes contact with a padded stop. The total head angle change is less than 30°. By adjusting the air pressure in the rifle used to accelerate the striker, resulting rotational acceleration between 0.3 and 2.1 Mrad/s(2) can be produced. Numerous combinations of trauma levels, post-trauma survival times, brain and serum retrieval, and tissue preparation techniques were adopted to characterize this new model. The trauma caused subdural bleedings in animals exposed to severe trauma. Staining brain tissue with β-Amyloid Precursor Protein antibodies and FD Neurosilver that detect degenerating axons revealed wide spread axonal injuries (AI) in the corpus callosum, the border between the corpus callosum and cortex and in tracts in the brain stem. The observed AIs were apparent only when the rotational acceleration level was moderate and above. On the contrary, only limited signs of contusion injuries were observed following trauma. Macrophage invasions, glial fibrillary acidic protein redistribution or hypertrophy, and blood brain barrier (BBB) changes were unusual. S100 serum analyses indicate that blood vessel and glia cell injuries occur following moderate levels of trauma despite the absence of obvious BBB injuries. We conclude that this rotational trauma model is capable of producing graded axonal injury, is repeatable and produces limited other types of traumatic brain injuries and as such is useful in the study of injury biomechanics, diagnostics, and treatment strategies following diffuse axonal injury.

  19. Natural Circulation Characteristics of a Symmetric Loop under Inclined Conditions

    Directory of Open Access Journals (Sweden)

    Xingtuan Yang

    2014-01-01

    Full Text Available Natural circulation is an important process for primary loops of some marine integrated reactors. The reactor works under inclined conditions when severe accidents happen to the ship. In this paper, to investigate the characteristics of natural circulation, experiments were conducted in a symmetric loop under the inclined angle of 0~45°. A CFD model was also set up to predict the behaviors of the loop beyond the experimental scope. Total circulation flow rate decreases with the increase of inclined angle. Meanwhile one circulation is depressed while the other is enhanced, and accordingly the disparity between the branch circulations arises and increases with the increase of inclined angle. Circulation only takes place in one branch circuit at large inclined angle. Also based on the CFD model, the influences of flow resistance distribution and loop configuration on natural circulation are predicted. The numerical results show that to design the loop with the configuration of big altitude difference and small width, it is favorable to reduce the influence of inclination; however too small loop width will cause severe reduction of circulation ability at large angle inclination.

  20. Sagittal x-ray beam deviation at asymmetric inclined diffractors

    Czech Academy of Sciences Publication Activity Database

    Korytár, D.; Hrdý, Jaromír; Artemiev, Nikolai; Ferrari, C.; Freund, A.

    2001-01-01

    Roč. 8, - (2001), s. 1136-1139 ISSN 0909-0495 R&D Projects: GA MŠk OK 305; GA MPO PZ-CH/22 Institutional research plan: CEZ:AV0Z1010914 Keywords : x-ray optics * Si(111) W/grooved crystals * inclined diffraction * out-of-diffraction-plane beams * sagittal focusing Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.519, year: 2001

  1. Pseudo Phase Plane and Fractional Calculus modeling of western global economic downturn

    Science.gov (United States)

    Tenreiro Machado, J. A.; Mata, Maria Eugénia

    2015-05-01

    This paper applies Pseudo Phase Plane (PPP) and Fractional Calculus (FC) mathematical tools for modeling world economies. A challenging global rivalry among the largest international economies began in the early 1970s, when the post-war prosperity declined. It went on, up to now. If some worrying threatens may exist actually in terms of possible ambitious military aggression, invasion, or hegemony, countries' PPP relative positions can tell something on the current global peaceful equilibrium. A global political downturn of the USA on global hegemony in favor of Asian partners is possible, but can still be not accomplished in the next decades. If the 1973 oil chock has represented the beginning of a long-run recession, the PPP analysis of the last four decades (1972-2012) does not conclude for other partners' global dominance (Russian, Brazil, Japan, and Germany) in reaching high degrees of similarity with the most developed world countries. The synergies of the proposed mathematical tools lead to a better understanding of the dynamics underlying world economies and point towards the estimation of future states based on the memory of each time series.

  2. Articulator-related registration and analysis of sagittal condylar inclination

    OpenAIRE

    Čimić, Samir; Kraljević Šimunković, Sonja; Simonić Kocijan, Sunčana; Matijević, Jurica; Dulčić, Nikša; Ćatić, Amir

    2015-01-01

    The purpose of this investigation was to study sagittal condylar inclination values within a uniform sample (Angle class I occlusion) using ‘articulator-related registration’ and Camper’s plane as a reference plane. The study was performed on a sample of 58 Angle class I subjects (mean age 25.1, SD 3.1). Measurements were performed with an ultrasonic jaw tracking device with six degrees of freedom. After a paraocclusal tray was fixed in the mouth, each subject had to make three protrusive ...

  3. An analytic solution of the static problem of inclined risers conveying fluid

    KAUST Repository

    Alfosail, Feras

    2016-05-28

    We use the method of matched asymptotic expansion to develop an analytic solution to the static problem of clamped–clamped inclined risers conveying fluid. The inclined riser is modeled as an Euler–Bernoulli beam taking into account its self-weight, mid-plane stretching, an applied axial tension, and the internal fluid velocity. The solution consists of three parts: an outer solution valid away from the two boundaries and two inner solutions valid near the two ends. The three solutions are then matched and combined into a so-called composite expansion. A Newton–Raphson method is used to determine the value of the mid-plane stretching corresponding to each applied tension and internal velocity. The analytic solution is in good agreement with those obtained with other solution methods for large values of applied tensions. Therefore, it can be used to replace other mathematical solution methods that suffer numerical limitations and high computational cost. © 2016 Springer Science+Business Media Dordrecht

  4. Tooth Wear Inclination in Great Ape Molars.

    Science.gov (United States)

    Knight-Sadler, Jordan; Fiorenza, Luca

    2017-01-01

    Primate dietary diversity is reflected in their dental morphology, with differences in size and shape of teeth. In particular, the tooth wear angle can provide insight into a species' ability to break down certain foods. To examine dietary and masticatory information, digitized polygon models of dental casts provide a basis for quantitative analysis of wear associated with tooth attrition. In this study, we analyze and compare the wear patterns of Pongo pygmaeus, Gorilla gorillagorilla and Pan troglodytes schweinfurthii lower molars, focusing on the degree of inclination of specific wear facets. The variation in wear angles appears to be indicative of jaw movements and the specific stresses imposed on food during mastication, reflecting thus the ecology of these species. Orangutans exhibit flatter wear angles, more typical of a diet consisting of hard and brittle foods, while gorillas show a wear pattern with a high degree of inclination, reflecting thus their more leafy diet. Chimpanzees, on the other hand, show intermediate inclinations, a pattern that could be related to their highly variable diet. This method is demonstrated to be a powerful tool for better understanding the relationship between food, mastication and tooth wear processes in living primates, and can be potentially used to reconstruct the diet of fossil species. © 2017 S. Karger AG, Basel.

  5. Interpretation of Microseismicity Observed From Surface and Borehole Seismic Arrays During Hydraulic Fracturing in Shale - Bedding Plane Slip Model

    Science.gov (United States)

    Stanek, F.; Jechumtalova, Z.; Eisner, L.

    2017-12-01

    We present a geomechanical model explaining microseismicity induced by hydraulic fracturing in shales developed from many datasets acquired with two most common types of seismic monitoring arrays, surface and dual-borehole arrays. The geomechanical model explains the observed source mechanisms and locations of induced events from two stimulated shale reservoirs. We observe shear dip-slip source mechanisms with nodal planes aligned with location trends. We show that such seismicity can be explained as a shearing along bedding planes caused by aseismic opening of vertical hydraulic fractures. The source mechanism inversion was applied only to selected high-quality events with sufficient signal-to-noise ratio. We inverted P- and P- and S-wave arrival amplitudes to full-moment tensor and decomposed it to shear, volumetric and compensated linear vector dipole components. We also tested an effect of noise presented in the data to evaluate reliability of non-shear components. The observed seismicity from both surface and downhole monitoring of shale stimulations is very similar. The locations of induced microseismic events are limited to narrow depth intervals and propagate along distinct trend(s) showing fracture propagation in direction of maximum horizontal stress from injection well(s). The source mechanisms have a small non-shear component which can be partly explained as an effect of noise in the data, i.e. events represent shearing on faults. We observe predominantly dip-slip events with a strike of the steeper (almost vertical) nodal plane parallel to the fracture propagation. Therefore the other possible nodal plane is almost horizontal. The rake angles of the observed mechanisms divide these dip-slips into two groups with opposite polarities. It means that we observe opposite movements on the nearly identically oriented faults. Realizing a typical structural weakness of shale in horizontal planes, we interpret observed microseismicity as a result of shearing

  6. A jig for measuring incisor inclination.

    Science.gov (United States)

    Shah, N; Spary, D J; Rock, W P

    2005-06-01

    The aim of this study was to design and construct a jig for measuring the inclination of the upper incisors to the maxillary plane and of the lower incisors to the mandibular plane. After several prototypes had been tested, the required properties for a successful jig were identified and a simple inexpensive device was produced. Measurements obtained when using the jig on 51 subjects were compared with cephalometric values by means of regression analysis. This revealed that measurements obtained using the jig against the upper and then the lower incisor crowns could be converted to cephalometric incisor angulations with 96 per cent accuracy to 10 degrees, by adding 23 and 3 degrees, respectively. The jig was accurate to 5 degrees on 69 per cent of occasions for the upper teeth. The 5 degrees accuracy with the lower incisors was only 27 per cent, although over a 6 degree range it improved to 78 per cent. For upper and lower tooth measurements combined, the jig was accurate to within 6 degrees on 75 per cent of occasions.

  7. A phase plane graph based model of the ovulatory cycle lacking the "positive feedback" phenomenon

    Directory of Open Access Journals (Sweden)

    Kurbel Sven

    2012-08-01

    Full Text Available Abstract When hormones during the ovulatory cycle are shown in phase plane graphs, reported FSH and estrogen values form a specific pattern that resembles the leaning “&" symbol, while LH and progesterone (Pg values form a "boomerang" shape. Graphs in this paper were made using data reported by Stricker et al. [Clin Chem Lab Med 2006;44:883–887]. These patterns were used to construct a simplistic model of the ovulatory cycle without the conventional "positive feedback" phenomenon. The model is based on few well-established relations: hypothalamic GnRH secretion is increased under estrogen exposure during two weeks that start before the ovulatory surge and lasts till lutheolysis. the pituitary GnRH receptors are so prone to downregulation through ligand binding that this must be important for their function. in several estrogen target tissue progesterone receptor (PgR expression depends on previous estrogen binding to functional estrogen receptors (ER, while Pg binding to the expressed PgRs reduces both ER and PgR expression. Some key features of the presented model are here listed: High GnRH secretion induced by the recovered estrogen exposure starts in the late follicular phase and lasts till lutheolysis. The LH and FSH surges start due to combination of accumulated pituitary GnRH receptors and increased GnRH secretion. The surges quickly end due to partial downregulation of the pituitary GnRH receptors (64% reduction of the follicular phase pituitary GnRH receptors is needed to explain the reported LH drop after the surge. A strong increase in the lutheal Pg blood level, despite modest decline in LH levels, is explained as delayed expression of pituitary PgRs. Postponed pituitary PgRs expression enforces a negative feedback loop between Pg levels and LH secretions not before the mid lutheal phase. Lutheolysis is explained as a consequence of Pg binding to hypothalamic and pituitary PgRs that reduces local ER expression. When hypothalamic

  8. The influence of incline walking on joint mechanics.

    Science.gov (United States)

    Haggerty, Mason; Dickin, D Clark; Popp, Jennifer; Wang, Henry

    2014-04-01

    Walking is a popular form of exercise and is associated with many health benefits; however, frontal-plane knee joint loading brought about by a large internal knee-abduction moment and cyclic loading could lead to cartilage degeneration over time. Therefore, knee joint mechanics during an alternative walking exercise needs to be analyzed. The purpose of this study was to examine the lower-extremity joint mechanics in the frontal and sagittal planes during incline walking. Fifteen healthy males walked on a treadmill at five gradients (0%, 5%, 10%, 15%, and 20%) at 1.34m/s, and lower-extremity joint mechanics in the frontal and sagittal planes were quantified. The peak internal knee-abduction moment significantly decreased from the level walking condition at all gradients except 5%. Also, a negative relationship between the internal knee-abduction moment and the treadmill gradient was found to exist in 10% increments (0-10%, 5-15%, and 10-20%). The decrease in the internal knee-abduction moment during incline walking could have positive effects on knee joint health such as potentially reducing cartilage degeneration of the knee joint, reducing pain, and decreasing the rate of development of medial tibiofemoral osteoarthritis. This would be beneficial for a knee surgery patient, obese persons, and older adults who are using incline walking for rehabilitation and exercise protocols. Findings from the current study can provide guidance for the development of rehabilitation and exercise prescriptions incorporating incline walking. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Plane Symmetric Dark Energy Models in the Form of Wet Dark Fluid ...

    Indian Academy of Sciences (India)

    5. Isotropization and the solution. The isotropy of the expansion can be parametrized after defining the directional. Hubble's parameters and the average Hubble's parameter of the expansion. The directional Hubble parameters in the directions X, Y, Z for the plane symmetric metric defined in (16) may be defined as follows:.

  10. Plane Symmetric Dark Energy Models in the Form of Wet Dark Fluid ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, we have investigated the plane symmetric space- time with wet dark fluid (WDF), which is a candidate for dark energy, in the framework of f(R, T ) gravity Harko et al. 2011, Phys. Rev. D,. 84, 024020), where R and T denote the Ricci scalar and the trace of the energy–momentum tensor respectively.

  11. Seismicity Induced by Hydraulic Fracturing in Shales: A Bedding Plane Slip Model

    Czech Academy of Sciences Publication Activity Database

    Staněk, František; Eisner, Leo

    2017-01-01

    Roč. 122, č. 10 (2017), s. 7912-7926 ISSN 2169-9313 Institutional support: RVO:67985891 Keywords : microseismic * seismicity * hydraulic fracturing * bedding plane slip Subject RIV: DC - Siesmology, Volcanology, Earth Structure OBOR OECD: 1.7 Other natural sciences Impact factor: 3.350, year: 2016

  12. Impact of slope inclination on salt accumulation

    Science.gov (United States)

    Nachshon, Uri

    2017-04-01

    Field measurements indicated on high variability in salt accumulation along natural and cultivated slopes, even for relatively homogeneous soil conditions. It was hypothesised that slope inclination has an impact on the location of salt accumulation along the slope. A set of laboratory experiments and numerical models were used to explore the impact of slope inclination on salt accumulation. It was shown, experimentally, that for conditions of saline water source at the lower boundary of the slope - salt accumulates in low concentrations and homogeneously along the entire slope, for moderate slopes. However, as inclination increases high salt concentrations were observed at the upper parts of the slope, leaving the lower parts of the slope relatively free of salt. The traditional flow and transport models did not predict the experimental observations as they indicated also for the moderate slopes on salt accumulation in the elevated parts of the slope, away of the saline water source. Consequently - a conceptual model was raised to explain the laboratory observations. It was suggested that the interactions between slope angle, evaporation rates, hydraulic conductivity of the medium and distribution of wetness along the slope affect the saline water flow path through the medium. This lead to preferential flow path close to the soil-atmosphere interface for the steep slopes, which leads to constant wash of the salts from the evaporation front upward towards the slope upper parts, whereas for the moderate slopes, flow path is below the soil-atmosphere interface, therefore salt that accumulates at the evaporation front is not being transported upward. Understanding of salt dynamics along slopes is important for agricultural and natural environments, as well as for civil engineering purposes. Better understanding of the salt transport processes along slopes will improve our ability to minimize and to cope with soil salinization processes. The laboratory experiments and

  13. Analytical theory of Mercury's rotation and reference planes

    Science.gov (United States)

    D'Hoedt, Sandrine; Noyelles, Benoit; Dufey, Julien; Lemaitre, Anne

    The space missions to Mercury (Messenger or BepiColombo) will provide new data about the rotation of the planet, which should induce a much better knowledge of its internal structure. Besides huge numerical integrations, an efficient treatment of these data requires a complete analytical model of rotation for Mercury, which is nowadays inexistent. Our team is implicated in the BepiColombo mission through the MORE project (Mercury Orbiter Radio Science Experiment). In particular, our task is to provide such a model of rotation, to be able to identify the parameters with the data. Our starting point is to take an Hamiltonian theory of the 3 : 2 resonant rotation of Mercury (D'Hoedt and Lemaˆ ıtre, 2004). In this kernel model, Mercury is supposed to be rigid and its orbits is considered as keplerian. The theory is a 2 degree of freedom one, limited at the second order in spherical harmonics and averaged over the short periods. These short periods (the orbital one and the rotational one, resp. 88 and 58 days) can be added on the averaged model as perturbations. In the same way, we can include the very long periods (longitude of the ascending node and of the pericenter argument) as perturbations on our Hamiltonian. Another method to insert the influence of the other planets is to consider that the orbital elements are slowly varying with time. More over, thanks to the adiabatic invariant theory, Peale (2006) and D'Hoedt and Lemaˆ (2008) showed that, if the eccentricity and the orbital inclination ıtre are slow functions of time, the angular momentum axis stays closed to the Cassini equilibrium. The precise definition of the Cassini states refers to different planes : in particular, an orbital plane, linked to a mean orbit of Mercury and a Laplace plane (orthogonal to the axis around which Mercury's orbit is precessing with a constant inclination). This mean orbital plane is obtained by numerical integration of the motion, on which we perform a frequency analysis to

  14. Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model

    Science.gov (United States)

    Taskjelle, Torbjørn; Hudson, Stephen R.; Granskog, Mats A.; Hamre, Børge

    2017-09-01

    Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400-900 nm) were found to be on average 0.15-0.20 under bare ice, and 0.39-0.46 under ponded ice. Radiative transfer modelling was done with a plane-parallel model. While simulated transmittances deviate significantly from measured transmittances close to the edge of ponds, spatially averaged bulk transmittances agree well. That is, transect-average bulk transmittances, calculated using typical simulated transmittances for ponded and bare ice weighted by the fractional coverage of the two surface types, are in good agreement with the measured values. Radiative heating rates calculated from model output indicates that about 20 % of the incident solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in pond itself, 15 % in the underlying ice). This large difference is due to the highly scattering surface scattering layer (SSL) increasing the albedo of the bare ice.

  15. Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model

    Directory of Open Access Journals (Sweden)

    T. Taskjelle

    2017-09-01

    Full Text Available Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400–900 nm were found to be on average 0.15–0.20 under bare ice, and 0.39–0.46 under ponded ice. Radiative transfer modelling was done with a plane-parallel model. While simulated transmittances deviate significantly from measured transmittances close to the edge of ponds, spatially averaged bulk transmittances agree well. That is, transect-average bulk transmittances, calculated using typical simulated transmittances for ponded and bare ice weighted by the fractional coverage of the two surface types, are in good agreement with the measured values. Radiative heating rates calculated from model output indicates that about 20 % of the incident solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in pond itself, 15 % in the underlying ice. This large difference is due to the highly scattering surface scattering layer (SSL increasing the albedo of the bare ice.

  16. Magnetoelastic plane waves in rotating media in thermoelasticity of type II (G-N model

    Directory of Open Access Journals (Sweden)

    S. K. Roychoudhuri

    2004-01-01

    Full Text Available A study is made of the propagation of time-harmonic plane waves in an infinite, conducting, thermoelastic solid permeated by a uniform primary external magnetic field when the entire medium is rotating with a uniform angular velocity. The thermoelasticity theory of type II (G-N model (1993 is used to study the propagation of waves. A more general dispersion equation is derived to determine the effects of rotation, thermal parameters, characteristic of the medium, and the external magnetic field. If the primary magnetic field has a transverse component, it is observed that the longitudinal and transverse motions are linked together. For low frequency (χ≪1, χ being the ratio of the wave frequency to some standard frequency ω∗, the rotation and the thermal field have no effect on the phase velocity to the first order of χ and then this corresponds to only one slow wave influenced by the electromagnetic field only. But to the second order of χ, the phase velocity, attenuation coefficient, and the specific energy loss are affected by rotation and depend on the thermal parameters cT, cT being the nondimensional thermal wave speed of G-N theory, and the thermoelastic coupling εT, the electromagnetic parameters εH, and the transverse magnetic field RH. Also for large frequency, rotation and thermal field have no effect on the phase velocity, which is independent of primary magnetic field to the first order of (1/χ (χ≫1, and the specific energy loss is a constant, independent of any field parameter. However, to the second order of (1/χ, rotation does exert influence on both the phase velocity and the attenuation factor, and the specific energy loss is affected by rotation and depends on the thermal parameters cT and εT, electromagnetic parameter εH, and the transverse magnetic field RH, whereas the specific energy loss is independent of any field parameters to the first order of (1/χ.

  17. Inclined solar chimney for power production

    Energy Technology Data Exchange (ETDEWEB)

    Panse, S.V., E-mail: sudhirpanse@yahoo.com [Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Jadhav, A.S.; Gudekar, A.S. [Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Joshi, J.B. [Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Homi Bhabha National Institute, Trombay, Mumbai 400 094 (India)

    2011-09-15

    Highlights: {yields} Solar energy harnessing using inclined face of high mountains as solar chimney. {yields} Solar chimneys with structural stability, ease of construction and lower cost. {yields} Mathematical model developed, using complete (mechanical and thermal) energy balance. {yields} Can harness wind power also, as wind velocities at mountain top add to power output. {yields} Air temperature and velocity increase, as air rises in inclined chimney. - Abstract: The present concept of solar chimney is a tall vertical chimney constructed at the center of a large area, which is the collector. This creates questions about stability and economic viability of the chimney and also demands elaborate engineering techniques for constructing a tall chimney. We suggest geometry of 'Inclined Solar Chimney' (ISC), which is constructed along the face of a high rising mountain, on which maximum solar insolation is incident throughout the year. The chimney and the collector get merged here. This makes the structure stable, cost effective and easy for construction. A mathematical model has been developed considering the total energy balance. It predicts the temperature and velocity and kinetic power of the emerging air draft for some chosen values of other parameters. The model also shows the proportion in which absorbed solar energy is divided into different forms, and hence predicts the dependence of kinetic of emerging air draft upon dimensions of the chimney and properties of materials used. Further, it is shown that external winds enhance the kinetic power of the emerging air. Thus ISC can also harness the wind energy, available at the top of the mountain.

  18. Uplift Capacity of Inclined Underreamed Piles Subjected to Vertical Load

    Science.gov (United States)

    Rahman, Md. Akilur; Sengupta, Siddhartha

    2017-12-01

    Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Inclined (batter) piles are used to support such structures, and to carry the horizontal and vertical loads resulted from the overturning moments. Though studies have been done with inclined piles having no underream bulb, little information is available in the literature about estimating the uplift capacity of inclined underreamed piles. In the present study laboratory experiments have been done with vertically loaded model piles having no underream as well as with one and two underreams. The piles were positioned at angle of inclination of θ = 0°, 10°, 20°, 30° (with vertical); and placed in locally available sand under vertical uplift load. Three different pile stem diameters (D = 20, 25, and 35 mm) were used. The corresponding pile length to stem diameter (l/D) ratio were 18, 14, and 10 respectively. Experiments had been conducted with two relative different densities (45 and 70%) of sand. The failure uplift loads were obtained in each case. It had been found that for inclined piles increase in number of underream bulbs from 0 to 2 was quite effective in resisting uplift loads corresponding to piles having l/D equals to 10. The percentage decreases in uplift capacity corresponding to increase in inclination angle were more pronounced for piles with double underreams.

  19. Particle acceleration in relativistic magnetized collisionless pair shocks: a survey of magnetic inclination angles

    Science.gov (United States)

    Sironi, Lorenzo

    We investigate particle acceleration in relativistic magnetized collisionless pair shocks with two-dimensional particle-in-cell numerical simulations. For fixed upstream bulk Lorentz factor γ0 = 15 and magnetic to kinetic energy fraction σ = 0.1, we explore a range of inclination angles θ between the magnetic field and the shock normal. The inclination is measured in the downstream rest frame and the magnetic field lies in a plane perpendicular to the simulation plane. The downstream energy spectrum for subluminal shocks consists of a relativistic Maxwellian and a high-energy power-law tail modified by an exponential cutoff. For parallel shocks (θ = 0° ), the tail accounts for ˜ 1% of the downstream particle number and ˜ 5% of the energy, and its energy spectral index is -2.7 ± 0.1. Accelerated particles bounce between the upstream and the downstream, and the upstream scattering is provided by oblique filaments, which have both an electromagnetic and an electrostatic component. Such filaments propagate towards the shock and are generated by the accelerated particles that escape upstream. For larger inclination angles the acceleration efficiency increases, and particles are efficiently boosted by the motional upstream electric field when gyrating across the shock. Close to the superluminality threshold θ ≈ 30° , the number and energy fractions of downstream accelerated particles are ˜ 3% and ˜ 12% respectively; the spectral index of the corresponding power-law tail is -2.4 ± 0.1. When the shock becomes superluminal (θ 30° ), the acceleration efficiency abruptly drops. Our results show that the range of upstream-frame inclination angles suitable for efficient acceleration in relativistic magnetized pair shocks is indeed very small 30° /γ0 , as suggested by previous Monte-Carlo simulations. Self-generated shock turbulence is shown to be not large enough to overcome the kinematic constraints for superluminal shocks. These findings place constraints

  20. Hysteresis modelling of GO laminations for arbitrary in-plane directions taking into account the dynamics of orthogonal domain walls

    Energy Technology Data Exchange (ETDEWEB)

    Baghel, A.P.S.; Sai Ram, B. [Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India); Chwastek, K. [Department of Electrical Engineering Czestochowa University of Technology (Poland); Daniel, L. [Group of Electrical Engineering-Paris (GeePs), CNRS(UMR8507)/CentraleSupelec/UPMC/Univ Paris-Sud, 11 rue Joliot-Curie, 91192 Gif-sur-Yvette (France); Kulkarni, S.V. [Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India)

    2016-11-15

    The anisotropy of magnetic properties in grain-oriented steels is related to their microstructure. It results from the anisotropy of the single crystal properties combined to crystallographic texture. The magnetization process along arbitrary directions can be explained using phase equilibrium for domain patterns, which can be described using Neel's phase theory. According to the theory the fractions of 180° and 90° domain walls depend on the direction of magnetization. This paper presents an approach to model hysteresis loops of grain-oriented steels along arbitrary in-plane directions. The considered description is based on a modification of the Jiles–Atherton model. It includes a modified expression for the anhysteretic magnetization which takes into account contributions of two types of domain walls. The computed hysteresis curves for different directions are in good agreement with experimental results. - Highlights: • An extended Jiles–Atherton description is used to model hysteresis loops in GO steels. • The model stresses the role of material anisotropy and different contributions of the two types of domain walls. • Hysteresis loops can be modeled along arbitrary in-plane directions. • Modeling results are in good agreement with experiments.

  1. Kinematic control of aerodynamic forces on an inclined flapping wing with asymmetric strokes

    International Nuclear Information System (INIS)

    Park, Hyungmin; Choi, Haecheon

    2012-01-01

    In the present study, we conduct an experiment using a one-paired dynamically scaled model of an insect wing, to investigate how asymmetric strokes with different wing kinematic parameters are used to control the aerodynamics of a dragonfly-like inclined flapping wing in still fluid. The kinematic parameters considered are the angles of attack during the mid-downstroke (α md ) and mid-upstroke (α mu ), and the duration (Δτ) and time of initiation (τ p ) of the pitching rotation. The present dragonfly-like inclined flapping wing has the aerodynamic mechanism of unsteady force generation similar to those of other insect wings in a horizontal stroke plane, but the detailed effect of the wing kinematics on the force control is different due to the asymmetric use of the angle of attack during the up- and downstrokes. For example, high α md and low α mu produces larger vertical force with less aerodynamic power, and low α md and high α mu is recommended for horizontal force (thrust) production. The pitching rotation also affects the aerodynamics of a flapping wing, but its dynamic rotational effect is much weaker than the effect from the kinematic change in the angle of attack caused by the pitching rotation. Thus, the influences of the duration and timing of pitching rotation for the present inclined flapping wing are found to be very different from those for a horizontal flapping wing. That is, for the inclined flapping motion, the advanced and delayed rotations produce smaller vertical forces than the symmetric one and the effect of pitching duration is very small. On the other hand, for a specific range of pitching rotation timing, delayed rotation requires less aerodynamic power than the symmetric rotation. As for the horizontal force, delayed rotation with low α md and high α mu is recommended for long-duration flight owing to its high efficiency, and advanced rotation should be employed for hovering flight for nearly zero horizontal force. The present

  2. Kinematic control of aerodynamic forces on an inclined flapping wing with asymmetric strokes.

    Science.gov (United States)

    Park, Hyungmin; Choi, Haecheon

    2012-03-01

    In the present study, we conduct an experiment using a one-paired dynamically scaled model of an insect wing, to investigate how asymmetric strokes with different wing kinematic parameters are used to control the aerodynamics of a dragonfly-like inclined flapping wing in still fluid. The kinematic parameters considered are the angles of attack during the mid-downstroke (α(md)) and mid-upstroke (α(mu)), and the duration (Δτ) and time of initiation (τ(p)) of the pitching rotation. The present dragonfly-like inclined flapping wing has the aerodynamic mechanism of unsteady force generation similar to those of other insect wings in a horizontal stroke plane, but the detailed effect of the wing kinematics on the force control is different due to the asymmetric use of the angle of attack during the up- and downstrokes. For example, high α(md) and low α(mu) produces larger vertical force with less aerodynamic power, and low α(md) and high α(mu) is recommended for horizontal force (thrust) production. The pitching rotation also affects the aerodynamics of a flapping wing, but its dynamic rotational effect is much weaker than the effect from the kinematic change in the angle of attack caused by the pitching rotation. Thus, the influences of the duration and timing of pitching rotation for the present inclined flapping wing are found to be very different from those for a horizontal flapping wing. That is, for the inclined flapping motion, the advanced and delayed rotations produce smaller vertical forces than the symmetric one and the effect of pitching duration is very small. On the other hand, for a specific range of pitching rotation timing, delayed rotation requires less aerodynamic power than the symmetric rotation. As for the horizontal force, delayed rotation with low α(md) and high α(mu) is recommended for long-duration flight owing to its high efficiency, and advanced rotation should be employed for hovering flight for nearly zero horizontal force. The

  3. Stability of satellite planes in M31 II: effects of the dark subhalo population

    Science.gov (United States)

    Fernando, Nuwanthika; Arias, Veronica; Lewis, Geraint F.; Ibata, Rodrigo A.; Power, Chris

    2018-01-01

    The planar arrangement of nearly half the satellite galaxies of M31 has been a source of mystery and speculation since it was discovered. With a growing number of other host galaxies showing these satellite galaxy planes, their stability and longevity have become central to the debate on whether the presence of satellite planes are a natural consequence of prevailing cosmological models, or represent a challenge. Given the dependence of their stability on host halo shape, we look into how a galaxy plane's dark matter environment influences its longevity. An increased number of dark matter subhaloes results in increased interactions that hasten the deterioration of an already-formed plane of satellite galaxies in spherical dark haloes. The role of total dark matter mass fraction held in subhaloes in dispersing a plane of galaxies presents non-trivial effects on plane longevity as well. But any misalignment of plane inclines to major axes of flattened dark matter haloes lead to their lifetimes being reduced to ≤3 Gyr. Distributing ≥40 per cent of total dark mass in subhaloes in the overall dark matter distribution results in a plane of satellite galaxies which is prone to change through the 5-Gyr integration time period.

  4. Dense, layered, inclined flows of spheres

    Science.gov (United States)

    Jenkins, James T.; Larcher, Michele

    2017-12-01

    We consider dense, inclined flows of spheres in which the particles translate in layers, whose existence may be promoted by the presence of a rigid base and/or sidewalls. We imagine that in such flows a sphere of a layer is forced up the back of a sphere of the layer below, lifting a column of spheres above it, and then falls down the front of the lower sphere, until it bumps against the preceding sphere of the lower layer. We calculate the forces and rate of momentum transfer associated with this process of rub, lift, fall, and bump and determine a relation between the ratio of shear stress to normal stress and the rate of strain that may be integrated to obtain the velocity profile. The fall of a sphere and that of the column above it results in a linear increase in the magnitude of the velocity fluctuations with distance from the base of the flow. We compare the predictions of the model with measured profiles of velocity and granular temperature in several different dense, inclined flows.

  5. Strength Calculation of Inclined Sections of Reinforced Concrete Elements under Transverse Bending

    Science.gov (United States)

    Filatov, V. B.

    2017-11-01

    The authors propose a design model to determine the strength of inclined sections of bent reinforced concrete elements without shear reinforcement for the action of transverse force taking into account the aggregate interlock forces in the inclined crack. The calculated dependences to find out the components of forces acting in an inclined section are presented. The calculated dependences are obtained from the consideration of equilibrium conditions of the block over the inclined crack. A comparative analysis of the experimental values of the failure loads of the inclined section and the theoretical values obtained for the proposed dependencies and normative calculation methods is performed. It is shown that the proposed design model makes it possible to take into account the effect the longitudinal reinforcement percentage has on the inclined section strength, the element cross section height without the introduction of empirical coefficients which contributes to an increase in the structural safety of design solutions including the safety of high-strength concrete elements.

  6. Laser-Guided Autonomous Landing of a Quadrotor UAV on an Inclined Surface

    Science.gov (United States)

    Dougherty, John A.

    This thesis presents measurement, estimation, and control schemes to aid a quadrotor unmanned aerial vehicle (UAV) in landing on a flat, inclined surface without prior knowledge of the surface's inclination. The system uses a single CMOS camera and several inexpensive laser modules for onboard sensing to measure the distance to and orientation of a landing surface. A nonlinear least squares estimation scheme yields the altitude of the quadrotor and the normal vector defining the ground plane. This information is used to design a hybrid landing trajectory composed of a position tracking phase and an attitude tracking phase. A geometric nonlinear control system is used during each phase and ensures that the quadrotor's attitude is aligned to the inclination of the ground surface at touchdown. A quadrotor is developed from the ground up to test the in-flight measurement process and to execute landing trajectories on an inclined surface. Experimental results demonstrate the quadrotor's ability to accurately estimate altitude and ground plane orientation during flight, and numerical simulations of landing trajectories for various surface inclinations are validated by experimental results up to a maximum inclination of thirty degrees.

  7. Effects of hip joint transverse plane range of motion with a modeled effusion and capsular tear: A cadaveric study.

    Science.gov (United States)

    Hebert, Casey; Smyth, Mark P; Woodard, Erik; Bills, Collin C; Mihalko, Marc J; Mihalko, William M

    2017-02-01

    Multiple factors contribute to range of motion of the hip joint in the transverse plane: bony anatomy, hip capsule, corresponding ligaments, articular labrum, ligamentum teres, and negative intra-articular pressure. We hypothesized that violation of the negative pressure of the hip and simulation of an effusion would increase range of motion in the transverse plane in a cadaver model. Ten hip specimens were obtained and dissected with the femur and iliac wing mounted in a custom joint-testing rig in neutral position. Specimens were tested at 0 and at 90° of flexion with 1.5Nm internal and external rotational torque. Three conditions were assessed: (1) intact specimen, (2) an effusion modeled by a 10ml saline infusion, and (3) a capsular tear. The modeled effusion decreased rotational range of motion limits in both 0 and 90° of flexion, with a greater effect on the specimens at 0° flexion in external rotation with 4.1° less external rotation (p=0.009). A modeled capsular tear increased rotational motion limits in 0° of flexion in both internal and external rotation and in 90° flexion in internal rotation only (phip, and a capsular tear may increase its rotation. This should be considered in hips with traumatic capsular tears or arthroscopic portals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Quasi-Rayleigh waves in transversely isotropic half-space with inclined axis of symmetry

    International Nuclear Information System (INIS)

    Yanovskaya, T.B.; Savina, L.S.

    2003-09-01

    A method for determination of characteristics of quasi-Rayleigh (qR) wave in a transversely isotropic homogeneous half-space with inclined axis of symmetry is outlined. The solution is obtained as a superposition of qP, qSV and qSH waves, and surface wave velocity is determined from the boundary conditions at the free surface and at infinity, as in the case of Rayleigh wave in isotropic half-space. Though the theory is simple enough, a numerical procedure for the calculation of surface wave velocity presents some difficulties. The difficulty is conditioned by necessity to calculate complex roots of a non-linear equation, which in turn contains functions determined as roots of nonlinear equations with complex coefficients. Numerical analysis shows that roots of the equation corresponding to the boundary conditions do not exist in the whole domain of azimuths and inclinations of the symmetry axis. The domain of existence of qR wave depends on the ratio of the elastic parameters: for some strongly anisotropic models the wave cannot exist at all. For some angles of inclination qR wave velocities deviate from those calculated on the basis of the perturbation method valid for weak anisotropy, though they have the same tendency of variation with azimuth. The phase of qR wave varies with depth unlike Rayleigh wave in isotropic half-space. Unlike Rayleigh wave in isotropic half-space, qR wave has three components - vertical, radial and transverse. Particle motion in horizontal plane is elliptic. Direction of the major axis of the ellipsis coincide with the direction of propagation only in azimuths 0 deg. (180 deg.) and 90 deg. (270 deg.). (author)

  9. A theoretical model of rain–wind–induced in-plane galloping on overhead transmission tower-lines system

    Directory of Open Access Journals (Sweden)

    Chao Zhou

    2015-09-01

    Full Text Available Rain–wind–induced galloping phenomenon often occurs on overhead transmission tower-lines system, just as icing galloping and vortex-excited vibration; this kind of instability oscillation can cause power-line breakage or tower failure. However, the existing theoretical models of rain–wind–induced galloping are mainly based on the hypothesis of the overhead power-lines with fixed ends, which is inconsistent with the actual operation situation. Therefore, this article thus presents a preliminary theoretical study and proposes a new theoretical model taking into account the effect of tower excitations on the in-plane galloping of the overhead power-line and on the motion of the upper rain-line. The theoretical model is solved by Galerkin method and verified by the comparison with the test data obtained in the available literature involved with the overhead power-lines with fixed towers or moving towers. It turns out that the tower excitations may intensify the in-plane galloping amplitude of the overhead power-line within a certain range of frequency ratio and enable better comprehension of rain–wind–induced galloping mechanism.

  10. A model for the chain-to-plane charge transfer in YBa2Cu3O6+x

    International Nuclear Information System (INIS)

    Matic, V. M.; Lazarov, N. Dj.; Milic, M.

    2012-01-01

    A model for the chain-to-plane charge transfer is proposed to account for the two plateaus, at 60 K and at 90 K, of the T c (x) characteristics of the YBa 2 Cu 3 O 6+x high-T c superconductor. It is assumed that the number of holes transferred from a CuO chain of length l to two nearby CuO 2 sheets is proportional to l (that is, to the number of oxygen atoms in the chain), if the chain length is greater than, or equal to, a certain critical chain length, l cr , that is required to trigger the charge transfer process. No holes are assumed to have been transferred from chains of length l cr . The calculated T c (x) dependence is found to be in excellent agreement with the experimentally reported T c (x). The critical chain length parameter is estimated to be equal to l cr = 11 (eleven oxygen atoms in a chain), which is a greater value than that obtained in the previously proposed model for the chain-to-plane charge transfer (l cr = 4). The results obtained out of the proposed model are briefly discussed

  11. Generation of inclined protoplanetary discs and misaligned planets through mass accretion - I. Coplanar secondary discs

    Science.gov (United States)

    Xiang-Gruess, M.; Kroupa, P.

    2017-10-01

    We study the three-dimensional (3D) evolution of a viscous protoplanetary disc that accretes gas material from a second protoplanetary disc during a close encounter in an embedded star cluster. The aim is to investigate the capability of the mass accretion scenario to generate strongly inclined gaseous discs that could later form misaligned planets. We use smoothed particle hydrodynamics to study mass transfer and disc inclination for passing stars and circumstellar discs with different masses. We explore different orbital configurations to find the parameter space that allows significant disc inclination generation. Thies et al. suggested that significant disc inclination and disc or planetary system shrinkage can generally be produced by the accretion of external gas material with a different angular momentum. We found that this condition can be fulfilled for a large range of gas mass and angular momentum. For all encounters, mass accretion from the secondary disc increases with decreasing mass of the secondary proto-star. Thus, higher disc inclinations can be attained for lower secondary stellar masses. Variations of the secondary disc's orientation relative to the orbital plane can alter the disc evolution significantly. The results taken together show that mass accretion can change the 3D disc orientation significantly resulting in strongly inclined discs. In combination with the gravitational interaction between the two star-disc systems, this scenario is relevant for explaining the formation of highly inclined discs that could later form misaligned planets.

  12. Droplet Depinning on Inclined Surfaces at High Reynolds Numbers

    Science.gov (United States)

    White, Edward; Singh, Natasha; Lee, Sungyon

    2017-11-01

    Contact angle hysteresis enables a sessile liquid drop to adhere to a solid surface when the surface is inclined, the drop is exposed to gas-phase flow, or the drop is exposed to both forcing modalities. Previous work by Schmucker and White (2012.DFD.M4.6) identified critical depinning Weber numbers for water drops subject to gravity- and wind-dominated forcing. This work extends the Schmucker and White data and finds the critical depinning Weber number obeys a two-slope linear model. Under pure wind forcing at Reynolds numbers above 1500 and with zero surface inclination, Wecrit = 8.0 . For non-zero inclinations, α, Wecrit decreases proportionally to A Bo sinα where A is the drop aspect ratio and Bo is its Bond number. The same relationship holds for α behavior. Supported by the National Science Foundation through Grant CBET-1605947.

  13. Finite element modelling of plastic collapse of metallic single mitred pipe bends subject to in-plane bending moments

    International Nuclear Information System (INIS)

    Kochekseraii, Sadegh Babaii

    2004-01-01

    Theoretical analysis based on the finite element (FE) method for plastic collapse of metallic single mitred pipe bends of various geometries, subject to in-plane bending moment, were carried out using both ABAQUS and ANSYS structural FE programs covering both linear small displacement and non-linear large displacement analysis. Parametric surveys presented interesting features including an increase in plastic collapse in-plane bending moments after mitre angles of around 40 deg. . Results obtained using either ANSYS or ABAQUS could not be compared against any available experimental data as they differ significantly in areas like strain hardening and other features of a real material that did not exist in the FE modelling. However, single case comparison with the only reported experimental work, known to the author, showed that large displacement FE analysis led to more realistic predictions. It is, therefore, concluded that despite complex behaviour of a real material as compared to material models available in FE analysis, effective plastic collapse moments can be predicted using the small displacement FE analysis

  14. Impinging Water Droplets on Inclined Glass Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Armijo, Kenneth Miguel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lance, Blake [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ho, Clifford K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    Multiphase computational models and tests of falling water droplets on inclined glass surfaces were developed to investigate the physics of impingement and potential of these droplets to self-clean glass surfaces for photovoltaic modules and heliostats. A multiphase volume-of-fluid model was developed in ANSYS Fluent to simulate the impinging droplets. The simulations considered different droplet sizes (1 mm and 3 mm), tilt angles (0°, 10°, and 45°), droplet velocities (1 m/s and 3 m/s), and wetting characteristics (wetting=47° contact angle and non-wetting = 93° contact angle). Results showed that the spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) decreased with increasing inclination angle due to the reduced normal force on the surface. The hydrophilic surface yielded greater spread factors than the hydrophobic surface in all cases. With regard to impact forces, the greater surface tilt angles yielded lower normal forces, but higher shear forces. Experiments showed that the experimentally observed spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) was significantly larger than the simulated spread factor. Observed spread factors were on the order of 5 - 6 for droplet velocities of ~3 m/s, whereas the simulated spread factors were on the order of 2. Droplets were observed to be mobile following impact only for the cases with 45° tilt angle, which matched the simulations. An interesting phenomenon that was observed was that shortly after being released from the nozzle, the water droplet oscillated (like a trampoline) due to the "snapback" caused by the surface tension of the water droplet being released from the nozzle. This oscillation impacted the velocity immediately after the release. Future work should evaluate the impact of parameters such as tilt angle and surface wettability on the impact of particle/soiling uptake and removal to investigate ways that

  15. [Occlusal plane control in hyperdivergents: regarding one case].

    Science.gov (United States)

    Rerhrhaye, Wiam; Zaoui, Fatima; Aalloula, El Housseine

    2009-06-01

    Management of occlusal plane inclination in the sagittal dimension is one of the main concerns of practitioners. Inclination maintenance or correction can condition the success and stability of treatment. By means of a clinical case, we will attempt to discuss the different aspects of management from diagnosis to treatment, bearing in mind the local and regional context. The adopted treatment plan takes into consideration the functional and esthetic issues specific to Moroccan patients without neglecting soft tissue harmony.

  16. Optimization of PV array inclination in India using ANN estimator ...

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana; Volume 40; Issue 5. Optimization of PV array inclination in India using ANN estimator: Method comparison study ... Although different non-linear, empirical models have been proposed by different researchers in India, they have too many constraints and needs complex and rigorous computational ...

  17. [Further study of the model of a human skull as a cupola with a plane base].

    Science.gov (United States)

    Cherneĭkin, V A; Sholpo, L N

    1976-01-01

    An experimental study of the base deformation of isolated human scull under conditions of scull collision with an obstacle has been carried out. The findings are compared with human cerebrospinal traums phenomena. An earlier suggested continuous scull model is modified on the basis of the data obtained. It is shown that the modified model (a part of spherical shell with the flat base) resembles scull behaviour in statics and dynamics better than the scull model in the form of spherical shell.

  18. On the Numerical Modeling of Confined Masonry Structures for In-plane Earthquake Loads

    Directory of Open Access Journals (Sweden)

    Mircea Barnaure

    2015-07-01

    Full Text Available The seismic design of confined masonry structures involves the use of numerical models. As there are many parameters that influence the structural behavior, these models can be very complex and unsuitable for the current design purposes of practicing engineers. Simplified models could lead to reasonably accurate results, but caution should be given to the simplification assumptions. An analysis of various parameters considered in the numerical modeling of confined masonry structural walls is made. Conclusions regarding the influence of simplified procedures on the results are drawn.

  19. Stochastic Response of an Inclined Shallow Cable with Linear Viscous Dampers under Stochastic Excitation

    DEFF Research Database (Denmark)

    Zhou, Qiang; Nielsen, Søren R.K.; Qu, Weilian

    2010-01-01

    of several factors, which include excitation level and direction as well as damper size, on the dynamic response of the cable is extensively investigated. It is found that the sum of mean square in-plane and out-of-plane displacement is primarily independent of the load direction when the excitation level...... and viscous coefficient of the damper are fixed. Moreover, the peak frequency and half-band width of the spectra of both the in-plane and the out-of-plane displacements are increasing with excitation level when the damper size is constant. It is also observed that, even though the actual optimal damper size......Considering the coupling between the in-plane and out-of-plane vibration, the stochastic response of an inclined shallow cable with linear viscous dampers subjected to Gaussian white noise excitation is investigated in this paper. Selecting the static deflection shape due to a concentrated force...

  20. Infants and young children modeling method for numerical dosimetry studies: application to plane wave exposure

    Science.gov (United States)

    Dahdouh, S.; Varsier, N.; Nunez Ochoa, M. A.; Wiart, J.; Peyman, A.; Bloch, I.

    2016-02-01

    Numerical dosimetry studies require the development of accurate numerical 3D models of the human body. This paper proposes a novel method for building 3D heterogeneous young children models combining results obtained from a semi-automatic multi-organ segmentation algorithm and an anatomy deformation method. The data consist of 3D magnetic resonance images, which are first segmented to obtain a set of initial tissues. A deformation procedure guided by the segmentation results is then developed in order to obtain five young children models ranging from the age of 5 to 37 months. By constraining the deformation of an older child model toward a younger one using segmentation results, we assure the anatomical realism of the models. Using the proposed framework, five models, containing thirteen tissues, are built. Three of these models are used in a prospective dosimetry study to analyze young child exposure to radiofrequency electromagnetic fields. The results lean to show the existence of a relationship between age and whole body exposure. The results also highlight the necessity to specifically study and develop measurements of child tissues dielectric properties.

  1. Infants and young children modeling method for numerical dosimetry studies: application to plane wave exposure

    International Nuclear Information System (INIS)

    Dahdouh, S; Wiart, J; Bloch, I; Varsier, N; Nunez Ochoa, M A; Peyman, A

    2016-01-01

    Numerical dosimetry studies require the development of accurate numerical 3D models of the human body. This paper proposes a novel method for building 3D heterogeneous young children models combining results obtained from a semi-automatic multi-organ segmentation algorithm and an anatomy deformation method. The data consist of 3D magnetic resonance images, which are first segmented to obtain a set of initial tissues. A deformation procedure guided by the segmentation results is then developed in order to obtain five young children models ranging from the age of 5 to 37 months. By constraining the deformation of an older child model toward a younger one using segmentation results, we assure the anatomical realism of the models. Using the proposed framework, five models, containing thirteen tissues, are built. Three of these models are used in a prospective dosimetry study to analyze young child exposure to radiofrequency electromagnetic fields. The results lean to show the existence of a relationship between age and whole body exposure. The results also highlight the necessity to specifically study and develop measurements of child tissues dielectric properties. (paper)

  2. VBMP Digital Terrain Models - 2006/2007 (VA State Plane South)

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — These files contain Digital Elevation Model (DTM) file data for the Commonwealth of Virginia developed from imagery acquired in spring 2006 and 2007. In the spring...

  3. Towards a data processing plane: An automata-based distributed dynamic data processing model

    NARCIS (Netherlands)

    Cushing, R.; Belloum, A.; Bubak, M.; de Laat, C.

    Data processing complexity, partitionability, locality and provenance play a crucial role in the effectiveness of distributed data processing. Dynamics in data processing necessitates effective modeling which allows the understanding and reasoning of the fluidity of data processing. Through

  4. An experimental investigation of stratified two-phase pipe flow at small inclinations

    Energy Technology Data Exchange (ETDEWEB)

    Espedal, Mikal

    1998-12-31

    The prediction of stratified flow is important for several industrial applications. Stratified flow experiments were carefully performed in order to investigate the performance of a typical model which uses wall friction factors based on single phase pipe flow as described above. The test facility has a 18.5 m long and 60 mm i.d. (L/D=300) acrylic test section which can be inclined between -10 {sup o} and +10 {sup o}. The liquid holdup was measured by using fast closing valves and the pressure gradients by using three differential pressure transducers. Interfacial waves were measured by thin wire conductance probes mounted in a plane perpendicular to the main flow. The experiments were performed using water and air at atmospheric pressure. The selected test section inclinations were between -3 {sup o} and +0.5 {sup o} to the horizontal plane. A large number of experiments were performed for different combinations of air and water flow rates and the rates were limited to avoid slug flow and stratified flow with liquid droplets. The pressure gradient and the liquid holdup were measured. In addition the wave probes were used to find the wave heights and the wave power spectra. The results show that the predicted pressure gradient using the standard models is approximately 30% lower than the measured value when large amplitude waves are present. When the flow is driven by the interfacial force the test section inclination has minor influence on the deviation between predicted and measured pressure gradients. Similar trends are apparent in data from the literature, although they seem to have gone unnoticed. For several data sets large spread in the predictions are observed when the model described above was used. Gas wall shear stress experiments indicate that the main cause of the deviation between measured and predicted pressure gradient and holdup resides in the modelling of the liquid wall friction term. Measurements of the liquid wall shear stress distribution

  5. Experimental Evaluation of Balance Prediction Models for Sit-to-Stand Movement in the Sagittal Plane

    Directory of Open Access Journals (Sweden)

    Oscar David Pena Cabra

    2013-01-01

    Full Text Available Evaluation of balance control ability would become important in the rehabilitation training. In this paper, in order to make clear usefulness and limitation of a traditional simple inverted pendulum model in balance prediction in sit-to-stand movements, the traditional simple model was compared to an inertia (rotational radius variable inverted pendulum model including multiple-joint influence in the balance predictions. The predictions were tested upon experimentation with six healthy subjects. The evaluation showed that the multiple-joint influence model is more accurate in predicting balance under demanding sit-to-stand conditions. On the other hand, the evaluation also showed that the traditionally used simple inverted pendulum model is still reliable in predicting balance during sit-to-stand movement under non-demanding (normal condition. Especially, the simple model was shown to be effective for sit-to-stand movements with low center of mass velocity at the seat-off. Moreover, almost all trajectories under the normal condition seemed to follow the same control strategy, in which the subjects used extra energy than the minimum one necessary for standing up. This suggests that the safety considerations come first than the energy efficiency considerations during a sit to stand, since the most energy efficient trajectory is close to the backward fall boundary.

  6. Experimental Evaluation of Balance Prediction Models for Sit-to-Stand Movement in the Sagittal Plane

    Science.gov (United States)

    Pena Cabra, Oscar David; Watanabe, Takashi

    2013-01-01

    Evaluation of balance control ability would become important in the rehabilitation training. In this paper, in order to make clear usefulness and limitation of a traditional simple inverted pendulum model in balance prediction in sit-to-stand movements, the traditional simple model was compared to an inertia (rotational radius) variable inverted pendulum model including multiple-joint influence in the balance predictions. The predictions were tested upon experimentation with six healthy subjects. The evaluation showed that the multiple-joint influence model is more accurate in predicting balance under demanding sit-to-stand conditions. On the other hand, the evaluation also showed that the traditionally used simple inverted pendulum model is still reliable in predicting balance during sit-to-stand movement under non-demanding (normal) condition. Especially, the simple model was shown to be effective for sit-to-stand movements with low center of mass velocity at the seat-off. Moreover, almost all trajectories under the normal condition seemed to follow the same control strategy, in which the subjects used extra energy than the minimum one necessary for standing up. This suggests that the safety considerations come first than the energy efficiency considerations during a sit to stand, since the most energy efficient trajectory is close to the backward fall boundary. PMID:24187580

  7. Extension of the engineering treatment model (ETM) to bending configurations under plane stress

    International Nuclear Information System (INIS)

    Schwalbe, K.H.

    1987-01-01

    The application of the previously introduced Engineering Treatment Model to bending configurations involves the prediction of the crack tip opening displacement, the load line displacement, and the J-integral. Using these, failure situations can be predicted. All predictions except one are in good agreement with experimental results (Al2024-FC, Al2024-T351, steel 35Ni(rMo16, pressure vessel steel 20MnMoNi55) or finite element calculations. The reason for the exception is clear and will be utilised for an improvement of the model. With 26 figs., 2 tabs [de

  8. [Relationship between occlusal plane and masticatory path in youth with individual normal occlusion].

    Science.gov (United States)

    Lin, Xue-feng; Li, Shao-hua; Huang, Zhuo-shan; Wu, Xia-yi

    2010-06-01

    To investigate the characteristics of and relationship between occlusal plane and masticatory path in young adults with individual normal occlusion, and to provide clinical implications on both morphological and functional reference of occlusal plane location. Forty-three young adults with individual normal occlusion were included. Lateral projections of cephalometric radiographs were taken. The parameters of anatomical landmarks were analyzed. The BioEGN mandibular kinesiography analyzer was used to record the path of incisal edge of mandibular central incisor movement during mastication. The Pearson's linear correlation analysis was performed to analyze the relationship of inclination of occlusal plane and data mentioned above with SPSS13.0 software. The inclination of occlusal plane (the angle between occlusal plane and Camper's line OP-CP) was (2.1 ± 3.8)° in youth with normal occlusion. Means of maximal distances of 3-dimensional masticatory mandibular movement paths were as follow: the vertical length was (20.22 ± 4.28) mm, the anterior-posterior width was (11.42 ± 2.45) mm, and the lateral width was (8.62 ± 1.52) mm. The inclination of occlusal plane was negatively correlated to the lateral width of masticatory path in frontal plane (r = -0.39, P Occlusal plane was approximately vertical to the opening and closing path in the vicinity of intercuspal position during mastication. The inclination of occlusal plane was positively related to occlusal plane-closing angles in the upper segments of closing path during mastication (P occlusal plane (P > 0.05). These results suggest that the sagittal inclination of occlusal plane can influence 3-dimensional morphology of masticatory path.The inclination of occlusal plane has a guiding effect on masticatory movement in the upper segments of closing path.

  9. Complex-plane strategy for computing rotating polytropic models - efficiency and accuracy of the complex first-order perturbation theory

    International Nuclear Information System (INIS)

    Geroyannis, V.S.

    1988-01-01

    In this paper, a numerical method is developed for determining the structure distortion of a polytropic star which rotates either uniformly or differentially. This method carries out the required numerical integrations in the complex plane. The method is implemented to compute indicative quantities, such as the critical perturbation parameter which represents an upper limit in the rotational behavior of the star. From such indicative results, it is inferred that this method achieves impressive improvement against other relevant methods; most important, it is comparable to some of the most elaborate and accurate techniques on the subject. It is also shown that the use of this method with Chandrasekhar's first-order perturbation theory yields an immediate drastic improvement of the results. Thus, there is no neeed - for most applications concerning rotating polytropic models - to proceed to the further use of the method with higher order techniques, unless the maximum accuracy of the method is required. 31 references

  10. Mechanics-Based Model for Predicting In-Plane Needle Deflection with Multiple Bends

    NARCIS (Netherlands)

    Roesthuis, Roy; Abayazid, Momen; Misra, Sarthak

    2012-01-01

    Bevel-tipped flexible needles naturally bend when inserted into soft tissue. Steering such needles along curved paths allows one to avoid anatomical obstacles and reach locations inside the human body which are unreachable with rigid needles. In this study, a mechanics-based model is presented which

  11. Dugdale-type model for a mixed-mode crack: plane stress state

    Science.gov (United States)

    Galatenko, G. V.

    2011-06-01

    Amixed-mode (I + II) crack model with a plastic strip on its continuation is proposed. The three unknown stress components within the strip are determined from the yield conditions, stress limitation, and relationship between the normal stress components defined via the principal stress state. The crack parameters are analyzed for the Mises yield condition

  12. Numerical modelling of micro-plasto-hydrodynamic lubrication in plane strip drawing

    DEFF Research Database (Denmark)

    Carretta, Y.; Bech, Jakob Ilsted; Legrand, N.

    2017-01-01

    This paper presents a new finite element model capable of predicting the onset of micro-plasto-hydrodynamic (MPH) lubrication and the amount of lubricant escaping from surface pockets in metal forming.The present approach is divided in two steps. First, a simulation at the macroscopic level is co...

  13. Fault-plane Solutions Determined by Waveform Modeling Confirm Tectonic Collision in the Eastern Adriatic

    Science.gov (United States)

    Louvari, E.; Kiratzi, A.; Papazachos, B.; Hatzidimitriou, P.

    - Source parameters for thirteen earthquakes in the SE Adriatic region have been determined using P and SH body-waveform inversion. The results of this modeling are combined with eleven other earthquakes with M>=5 whose focal mechanisms have been determined mainly by waveform modeling. The results confirm that movement on mainly low-angle reverse faults causes the deformation in coastal southern Yugoslavia through Albania up to the Lefkada Island in NW Greece. This zone of thrusting has a NW-SE trend (N34°W), follows the coastline, and dips towards the continent. The slip vectors of these events trend at N229° along the Dalmatian coasts, to N247° along Albania and NW Greece. The deformation is attributed to the continental collision between the Adriatic block to the west and Eurasia to the east. Along the mountain line in eastern Albania (Albanides Mts.) and in NW Greece (Hellenides Mts.), E-W extension is occurring. The E-W extension associated with the orogenic belt could be attributed to a variety of models such as: gravity, internal deformation of the thrust wedge, a probable down bulge of the dense lithosphere of the Adriatic block beneath the Eurasian lithospheric plate in combination with the compressional stresses applied along the collision belt.

  14. Tsunami hazard preventing based land use planing model using GIS technique in Muang Krabi, Thailand

    International Nuclear Information System (INIS)

    Soormo, A.S.

    2012-01-01

    The terrible tsunami disaster, on 26 December 2004 hit Krabi, one of the ecotourist and very fascinating provinces of southern Thailand including its various regions e.g. Phangna and Phuket by devastating the human lives, coastal communications and the financially viable activities. This research study has been aimed to generate the tsunami hazard preventing based lands use planning model using GIS (Geographical Information Systems) based on the hazard suitability analysis approach. The different triggering factors e.g. elevation, proximity to shore line, population density, mangrove, forest, stream and road have been used based on the land use zoning criteria. Those criteria have been used by using Saaty scale of importance one, of the mathematical techniques. This model has been classified according to the land suitability classification. The various techniques of GIS, namely subsetting, spatial analysis, map difference and data conversion have been used. The model has been generated with five categories such as high, moderate, low, very low and not suitable regions illustrating with their appropriate definition for the decision makers to redevelop the region. (author)

  15. Effects of occlusal inclination and loading on mandibular bone remodeling: a finite element study.

    Science.gov (United States)

    Rungsiyakull, Chaiy; Rungsiyakull, Pimdeun; Li, Qing; Li, Wei; Swain, Michael

    2011-01-01

    To provide a preliminary understanding of the biomechanics with respect to the effect of cusp inclination and occlusal loading on the mandibular bone remodeling. Three different cusp inclinations (0, 10, and 30 degrees) of a ceramic crown and different occlusal loading locations (central fossa and 1- and 2-mm offsets horizontally) were taken into account to explore the stresses and strains transferred from the crown to the surrounding dental bone through the implant. A strain energy density obtained from two-dimensional plane-strain finite element analysis was used as the mechanical stimulus to drive cancellous and cortical bone remodeling in a buccolingual mandibular section. Different ceramic cusp inclinations had a significant effect on bone remodeling responses in terms of the change in the average peri-implant bone density and overall stability. The remodeling rate was relatively high in the first few months of loading and gradually decreased until reaching its equilibrium. A larger cusp inclination and horizontal offset (eg, 30 degrees and 2-mm offset) led to a higher bone remodeling rate and greater interfacial stress. The dental implant superstructure design (in terms of cusp inclination and loading location) determines the load transmission pattern and thus largely affects bone remodeling activities. Although the design with a lower cusp inclination recommended in previous studies may reduce damage and fracture failure, it could, to a certain extent, compromise bone engagement and long-term stability.

  16. Numerical Analysis of Aerodynamic Characteristics of the Finned Surfaces with Cross-inclined Fins

    Directory of Open Access Journals (Sweden)

    Lagutin A. E.

    2016-12-01

    Full Text Available This paper presents results of numerical research and analyses air-side hydraulic performance of tube bundles with cross inclined fins. The numerical simulation of the fin-tube heat exchanger was performed using the Comsol Femlab software. The results of modeling show the influence of fin inclination angle and tube pitch on hydraulic characteristics of finned surfaces. A series of numerical tests were carried out for tube bundles with different inclination angles (γ =900, 850, 650, 60, the fin pitch u=4 mm. The results indicate that tube bundles with cross inclined fins can significantly enhance the average integral value of the air flow rate in channel between fins in comparison with conventional straight fins. Aerodynamic processes on both sides of modificated channel between inclined fins were analyzed. The verification procedures for received results of numerical modeling with experimental data were performed.

  17. Modelling Plane Geometry: the connection between Geometrical Visualization and Algebraic Demonstration

    Science.gov (United States)

    Pereira, L. R.; Jardim, D. F.; da Silva, J. M.

    2017-12-01

    The teaching and learning of Mathematics contents have been challenging along the history of the education, both for the teacher, in his dedicated task of teaching, as for the student, in his arduous and constant task of learning. One of the topics that are most discussed in these contents is the difference between the concepts of proof and demonstration. This work presents an interesting discussion about such concepts considering the use of the mathematical modeling approach for teaching, applied to some examples developed in the classroom with a group of students enrolled in the discipline of Geometry of the Mathematics curse of UFVJM.

  18. Modeling the process of interaction of 10 keV electrons with a plane dielectric surface

    Science.gov (United States)

    Vokhmyanina, Kristina; Sotnikova, Valentina; Sotnikov, Alexey; Kaplii, Anna; Nikulicheva, Tatyana; Kubankin, Alexandr; Kishin, Ivan

    2018-05-01

    The effect of guiding of charged particles by dielectric channels is of noticeable interest at the present time. The phenomenon is widely studied experimentally and theoretically but some points still need to be clarified. A previously developed model of interaction of fast electrons with dielectric surface at grazing incidence is used to study the independence of electron deflection on the value of electron beam current. The calculations were performed assuming a smooth dependence of the surface conductivity on the beam current in the 40-3000 nA range.

  19. Flying personal planes: modeling the airport choices of general aviation pilots using stated preference methodology.

    Science.gov (United States)

    Camasso, M J; Jagannathan, R

    2001-01-01

    This study employed stated preference (SP) models to determine why general aviation pilots choose to base and operate their aircraft at some airports and not others. Thirteen decision variables identified in pilot focus groups and in the general aviation literature were incorporated into a series of hypothetical choice tasks or scenarios. The scenarios were offered within a fractional factorial design to establish orthogonality and to preclude dominance in any combination of variables. Data from 113 pilots were analyzed for individual differences across pilots using conditional logit regression with and without controls. The results demonstrate that some airport attributes (e.g., full-range hospitality services, paved parallel taxiway, and specific types of runway lighting and landing aids) increase pilot utility. Heavy airport congestion and airport landing fees, on the other hand, decrease pilot utility. The importance of SP methodology as a vehicle for modeling choice behavior and as an input into the planning and prioritization process is discussed. Actual or potential applications include the development of structured decision-making instruments in the behavioral sciences and in human service programs.

  20. Spatio-temporal Rich Model Based Video Steganalysis on Cross Sections of Motion Vector Planes.

    Science.gov (United States)

    Tasdemir, Kasim; Kurugollu, Fatih; Sezer, Sakir

    2016-05-11

    A rich model based motion vector steganalysis benefiting from both temporal and spatial correlations of motion vectors is proposed in this work. The proposed steganalysis method has a substantially superior detection accuracy than the previous methods, even the targeted ones. The improvement in detection accuracy lies in several novel approaches introduced in this work. Firstly, it is shown that there is a strong correlation, not only spatially but also temporally, among neighbouring motion vectors for longer distances. Therefore, temporal motion vector dependency along side the spatial dependency is utilized for rigorous motion vector steganalysis. Secondly, unlike the filters previously used, which were heuristically designed against a specific motion vector steganography, a diverse set of many filters which can capture aberrations introduced by various motion vector steganography methods is used. The variety and also the number of the filter kernels are substantially more than that of used in previous ones. Besides that, filters up to fifth order are employed whereas the previous methods use at most second order filters. As a result of these, the proposed system captures various decorrelations in a wide spatio-temporal range and provides a better cover model. The proposed method is tested against the most prominent motion vector steganalysis and steganography methods. To the best knowledge of the authors, the experiments section has the most comprehensive tests in motion vector steganalysis field including five stego and seven steganalysis methods. Test results show that the proposed method yields around 20% detection accuracy increase in low payloads and 5% in higher payloads.

  1. Mathematical Optimal Sequence Model Development to Process Planes and Other Interconnected Surfaces of Complex Body Parts

    Directory of Open Access Journals (Sweden)

    I. I. Kravchenko

    2016-01-01

    Full Text Available Experience in application of multi-operational machines CNC (MOM CNC shows that they are efficient only in case of significantly increasing productivity and dramatically reducing time-to-market cycle of new products. Most full technological MOM capabilities are revealed when processing the complex body parts. The more complex is a part design and the more is its number of machined surfaces, the more tools are necessary for its processing and positioning, the more is an efficiency of their application. At the same time, the case history of using these machines in industry shows that MOM CNC are, virtually, used mostly for technological processes of universal equipment, which is absolutely unacceptable. One way to improve the processing performance on MOM CNC is to reduce nonproductive machine time through reducing the mutual idle movements of the working machine. This problem is solved using dynamic programming methods, one of which is the solution of the traveling salesman problem (Bellman's method. With a known plan for treatment of all elementary surfaces of the body part, i.e. the known number of performed transitions, each transition is represented as a vertex of some graph, while technological links between the vertices are its edges. A mathematical model is developed on the Bellman principle, which is adapted to technological tasks to minimize the idle time of mutual idle movements of the working machine to perform all transitions in the optimal sequence. The initial data to fill matrix of time expenditures are time consumed by the hardware after executing the i-th transition, and necessary to complete the j-transition. The programmer fills in matrix cells according to known routing body part taking into account the time for part and table positioning, tool exchange, spindle and table approach to the working zone, and the time of table rotation, etc. The mathematical model was tested when machining the body part with 36 transitions on the

  2. Segmentation of Three Dimensional Cell Culture Models from aSingle Focal Plane

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hang; Parvin, Bahram

    2006-11-01

    Three dimensional cell culture models offer new opportunities for development of computational techniques for segmentation and localization. These assays have a unique signature of a clump of cells that correspond to a functioning colony. Often the nuclear compartment is labeled and then imaged with fluorescent microscopy to provide context for protein localization. These colonies are first delineated from background using the level set method. Within each colony, nuclear regions are then bounded by their center of mass through radial voting, and a local neighborhood for each nucleus is established through Voronoi tessellation. Finally, the level set method is applied again within each Voronoi region to delineate the nuclear compartment. The paper concludes with the application of the proposed method to a dataset of experimental data demonstrating a stable solution when iterative radial voting and level set methods are used synergistically.

  3. Modeling fracture in the context of a strain-limiting theory of elasticity: a single anti-plane shear crack

    KAUST Repository

    Rajagopal, K. R.

    2011-01-06

    This paper is the first part of an extended program to develop a theory of fracture in the context of strain-limiting theories of elasticity. This program exploits a novel approach to modeling the mechanical response of elastic, that is non-dissipative, materials through implicit constitutive relations. The particular class of models studied here can also be viewed as arising from an explicit theory in which the displacement gradient is specified to be a nonlinear function of stress. This modeling construct generalizes the classical Cauchy and Green theories of elasticity which are included as special cases. It was conjectured that special forms of these implicit theories that limit strains to physically realistic maximum levels even for arbitrarily large stresses would be ideal for modeling fracture by offering a modeling paradigm that avoids the crack-tip strain singularities characteristic of classical fracture theories. The simplest fracture setting in which to explore this conjecture is anti-plane shear. It is demonstrated herein that for a specific choice of strain-limiting elasticity theory, crack-tip strains do indeed remain bounded. Moreover, the theory predicts a bounded stress field in the neighborhood of a crack-tip and a cusp-shaped opening displacement. The results confirm the conjecture that use of a strain limiting explicit theory in which the displacement gradient is given as a function of stress for modeling the bulk constitutive behavior obviates the necessity of introducing ad hoc modeling constructs such as crack-tip cohesive or process zones in order to correct the unphysical stress and strain singularities predicted by classical linear elastic fracture mechanics. © 2011 Springer Science+Business Media B.V.

  4. Multi-modal vibration amplitudes of taut inclined cables due to direct and/or parametric excitation

    Science.gov (United States)

    Macdonald, J. H. G.

    2016-02-01

    Cables are often prone to potentially damaging large amplitude vibrations. The dynamic excitation may be from external loading or motion of the cable ends, the latter including direct excitation, normally from components of end motion transverse to the cable, and parametric excitation induced by axial components of end motion causing dynamic tension variations. Geometric nonlinearity can be important, causing stiffening behaviour and nonlinear modal coupling. Previous analyses of the vibrations, often neglecting sag, have generally dealt with direct and parametric excitation separately or have reverted to numerical solutions of the responses. Here a nonlinear cable model is adopted, applicable to taut cables such as on cable-stayed bridges, that allows for cable inclination, small sag (such that the vibration modes are similar to those of a taut string), multiple modes in both planes and end motion and/or external forcing close to any natural frequency. Based on the method of scaling and averaging it is found that, for sinusoidal inputs and positive damping, non-zero steady state responses can only occur in the modes in each plane with natural frequencies close to the excitation frequency and those with natural frequencies close to half this frequency. Analytical solutions, in the form of non-dimensional polynomial equations, are derived for the steady state vibration amplitudes in up to three modes simultaneously: the directly excited mode, the corresponding nonlinearly coupled mode in the orthogonal plane and a parametrically excited mode with half the natural frequency. The stability of the solutions is also identified. The outputs of the equations are consistent with previous results, where available. Example results from the analytical solutions are presented for a typical inclined bridge cable subject to vertical excitation of the lower end, and they are validated by numerical integration of the equations of motion and against some previous experimental

  5. Investigating the heat transfer on the top side of inclined printed circuit boards during vapour phase soldering

    International Nuclear Information System (INIS)

    Illés, Balázs; Géczy, Attila

    2016-01-01

    Highlights: • Investigating the effect of inclination on heat transfer uniformity and intensity during VPS. • Even moderate inclination has high impact on the condensate layer and on the heat transfer. • Inclination under 1° has negative effect on temperature distribution of the soldered board. • Inclination from 1° to 10° improves heat transfer uniformity of vapour phase soldering. • Inclination can help to reduce soldering failures during vapour phase soldering. - Abstract: In this paper, heat transfer and condensate layer formation was investigated by numerical simulations on the top side of inclined printed circuit boards during vapour phase soldering. The phase change on the inclined surface and the transfer mechanisms in the condensate layer were embedded in a three-dimensional model. Steady-state and saturated vapour conditions were applied as boundary conditions in order to study the pure effect of the inclination. Due to the electronic component and circuit board structures during soldering only moderate inclination angles were studied between 0° and 10°. It was found that a moderate inclination of the printed circuit board has considerable effects on the formation of condensate layer and consequently on heat transfer. Compared to the default horizontal orientation of the board, the thickness differences of the condensate layer can be decreased with an optimised inclination of the printed circuit board. This effect homogenizes heat transfer during the process, enabling improved solder joint quality, with reduced overall soldering failure count.

  6. Importance of occlusal plane reproduction on the semi-adjustable articulator in planning maxillary impactions for orthognathic surgery.

    Science.gov (United States)

    Marchiori, Erica Cristina; Garcia, Robson Rodrigues; Moreira, Roger William Fernandes

    2013-06-01

    The aim of this study was to evaluate whether a 6° counterclockwise change in occlusal plane inclination would produce significant modifications on the final result of a maxillary impaction and mandible advancement model surgery. Four groups were used in this study, with ten identical maxillary casts and one mandibular cast mounted on the same semi-adjustable articulator, with the same malocclusion. The occlusal plane of the two control and study groups had an inclination of 13° and 7°, respectively. Preoperative and postoperative measures were performed using the Erickson platform and impactions of 6 and 10 mm were tested. To control these movements during model surgery, two splints were fabricated using another two maxillary and mandibular casts mounted with occlusal plane of 13°, simulating the proposed movement. The results were compared using the t test. Only the antero-posterior movement of the upper incisor was statistically significant for both study groups (p occlusal plane transference occur, it will not be clinically significant, because differences smaller than 1 mm does not have influence on soft and hard tissue final result.

  7. Magnetic properties of 2D nano-islands II: Ising spin model with out-of-plane magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Abou Ghantous, M., E-mail: michel.aboughantous@qatar.tamu.edu [Department of Physics, Texas A and M University at Qatar, Education City, PO Box 23874, Doha (Qatar); Khater, A. [Laboratoire de Physique de L' Etat Condense, UMR 6087, Universite du Maine, 72085 Le Mans (France)

    2011-10-15

    An Ising effective field theory model is presented to calculate the magnetic properties of 2D nano-islands on a nonmagnetic substrate, subject to an externally out-of-plane applied magnetic field. The system Hamiltonian contains nearest neighbor exchange interactions, single-atom magnetic anisotropies, and the Zeeman term. The calculations yield, in particular, the single site spin correlations, the magnetizations, and the isothermal susceptibilities, for the core and periphery domains of the nano-island. The choice of a spin S=1 for the atoms of the system permits the analysis of local spin fluctuations via the single site spin correlations. We investigate in this respect the effects due to the different magnetocrystalline anisotropies and reduced dimensionalities, for the core and periphery domains, and in particular the critical influence of the applied magnetic field. Detailed theoretical results are presented for the square and hexagonal lattice symmetries, with numerical applications for the 2D monolayer Co nano-islands on a Pt substrate. It is shown that the remarkable differences between the magnetic properties of the core and periphery domains in zero field are washed out when an out-of-plane field is applied. The applied field also provokes critical discontinuities for the spin correlations and magnetization reversals, for the core and periphery domains, which are especially evident for the hexagonal lattice nano-island in the range of fields of interest. The discontinuities and magnetization reversals occur over elementary temperature widths, and shift to lower temperatures with increasing field. The field-dependant isothermal susceptibilities show new features very different from those for the susceptibilities in zero field. The present Ising model does not show any blocking temperature transition to superparamagnetism. - Highlights: > An EFT model is presented to calculate the magnetic properties of 2D nano-islands. > The Hamiltonian contains n

  8. The Classical Laplace Plane and Its use as a Stable Disposal Orbit for GEO

    Science.gov (United States)

    Rosengren, A.; Scheeres, D.; McMahon, J.

    2013-09-01

    about the pole of this plane with a period of nearly 53 years. The significance of the Laplace plane for use as a GEO disposal orbit is that the orbits of satellites placed in this stable equilibrium will be fixed on average, and that any orbit at small inclination to it regresses around this plane at nearly constant inclination and rate. This stable graveyard can be specified for a range of semi-major axes above GEO, and satellites placed in this region will have significantly reduced relative encounter velocities, compared to the current graveyard. Thus, if collisions were to occur between satellites in the stable graveyard, they would occur at very low velocities, thereby damping out the relative motion of these objects. We explore the use of the classical Laplace plane as a long-term GEO disposal orbit. We show that HAMR objects released from satellites located in this stable equilibrium will be trapped in inclination and node phase space, and will not likely cross the GEO protected region. This is followed by a discussion of the robustness of these solutions to more realistic SRP models and an investigation of the economic viability of our proposed GEO graveyard.

  9. Percentiles relative to maxillary permanent canine inclination by age: a radiologic study.

    Science.gov (United States)

    Alessandri Bonetti, Giulio; Zanarini, Matteo; Danesi, Margherita; Parenti, Serena Incerti; Gatto, Maria Rosaria

    2009-10-01

    Few studies have investigated developmental norms for maxillary permanent canine eruption. In this observational cross-sectional study, we aimed to provide an age-related description of the percentiles relative to canine inclination in a large sample of nonorthodontic patients. Associations between inclination and sector were also analyzed. Canine inclination and sector location were measured on 1020 panoramic radiographs obtained from subjects of white ancestry aged between 8 and 11 years not seeking orthodontic treatment. The total sample comprised 2037 canines. Canine inclination increases between 8 and 9 years and decreases between 9 and 11 years. The greatest value for each percentile is at 9 years. A linear model should be hypothesized for differences in canine inclination between 2 successive ages in correspondence to each percentile. The proportion of sector 2 canines decreases and that of sector 1 increases with age. In the same age group, the inclination generally decreases as the sector decreases. Percentiles by age show the average canine inclination in a certain population. Further studies are required to verify whether percentiles can be a diagnostic aid for determining normal canine inclination at a given age and for quantifying the risk of canine impaction or adjacent root resorption.

  10. FEM Modeling of In-Plane Stress Distribution in Thick Brittle Coatings/Films on Ductile Substrates Subjected to Tensile Stress to Determine Interfacial Strength

    Directory of Open Access Journals (Sweden)

    Kaishi Wang

    2018-03-01

    Full Text Available The ceramic-metal interface is present in various material structures and devices that are vulnerable to failures, like cracking, which are typically due to their incompatible properties, e.g., thermal expansion mismatch. In failure of these multilayer systems, interfacial shear strength is a good measure of the robustness of interfaces, especially for planar films. There is a widely-used shear lag model and method by Agrawal and Raj to analyse and measure the interfacial shear strength of thin brittle film on ductile substrates. The use of this classical model for a type of polymer derived ceramic coatings (thickness ~18 μm on steel substrate leads to high values of interfacial shear strength. Here, we present finite element simulations for such a coating system when it is subjected to in-plane tension. Results show that the in-plane stresses in the coating are non-uniform, i.e., varying across the thickness of the film. Therefore, they do not meet one of the basic assumptions of the classical model: uniform in-plane stress. Furthermore, effects of three significant parameters, film thickness, crack spacing, and Young’s modulus, on the in-plane stress distribution have also been investigated. ‘Thickness-averaged In-plane Stress’ (TIS, a new failure criterion, is proposed for estimating the interfacial shear strength, which leads to a more realistic estimation of the tensile strength and interfacial shear strength of thick brittle films/coatings on ductile substrates.

  11. Seismic Hazard of the Uttarakhand Himalaya, India, from Deterministic Modeling of Possible Rupture Planes in the Area

    Directory of Open Access Journals (Sweden)

    Anand Joshi

    2013-01-01

    Full Text Available This paper presents use of semiempirical method for seismic hazard zonation. The seismotectonically important region of Uttarakhand Himalaya has been considered in this work. Ruptures along the lineaments in the area identified from tectonic map are modeled deterministically using semi empirical approach given by Midorikawa (1993. This approach makes use of attenuation relation of peak ground acceleration for simulating strong ground motion at any site. Strong motion data collected over a span of three years in this region have been used to develop attenuation relation of peak ground acceleration of limited magnitude and distance applicability. The developed attenuation relation is used in the semi empirical method to predict peak ground acceleration from the modeled rupture planes in the area. A set of values of peak ground acceleration from possible ruptures in the area at the point of investigation is further used to compute probability of exceedance of peak ground acceleration of values 100 and 200 gals. The prepared map shows that regions like Tehri, Chamoli, Almora, Srinagar, Devprayag, Bageshwar, and Pauri fall in a zone of 10% probability of exceedence of peak ground acceleration of value 200 gals.

  12. Femoral bowing plane adaptation to femoral anteversion.

    Science.gov (United States)

    Akman, Alp; Demirkan, Fahir; Sabir, Nuran; Oto, Murat; Yorukoglu, Cagdas; Kiter, Esat

    2017-01-01

    Femoral bowing plane (FBP) is the unattended subject in the literature. More over the femoral shaft with its bowing is neglected in established anteversion determination methods. There is limited information about the relationship between FBP and anteversion. Thus we focused on this subject and hypothesized that there could be an adaptation of FBP to anteversion. FBP is determined on three-dimensional solid models derived from the left femoral computerized tomography data of 47 patients which were taken before for another reason and comparatively evaluated with anteversion. There were 20 women and 27 men. The mean age of patients was 56 years (range 21-84 years). The anteversion values were found as the angle between a distal condylar axis (DCA) and femoral neck anteversion axis (FNAA) along an imaginary longitudinal femoral axis (LFA) in the true cranio-caudal view. The FBP was determined as a plane that passes through the centre-points of three pre-determinated sections on the femoral shaft. The angles between DCA, FNAA and FBP were comparatively evaluated. The independent samples t -test was used for statistical analysis. At the end, it was found that FBP lies nearly perpendicular to the anteversion axis for the mean of our sample which is around 89° in females and 93° in males (range 78-102°). On the other hand, FBP does not lie close to the sagittal femoral plane (SFP); instead, there is an average 12.5° external rotation relative to the SFP. FBP is correlated well with anteversion in terms of FBP inclination from SFP and femoral torsion (i.e., angle between FBP and femoral neck anteversion axis ( P < 0.001; r = 0.680 and r = -0.682, respectively). Combined correlation is perfect ( R 2 = 1) as the FBP, SFP, and posterior femoral plane forms a triangle in the cranio-caudal view. We found that FBP adapts to anteversion. As FBP lies close to perpendicularity for the mean, femoral component positioning perpendicular to the FBP can be an alternate way in the

  13. Femoral bowing plane adaptation to femoral anteversion

    Directory of Open Access Journals (Sweden)

    Alp Akman

    2017-01-01

    Full Text Available Background: Femoral bowing plane (FBP is the unattended subject in the literature. More over the femoral shaft with its bowing is neglected in established anteversion determination methods. There is limited information about the relationship between FBP and anteversion. Thus we focused on this subject and hypothesized that there could be an adaptation of FBP to anteversion. Materials and Methods: FBP is determined on three-dimensional solid models derived from the left femoral computerized tomography data of 47 patients which were taken before for another reason and comparatively evaluated with anteversion. There were 20 women and 27 men. The mean age of patients was 56 years (range 21-84 years. Results: The anteversion values were found as the angle between a distal condylar axis (DCA and femoral neck anteversion axis (FNAA along an imaginary longitudinal femoral axis (LFA in the true cranio-caudal view. The FBP was determined as a plane that passes through the centre-points of three pre-determinated sections on the femoral shaft. The angles between DCA, FNAA and FBP were comparatively evaluated. The independent samples t-test was used for statistical analysis. At the end, it was found that FBP lies nearly perpendicular to the anteversion axis for the mean of our sample which is around 89° in females and 93° in males (range 78-102°. On the other hand, FBP does not lie close to the sagittal femoral plane (SFP; instead, there is an average 12.5° external rotation relative to the SFP. FBP is correlated well with anteversion in terms of FBP inclination from SFP and femoral torsion (i.e., angle between FBP and femoral neck anteversion axis (P0 < 0.001; r = 0.680 and r = −0.682, respectively. Combined correlation is perfect (R[2] = 1 as the FBP, SFP, and posterior femoral plane forms a triangle in the cranio-caudal view. Conclusions: We found that FBP adapts to anteversion. As FBP lies close to perpendicularity for the mean, femoral component

  14. Physical and numerical modeling of an inclined three-layer (silt/gravelly sand/clay) capillary barrier cover system under extreme rainfall.

    Science.gov (United States)

    Ng, Charles W W; Liu, Jian; Chen, Rui; Xu, Jie

    2015-04-01

    As an extension of the two-layer capillary barrier, a three-layer capillary barrier landfill cover system is proposed for minimizing rainfall infiltration in humid climates. This system consists of a compacted clay layer lying beneath a conventional cover with capillary barrier effects (CCBE), which is in turn composed of a silt layer sitting on top of a gravelly sand layer. To explore the effectiveness of the new system in minimizing rainfall infiltration, a flume model (3.0 m × 1.0 m × 1.1 m) was designed and set up in this study. This physical model was heavily instrumented to monitor pore water pressure, volumetric water content, surface runoff, infiltration and lateral drainage of each layer, and percolation of the cover system. The cover system was subjected to extreme rainfall followed by evaporation. The experiment was also back-analyzed using a piece of finite element software called CODE_BRIGHT to simulate transient water flows in the test. Based on the results obtained from various instruments, it was found that breakthrough of the two upper layers occurred for a 4-h rainfall event having a 100-year return period. Due to the presence of the newly introduced clay layer, the percolation of the three-layer capillary barrier cover system was insignificant because the clay layer enabled lateral diversion in the gravelly sand layer above. In other words, the gravelly sand layer changed from being a capillary barrier in a convention CCBE cover to being a lateral diversion passage after the breakthrough of the two upper layers. Experimental and back-analysis results confirm that no infiltrated water seeped through the proposed three-layer barrier system. The proposed system thus represents a promising alternative landfill cover system for use in humid climates. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. An ab initio model of electron transport in hematite (a-Fe2O3) basal planes

    International Nuclear Information System (INIS)

    Rosso, Kevin M.; Smith, Dayle MA; Dupuis, Michel

    2003-01-01

    Transport of conduction electrons through basal planes of the hematite lattice was modeled as a valence alternation of iron cations using ab initio molecular orbital calculations and electron transfer theory. A cluster approach was successfully implemented to compute electron transfer rate-controlling quantities such as the reorganization energy and electronic coupling matrix element. Localization of a conduction electron at an iron lattice site is accompanied by large iron/oxygen bond length increases that give rise to a large inner-sphere component of the reorganization energy. The interaction between the reactant and product electronic states in the crossing?point configuration is substantial and leads to an adiabatic electron transfer system. Electron transfer is predicted to possess a small positive activation energy that turns out to be in excellent agreement with values deduced from conductivity measurements. Measured electron mobility can be explained in terms of nearest neighbor electron hops without significant contribution from iron atoms further away. Comparison of the predicted maximum polaron binding energy with the predicted half bandwidth indicates compliance with the small polaron condition. Therefore the localized electron treatment is appropriate to describe electron transport in this system

  16. Thermodynamic and Modeling Study of Cyclopentane on MgO (100), hBN and Graphite Basal Plane

    Science.gov (United States)

    Wahida, Fatema; Strange, Nicholas; Larese, John Z.

    Investigation of the adsorption of cyclopentane on magnesium oxide (100), hexagonal boron nitride and the graphite basal plane was undertaken to explore the role of surface symmetry on the physicochemical properties. This is one portion of a broader study of 2D layers of cyclic organic molecules adsorbed on these scientifically and industrially important substrates. A series of high-resolution volumetric adsorption isotherms over the temperature range of 195-265K were measured on each of the substrates and used to calculate such thermodynamic properties as the heat of adsorption and isosteric heat, differential enthalpy, and differential entropy of adsorption during the layer growth process. The behavior of the two dimensional isothermal compressibility as a function of temperature and coverage was used to identify the locations of layering and potential phase transitions. To gain additional insight into the microscopic details of the adsorption process, classical molecular dynamics simulations were performed using a centralized force field (COMPASS) in tandem with thermodynamic experiments. The results of these modeling studies will be used to aid future quasi- and inelastic neutron scattering experiments aimed at exploring the rotational and translational diffusion and vibrational motion of the single and multilayer molecular films.

  17. Compact Planetary Systems Perturbed by an Inclined Companion. II. Stellar Spin-Orbit Evolution

    Science.gov (United States)

    Boué, Gwenaël; Fabrycky, Daniel C.

    2014-07-01

    The stellar spin orientation relative to the orbital planes of multiplanet systems is becoming accessible to observations. Here, we analyze and classify different types of spin-orbit evolution in compact multiplanet systems perturbed by an inclined outer companion. Our study is based on classical secular theory, using a vectorial approach developed in a separate paper. When planet-planet perturbations are truncated at the second order in eccentricity and mutual inclination, and the planet-companion perturbations are developed at the quadrupole order, the problem becomes integrable. The motion is composed of a uniform precession of the whole system around the total angular momentum, and in the rotating frame, the evolution is periodic. Here, we focus on the relative motion associated with the oscillations of the inclination between the planet system and the outer orbit and of the obliquities of the star with respect to the two orbital planes. The solution is obtained using a powerful geometric method. With this technique, we identify four different regimes characterized by the nutation amplitude of the stellar spin axis relative to the orbital plane of the planets. In particular, the obliquity of the star reaches its maximum when the system is in the Cassini regime where planets have more angular momentum than the star and where the precession rate of the star is similar to that of the planets induced by the companion. In that case, spin-orbit oscillations exceed twice the inclination between the planets and the companion. Even if the mutual inclination is only ~= 20°, this resonant case can cause the spin-orbit angle to oscillate between perfectly aligned and retrograde values.

  18. Locomotor Behavior of Chickens Anticipating Incline Walking

    Directory of Open Access Journals (Sweden)

    Chantal LeBlanc

    2018-01-01

    Full Text Available Keel bone damage (KBD is prevalent in hens raised for egg production, and ramps between different tiers in aviaries have potential to reduce the frequency of falls resulting in KBD. Effective use of ramps requires modulation of locomotion in anticipation of the incline. Inadequate adaptive locomotion may be one explanation why domestic layer hens (Gallus gallus domesticus exhibit high rates of KBD. To improve understanding of the capacity of hens to modulate their locomotion in anticipation of climbing, we measured the effects of incline angle upon the mechanics of the preparatory step before ascending a ramp. Because the energetic challenge of climbing increases with slope, we predicted that as angle of incline increased, birds during foot contact with the ground before starting to climb would increase their peak force and duration of contact and reduce variation in center of pressure (COP under their foot. We tested 20 female domestic chickens on ramp inclines at slopes of +0°, +40°, and +70° when birds were 17, 21, 26, 31, and 36 weeks of age. There were significantly higher vertical peak ground reaction forces in preparation at the steepest slope, and ground contact time increased significantly with each increase in ramp angle. Effects upon variation in COP were not apparent; likewise, effects of limb length, age, body mass were not significant. Our results reveal that domestic chickens are capable of modulating their locomotion in response to incline angle.

  19. Plane partition vesicles

    International Nuclear Information System (INIS)

    Rensburg, E J Janse van; Ma, J

    2006-01-01

    We examine partitions and their natural three-dimensional generalizations, plane partitions, as models of vesicles undergoing an inflation-deflation transition. The phase diagrams of these models include a critical point corresponding to an inflation-deflation transition, and exhibits multicritical scaling in the vicinity of a multicritical point located elsewhere on the critical curve. We determine the locations of the multicritical points by analysing the generating functions using analytic and numerical means. In addition, we determine the numerical values of the multicritical scaling exponents associated with the multicritical scaling regimes in these models

  20. An analysis of the stratified and nonstartified flow transition criterion in horizontal/inclined pipes

    International Nuclear Information System (INIS)

    Sung, Chang Kyung

    1996-02-01

    The present studies are developed to present the two-step approach which is used in extending the phase-plane method and the hyperbolicity breaking concept for instability analyses of one-dimensional two-phase flow equations to the derivations of the new criterion for the stratified and non-stratified flow transition (e.g., onset of slugging), the critical flow condition criterion, and the flooding criterion. In the first step, more general forms for the onset of slugging criterion, the critical flow condition criterion, and the flooding criterion are derived based on the nonlinear analysis: more specifically, analyses of the phase-plane method and hyperbolicity breaking concept of the 'inflected nodes' (neutral stability conditions) and 'parallel lines' in the topological patterns of the linear system obtained from the transient one-dimensional two-phase flow equations of a two-fluid model. In the second step, through the introduction of simplifications and incorporation of a parameter (at the onset of slugging criterion) or an empirical constant (at the flooding criterion) into the general expression derived in the first step to satisfy a number of physical conditions a priori specified, new criteria for the onset of slugging and the onset of flooding have been derived. Validation of the present stratified and non-stratified flow transition criterion is achieved by comparison with the existing analytical criteria (Taitel and Dukler model and one-dimensional wave model) and experimental data from large test facilities (IFP, SINTEF, Harwell, Creare/PRC, ROSA and UPTF). The result of the validation shows good agreement at large pipe diameters and at high gas velocities. Present studies have revealed that the two-phase density ratio and pipe inclination angle are very important parameters that should be handled properly to determine the flow regime boundary correctly. Comparison between the present critical flow condition criterion with Gardner's critical flow

  1. An Evaluation of the Instruction Carried out with Printed Laboratory Materials Designed in Accordance with 5E Model: Reflection of Light and Image on a Plane Mirror

    Science.gov (United States)

    Ayvaci, Hakan Sevki; Yildiz, Mehmet; Bakirci, Hasan

    2015-01-01

    This study employed a print laboratory material based on 5E model of constructivist learning approach to teach reflection of light and Image on a Plane Mirror. The effect of the instruction which conducted with the designed print laboratory material on academic achievements of prospective science and technology teachers and their attitudes towards…

  2. Studies from Cassini's high-inclination orbits: ion cyclotron wave belt

    Science.gov (United States)

    Leisner, J. S.; Russell, C. T.; Dougherty, M. K.; Persoon, A. M.; Blanco-Cano, X.; Strangeway, R. J.; Cowee, M. M.

    2007-08-01

    Surrounding Saturn is a cloud of neutral water-group molecules. When these particles are ionized and accelerated by Saturn's corotating magnetized plasma, they generate ion cyclotron waves. When the inclination of the Cassini spacecraft's orbits rose to about fifty-five degrees in late 2006, new insights into the behavior of these ion cyclotron waves were obtained as the spacecraft passed through the equatorial plane, revealing latitudinal structure of the wave belt. Centered at the magnetic equator the wave amplitude grows with height in either direction, reaching a maximum at +/- 0.2 Rs and then decreasing until they disappear by +/- 0.3 Rs. Doppler shifts caused by the motion of the spacecraft reveal that these waves propagate primarily away from the equatorial plane. Using these high-inclination orbits, we study the wave growth and damping regions and their propagation characteristics. These properties give insight into the structure and ionization of Saturn's water cloud.

  3. Inclined nanoimprinting lithography for 3D nanopatterning

    International Nuclear Information System (INIS)

    Liu Zhan; Bucknall, David G; Allen, Mark G

    2011-01-01

    We report a non-conventional shear-force-driven nanofabrication approach, inclined nanoimprint lithography (INIL), for producing 3D nanostructures of varying heights on planar substrates in a single imprinting step. Such 3D nanostructures are fabricated by exploiting polymer anisotropic dewetting where the degree of anisotropy can be controlled by the magnitude of the inclination angle. The feature size is reduced from micron scale of the template to a resultant nanoscale pattern. The underlying INIL mechanism is investigated both experimentally and theoretically. The results indicate that the shear force generated at a non-zero inclination angle induced by the INIL apparatus essentially leads to asymmetry in the polymer flow direction ultimately resulting in 3D nanopatterns with different heights. INIL removes the requirements in conventional nanolithography of either utilizing 3D templates or using multiple lithographic steps. This technique enables various 3D nanoscale devices including angle-resolved photonic and plasmonic crystals to be fabricated.

  4. Evaluation of the lower incisor inclination during alignment and leveling using superelastic NiTi archwires: a laboratory study

    Directory of Open Access Journals (Sweden)

    Carolina Baratieri

    2012-06-01

    Full Text Available OBJECTIVE: The aim of this laboratory study is to evaluate the influence of the shape and the length limitation of superelastic nickel-titanium (NiTi archwires on lower incisors inclination during alignment and leveling. METHODS: Metal teeth mounted on a typodont articulator device were used to simulate a malocclusion of the mandibular arch (-3.5 mm model discrepancy. Three different shapes (Standard, Accuform and Ideal of superelastic NiTi archwires (Sentalloy, GAC, USA were tested. Specimens were divided in two groups: Group I, with no limitation of the archwire length; and Group II, with distal limitation. Each group had thirty specimens divided into three subgroups differentiated by the archwire shape. All groups used round wires with diameters of 0.014-in, 0.016-in, 0.018-in and 0.020-in. The recording of all intervals was accomplished using standardized digital photographs with orthogonal norm in relation to median sagittal plane. The buccolingual inclination of the incisor was registered using photographs and software CorelDraw. RESULTS: The results were obtained using ANOVA and Tukey's test at a significant level of 5%. The inclination of the lower incisor increased in both groups and subgroups. The shape of the archwire had statistically significant influence only in Group I - Standard (11.76º, Ideal (5.88º and Accuform (1.93º. Analyzing the influence of the length limitation, despite the mean incisor tipping in Group II (3.91º had been smaller than Group I (6.52º, no statistically significant difference was found, except for Standard, 3.89º with limitation and 11.76º without limitation. The greatest incisor tipping occurred with the 0.014-in archwires.

  5. Spectrum of 100-kyr glacial cycle: orbital inclination, not eccentricity.

    Science.gov (United States)

    Muller, R A; MacDonald, G J

    1997-08-05

    Spectral analysis of climate data shows a strong narrow peak with period approximately 100 kyr, attributed by the Milankovitch theory to changes in the eccentricity of the earth's orbit. The narrowness of the peak does suggest an astronomical origin; however the shape of the peak is incompatible with both linear and nonlinear models that attribute the cycle to eccentricity or (equivalently) to the envelope of the precession. In contrast, the orbital inclination parameter gives a good match to both the spectrum and bispectrum of the climate data. Extraterrestrial accretion from meteoroids or interplanetary dust is proposed as a mechanism that could link inclination to climate, and experimental tests are described that could prove or disprove this hypothesis.

  6. Inclined asymmetric librations in exterior resonances

    Science.gov (United States)

    Voyatzis, G.; Tsiganis, K.; Antoniadou, K. I.

    2018-04-01

    Librational motion in Celestial Mechanics is generally associated with the existence of stable resonant configurations and signified by the existence of stable periodic solutions and oscillation of critical (resonant) angles. When such an oscillation takes place around a value different than 0 or π , the libration is called asymmetric. In the context of the planar circular restricted three-body problem, asymmetric librations have been identified for the exterior mean motion resonances (MMRs) 1:2, 1:3, etc., as well as for co-orbital motion (1:1). In exterior MMRs the massless body is the outer one. In this paper, we study asymmetric librations in the three-dimensional space. We employ the computational approach of Markellos (Mon Not R Astron Soc 184:273-281, https://doi.org/10.1093/mnras/184.2.273, 1978) and compute families of asymmetric periodic orbits and their stability. Stable asymmetric periodic orbits are surrounded in phase space by domains of initial conditions which correspond to stable evolution and librating resonant angles. Our computations were focused on the spatial circular restricted three-body model of the Sun-Neptune-TNO system (TNO = trans-Neptunian object). We compare our results with numerical integrations of observed TNOs, which reveal that some of them perform 1:2 resonant, inclined asymmetric librations. For the stable 1:2 TNO librators, we find that their libration seems to be related to the vertically stable planar asymmetric orbits of our model, rather than the three-dimensional ones found in the present study.

  7. Inclined Fiber Pullout from a Cementitious Matrix: A Numerical Study

    Directory of Open Access Journals (Sweden)

    Hui Zhang

    2016-09-01

    Full Text Available It is well known that fibers improve the performance of cementitious composites by acting as bridging ligaments in cracks. Such bridging behavior is often studied through fiber pullout tests. The relation between the pullout force vs. slip end displacement is characteristic of the fiber-matrix interface. However, such a relation varies significantly with the fiber inclination angle. In the current work, we establish a numerical model to simulate the entire pullout process by explicitly representing the fiber, matrix and the interface for arbitrary fiber orientations. Cohesive elements endorsed with mixed-mode fracture capacities are implemented to represent the bond-slip behavior at the interface. Contact elements with Coulomb’s friction are placed at the interface to simulate frictional contact. The bond-slip behavior is first calibrated through pull-out curves for fibers aligned with the loading direction, then validated against experimental results for steel fibers oriented at 30 ∘ and 60 ∘ . Parametric studies are then performed to explore the influences of both material properties (fiber yield strength, matrix tensile strength, interfacial bond and geometric factors (fiber diameter, embedment length and inclination angle on the overall pullout behavior, in particular on the maximum pullout load. The proposed methodology provides the necessary pull-out curves for a fiber oriented at a given angle for multi-scale models to study fracture in fiber-reinforced cementitious materials. The novelty lies in its capacity to capture the entire pullout process for a fiber with an arbitrary inclination angle.

  8. Breakwaters with Vertical and Inclined Concrete Walls

    DEFF Research Database (Denmark)

    Burcharth, Hans Falk

    Following the PIANC PTC II working group on Analyses of Rubble Mound Breakwaters it was, in 1991, decided to form Working Group (WG) n° 28 on "Breakwaters with vertical and inclined concrete walls" The scope of the work was to achieve a better understanding of the overall safety aspects in the de......Following the PIANC PTC II working group on Analyses of Rubble Mound Breakwaters it was, in 1991, decided to form Working Group (WG) n° 28 on "Breakwaters with vertical and inclined concrete walls" The scope of the work was to achieve a better understanding of the overall safety aspects...

  9. Effect of wall inclination on natural convection in a porous trapezoidal cavity

    Science.gov (United States)

    Cheong, H. T.; Sivasankaran, S.; Siri, Z.

    2014-07-01

    The present study investigates numerically the effect of wall inclination of a trapezoidal cavity on natural convective flow and heat transfer. The cavity is filled with porous medium. Sinusoidal temperature is applied on the inclined wall and the opposite wall is maintained at a constant temperature. The top and bottom walls are adiabatic. The Darcy model is adopted for porous medium. The governing equations are solved using the finite difference method with various values of wall inclination and Rayleigh number. The heat transfer of the square cavity is found to be higher than that of trapezoidal and triangular cavities.

  10. Numerical modelling of the impedance plane for simultaneous determining, by eddy currents, the oxide thickness and conductivity in Zircaloy

    International Nuclear Information System (INIS)

    Lois, Alejandro E.

    2001-01-01

    During service at high temperature or in aggressive media, metallic structures and components may suffer different types of changes or degradation. As an example, phase transformations may occur, second phases may precipitate, and in consequence the mechanical and chemical properties of the material may change. Their behavior will therefore differ from that considered for the design of the component. The knowledge of the amount of a precipitated second phase in a component should be an important tool in the hands of the maintenance engineer. And it would be very important to obtain this knowledge nondestructively and reliably. The objective of this project is to evaluate by eddy currents the amount of the hydrogen incorporated during service in structural zirconium base materials. For this purpose, a series of Zircaloy-4 specimens with oxide layers of different thickness and different concentration of hydrogen obtained by controlled autoclave treatments were used. These specimens were tested with eddy current equipment. The information produced by an eddy current test is the superposition of many variables, e.g.: thickness of oxide layers, conductance, thickness of specimen, etc. In order to sort out this information, an analytical model of the impedance plane was programmed in a PC, with which this information was processed, permitting, in this way, to evaluate the conductivity of materials, taking into account the effect of oxide layers thickness. A linear relationship between the conductivity and the hydrogen content in the range of hydrogen concentrations of technological interest was observed. Therefore, the calculated electrical conductivity may be transformed to the amount of hydrogen content, using a suitable calibration curve. This process will allow for the nondestructive assessment of the amount of hydrogen in reactor components, such as pressure and calandria tubes, a knowledge which will enable the experts to predict the degree of fragility of those

  11. The Mid-plane of the Main Asteroid Belt

    Science.gov (United States)

    Cambioni, Saverio; Malhotra, Renu

    2018-03-01

    We measure the mid-plane of the main asteroid belt by using the observational data of a nearly complete and unbiased sample of asteroids and find that it has inclination \\bar{I}=0\\buildrel{\\circ}\\over{.} 93+/- 0\\buildrel{\\circ}\\over{.} 04 and longitude of ascending node \\bar{{{Ω }}}=87\\buildrel{\\circ}\\over{.} 6+/- 2\\buildrel{\\circ}\\over{.} 6 (in J2000 ecliptic-equinox coordinate system). This plane differs significantly from previously published measurements, and it is also distinctly different than the solar system’s invariable plane as well as Jupiter’s orbit plane. The mid-plane of the asteroid belt is theoretically expected to be a slightly warped sheet whose local normal is controlled by the gravity of the major planets. Specifically, its inclination and longitude of ascending node varies with semimajor axis and time (on secular timescales) and is defined by the forced solution of secular perturbation theory; the ν 16 nodal secular resonance is predicted to cause a significant warp of the mid-plane in the inner asteroid belt. We test the secular theory by measuring the current location of the asteroids’ mid-plane in finer semimajor axis bins. We find that the measured mid-plane in the middle and outer asteroid belt is consistent, within the 3σ confidence level, with the prediction of secular perturbation theory, but a notable discrepancy is present in the inner asteroid belt near ∼2 au.

  12. Stochastic Response of an Inclined Shallow Cable with Linear Viscous Dampers under Stochastic Excitation

    DEFF Research Database (Denmark)

    Zhou, Qiang; Nielsen, Søren R.K.; Qu, Weilian

    2010-01-01

    Considering the coupling between the in-plane and out-of-plane vibration, the stochastic response of an inclined shallow cable with linear viscous dampers subjected to Gaussian white noise excitation is investigated in this paper. Selecting the static deflection shape due to a concentrated force...... at the dampers location and the first sine term as shape functions, a reduced four-degree-of-freedom system of nonlinear stochastic ordinary differential equations are derived to describe dynamic response of the cable. Since only polynomial-type terms are contained, the fourth-order cumulant-neglect closure...... and viscous coefficient of the damper are fixed. Moreover, the peak frequency and half-band width of the spectra of both the in-plane and the out-of-plane displacements are increasing with excitation level when the damper size is constant. It is also observed that, even though the actual optimal damper size...

  13. The use of the greater trochanter marker in the thigh segment model: Implications for hip and knee frontal and transverse plane motion

    Directory of Open Access Journals (Sweden)

    Valentina Graci

    2016-03-01

    Conclusion: Hip and knee kinematics differed across different segment definitions including or excluding the greater trochanter marker, especially in the transverse plane. Therefore when considering whether to include the greater trochanter in the thigh segment model when using a surface markers to calculate 3D kinematics for movement assessment, it is important to have a clear understanding of the effect of different marker sets and segment models in use.

  14. Internally cooled V-shape inclined monochromator

    Czech Academy of Sciences Publication Activity Database

    Oberta, Peter; Áč, V.; Hrdý, Jaromír

    2008-01-01

    Roč. 15, - (2008), 8-11 ISSN 0909-0495 R&D Projects: GA AV ČR IAA100100716 Grant - others:VEGA(SK) 1/4134/07 Institutional research plan: CEZ:AV0Z10100522 Keywords : inclined monochromator * heat load * internal cooling Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.333, year: 2008

  15. A matter of chance, environment and inclination

    Indian Academy of Sciences (India)

    Lawrence

    Why did I opt for science subjects in school, and choose a career in science? Perhaps the best answer would be. 'Chance, Environment and Inclination'. Here I am, considered to be a professional woman scien- tist, working towards understanding the biology of the malaria parasite and the challenges put up by the same.

  16. Inclined test of nacelle wind lidar

    DEFF Research Database (Denmark)

    Courtney, Michael

    A nacelle wind lidar, placed at ground level, is tested by inclining the laser beams to bisect a measurement mast at a known distance and height. The horizontal wind speed reported by the lidar is compared to a reference cup anemometer mounted on the mast at the comparison height....

  17. Vehicle with inclinable caterpillar propulsion units

    International Nuclear Information System (INIS)

    Clar, G.

    1991-01-01

    This vehicle usable in hostile environment such nuclear industry has four propulsion units with a caterpillar track and two integrated motors: one for advancing the caterpillar track and the other for inclining the propulsion unit when overcoming obstacles. Each propulsion unit is easily replaceable because there are no mechanical parts in the body of the vehicle [fr

  18. Measurement of the buccolingual inclination of teeth: manual technique vs 3-dimensional software.

    Science.gov (United States)

    Nouri, Mahtab; Abdi, Amir Hossein; Farzan, Arash; Mokhtarpour, Faraneh; Baghban, AliReza Akbarzadeh

    2014-10-01

    In this study, we aimed to measure the inclination of teeth on dental casts by a manual technique with the tooth inclination protractor (TIP; MBI, Newport, United Kingdom) and a newly designed 3-dimensional (3D) software program. The correlation of the 2 techniques was evaluated, and the reliability of each technique was assessed separately. This study was conducted on 36 dental casts of normal, well-aligned Class I occlusions; we assessed 432 teeth. All casts had a normal Class I occlusion. After determining the facial axis of the clinical crown and the facial axis points on the dental casts, we measured the inclinations of the incisors and posterior teeth up to the first molars in each dental arch relative to Andrews' occlusal plane and the posterior occlusal plane using the TIP. Moreover, the casts were scanned by a structured-light 3D scanner. The inclination of teeth relative to the occlusal plane was determined using the new software. To assess the reliability, measurements of all teeth from 15 casts were repeated twice by the 2 methods. Intraclass correlation coefficient and Dahlberg's formula were used for calculation of correlation and reliability. Overall, the 2 techniques were not significantly different in the measurements of the inclinations of the teeth in both jaws. The ranges of Dahlberg's formula were 3.1° to 5.8° for the maxilla and 3.3° to 5.9° for the mandible. The overall correlation of the 2 techniques according to the intraclass correlation coefficient was 0.91. For calculation of reliability, the intraclass correlation coefficients for the TIP and the 3D method were 0.73 and 0.82, respectively. The TIP and the 3D software showed a high correlation for measurement of the inclinations of maxillary and mandibular teeth relative to the occlusal plane. Also, the reproducibility of the measurements in each method was high. Copyright © 2014 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  19. New inclination changing eclipsing binaries in the Magellanic Clouds

    Science.gov (United States)

    Juryšek, J.; Zasche, P.; Wolf, M.; Vraštil, J.; Vokrouhlický, D.; Skarka, M.; Liška, J.; Janík, J.; Zejda, M.; Kurfürst, P.; Paunzen, E.

    2018-01-01

    Context. Multiple stellar systems are unique laboratories for astrophysics. Analysis of their orbital dynamics, if well characterized from their observations, may reveal invaluable information about the physical properties of the participating stars. Unfortunately, there are only a few known and well described multiple systems, this is even more so for systems located outside the Milky Way galaxy. A particularly interesting situation occurs when the inner binary in a compact triple system is eclipsing. This is because the stellar interaction, typically resulting in precession of orbital planes, may be observable as a variation of depth of the eclipses on a long timescale. Aims: We aim to present a novel method to determine compact triples using publicly available photometric data from large surveys. Here we apply it to eclipsing binaries (EBs) in Magellanic Clouds from OGLE III database. Our tool consists of identifying the cases where the orbital plane of EB evolves in accord with expectations from the interaction with a third star. Methods: We analyzed light curves (LCs) of 26121 LMC and 6138 SMC EBs with the goal to identify those for which the orbital inclination varies in time. Archival LCs of the selected systems, when complemented by our own observations with Danish 1.54-m telescope, were thoroughly analyzed using the PHOEBE program. This provided physical parameters of components of each system. Time dependence of the EB's inclination was described using the theory of orbital-plane precession. By observing the parameter-dependence of the precession rate, we were able to constrain the third companion mass and its orbital period around EB. Results: We identified 58 candidates of new compact triples in Magellanic Clouds. This is the largest published sample of such systems so far. Eight of them were analyzed thoroughly and physical parameters of inner binary were determined together with an estimation of basic characteristics of the third star. Prior to our

  20. Optimized 3D simulation method for modeling of out-of-plane radiation in silicon photonic integrated circuits

    NARCIS (Netherlands)

    Westerveld, W.J.; Urbach, H.P.; Yousefi, M.

    2011-01-01

    We present an accurate and fast 3D simulation scheme for out-of-plane grating couplers, based on two dimensional rigorous (finite difference time domain) grating simulations, the effective index method (EIM), and the Rayleigh-Sommerfeld diffraction formula. In comparison with full 3D FDTD

  1. Fully atomistic molecular dynamics simulations of the behavior of a simple model of crude oil confined between graphene planes.

    Science.gov (United States)

    Maldonado, E; Roth, M W; Gray, Paul A

    2009-06-01

    We present and discuss the results of molecular dynamics computer simulations of crude oil confined between graphene planes. The crude oil is represented as a mixture of alkanes having 6 method of separating alkane mixtures at temperatures significantly different from those of conventional refining processes.

  2. The Effect of Inclination Angle on Critical Heat Flux in a Locally Heated Liquid Film Moving Under the Action of Gas Flow in a Mini-Channel

    Directory of Open Access Journals (Sweden)

    Tkachenko Egor M.

    2016-01-01

    Full Text Available Intensively evaporating liquid films moving under the action of the cocurrent gas flow in a microchannel are promising for the use in modern cooling systems of semiconductor devices with high local heat release. This work has studied the dependence of the critical heat flux on the inclination angle of the channel. It has been found that the inclination angle in the plane parallel to the flow has no significant effect on the critical heat flux. Whereas the inclination angle in the plane perpendicular to the flow, on the contrary, significantly changes the value of the critical heat flux. However, for a given flow rate of fluid there is a threshold gas velocity at which the critical heat flux does not differ from the case of zero inclination of the channel. Thus, it can be concluded that the cooling system based on shear-driven liquid films can be potentially used when direction of the gravity changes.

  3. Homogenized rigid body and spring-mass (HRBSM) model for the pushover analysis of out-of-plane loaded unreinforced and FRP reinforced walls

    Science.gov (United States)

    Bertolesi, Elisa; Milani, Gabriele

    2017-07-01

    The present paper is devoted to the discussion of a series of unreinforced and FRP retrofitted panels analyzed adopting the Rigid Body and Spring-Mass (HRBSM) model developed by the authors. To this scope, a total of four out of plane loaded masonry walls tested up to failure are considered. At a structural level, the non-linear analyses are conducted replacing the homogenized orthotropic continuum with a rigid element and non-linear spring assemblage by means of which out of plane mechanisms are allowed. FRP retrofitting is modeled adopting two noded truss elements whose mechanical properties are selected in order to describe possible debonding phenomenon or tensile rupture of the strengthening. The outcome provided numerically are compared to the experimental results showing a satisfactory agreement in terms of global pressure-deflection curves and failure mechanisms.

  4. LONG-LIVED CHAOTIC ORBITAL EVOLUTION OF EXOPLANETS IN MEAN MOTION RESONANCES WITH MUTUAL INCLINATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Rory; Deitrick, Russell; Quinn, Thomas R. [Astronomy Department, University of Washington, Box 951580, Seattle, WA 98195 (United States); Greenberg, Richard [Lunar and Planetary Laboratory, University of Arizona, 1629 E. University Boulevard, Tucson, AZ 86716 (United States); Raymond, Sean N., E-mail: rory@astro.washington.edu [NASA Astrobiology Institute-Virtual Planetary Laboratory Lead Team (United States)

    2015-03-10

    We present N-body simulations of resonant planets with inclined orbits that show chaotically evolving eccentricities and inclinations that can persist for at least 10 Gyr. A wide range of behavior is possible, from fast, low amplitude variations to systems in which eccentricities reach 0.9999 and inclinations 179.°9. While the orbital elements evolve chaotically, at least one resonant argument always librates. We show that the HD 73526, HD 45364, and HD 60532 systems may be in chaotically evolving resonances. Chaotic evolution is apparent in the 2:1, 3:1, and 3:2 resonances, and for planetary masses from lunar- to Jupiter-mass. In some cases, orbital disruption occurs after several gigayears, implying the mechanism is not rigorously stable, just long-lived relative to the main sequence lifetimes of solar-type stars. Planet-planet scattering appears to yield planets in inclined resonances that evolve chaotically in about 0.5% of cases. These results suggest that (1) approximate methods for identifying unstable orbital architectures may have limited applicability, (2) the observed close-in exoplanets may be produced during epochs of high eccentricit induced by inclined resonances, (3) those exoplanets' orbital planes may be misaligned with the host star's spin axis, (4) systems with resonances may be systematically younger than those without, (5) the distribution of period ratios of adjacent planets detected via transit may be skewed due to inclined resonances, and (6) potentially habitable planets may have dramatically different climatic evolution than Earth. The Gaia spacecraft is capable of discovering giant planets in these types of orbits.

  5. Radiography method mprising determination of corrected absorption values for members of sets of mutually inclined beam paths

    International Nuclear Information System (INIS)

    McLeMay, C.A.G.

    1978-01-01

    An x-ray apparatus is described for examining a body including a source of a fan of radiation and detectors of the radiation along beams in the fan are transversed in a plane to provide data for a number of sets of parallel beams in the plane. An orbital motion is provided to give data for further sets at different inclinations in the plane. The data can be processed by arrangements using such parallel sets. The orbital motion is continuous but the extent of angular change in one lateral scan is kept small so that lack of parallelism in the parallel sets does not give excessive errors

  6. Inclined Weight-Loaded Walking at Different Speeds: Pelvis-Shoulder Coordination, Trunk Movements and Cost of Transport.

    Science.gov (United States)

    Rosa, Rodrigo Gomes da; Gomeñuka, Natalia Andrea; Oliveira, Henrique Bianchi de; Peyré-Tartaruga, Leonardo Alexandre

    2018-01-01

    Although studied at level surface, the trunk kinematics and pelvis-shoulder coordination of incline walking are unknown. The aim of this study was to evaluate the speed effects on pelvis-shoulder coordination and trunk movement and the cost of transport (C) during unloaded and loaded (25% of body mass) 15% incline walking. We collected 3-dimensional kinematic and oxygen consumption data from 10 physically active young men. The movements were analyzed in the sagittal plane (inclination and range of trunk motion) and the transverse plane (range of shoulder and pelvic girdle motion and phase difference). The rotational amplitude of the shoulder girdle decreased with load at all speeds, and it was lower at the highest speeds. The rotational amplitude of the pelvic girdle did not change with the different speeds. The phase difference was greater at optimal speed (3 km.hr -1 , at the lowest C) in the loaded and the unloaded conditions. The trunk inclination was greater with load and increased with speed, whereas the range of trunk motion was lower in the loaded condition and decreased with increasing speed. In conclusion, the load decreased the range of girdles and trunk motion, and the pelvis-shoulder coordination seemed to be critical for the incline walking performance.

  7. The effect of speleothem surface slope on the remanent magnetic inclination

    Science.gov (United States)

    Ponte, J. M.; Font, E.; Veiga-Pires, C.; Hillaire-Marcel, C.; Ghaleb, B.

    2017-06-01

    Speleothems are of interest for high-resolution reconstruction of the Earth's magnetic field. However, little is known about the influence of speleothem morphologies on their natural remanent magnetization (NRM) record. Here we report on a high-resolution paleomagnetic study of a dome-shaped speleothem of middle Holocene age from southern Portugal, with special attention to the anisotropy of magnetic susceptibility (AMS) and anisotropy of anhysteretic remanent magnetization (AARM). To assess the potential influence of the slope of the speleothem surface on the recorded remanent magnetization, we compare magnetic directions and AMS and AARM fabrics from subhorizontal to gradually subvertical calcite growth layers collected in a transversal cross section of the speleothem. A linear correlation is observed between magnetic inclinations, calcite laminae slope, and AARM k1 inclination. The AMS fabric is mostly controlled by calcite crystals, with direction of the minimum axes (k3) perpendicular to laminae growth. Magnetic inclinations recorded in inclined and vertical calcite growth layers are underestimated when compared to a global paleosecular variation (PSV) model. After extrapolating magnetic inclinations to the horizontal, the corrected data better fit the PSV model but are still lower than the predicted magnetic inclinations, suggesting that inclination shallowing affects the entire speleothem. We suggest that speleothem morphology exerts a critical role on the magnetic inclination recording, which is controlled by the Earth's magnetic field but also influenced by particle rolling along the sloping surfaces. These observations open new avenues for reconstructing high-resolution paleomagnetic secular variation records from speleothems and provide new insights into their NRM acquisition mechanisms.

  8. A thermodynamic model for predicting surface melting and overheating of different crystal planes in BCC, FCC and HCP pure metallic thin films

    International Nuclear Information System (INIS)

    Jahangir, Vafa; Riahifar, Reza; Sahba Yaghmaee, Maziar

    2016-01-01

    In order to predict as well as study the surface melting phenomena in contradiction to surface overheating, a generalized thermodynamics model including the surface free energy of solid and the melt state along with the interfacial energy of solid–liquid (melt on substrate) has been introduced. In addition, the effect of different crystal structures of surfaces in fcc, bcc and hcp metals was included in surface energies as well as in the atomistic model. These considerations lead us to predict surface melting and overheating as two contradictory melting phenomena. The results of the calculation are demonstrated on the example of Pb and Al thin films in three groups of (100), (110) and (111) surface planes. Our conclusions show good agreement with experimental results and other theoretical investigations. Moreover, a computational algorithm has been developed which enables users to investigate the surface melt or overheating of single component metallic thin film with variable crystal structures and different crystalline planes. This model and developed software can be used for studying all related surface phenomena. - Highlights: • Investigating the surface melting and overheating phenomena • Effect of crystal orientations, surface energies, geometry and different atomic surface layers • Developing a computational algorithm and its related code (free-software SMSO-Ver1) • Thickness and orientation of surface plane dominate the surface melting or overheating. • Total excess surface energy as a function of thickness and temperature explains melting.

  9. Stress field of a dislocating inclined fault

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F.; Wang, T.

    1980-02-01

    Analytical expressions are derived for the stress field caused by a rectangular dislocating fault of an arbitrary dip in a semi-infinite elastic medium for the case of unequal Lame constants. The results of computations for the stress fields on the ground surface of an inclined strike-slip and an inclined dip-slip fault are represented by contour maps. The effects of Poisson Ratio of the medium, the dip angle, upper and lower boundaries of the faults on the stress field at surface have been discussed. As an application, the contour maps for shear stress and hydrostatic stress of near fields of the Tonghai (1970), Haicheng (1975) and Tangshan (1976) earthquakes have been calculated and compared with the spatial distributions of strong aftershocks of these earthquakes. It is found that most of the strong aftershocks are distributed in the regions of tensional stress, where the hydrostatic stress is positive.

  10. Stress field of a dislocating inclined fault

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F.; Wang, T.

    1980-02-01

    In this paper, analytical expressions of the stress field given rise by a rectangular dislocating fault of an arbitrary dip in a semi-infinite elastic medium for the case of unequal Lame constants are derived. The results of computations for the stress fields on the ground surface of an inclined strike-slip and an inclined dip-slip fault are represented by contour maps. The effects of the Poisson Ratio of the medium, the dip angle, upper and lower boundaries of the faults on the stress field at the surface have been discussed. As an application, the contour maps for shear stress and hydrostatic stress of near fields of the Tonghai (1970), Haicheng, (1975) and Tangshan (1976) earthquakes have been calculated and compared with the spatial distributions of strong aftershocks of these earthquakes. It is found that most of the strong aftershocks are distributed in the regions of tensional stress where the hydrostatic stress is positive.

  11. Bubble streams rising beneath an inclined surface

    Science.gov (United States)

    Bird, James; Brasz, Frederik; Kim, Dayoung; Menesses, Mark; Belden, Jesse

    2017-11-01

    Bubbles released beneath a submerged inclined surface can tumble along the wall as they rise, dragging the surrounding fluid with them. This effect has recently regained attention as a method to mitigate biofouling in marine environment, such as a ship hull. It appears that the efficacy of this approach may be related to the velocity of the rising bubbles and the extent that they spread laterally as they rise. Yet, it is unclear how bubble stream rise velocity and lateral migration depend on bubble size, flow rate, and inclination angle. Here we perform systematic experiments to quantify these relationships for both individual bubble trajectories and ensemble average statistics. Research supported by the Office of Naval Research under Grant Number award N00014-16-1-3000.

  12. HIGH-INCLINATION ASTEROID FAMILIES V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the high-inclination asteroid families of Gil-Hutton (2006). A data set of 3652 high-inclination numbered asteroids was analyzed to search for...

  13. A jumping cylinder in an incline

    Science.gov (United States)

    Gomez, Raul W.; Hernandez, Jorge; Marquina, Vivianne

    2012-02-01

    The problem of a cylinder of mass m and radius r, with its center of mass out of the cylinder axis, rolling in an incline that makes an angle α respect to the horizontal is analyzed. The equation of motion is solved to obtain the site where the cylinder loses contact with the incline (jumps). Several simplifications are made: the analyzed system consists of an homogeneous disc with a one dimensional straight line of mass parallel to the disc axis at a distance d Styrofoam cylinder of radius r = 10.0 ± 0.05 cm, high h = 5.55 ± 0.05 cm and a mass m1 = 24.45 ± 0.05 g, to which a 9.50 ± 0.01 mm diameter and 5.10 ± 0.001 cm long brass road of mass m2 = 30.75 ± 0.05 g was imbibed parallel to the disc axis at a distance of 5.40 ± 0.05 cm from it. Then the disc rolls on a 3.20 m long wooden ramp inclined at 30 and 45 respect to the horizontal. To determine the jumping site, the movements were recorded with a high-speed video camera (Casio EX ZR100) at 400 frames per second. The experimental results agree well with the theoretical predictions.

  14. SU-C-209-05: Monte Carlo Model of a Prototype Backscatter X-Ray (BSX) Imager for Projective and Selective Object-Plane Imaging

    International Nuclear Information System (INIS)

    Rolison, L; Samant, S; Baciak, J; Jordan, K

    2016-01-01

    Purpose: To develop a Monte Carlo N-Particle (MCNP) model for the validation of a prototype backscatter x-ray (BSX) imager, and optimization of BSX technology for medical applications, including selective object-plane imaging. Methods: BSX is an emerging technology that represents an alternative to conventional computed tomography (CT) and projective digital radiography (DR). It employs detectors located on the same side as the incident x-ray source, making use of backscatter and avoiding ring geometry to enclose the imaging object. Current BSX imagers suffer from low spatial resolution. A MCNP model was designed to replicate a BSX prototype used for flaw detection in industrial materials. This prototype consisted of a 1.5mm diameter 60kVp pencil beam surrounded by a ring of four 5.0cm diameter NaI scintillation detectors. The imaging phantom consisted of a 2.9cm thick aluminum plate with five 0.6cm diameter holes drilled halfway. The experimental image was created using a raster scanning motion (in 1.5mm increments). Results: A qualitative comparison between the physical and simulated images showed very good agreement with 1.5mm spatial resolution in plane perpendicular to incident x-ray beam. The MCNP model developed the concept of radiography by selective plane detection (RSPD) for BSX, whereby specific object planes can be imaged by varying kVp. 10keV increments in mean x-ray energy yielded 4mm thick slice resolution in the phantom. Image resolution in the MCNP model can be further increased by increasing the number of detectors, and decreasing raster step size. Conclusion: MCNP modelling was used to validate a prototype BSX imager and introduce the RSPD concept, allowing for selective object-plane imaging. There was very good visual agreement between the experimental and MCNP imaging. Beyond optimizing system parameters for the existing prototype, new geometries can be investigated for volumetric image acquisition in medical applications. This material is

  15. Articular Eminence Inclination, Height, and Condyle Morphology on Cone Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Dilhan İlgüy

    2014-01-01

    Full Text Available Aim. The aim of the present study was to examine the relationship between articular eminence inclination, height, and thickness of the roof of the glenoid fossa (RGF according to age and gender and to assess condyle morphology including incidental findings of osseous characteristics associated with osteoarthritis (OA of the temporomandibular joint (TMJ using cone beam computed tomography (CBCT. Materials and Methods. CBCT images of 105 patients were evaluated retrospectively. For articular eminence inclination and height, axial views on which the condylar processes were seen with their widest mediolateral extent being used as a reference view for secondary reconstruction. Condyle morphology was categorized both in the sagittal and coronal plane. Results. The mean values of eminence inclination and height of males were higher than those of females (P<0.05. There were significant differences in the RGF thickness in relation to sagittal condyle morphology. Among the group of OA, the mean value of the RGF thickness for “OA-osteophyte” group was the highest (1.59 mm, whereas the lowest RGF values were seen in the “OA-flattening.” Conclusion. The sagittal osteoarthritic changes may have an effect on RGF thickness by mechanical stimulation and changed stress distribution. Gender has a significant effect on eminence height (Eh and inclination.

  16. Coordinating bracket torque and incisor inclination : Part 3: Validity of bracket torque values in achieving norm inclinations.

    Science.gov (United States)

    Zimmer, Bernd; Sino, Hiba

    2018-03-19

    To analyze common values of bracket torque (Andrews, Roth, MBT, Ricketts) for their validity in achieving incisor inclinations that are considered normal by different cephalometric standards. Using the equations developed in part 1 (eU1 (BOP) = 90° - BT (U1) - TCA (U1) + α 1 - α 2 and eL1 (BOP) = 90° - BT (L1) - TCA (L1) + β 1 - β 2 ) (abbreviations see part 1) and the mean values (± SD) obtained as statistical measures in parts 1 and 2 of the study (α 1 and β 1 [1.7° ± 0.7°], α 2 [3.6° ± 0.3°], β 2 [3.2° ± 0.4°], TCA (U1) [24.6° ± 3.6°] and TCA (L1) [22.9° ± 4.3°]) expected (= theoretically anticipated) values were calculated for upper and lower incisors (U1 and L1) and compared to targeted (= cephalometric norm) values. For U1, there was no overlapping between the ranges of expected and targeted values, as the lowest targeted value of (58.3°; Ricketts) was higher than the highest expected value (56.5°; Andrews) relative to the bisected occlusal plane (BOP). Thus all of these torque systems will aim for flatter inclinations than prescribed by any of the norm values. Depending on target values, the various bracket systems fell short by 1.8-5.5° (Andrews), 6.8-10.5° (Roth), 11.8-15.5° (MBT), or 16.8-20.5° (Ricketts). For L1, there was good agreement of the MBT system with the Ricketts and Björk target values (Δ0.1° and Δ-0.8°, respectively), and both the Roth and Ricketts systems came close to the Bergen target value (both Δ2.3°). Depending on target values, the ranges of deviation for L1 were 6.3-13.2° for Andrews (Class II prescription), 2.3°-9.2° for Roth, -3.7 to -3.2° for MBT, and 2.3-9.2° for Ricketts. Common values of upper incisor bracket torque do not have acceptable validity in achieving normal incisor inclinations. A careful selection of lower bracket torque may provide satisfactory matching with some of the targeted norm values.

  17. Pool Boiling CHF in Inclined Narrow Annuli

    International Nuclear Information System (INIS)

    Kang, Myeong Gie

    2010-01-01

    Pool boiling heat transfer has been studied extensively since it is frequently encountered in various heat transfer equipment. Recently, it has been widely investigated in nuclear power plants for application to the advanced light water reactors designs. Through the review on the published results it can be concluded that knowledge on the combined effects of the surface orientation and a confined space on pool boiling heat transfer is of great practical importance and also of great academic interest. Fujita et al. investigated pool boiling heat transfer, from boiling inception to the critical heat flux (CHF, q' CHF ), in a confined narrow space between heated and unheated parallel rectangular plates. They identified that both the confined space and the surface orientation changed heat transfer much. Kim and Suh changed the surface orientation angles of a downward heating rectangular channel having a narrow gap from the downward-facing position (180 .deg.) to the vertical position (90 .deg.). They observed that the CHF generally decreased as the inclination angle (θ ) increased. Yao and Chang studied pool boiling heat transfer in a confined heat transfer for vertical narrow annuli with closed bottoms. They observed that when the gap size ( s ) of the annulus was decreased the effect of space confinement to boiling heat transfer increased. The CHF was occurred at much lower value for the confined space comparing to the unconfined pool boiling. Pool boiling heat transfer in narrow horizontal annular crevices was studied by Hung and Yao. They concluded that the CHF decreased with decreasing gap size of the annuli and described the importance of the thin film evaporation to explain the lower CHF of narrow crevices. The effect of the inclination angle on the CHF on countercurrent boiling in an inclined uniformly heated tube with closed bottoms was also studied by Liu et al. They concluded that the CHF reduced with the inclination angle decrease. A study was carried out

  18. A volumetric model-based 2D to 3D registration method for measuring kinematics of natural knees with single-plane fluoroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Tsung-Yuan; Lu, Tung-Wu; Chen, Chung-Ming; Kuo, Mei-Ying; Hsu, Horng-Chaung [Institute of Biomedical Engineering, National Taiwan University, No. 1, Sec. 1, Jen-Ai Road, Taipei 10051, Taiwan (China); Institute of Biomedical Engineering, National Taiwan University, No. 1, Sec. 1, Jen-Ai Road, Taipei 10051, Taiwan (China) and Department of Physical Therapy, China Medical University, Taichung 40402, Taiwan (China); Department of Orthopaedic Surgery, China Medical University Hospital, Taichung 40447, Taiwan (China)

    2010-03-15

    Purpose: Accurate measurement of the three-dimensional (3D) rigid body and surface kinematics of the natural human knee is essential for many clinical applications. Existing techniques are limited either in their accuracy or lack more realistic experimental evaluation of the measurement errors. The purposes of the study were to develop a volumetric model-based 2D to 3D registration method, called the weighted edge-matching score (WEMS) method, for measuring natural knee kinematics with single-plane fluoroscopy to determine experimentally the measurement errors and to compare its performance with that of pattern intensity (PI) and gradient difference (GD) methods. Methods: The WEMS method gives higher priority to matching of longer edges of the digitally reconstructed radiograph and fluoroscopic images. The measurement errors of the methods were evaluated based on a human cadaveric knee at 11 flexion positions. Results: The accuracy of the WEMS method was determined experimentally to be less than 0.77 mm for the in-plane translations, 3.06 mm for out-of-plane translation, and 1.13 deg. for all rotations, which is better than that of the PI and GD methods. Conclusions: A new volumetric model-based 2D to 3D registration method has been developed for measuring 3D in vivo kinematics of natural knee joints with single-plane fluoroscopy. With the equipment used in the current study, the accuracy of the WEMS method is considered acceptable for the measurement of the 3D kinematics of the natural knee in clinical applications.

  19. Computational stability appraisal of rectangular natural circulation loop: Effect of loop inclination

    International Nuclear Information System (INIS)

    Krishnani, Mayur; Basu, Dipankar N.

    2017-01-01

    Highlights: • Computational model developed for single-phase rectangular natural circulation loop. • Role of loop inclination to vertical on thermalhydraulic stability is explored. • Inclination has strong stabilizing effect due to lower effective gravitation force. • Increase in tilt angle reduces settling time and highest amplitude of oscillation. • An angle of 15° is suggested for the selected loop geometry. - Abstract: Controlling stability behavior of single-phase natural circulation loops, without significantly affecting its steady-state characteristics, is a topic of wide research interest. Present study explores the role of loop inclination on a particular loop geometry. Accordingly a 3D computational model of a rectangular loop is developed and transient conservation equations are solved to obtain the temporal variation in flow parameters. Starting from the quiescent state, simulations are performed for selected sets of operating conditions and also with a few selected inclination angles. System experiences instability at higher heater powers and also with higher sink temperatures. Inclination is found to have a strong stabilizing influence owing to the reduction in the effective gravitational acceleration and subsequent decline in local buoyancy effects. The settling time and highest amplitude of oscillations substantially reduces for a stable system with a small inclination. Typically-unstable systems can also suppress the oscillations, when subjected to tilting, within a reasonable period of time. It is possible to stabilize the loop within shorter time span by increasing the tilt angle, but at the expense of reduction in steady-state flow rate. Overall a tilt angle of 15° is suggested for the selected geometry. Results from the 3D model is compared with the predictions from an indigenous 1D code. While similar qualitative influence of inclination is observed, the 1D model predicts early appearance of the stability threshold and hence hints

  20. Improvement of image quality of holographic projection on tilted plane using iterative algorithm

    Science.gov (United States)

    Pang, Hui; Cao, Axiu; Wang, Jiazhou; Zhang, Man; Deng, Qiling

    2017-12-01

    Holographic image projection on tilted plane has an important application prospect. In this paper, we propose a method to compute the phase-only hologram that can reconstruct a clear image on tilted plane. By adding a constant phase to the target image of the inclined plane, the corresponding light field distribution on the plane that is parallel to the hologram plane is derived through the titled diffraction calculation. Then the phase distribution of the hologram is obtained by the iterative algorithm with amplitude and phase constrain. Simulation and optical experiment are performed to show the effectiveness of the proposed method.

  1. Complex plane integration in the modelling of electromagnetic fields in layered media: part 1. Application to a very large loop

    International Nuclear Information System (INIS)

    Da Silva e Silva, Valdelírio; Régis, Cícero; Howard, Allen Q Jr

    2014-01-01

    This paper analyses the details of a procedure for the numerical integration of Hankel transforms in the calculation of the electromagnetic fields generated by a large horizontal loop over a 1D earth. The method performs the integration by deforming the integration path into the complex plane and applying Cauchy's theorem on a modified version of the integrand. The modification is the replacement of the Bessel functions J 0 and J 1 by the Hankel functions H 0 (1) and H 1 (1) respectively. The integration in the complex plane takes advantage of the exponentially decaying behaviour of the Hankel functions, allowing calculation on very small segments, instead of the infinite line of the original improper integrals. A crucial point in this problem is the location of the poles. The companion paper shows two methods to estimate the pole locations. We have used this method to calculate the fields of very large loops. Our results show that this method allows the estimation of the integrals with fewer evaluations of the integrand functions than other methods. (paper)

  2. Effect of Initial Stress on the Dynamic Response of a Multi-Layered Plate-Strip Subjected to an Arbitrary Inclined Time-Harmonic Force

    Science.gov (United States)

    Daşdemir, A.

    2017-08-01

    The forced vibration of a multi-layered plate-strip with initial stress under the action of an arbitrary inclined time-harmonic force resting on a rigid foundation is considered. Within the framework of the piecewise homogeneous body model with the use of the three-dimensional linearized theory of elastic waves in initially stressed bodies (TLTEWISB), a mathematical modelling is presented in plane strain state. It is assumed that there exists the complete contact interaction at the interface between the layers and the materials of the layer are linearly elastic, homogeneous and isotropic. The governing system of the partial differential equations of motion for the considered problem is solved approximately by employing the Finite Element Method (FEM). Further, the influence of the initial stress parameter on the dynamic response of the plate-strip is presented.

  3. Microstructure of nitrides grown on inclined c-plane sapphire and SiC substrate

    International Nuclear Information System (INIS)

    Imura, M.; Honshio, A.; Miyake, Y.; Nakano, K.; Tsuchiya, N.; Tsuda, M.; Okadome, Y.; Balakrishnan, K.; Iwaya, M.; Kamiyama, S.; Amano, H.; Akasaki, I.

    2006-01-01

    High-quality (112-bar 0) GaN layers with atomically flat surface have been grown on a precisely offset-angle-controlled (11-bar 02) sapphire substrate by metal-organic vapor phase epitaxy (MOVPE). Insertion of AlGaN layer between underlying AlN layer and GaN was found to improve crystalline quality of upper GaN layer. In addition, a combination of high growth condition followed and epitaxial lateral overgrowth has been employed for the growth of GaN and this helped in reducing the dislocation density in the resultant layers. GaN and AlN were grown on (303-bar 8) SiC substrates by MOVPE and sublimation methods, respectively. The crystal orientation of GaN and AlN could be just aligned to that of the substrate. Microstructure analysis of the layers was also carried out by transmission electron microscopy

  4. Surprising Behavior of Spinning Tops and Eggs on an Inclined Plane

    Science.gov (United States)

    Cross, Rod

    2016-01-01

    A spinning top or a spinning hard-boiled egg is fascinating to observe since both objects can remain upright for a relatively long time without falling over. If spun at sufficient speed on a horizontal surface, the spin axis rises to a vertical position and the bottom end tends to remain fixed in position on the surface. If the initial spin is…

  5. Changing Images of the Inclined Plane: A Case Study of a Revolution in American Science Education

    Science.gov (United States)

    Turner, Steven C.

    2012-01-01

    Between 1880 and 1920 the way science was taught in American High Schools changed dramatically. The old "lecture/demonstration" method, where information was presented to essentially passive students, was replaced by the "laboratory" method, where students performed their own experiments in specially constructed student laboratories. National…

  6. Approaching the Brachistochrone Using Inclined Planes--Striving for Shortest or Equal Travelling Times

    Science.gov (United States)

    Theilmann, Florian

    2017-01-01

    The classical "brachistochrone" problem asks for the path on which a mobile point M just driven by its own gravity will travel in the shortest possible time between two given points "A" and "B." The resulting curve, the cycloid, will also be the "tautochrone" curve, i.e. the travelling time of the mobile…

  7. Articular Eminence Inclination in Medieval and Contemporary Croatian Population

    Science.gov (United States)

    Kranjčić, Josip; Šlaus, Mario; Vodanović, Marin; Peršić, Sanja; Vojvodić, Denis

    2016-12-01

    Articular eminence inclination (AEI) of the temporomandibular joint leads the mandible in its movements. Therefore, the aim of the present study was to determine AEI values in medieval (MP) and recent (RP) Croatian population. The study was carried out on two groups of specimens: first group with 30 MP human dry skulls, while the other, serving as control group consisted of 137 dry skulls. The AEI was measured on lateral digital skull images as the angle between the best fi t line drawn along the posterior wall of the articular eminence and the Frankfurt horizontal plane. No statistically significant (p>0.05) differences between the left and right side AEI were found between MP skulls and RP skulls. The mean value of MP AEI was 45.5˚, with a range of 20.9˚-64˚. The mean RP AEI value was steeper (61.99˚), with a range of 30˚-94˚. Difference between the mean MP and RP AEI values was statistically significant (pmedieval time, and consequently different masticatory loads and forces.

  8. In-Clinic Blood Pressure Prediction of Normal Ambulatory Blood Pressure Monitoring in Pediatric Hypertension Referrals.

    Science.gov (United States)

    Johnson, Philip K; Ferguson, Michael A; Zachariah, Justin P

    2016-07-01

    Since younger patients have low pretest probability of hypertension and are susceptible to reactive and masked hypertension, ambulatory blood pressure monitoring (ABPM) can be useful. To better target use in referred patients, we sought to define in-clinic systolic blood pressure (SBP) measures that predicted normal ABPM and target end organ damage. Data were collected on consecutive patients referred for high BP undergoing an ambulatory BP monitor from 2010 to 2013 (n = 248, 33.9% female, mean age 15.5 ± 3.6 years). Candidate in-clinic predictors were systolic maximum, minimum, or average BPs obtained by auscultative, oscillometric, or both. Multivariable logistic regression models were used to determine the prediction of normal ABPM by in-clinic BP predictors. Separate models considered predicting left ventricular hypertrophy (LVH) by in-clinic SBP vs. ABPM-defined hypertension. Identified predictor utility was tested with receiver operator characteristic curves. Maximum (OR 0.97 [95% CI 0.94-0.99]; P = .047), minimum (0.96 [0.94-0.99]; P = .002), and average (0.97 [0.95-1.00]; P = .04) in-clinic auscultative SBP predicted normal ABPM. Each had a c-statistic of 0.58. LVH was associated with in-clinic auscultative minimum SBP treated continuously (1.05, [1.01-1.10], P = .01) or dichotomized at the 90th percentile (8.23, [1.48-45.80], P = .02), as well as ABPM-defined hypertension (3.31, [1.23-8.91], P = .02). Both predictors had poor sensitivity and specificity. In youth, normal auscultative in-clinic systolic blood pressure indices weakly predicted normal ambulatory blood pressure and target end organ damage. © 2016 Wiley Periodicals, Inc.

  9. Factors influencing superimposition error of 3D cephalometric landmarks by plane orientation method using 4 reference points: 4 point superimposition error regression model.

    Science.gov (United States)

    Hwang, Jae Joon; Kim, Kee-Deog; Park, Hyok; Park, Chang Seo; Jeong, Ho-Gul

    2014-01-01

    Superimposition has been used as a method to evaluate the changes of orthodontic or orthopedic treatment in the dental field. With the introduction of cone beam CT (CBCT), evaluating 3 dimensional changes after treatment became possible by superimposition. 4 point plane orientation is one of the simplest ways to achieve superimposition of 3 dimensional images. To find factors influencing superimposition error of cephalometric landmarks by 4 point plane orientation method and to evaluate the reproducibility of cephalometric landmarks for analyzing superimposition error, 20 patients were analyzed who had normal skeletal and occlusal relationship and took CBCT for diagnosis of temporomandibular disorder. The nasion, sella turcica, basion and midpoint between the left and the right most posterior point of the lesser wing of sphenoidal bone were used to define a three-dimensional (3D) anatomical reference co-ordinate system. Another 15 reference cephalometric points were also determined three times in the same image. Reorientation error of each landmark could be explained substantially (23%) by linear regression model, which consists of 3 factors describing position of each landmark towards reference axes and locating error. 4 point plane orientation system may produce an amount of reorientation error that may vary according to the perpendicular distance between the landmark and the x-axis; the reorientation error also increases as the locating error and shift of reference axes viewed from each landmark increases. Therefore, in order to reduce the reorientation error, accuracy of all landmarks including the reference points is important. Construction of the regression model using reference points of greater precision is required for the clinical application of this model.

  10. Changing inclination of earth satellites using the gravity of the moon

    Directory of Open Access Journals (Sweden)

    Karla de Souza Torres

    2006-01-01

    Full Text Available We analyze the problem of the orbital control of an Earth's satellite using the gravity of the Moon. The main objective is to study a technique to decrease the fuel consumption of a plane change maneuver to be performed in a satellite that is in orbit around the Earth. The main idea of this approach is to send the satellite to the Moon using a single-impulsive maneuver, use the gravity field of the Moon to make the desired plane change of the trajectory, and then return the satellite to its nominal semimajor axis and eccentricity using a bi-impulsive Hohmann-type maneuver. The satellite is assumed to start in a Keplerian orbit in the plane of the lunar orbit around the Earth and the goal is to put it in a similar orbit that differs from the initial orbit only by the inclination. A description of the close-approach maneuver is made in the three-dimensional space. Analytical equations based on the patched conics approach are used to calculate the variation in velocity, angular momentum, energy, and inclination of the satellite. Then, several simulations are made to evaluate the savings involved. The time required by those transfers is also calculated and shown.

  11. Study on natural circulation characteristics of an IPWR under inclined and rolling condition

    Energy Technology Data Exchange (ETDEWEB)

    He, Lihui [College of Computer Science and Information Technology, Harbin Normal University, Harbin (China); Wang, Bing [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin (China); Xia, Genglei, E-mail: xiagenglei@163.com [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin (China); Peng, Minjun [Fundamental Science on Nuclear Safety and Simulation Technology Laboratory, Harbin Engineering University, Harbin (China)

    2017-06-15

    Highlights: • An ocean-based thermal-hydraulic analysis code was developed based on RELAP5 codes. • The inclination condition can reduce the mass flow rate of reactor core. • The system parameters asymmetry increases with the increasing inclination angle. • Flow oscillation of different loops cancel each other due to the symmetrical arrangement of the reactor. • The off-center roll axis location can break the symmetry and enlarge fluctuation amplitude of the core flow rate. - Abstract: An ocean-based thermal-hydraulic system analysis code was developed based on RELAP5/MOD3 code by adding additional force model of ocean condition and control volume coordinate solver model. The natural circulation operation characteristics of integrated pressurized water reactor (IPWR) under ocean conditions were studied and the effects of inclination and rolling motions were analyzed. The results conclude that, the inclination condition can reduce the mass flow rate of reactor core and lead to inconsistent coolant flow rates of the left and right loops, furthermore, it affects the heat transfer of once-through steam generators (OTSGs). In the case of rolling motion, the additional pressure drop of the loop is dominated by tangential force, and flow oscillation of different loops cancel each other due to the symmetrical arrangement of the reactor. The off-center roll axis location, the combination of the inclination and rolling motion, both can break the thermal-hydraulic symmetry among different loops and enlarge fluctuation amplitude of the core flow rate.

  12. A dual length scale method for plane-wave-based, simulation studies of chemical systems modeled using mixed ab initio/empirical force field descriptions

    Science.gov (United States)

    Yarne, Dawn A.; Tuckerman, Mark E.; Martyna, Glenn J.

    2001-08-01

    Mixed ab initio/empirical force-field simulation studies, calculations in which one part of the system is treated using a fully ab initio description and another part is treated using an empirical description, are becoming increasingly popular. Here, the ability of the commonly used, plane wave-based generalized gradient approximation to density functional theory is extended to model systems in which the electrons are assumed to be localized in a single small region of space, that is, itself, embedded within a large chemically inert bath. This is accomplished by introducing two length scales, so that the rapidly varying, short range, electron-electron and electron-atom interactions, arising from the region where the electrons are localized, can be treated using an appropriately large plane wave basis, while the corresponding, slowly varying, long range interactions of the electrons with the full system or bath, can be treated using a small basis. Briefly, a novel Cardinal B-spline based formalism is employed to derive a smooth, differentiable, and rapidly convergent (with respect to the small basis) expression for the total electronic energy, which explicitly contains the two length scales. The method allows reciprocal space based techniques designed to treat clusters, wires, surfaces and solids/liquids (open, and 1-D and 2-D periodic boundary conditions, respectively) to be utilized. Other plane wave-based "mixed" methods are restricted to clusters. The new methodology, which scales as N log N at fixed size of the chemically active region, has been implemented for parallel computing platforms and tested through applications to both model and realistic problems including an enzyme, human carbonic anhydrase II solvated in an explicit bath of water molecules.

  13. Plane waves as tractor beams

    Science.gov (United States)

    Forgács, Péter; Lukács, Árpád; Romańczukiewicz, Tomasz

    2013-12-01

    It is shown that in a large class of systems, plane waves act as tractor beams: i.e., an incident plane wave can exert a pulling force on the scatterer. The underlying physical mechanism for the pulling force is due to the sufficiently strong scattering of the incoming wave into another mode carrying more momentum, in which case excess momentum is created behind the scatterer. This tractor beam or negative radiation pressure (NRP) effect, is found to be generic in systems with multiple scattering channels. In a birefringent medium, electromagnetic plane waves incident on a thin plate exert NRP of the same order of magnitude as optical radiation pressure, while in artificial dielectrics (metamaterials), the magnitude of NRP can even be macroscopic. In two dimensions, we study various scattering situations on vortices, and NRP is shown to occur by the scattering of heavy baryons into light leptons off cosmic strings, and by neutron scattering off vortices in the XY model.

  14. Electro-hydrodynamics and kinetic modelling of polluted air flow activated by multi-tip-to-plane corona discharge

    Science.gov (United States)

    Meziane, M.; Eichwald, O.; Sarrette, J. P.; Ducasse, O.; Yousfi, M.; Marchal, F.

    2013-04-01

    The present paper is devoted to the 2D simulation of an Atmospheric Corona Discharge Reactor (ACDR) involving 10 pins powered by a DC high voltage and positioned 7 mm above a grounded metallic plane. The corona reactor is periodically crossed by thin mono filamentary streamers with a natural repetition frequency of some tens of kHz. The simulation involves the electro-dynamic, chemical kinetic, and neutral gas hydrodynamic phenomena that influence the kinetics of the chemical species transformation. Each discharge stage (including the primary and the secondary streamers development and the resulting thermal shock) lasts about one hundred nanoseconds while the post-discharge stages occurring between two successive discharge phases last one hundred microseconds. The ACDR is crossed by a lateral air flow including 400 ppm of NO. During the considered time scale of 10 ms, one hundred discharge/post-discharge cycles are simulated. The simulation involves the radical formation and thermal exchange between the discharges and the background gas. The results show how the successive discharges activate the flow gas and how the induced turbulence phenomena affect the redistribution of the thermal energy and the chemical kinetics inside the ACDR.

  15. On liquid films on an inclined plate

    KAUST Repository

    BENILOV, E. S.

    2010-08-18

    This paper examines two related problems from liquid-film theory. Firstly, a steady-state flow of a liquid film down a pre-wetted plate is considered, in which there is a precursor film in front of the main film. Assuming the former to be thin, a full asymptotic description of the problem is developed and simple analytical estimates for the extent and depth of the precursor film\\'s influence on the main film are provided. Secondly, the so-called drag-out problem is considered, where an inclined plate is withdrawn from a pool of liquid. Using a combination of numerical and asymptotic means, the parameter range where the classical Landau-Levich-Wilson solution is not unique is determined. © 2010 Cambridge University Press.

  16. Inclined Buildings – Some Reasons and Solutions

    Science.gov (United States)

    Kijanka, Małgorzata; Kowalska, Magdalena

    2017-10-01

    To straighten a leaning building is never easy. There are no standard solutions. On the other hand, there are several, usually historical, leaning structures which have not been rectified, mostly because in the current shape they are a touristic attraction - the best example being the famous Leaning Tower of Pisa. This does not mean however that inclination of load bearing walls can be ignored. Even though in some cases the problem can be treated in terms of serviceability limit states (the deformation is only decreasing the comfort of ‘normal use’ of the building), in the other – it may be a signal of the forthcoming structural failure. The situation must always be treated individually – if the problem concerns a residential building, then cracks on the walls, not-opening doors or tilted ceilings, which often coincide with the leaning of the external walls, are always the reason of worry and such a building needs to be straightened. The reasons of the problem lie usually in uneven settlement of the ground, which in turn, may be caused by various problems, such as the presence of too soft, too weak, unconsolidated or expansive soils under the building, varying groundwater table, mining activity etc. Solving of the problem by just straightening the building is often not enough. To prevent further deformations a detailed analysis of the possible causes is necessary. Sometimes it may be helpful to review similar cases. The paper contains a general overview of selected inclined buildings: starting with the well-known historical examples and ending with individual houses from the Region of Silesia. Since the problem of instability mostly affects structures with critical height to width ratio, tall and narrow structures (towers) are dominating in the work. The aim of the study was to describe the reasons of the problems and present solutions that have been successfully applied and can be also useful to engineers and designers to prevent similar situations.

  17. A Liquid-Surface-Based Three-Axis Inclination Sensor for Measurement of Stage Tilt Motions.

    Science.gov (United States)

    Shimizu, Yuki; Kataoka, Satoshi; Ishikawa, Tatsuya; Chen, Yuan-Liu; Chen, Xiuguo; Matsukuma, Hiraku; Gao, Wei

    2018-01-30

    In this paper a new concept of a liquid-surface-based three-axis inclination sensor for evaluation of angular error motion of a precision linear slide, which is often used in the field of precision engineering such as ultra-precision machine tools, coordinate measuring machines (CMMs) and so on, is proposed. In the liquid-surface-based three-axis inclination sensor, a reference float mounting a line scale grating having periodic line grating structures is made to float over a liquid surface, while its three-axis angular motion is measured by using an optical sensor head based on the three-axis laser autocollimation capable of measuring three-axis angular motion of the scale grating. As the first step of research, in this paper, theoretical analysis on the angular motion of the reference float about each axis has been carried out based on simplified kinematic models to evaluate the possibility of realizing the proposed concept of a three-axis inclination sensor. In addition, based on the theoretical analyses results, a prototype three-axis inclination sensor has been designed and developed. Through some basic experiments with the prototype, the possibility of simultaneous three-axis inclination measurement by the proposed concept has been verified.

  18. Peri-implant strain around mesially inclined two-implant-retained mandibular overdentures with Locator attachments.

    Science.gov (United States)

    Elsyad, Moustafa A; Eltowery, Salem M; Gebreel, Ashraf A

    2017-12-27

    This study aimed to evaluate the peri-implant strain around mesially inclined implants used to retain mandibular overdentures with Locator resilient attachments. Four mandibular edentulous acrylic resin models received two implants in the canine areas with 0°, 5°, 10°, and 20° mesial inclinations. Overdentures were connected to the implants using Locator attachments. Pink nylon inserts (light retention) were used for all implant inclinations, and red inserts were used for 20° inclination (20°red). Four strain gages were bonded on the mesial (M), distal (D), buccal (B), and lingual (L) surfaces of each implant. Peri-implant strains were measured during bilateral and unilateral loading. The 20° inclination showed the highest strain, followed by 10° and 5°, and both 0° and 20°red presented with the lowest strain. Site D was associated with the highest strain, followed by M, B, and L, which showed the lowest strain values. Unilateral loading and the loading side presented with significantly higher strain values than bilateral loading and the nonloading side, respectively. Hence, in this study, strains around the two-implant-retained overdentures with Locator attachments increased with increases in mesial implant angulation, except when red male inserts were used.

  19. The Gothic arch (needle point) tracing and condylar inclination.

    Science.gov (United States)

    el-Gheriani, A S; Winstanley, R B

    1987-11-01

    The records of 11 patients referred for treatment of TMJ disorders were used to compare condylar inclination found by drawing a tangent and by using a mathematic technique. Needle point tracing angles were also measured for the same patients and were compared with the condylar inclination. It can be concluded that (1) the mathematic technique outlined records a more accurate condylar angulation, and (2) there is a great variation in condylar inclination values between patients and between left and right sides of the same patient, and (3) there is no direct relationship between condylar inclination and the needle point tracing angle.

  20. Lieb's correlation inequality for plane rotors

    International Nuclear Information System (INIS)

    Rivasseau, V.

    1980-01-01

    We prove a conjecture by E. Lieb, which leads to the Lieb inequality for plane rotors. As in the Ising model case, this inequality implies the existence of an algorithm to compute the transition temperature of this model. (orig.)

  1. High order models for the nonlinear shallow water wave equations on the equatorial beta-plane with application to Kelvin wave frontogenesis

    Science.gov (United States)

    Boyd, John P.

    1998-08-01

    We describe two new numerical models for solving the nonlinear shallow water wave equations on the equatorial beta-plane. The finite difference code is eighth order in space and 4th order in time. The second model is a four-mode Hermite-Galerkin scheme in latitude combined with a Fourier pseudospectral algorithm in longitude and 4th order time-marching. As a first application, we test the Boyd-Ripa theory for Kelvin wave frontogenesis. The zeroth order strained coordinates approximation is good even for waves of nondimensional unit amplitude. The first order corrections grow. Even so, for small amplitude, the first order analytical approximations encapsulate most of the difference between the zeroth order approximation and the numerical solution if the longitudinal derivatives are interpreted as x-derivatives rather than as derivatives with respect to the strained coordinate ξ. The main discrepancy is that for moderate and large amplitude, the front curves westward with increasing latitude.

  2. HEAT EXCHANGE AND AERODYNAMICS OF THE COMBINED TUBING BUNDLES WITH CROSS INCLINED FINS

    Directory of Open Access Journals (Sweden)

    Knyazyuk V. I

    2013-04-01

    Full Text Available The paper presents results of experimental research and analyses air-side thermal performance of combined tube bundles with cross inclined fins. The empirical correlations for heat transfer and flow friction of tubes with inclined fins at different orientation finned tubes relatively of air flow are presented. The errors of thermal and aerodynamic tests are 3-5% and 9.2%, respectively. The proposed correlations describe an experimental data with a coefficient of determination about 0.979-0.998. The impact of tubes arrangement in a bundle on energy performance of heat exchanger were analyzed using complete and local heat modeling methods at a stationary heat flux. Experimental research indicates that efficiency of inclined fins can be calculated by using the equation for cross rectangular fins with average deviation of ±5 %.

  3. Linearized transfer between inclined circular orbits using low-thrust blow down propulsion system

    Science.gov (United States)

    Kechichian, J. A.; White, L. K.

    1983-01-01

    Noncoplanar transfers between neighboring circular orbits are presented for spacecraft using their own low-thrust blow down propulsion system. It is assumed that the out-of-plane angle between the decaying thrust vector and the current orbit plane remains constant for each extended burn. Switching conditions are derived for the cutoff and relight of the propulsion system in order to carry out a given transfer with inclination change. Furthermore the location where the thrust acceleration is initially applied with respect to the line of nodes of the two orbits is uniquely determined. Finally an analytic derivation of the linearized coplanar motion for stationkeeping and terminal rendezvous studies is also presented and a scheme for deriving the second order correction shown.

  4. Correlation between cuspal inclination and tooth cracked syndrome: a three-dimensional reconstruction measurement and finite element analysis.

    Science.gov (United States)

    Qian, Yunzhu; Zhou, Xuefeng; Yang, Jianxin

    2013-06-01

    This paper explored the correlation between cuspal inclination and tooth cracked syndrome by measuring and reconstructing the cuspal inclinations of cracked maxillary first molars through three-dimensional (3D) finite element analysis (FEA). The cuspal inclinations of 11 maxillary left first molars with cracked tooth syndrome and 22 intact controls were measured by 3D reconstruction. The mean values of each group were used to construct two 3D finite element models of maxillary first molar for comparing stress distribution under the loads of 200N at 0°, 45°, and 90°, respectively, to the tooth axis. There was statistically significant difference in the cuspal inclination between the incompletely fractured group and the intact control group ( P  < 0.001), which was 5.5-6.7 degrees steeper. The model from the mean cuspal inclinations of the incompletely fractured molars showed the maximum tensile stress of 5.83, 10.87, and 25.32 MPa, respectively, in comparison with 5.40, 8.49, and 22.76 MPa for the model of the control group. Besides, the tensile stress was mainly at the center groove and cervical region of the molar model. Steeper cuspal inclinations resulted in an increment in tensile stress that was mainly at the center groove and cervical region of the molar model under equivalent loads. Higher unfavorable tensile stress was generated with the increasing horizontal component load on the cuspal incline. This indicates an effective reduction of cuspal inclination to the compromised teeth for dentists. © 2012 John Wiley & Sons A/S.

  5. Unique operations for a highly inclined, elliptical, geosynchronous satellite

    Science.gov (United States)

    Anglin, Patrick T.; Briskman, Robert D.

    2004-08-01

    The first space segment devoted to a Digital Audio Radio Service (DARS) for the Continental United States (CONUS) was established when the last satellite of a three satellite constellation (Flight Models FM-1, FM-2 and FM-3) was launched in November 2000. Each satellite is in a highly inclined, elliptical, geosynchronous orbit that is separated by 120° in Right Angle of the Ascending Node (RAAN) from the other two satellites' orbits. This results in an 8 h phasing in ground track between each satellite. These distinct orbits provide superior look angles and signal availability to mobile receivers in the northern third of the United States when compared to geostationary satellites. However, this unique orbital constellation results in some particular performance and operational differences from geostationary orbit satellites. Some of these are: Earth Sensor noise, maneuver implementation and power management. Descriptions and performance improvements of these orbit specific operations are detailed herein.

  6. Simulation of Solar Radiation Incident on Horizontal and Inclined Surfaces

    Directory of Open Access Journals (Sweden)

    MA Basunia

    2012-12-01

    Full Text Available A computer model was developed to simulate the hourly, daily and monthly average of daily solar radiation on horizontal and inclined surfaces. The measured hourly and daily solar radiation was compared with simulated radiation, and favourable agreement was observed for the measured and predicted values on clear days. The measured and simulated monthly averages of total (diffuse and beam daily solar radiation were compared and a reasonable agreement was observed for a number of stations in Japan. The simulation showed that during the rice harvesting season, September to October, there is a daily average of 14.7 MJ/m2 of solar irradiation on a horizontal surface in Matsuyama, Japan. There is a similar amount of solar radiation on a horizontal surface during the major rice harvesting season, November to December, in Bangladesh. This radiation can be effectively utilized for drying rough rice and other farm crops.

  7. Application of a plane-stratified emission model to predict the effects of vegetation in passive microwave radiometry

    Directory of Open Access Journals (Sweden)

    K. Lee

    2002-01-01

    Full Text Available This paper reports the application to vegetation canopies of a coherent model for the propagation of electromagnetic radiation through a stratified medium. The resulting multi-layer vegetation model is plausibly realistic in that it recognises the dielectric permittivity of the vegetation matter, the mixing of the dielectric permittivities for vegetation and air within the canopy and, in simplified terms, the overall vertical distribution of dielectric permittivity and temperature through the canopy. Any sharp changes in the dielectric profile of the canopy resulted in interference effects manifested as oscillations in the microwave brightness temperature as a function of canopy height or look angle. However, when Gaussian broadening of the top and bottom of the canopy (reflecting the natural variability between plants was included within the model, these oscillations were eliminated. The model parameters required to specify the dielectric profile within the canopy, particularly the parameters that quantify the dielectric mixing between vegetation and air in the canopy, are not usually available in typical field experiments. Thus, the feasibility of specifying these parameters using an advanced single-criterion, multiple-parameter optimisation technique was investigated by automatically minimizing the difference between the modelled and measured brightness temperatures. The results imply that the mixing parameters can be so determined but only if other parameters that specify vegetation dry matter and water content are measured independently. The new model was then applied to investigate the sensitivity of microwave emission to specific vegetation parameters. Keywords: passive microwave, soil moisture, vegetation, SMOS, retrieval

  8. Entrepreneurial inclinations of women from rural areas

    Directory of Open Access Journals (Sweden)

    Marković-Savić Olivera S.

    2014-01-01

    Full Text Available Entrepreneurial inclinations of women from rural areas are shaped by the lack of business ideas and economic capital, which, in addition to financial resources, includes cultural capital in the form of knowledge and skills. The paper presents a part of a broader study on the social position of women from the rural areas of northern Kosovo and Metohija, conducted in 2013. The research was predominantly focused on entrepreneurial inclinations of rural women, and the findings suggest that private enterprise in the studied population is undeveloped as a result of two dominant reasons. The first reason is the situation which is unfavorable in terms of politics and security, and therefore, not conducive to investment security, together with the specificity in the form of complex administrative business conditions requiring compliance to parallel and mutually incompatible standards (of the Republic of Serbia and of the UNMIK administration. The second important reason for the lack of entrepreneurial initiatives is the lack of ownership of property and the means of production, since banks do not give loans without guarantees in the form of ownership of the mortgage, while other forms of financial incentives are unavailable. The respondents attended programs for acquiring new knowledge and skills only in a small number of cases, while showing the greatest susceptibility to education in traditional skills, such as training in agriculture and handicrafts, which are not the skills in line with the needs of the labor market. As the most important reasons that -prevent them from having their own business, the respondents -mentioned: the lack of ideas and the lack of financial resources. In this regard, they would find incentives in the form of grants most helpful to start their own business. The absence of funds and gender inequality form the basis for the lack of ownership of property and means of production. In addition to the shortage of financial

  9. Constraining the Relative Inclinations of the Planets B and C of the ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... We investigate on the relative inclination of the planets B and C orbiting the pulsar PSR B1257+12. First, we show that the third Kepler's law does represent an adequate model for the orbital periods of the planets, because other Newtonian and Einsteinian corrections are orders of magnitude smaller than ...

  10. A Study of Static Performance of Fixed Inclined Slider Bearings – A ...

    African Journals Online (AJOL)

    In this paper, the performance of a fixed inclined slider bearing whose surfaces are lubricated by a non Newtonian power law lubricant is investigated numerically. Based on the power law model, the modified Reynolds equation is derived and solved using the finite element method. The effect of flow index on pressure ...

  11. A Study of Static Performance of Fixed Inclined Slider Bearings – A ...

    African Journals Online (AJOL)

    Michael Horsfall

    and friction. He compared numerical solutions for the bearing performance metrics with analytical solution using a range of bearing aspect ratios and power law indices. In this paper, we present the effect of power law fluids on the static performance characteristics of inclined slider bearings. Based on the power law model ...

  12. Self-filtering extremely inclined x-ray crystal monochromator

    Czech Academy of Sciences Publication Activity Database

    Hrdá, Jaromíra; Hrdý, Jaromír

    2011-01-01

    Roč. 44, č. 6 (2011), 1169-1172 ISSN 0021-8898 R&D Projects: GA MPO FR-TI1/412 Institutional research plan: CEZ:AV0Z10100522 Keywords : synchrotron radiation monochromator * x-ray crystal monochromator * inclined monochromator * inclined diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.152, year: 2011

  13. Shallow bias in Mediterranean paleomagnetic directions caused by inclination error

    NARCIS (Netherlands)

    Krijgsman, W.; Tauxe, Lisa

    2004-01-01

    A variety of paleomagnetic data from the Mediterranean region show a strong bias toward shallow inclinations. This pattern of shallow inclinations has been interpreted to be the result of (1) major northward terrane displacement, (2) large nondipole components in the Earth’s magnetic field, and

  14. Analysis of deformation due to inclined load in generalized ...

    African Journals Online (AJOL)

    The present investigation deals with study of deformation in homogeneous, isotropic thermodiffusion elastic half-space as a result of inclined load. The inclined load is assumed to be a linear combination of normal load and tangential load. The integral transform technique is used to solve the problem. As an application of ...

  15. 46 CFR 58.01-40 - Machinery, angles of inclination.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery, angles of inclination. 58.01-40 Section 58.01-40 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-40 Machinery, angles of inclination. (a) Propulsion machinery and all auxiliary...

  16. Dynamic phase transition in the kinetic spin-32 Blume-Capel model: Phase diagrams in the temperature and crystal-field interaction plane

    International Nuclear Information System (INIS)

    Keskin, Mustafa; Canko, Osman; Deviren, Bayram

    2007-01-01

    We analyze, within a mean-field approach, the stationary states of the kinetic spin-32 Blume-Capel (BC) model by the Glauber-type stochastic dynamics and subject to a time-dependent oscillating external magnetic field. The dynamic phase transition (DPT) points are obtained by investigating the behavior of the dynamic magnetization as a function of temperature and as well as calculating the Liapunov exponent. Phase diagrams are constructed in the temperature and crystal-field interaction plane. We find five fundamental types of phase diagrams for the different values of the reduced magnetic field amplitude parameter (h) in which they present a disordered, two ordered phases and the coexistences phase regions. The phase diagrams also exhibit a dynamic double-critical end point for 0 5.06

  17. Dynamic phase transition in the kinetic spin-1 Blume-Capel model: Phase diagrams in the temperature and crystal-field interaction plane

    International Nuclear Information System (INIS)

    Keskin, M.; Canko, O.; Temizer, U.

    2007-01-01

    Within a mean-field approach, the stationary states of the kinetic spin-1 Blume-Capel model in the presence of a time-dependent oscillating external magnetic field is studied. The Glauber-type stochastic dynamics is used to describe the time evolution of the system and obtain the mean-field dynamic equation of motion. The dynamic phase-transition points are calculated and phase diagrams are presented in the temperature and crystal-field interaction plane. According to the values of the magnetic field amplitude, three fundamental types of phase diagrams are found: One exhibits a dynamic tricritical point, while the other two exhibit a dynamic zero-temperature critical point

  18. Dynamic phase transition in the kinetic spin-32 Blume-Capel model: Phase diagrams in the temperature and crystal-field interaction plane

    Energy Technology Data Exchange (ETDEWEB)

    Keskin, Mustafa [Department of Physics, Erciyes University, 38039 Kayseri (Turkey)]. E-mail: keskin@erciyes.edu.tr; Canko, Osman [Department of Physics, Erciyes University, 38039 Kayseri (Turkey); Deviren, Bayram [Department of Physics, Erciyes University, 38039 Kayseri (Turkey)

    2007-06-15

    We analyze, within a mean-field approach, the stationary states of the kinetic spin-32 Blume-Capel (BC) model by the Glauber-type stochastic dynamics and subject to a time-dependent oscillating external magnetic field. The dynamic phase transition (DPT) points are obtained by investigating the behavior of the dynamic magnetization as a function of temperature and as well as calculating the Liapunov exponent. Phase diagrams are constructed in the temperature and crystal-field interaction plane. We find five fundamental types of phase diagrams for the different values of the reduced magnetic field amplitude parameter (h) in which they present a disordered, two ordered phases and the coexistences phase regions. The phase diagrams also exhibit a dynamic double-critical end point for 05.06.

  19. Prediction of Individual Muscle Forces Using Lagrange Multipliers Method - A Model of the Upper Human Limb in the Sagittal Plane: I. Theoretical Considerations.

    Science.gov (United States)

    Raikova, ROSITSA

    2000-01-01

    Analytical solutions of indeterminate problems formulated for biomechanical models with more than one degree of freedom (DOF) are rarely found. This paper is an extension of the investigations of a 1 DOF model (Raikova, 1996, J. Biomechanics, 763-772) for a more complex 3 DOF model. The proposed model of the human upper limb is in the sagittal plane and includes ten muscle elements, four of them being two-joint ones. The formulated optimization task is solved analytically using the method of Lagrange multipliers. It is supposed that the optimization function is complex but can be approximated by a weighted sum of the squared muscle forces, where the nature of the weight factors of the muscles are unknown. The proposed computational algorithm for determination of the unknown individual muscle forces and joint reactions is easily implemented and may be extended without difficulties for more DOF and muscles. The aim is to establish a means of investigation of the possible weight coefficients for different modelled situations, which will help in searching for their physiological interpretation and analytical description.

  20. Disturbed flow mediated modulation of shear forces on endothelial plane: A proposed model for studying endothelium around atherosclerotic plaques

    Science.gov (United States)

    Balaguru, Uma Maheswari; Sundaresan, Lakshmikirupa; Manivannan, Jeganathan; Majunathan, Reji; Mani, Krishnapriya; Swaminathan, Akila; Venkatesan, Saravanakumar; Kasiviswanathan, Dharanibalan; Chatterjee, Suvro

    2016-06-01

    Disturbed fluid flow or modulated shear stress is associated with vascular conditions such as atherosclerosis, thrombosis, and aneurysm. In vitro simulation of the fluid flow around the plaque micro-environment remains a challenging approach. Currently available models have limitations such as complications in protocols, high cost, incompetence of co-culture and not being suitable for massive expression studies. Hence, the present study aimed to develop a simple, versatile model based on Computational Fluid Dynamics (CFD) simulation. Current observations of CFD have shown the regions of modulated shear stress by the disturbed fluid flow. To execute and validate the model in real sense, cell morphology, cytoskeletal arrangement, cell death, reactive oxygen species (ROS) profile, nitric oxide production and disturbed flow markers under the above condition were assessed. Endothelium at disturbed flow region which had been exposed to low shear stress and swirling flow pattern showed morphological and expression similarities with the pathological disturbed flow environment reported previously. Altogether, the proposed model can serve as a platform to simulate the real time micro-environment of disturbed flow associated with eccentric plaque shapes and the possibilities of studying its downstream events.

  1. Studi Numerik Pengaruh Baffle Inclination Pada Alat Penukar Kalor Tipe U – Tube Terhadap Aliran Fluida Dan Perpindahan Panas

    Directory of Open Access Journals (Sweden)

    Reza Hidayatullah

    2014-09-01

    Full Text Available Alat penukar kalor sangat berpengaruh dalam industri terhadap keberhasilan keseluruhan rangkaian proses, karena kegagalan operasi alat ini baik akibat kegagalan mekanikal maupun opersional dapat menyebabkan berhentinya operasi unit. Penelitian terhadap desain heat exchanger masih terus dilakukan untuk mencari kinerja dari heat exchanger yang paling optimal, baik pada bagian baffle cut dan baffles inclination maupun susunan dari tube dengan menggunakan heat exchanger ukuran kecil sebagai model. Berdasarkan pada permasalahan di atas, maka dilakukan penelitian terhadap kinerja heat exchanger tipe U-tube dengan memvariasikan baffle inclination. Penelitian ini dilakukan secara numerik dengan variasi baffle inclination sebesar 0o, 10o, 20o dan variasi laju aliran massa sebesar 0,5 kg/s, 1kg/s, dan 2 kg/s. Tube yang digunakan adalah tipe U-tube yang disusun secara persegi. Model viskous yang digunakan adalah turbulensi model yaitu k-ε standar, dimana fluida yang digunakan adalah air pada boundary condition. Hasil analisa numerik menunjukkan adanya pengaruh baffle inclination pada alat penukar kalor tipe U – tube terhadap aliran fluida dan perpindahan panas. Peningkatan laju aliran massa dapat meningkatkan pressure drop secara cepat, alat penukar kalor shell and tube tipe U – tube dengan baffle inclination 20o memiliki unjuk kerja yang terbaik dibandingkan dengan baffle inclination 0o dan 10o.

  2. Economic analysis and prospective simulation in the low carbon town planing. Application of TRANUS+ model to Grenoble city

    International Nuclear Information System (INIS)

    Saujot, Mathieu

    2013-01-01

    Strategic spatial planning in France is currently given a rising importance for environmental and climate issues. Is this tool really able to reduce urban sprawl and produce an efficient framework for reducing transport emissions? What are the potential contributions of economic analysis and prospective modelling to planning? To answer these questions, we developed a study on the contributions of economic tools to planning into the broader context of political and administrative reforms in France. We then produced a critical analysis of current planning practices and attempted to define the conditions for a better integration of economic analysis into planning processes and methods. For our case study on the Grenoble urban area, we built and applied a series of economic tools able to inform decision-making on local climate policies in the framework of urban planning. In addition to being the first implementation of the integrated transport - land-use model TRANUS in France, this study further links the TRANUS model to an original economic methodology to obtain a tool we call TRANUS+. This tool is able to take into account the systemic nature of cities and then help to define better transport policies, notably by producing marginal abatement cost curves useful at the urban level. To have a more complete view of urban planning and the way in which it can be improved, we investigated several issues from a planning perspective: the choice of modelling tool and the role of cost-benefit analysis, energy poverty in the transport sector and electric vehicle deployment. (author) [fr

  3. The Effects of Boundary Conditions and Friction on the Helical Buckling of Coiled Tubing in an Inclined Wellbore.

    Science.gov (United States)

    Gong, Yinchun; Ai, Zhijiu; Sun, Xu; Fu, Biwei

    2016-01-01

    Analytical buckling models are important for down-hole operations to ensure the structural integrity of the drill string. A literature survey shows that most published analytical buckling models do not address the effects of inclination angle, boundary conditions or friction. The objective of this paper is to study the effects of boundary conditions, friction and angular inclination on the helical buckling of coiled tubing in an inclined wellbore. In this paper, a new theoretical model is established to describe the buckling behavior of coiled tubing. The buckling equations are derived by applying the principles of virtual work and minimum potential energy. The proper solution for the post-buckling configuration is determined based on geometric and natural boundary conditions. The effects of angular inclination and boundary conditions on the helical buckling of coiled tubing are considered. Many significant conclusions are obtained from this study. When the dimensionless length of the coiled tubing is greater than 40, the effects of the boundary conditions can be ignored. The critical load required for helical buckling increases as the angle of inclination and the friction coefficient increase. The post-buckling behavior of coiled tubing in different configurations and for different axial loads is determined using the proposed analytical method. Practical examples are provided that illustrate the influence of the angular inclination on the axial force. The rate of change of the axial force decreases with increasing angular inclination. Moreover, the total axial friction also decreases with an increasing inclination angle. These results will help researchers to better understand helical buckling in coiled tubing. Using this knowledge, measures can be taken to prevent buckling in coiled tubing during down-hole operations.

  4. The Effects of Boundary Conditions and Friction on the Helical Buckling of Coiled Tubing in an Inclined Wellbore.

    Directory of Open Access Journals (Sweden)

    Yinchun Gong

    Full Text Available Analytical buckling models are important for down-hole operations to ensure the structural integrity of the drill string. A literature survey shows that most published analytical buckling models do not address the effects of inclination angle, boundary conditions or friction. The objective of this paper is to study the effects of boundary conditions, friction and angular inclination on the helical buckling of coiled tubing in an inclined wellbore. In this paper, a new theoretical model is established to describe the buckling behavior of coiled tubing. The buckling equations are derived by applying the principles of virtual work and minimum potential energy. The proper solution for the post-buckling configuration is determined based on geometric and natural boundary conditions. The effects of angular inclination and boundary conditions on the helical buckling of coiled tubing are considered. Many significant conclusions are obtained from this study. When the dimensionless length of the coiled tubing is greater than 40, the effects of the boundary conditions can be ignored. The critical load required for helical buckling increases as the angle of inclination and the friction coefficient increase. The post-buckling behavior of coiled tubing in different configurations and for different axial loads is determined using the proposed analytical method. Practical examples are provided that illustrate the influence of the angular inclination on the axial force. The rate of change of the axial force decreases with increasing angular inclination. Moreover, the total axial friction also decreases with an increasing inclination angle. These results will help researchers to better understand helical buckling in coiled tubing. Using this knowledge, measures can be taken to prevent buckling in coiled tubing during down-hole operations.

  5. Inclined transpression in the Neka Valley, eastern Alborz, Iran

    Science.gov (United States)

    Nabavi, Seyed Tohid; Díaz-Azpiroz, Manuel; Talbot, Christopher J.

    2017-07-01

    Three major nappes in the Neka Valley in the eastern Alborz Mountains of Iran allow the Cimmerian to present convergence following the oblique collision between Iran and the southern margin of Eurasia. This work reports the identification of an inclined transpression zone recognized by field investigations and strain analyses of the geometries of formations and detailed mesoscopic structural analyses of multiple faults, folds and a cleavage. The main structures encountered include refolded recumbent asymmetric fold nappes, highly curved fold hinges, in a transpression zone that dips 37° to the NW between boundaries thrusts striking from N050° to N060°. The β angle (the angle between the zone boundary and direction of horizontal far-field shortening) is about 80°. The north-west and south-east boundaries of this zone coincide with the Haji-abad thrust and the Shah-Kuh thrust, respectively. Fold axes generally trend NE-SW and step to both right and left as a result of strike-slip components of fault displacements. Strain analyses using Fry's method on macroscopic ooids and fusulina deformed into oblate ellipsoids indicate that the natural strain varies between 2.1 and 3.14. The estimated angle between the maximum instantaneous strain axis (ISAmax) and the transpression zone boundary ( θ') is between 6° and 20°. The estimated oblique convergence angle ( α), therefore, ranges between 31° and 43°. The average kinematic vorticity number ( W k ) is 0.6, in a zone of sinistral pure shear-dominated inclined triclinic transpression. These results support the applicability of kinematic models of triclinic transpression to natural brittle-ductile shear zones.

  6. Method to reduce variations of inclination angle of the acetabular component during mini-incision hip arthroplasty.

    Science.gov (United States)

    Nakamura, Shigeru; Matsuda, Kenta; Arai, Noriyuki; Kobayashi, Makoto; Wakimoto, Nobuhiro; Matsushita, Takashi

    2006-05-01

    To reduce variations of cup inclination after total hip arthroplasty using the mini-incision posterior approach, we introduced two techniques, one at a time. The first technique is measuring a pelvic tilt angle in the frontal plane in the initial lateral position in the operating room. The second technique is using a tilt-meter to adjust the direction of a cup holder. The purpose of this study was to evaluate the usefulness of these techniques. For 106 hips operated on, the cementless acetabular component was impacted using a cup holder targeting 45 degrees in inclination and 20 degrees in anteversion. These hips were divided into three consecutive groups. For the first group (30 hips), no radiograph in the lateral position was obtained, and the alignment frame of the cup holder was aligned parallel to the floor by eye measurement. For the second group (56 hips), we measured the pelvic tilt angle, and tilted the alignment frame by eye measurement. For the third group (20 hips), we measured the pelvic tilt angle and tilted the alignment frame using the tilt meter. Inclination and anteversion angles were measured on postoperative radiographs. The absolute value of the difference between the measured angle and the target angle was defined as the inclination error or anteversion error, respectively. The inclination error was more than 5 degrees for 33% in the first group, 20% in the second group, and 0% in the third group (P = 0.015, chi-squared test). There was a significant difference between the first group and the third group (P = 0.0039). For the anteversion error, there were no significant differences among the three groups. Adjustment using a tilt-meter after measuring a pelvic tilt angle is a useful method to reduce the rate of large inclination error.

  7. Out-of-plane buckling of pantographic fabrics in displacement-controlled shear tests: experimental results and model validation

    Science.gov (United States)

    Barchiesi, Emilio; Ganzosch, Gregor; Liebold, Christian; Placidi, Luca; Grygoruk, Roman; Müller, Wolfgang H.

    2018-01-01

    Due to the latest advancements in 3D printing technology and rapid prototyping techniques, the production of materials with complex geometries has become more affordable than ever. Pantographic structures, because of their attractive features, both in dynamics and statics and both in elastic and inelastic deformation regimes, deserve to be thoroughly investigated with experimental and theoretical tools. Herein, experimental results relative to displacement-controlled large deformation shear loading tests of pantographic structures are reported. In particular, five differently sized samples are analyzed up to first rupture. Results show that the deformation behavior is strongly nonlinear, and the structures are capable of undergoing large elastic deformations without reaching complete failure. Finally, a cutting edge model is validated by means of these experimental results.

  8. Evaluation of Bearing Capacity of Strip Foundation Subjected to Eccentric Inclined Loads Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Ahmed Majeed Ali

    2016-08-01

    Full Text Available In real conditions of structures, foundations like retaining walls, industrial machines and platforms in offshore areas are commonly subjected to eccentrically inclined loads. This type of loading significantly affects the overall stability of shallow foundations due to exposing the foundation into two components of loads (horizontal and vertical and consequently reduces the bearing capacity Based on a numerical analysis performed using finite element software (Plaxis 3D Foundation, the behavior of model strip foundation rested on dry sand under the effect of eccentric inclined loads with different embedment ratios (D/B ranging from (0-1 has been explored. The results display that, the bearing capacity of strip foundation is noticeably decreased with the increase of inclination angle (α and eccentricity ratio (e/B. As well as, a reduction factor (RF expression was appointed to measure the degree of decreasing in the bearing capacity when the model footing is subjected to eccentric inclined load. It was observed that, the (RF decreases as the embedment ratio increases. Moreover, the test results also exhibit that, the model footing bearing capacity is reduced by about (69% when the load inclination is varied from (0° to 20° and the model footing is on the surface. While, the rate of decreasing in the bearing capacity was found to be (58%, for both cases of footing when they are at embedment ratios of (0.5 and 1.0. Also, a comparative study was carried out between the present results and previous experimental test results under the same conditions (soil properties and boundary condition. A good agreement was obtained between the predicted bearing capacities for the two related studies.

  9. Observed changes in radiographic measurements of the first ray after frontal plane rotation of the first metatarsal in a cadaveric foot model.

    Science.gov (United States)

    Dayton, Paul; Feilmeier, Mindi; Hirschi, Jordan; Kauwe, Merrell; Kauwe, John S K

    2014-01-01

    We observed the changes in the angular measurements commonly used in the evaluation of the first metatarsal and first metatarsophalangeal joint in cadaveric specimens before and after frontal plane rotation of the first metatarsal. Measurements of the first and second intermetatarsal angle (IMA), hallux abductus angle, proximal articular set angle, and tibial sesamoid position (TSP) were taken after varying degrees of varus and valgus rotation of the first metatarsal. Standard dorsoplantar radiographs were taken at 0°, 10°, 20°, and 30° of valgus rotation of the first metatarsal and repeated at 10°, 20°, and 30° varus rotation of the first metatarsal. The data were analyzed using a mixed linear model to compare the change in each angle measurement over the range of valgus and varus rotation. The change in the TSP was significant in both valgus and varus rotations (p = .0004 and p = .028, respectively), an increase in valgus rotation causing an increase in the TSP and an increase in varus rotation causing a decrease in TSP. The change in the IMA was significant compared with valgus rotation (p = .028), showing that as the valgus rotation increased, the IMA also increased. However, compared with the varus rotation, the correlation was not significant (p = .18). The proximal articular set angle and hallux abductus angle measurements, compared with metatarsal rotation, showed positive trends but were not statistically significant. From our results and a review of the published data, we have hypothesized that frontal plane rotation of the first metatarsal is an integral component of hallux abducto valgus pathologic features, specifically in relation to the TSP and IMA. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  10. Transformational plane geometry

    CERN Document Server

    Umble, Ronald N

    2014-01-01

    Axioms of Euclidean Plane Geometry The Existence and Incidence Postulates The Distance and Ruler Postulates The Plane Separation Postulate The Protractor Postulate The Side-Angle-Side Postulate and the Euclidean Parallel Postulate Theorems of Euclidean Plane Geometry The Exterior Angle Theorem Triangle Congruence Theorems The Alternate Interior Angles Theorem and the Angle Sum Theorem Similar Triangles Introduction to Transformations, Isometries, and Similarities Transformations Isometries and SimilaritiesAppendix: Proof of Surjectivity Translations, Rotations, and Reflections Translations Rotations Reflections Appendix: Geometer's Sketchpad Commands Required by Exploratory Activities Compositions of Translations, Rotations, and Reflections The Three Points Theorem Rotations as Compositions of Two Reflections Translations as Compositions of Two Halfturns or Two Reflections The Angle Addition Theorem Glide Reflections Classification of Isometries The Fundamental Theorem and Congruence Classification of Isometr...

  11. EFFECT OF BRIDGE PIERS INCLINATION AND ROUGHNESS ON SCOUR PIT DIMENSIONS

    Directory of Open Access Journals (Sweden)

    Moaed S. Khalil

    2013-05-01

    Full Text Available In this paper a laboratory work was performed to study the effect of bridge piers inclination and surface roughness on scour pit dimensions. Fifty four experiments were conducted using three different sizes and inclinations Pier models fixed in a sandy bed channel. First, the axis of the pier was parallel to the flow, then it was inclined by 30° and finally by 45°. Each model was tested under three different flow discharges for a period not less than two hours and at the end of each experiment the dimensions of the scour pit were measured. The same experiments were repeated after roughening the surface of each pier by fine gravel of 2mm in diameter to increase its roughness.The results of the experiment showed a clear reduction in scour pit dimensions after increasing pier roughness, the percentage of decreases in scour depth was between 2 % and 61%, while the scour length decreased between 2.5% and 22%, and finally the width of scour decreases was between 3% and 19.7%. The results also showed that the inclination of pier's axis produced an increase in scour pit dimensions. Finally, the empirical relationships of the results showed that it's possible to explain the relation between the flow discharge and each of scour pit dimensions by a simple linear equation, where the determination coefficient were more than 0.94 for all relations. 

  12. Development of locomotion over inclined surfaces in laying hens.

    Science.gov (United States)

    LeBlanc, C; Tobalske, B; Bowley, S; Harlander-Matauschek, A

    2018-03-01

    The purpose of the present study was to evaluate locomotor strategies during development in domestic chickens (Gallus gallus domesticus); we were motivated, in part, by current efforts to improve the design of housing systems for laying hens which aim to reduce injury and over-exertion. Using four strains of laying hens (Lohmann Brown, Lohmann LSL lite, Dekalb White and Hyline Brown) throughout this longitudinal study, we investigated their locomotor style and climbing capacity in relation to the degree (0 to 70°) of incline, age (2 to 36 weeks) and the surface substrate (sandpaper or wire grid). Chicks and adult fowl performed only walking behavior to climb inclines ⩽40° and performed a combination of wing-assisted incline running (WAIR) or aerial ascent on steeper inclines. Fewer birds used their wings to aid their hind limbs when climbing 50° inclines on wire grid surface compared with sandpaper. The steepness of angle achieved during WAIR and the tendency to fly instead of using WAIR increased with increasing age and experience. White-feathered strains performed more wing-associated locomotor behavior compared with brown-feathered strains. A subset of birds was never able to climb incline angles >40° even when using WAIR. Therefore, we suggest that inclines of up to 40° should be provided for hens in three-dimensional housing systems, which are easily negotiated (without wing use) by chicks and adult fowl.

  13. RMS noise modeling and detection for high-reliability HgCdTe infrared focal plane arrays development

    Science.gov (United States)

    Cathignol, A.; Vauquelin, G.; Brunner, A.; Destefanis, V.; Rubaldo, L.; Maillard, M.; Runtz, M.

    2015-06-01

    This paper presents recent improvements introduced in production lines of Mid-Wavelength Infra-Red (MWIR) and Long-Wavelength Infra-Red (LWIR) HgCdTe detectors that increase performances, image quality, and reliability. This was achieved thanks to accurate characterization of RMS noise distributions. Based on many MWIR and LWIR devices RMS distributions, a RMS noise distribution model that accounts for both Background Limited diodes and 1/f noise affected isolated diodes is first proposed. Then, a figure of merit for quantifying the defective pixels is introduced. This figure of merit is shown to be easy to use and robust to statistical variability. Moreover, it does also very well correlate with physics : there is high correlation between the total number of calculated defects and other figures of merit that gauge the material quality or the low frequency noise. The ability to accurately and efficiently quantify RMS noise benefits to Sofradir in its development of highly reliable and performant technologies. Such benefits are illustrated on the latest Sofradir MWIR and LWIR technologies that are demonstrated to be very robust regarding thermal stress and thermal cycling. Finally those technologies are shown to reach high image quality and stability.

  14. Plane waves with weak singularities

    International Nuclear Information System (INIS)

    David, Justin R.

    2003-03-01

    We study a class of time dependent solutions of the vacuum Einstein equations which are plane waves with weak null singularities. This singularity is weak in the sense that though the tidal forces diverge at the singularity, the rate of divergence is such that the distortion suffered by a freely falling observer remains finite. Among such weak singular plane waves there is a sub-class which does not exhibit large back reaction in the presence of test scalar probes. String propagation in these backgrounds is smooth and there is a natural way to continue the metric beyond the singularity. This continued metric admits string propagation without the string becoming infinitely excited. We construct a one parameter family of smooth metrics which are at a finite distance in the space of metrics from the extended metric and a well defined operator in the string sigma model which resolves the singularity. (author)

  15. Fault plane modelling of the 2003 August 14 Lefkada Island (Greece) earthquake based on the analysis of ENVISAT SAR interferograms

    Science.gov (United States)

    Ilieva, M.; Briole, P.; Ganas, A.; Dimitrov, D.; Elias, P.; Mouratidis, A.; Charara, R.

    2016-12-01

    On 2003 August 14, a Mw = 6.2 earthquake occurred offshore the Lefkada Island in the eastern Ionian Sea, one of the most seismically active areas in Europe. The earthquake caused extended damages in the island, and a number of ground failures, especially along the north-western coast. Seven ascending ENVISAT/ASAR images are used to process six co-seismic interferograms. The ROI-PAC package is used for interferogram generation with the SRTM DEM applied in a two-pass method. The formation of the co-seismic pairs is limited due to the existence of one pre-seismic image only. Dense vegetation is covering the island, which is an obstacle in getting good coherence, since C-band images are used. Nevertheless, ground deformation, of > 56 mm (two fringes) in the line of sight of the satellite, is detected in all six co-seismic interferograms. By inversion of the data from the observed fringes, a best fitting model of the activated fault is calculated assuming a dislocation in an elastic half space. The inferred fault is a pure dextral strike-slip fault, dipping 59 ± 5° eastward, 16 ± 2 km long and 10 ± 2 km wide. It is located north of the fault of the Mw = 6.5 2015 November 17 earthquake, and a 10-15 km gap remains between the two faults. The 2003 fault does not reach the surface and its upper edge is at a depth of 3.5 ± 1 km. No evidence is found of slip south of the Lefkada Island as suggested by some seismological studies.

  16. Fast Plane Wave Imaging

    DEFF Research Database (Denmark)

    Jensen, Jonas

    This PhD project investigates and further develops methods for ultrasound plane wave imaging and blood flow estimation with the objective of overcoming some of the major limitations in conventional ultrasound systems, which are related to low frame rates and only estimation of velocities along th...

  17. Simple quasi-analytical holonomic homogenization model for the non-linear analysis of in-plane loaded masonry panels: Part 2, structural implementation and validation

    Science.gov (United States)

    Milani, G.; Bertolesi, E.

    2017-07-01

    The simple quasi analytical holonomic homogenization approach for the non-linear analysis of in-plane loaded masonry presented in Part 1 is here implemented at a structural leveland validated. For such implementation, a Rigid Body and Spring Mass model (RBSM) is adopted, relying into a numerical modelling constituted by rigid elements interconnected by homogenized inelastic normal and shear springs placed at the interfaces between adjoining elements. Such approach is also known as HRBSM. The inherit advantage is that it is not necessary to solve a homogenization problem at each load step in each Gauss point, and a direct implementation into a commercial software by means of an external user supplied subroutine is straightforward. In order to have an insight into the capabilities of the present approach to reasonably reproduce masonry behavior at a structural level, non-linear static analyses are conducted on a shear wall, for which experimental and numerical data are available in the technical literature. Quite accurate results are obtained with a very limited computational effort.

  18. Flow Over Backward Facing Step with Inclined Wall Solved by Finite Volume and Finite Element Method

    Science.gov (United States)

    Louda, Petr; Sváček, Petr; Kozel, Karel; Příhoda, Jaromír

    2010-09-01

    The work deals with numerical solution of 2D incompressible flow over backward facing step. The inclination angles of the upper wall of the channel were chosen as in measurements by Driver and Seegmiller [1]. Two numerical methods are considered. One is finite volume method, the other one is finite element method. Turbulence is modeled using two-equation turbulence models of k-ω type. The influence of outlet boundary condition is discussed and do-nothing-like condition found suitable also for finite volume method. The comparison of both methods is presented for laminar as well as turbulent cases, including experimental results. The differences of the results are studied using one turbulence model and both numerical methods or one method and more turbulence models. It is found that sensitivity of the computation to these circumstances increases for higher inclination angles (diffuser flow).

  19. Complex network analysis in inclined oil–water two-phase flow

    International Nuclear Information System (INIS)

    Zhong-Ke, Gao; Ning-De, Jin

    2009-01-01

    Complex networks have established themselves in recent years as being particularly suitable and flexible for representing and modelling many complex natural and artificial systems. Oil–water two-phase flow is one of the most complex systems. In this paper, we use complex networks to study the inclined oil–water two-phase flow. Two different complex network construction methods are proposed to build two types of networks, i.e. the flow pattern complex network (FPCN) and fluid dynamic complex network (FDCN). Through detecting the community structure of FPCN by the community-detection algorithm based on K-means clustering, useful and interesting results are found which can be used for identifying three inclined oil–water flow patterns. To investigate the dynamic characteristics of the inclined oil–water two-phase flow, we construct 48 FDCNs under different flow conditions, and find that the power-law exponent and the network information entropy, which are sensitive to the flow pattern transition, can both characterize the nonlinear dynamics of the inclined oil–water two-phase flow. In this paper, from a new perspective, we not only introduce a complex network theory into the study of the oil–water two-phase flow but also indicate that the complex network may be a powerful tool for exploring nonlinear time series in practice. (general)

  20. A Numerical Study on a Vertical-Axis Wind Turbine with Inclined Arms

    Directory of Open Access Journals (Sweden)

    Agostino De Marco

    2014-01-01

    Full Text Available This work focuses on a particular type of vertical-axis wind turbine, in which a number of inclined arms with airfoil-shaped cross-sections are mounted to connect the principal blades to their hub. While the majority of the known studies on vertical-axis turbines is devoted to the role of principal blades, in most of the cases without taking into account other parts of the wind turbine, the objective of this work is to investigate the effect of uncommon arm geometries, such as the inclined arms. The inclined arms are known to have a potentially beneficial role in the power extraction from the wind current but, due to the complexity of the phenomena, the investigation on aerodynamics of this type of turbine is often impossible through analytical models, such as blade-element momentum theory. It turns out that adequate studies can only be carried out by wind tunnel experiments or CFD simulations. This work presents a methodical CFD study on how inclined arms can be used on a selected wind turbine configuration to harvest additional power from the wind. The turbine configuration, geometry, and some fundamental definitions are introduced first. Then an in-depth CFD analysis is presented and discussed.

  1. Biomimetic walking trajectory generation of humanoid robot on an inclined surface using Fourier series.

    Science.gov (United States)

    Park, Ill-Woo; Kim, Jung-Yup

    2014-10-01

    This article describes a novel method to generate a biomimetic walking trajectory for a biped humanoid robot on an inclined surface. We assume that the configuration of the inclined surface is known, and we solve the human-like walking trajectory generation problem by obtaining the solution from the desired zero moment point (ZMP) trajectory to the center of gravity (CoG) trajectory. We present an analytic solution for the walking trajectory generation by using Fourier series. From the given ZMP trajectory biomimetically represented by the Fourier series, we focus on how to find the CoG trajectory in an analytical way. A time-segmentation based approach is adopted for generating the trajectories. The trajectory functions need to be continuous between the segments; thus, the solution is found by calculating the coefficients under these connectivity conditions. We derive a general form of the ZMP equation using a simple inverted pendulum model (SIPM), which includes the ZMP and the CoG trajectories in the horizontal and vertical directions to quantify the walking parameters on the inclined surface. The performance of the proposed approach is verified by conducting walking simulations using a full-body dynamic simulator on three different inclined surfaces and comparing them to the authors' previous approach.

  2. Investigation on novel raceway pond with inclined paddle wheels through simulation and microalgae culture experiments.

    Science.gov (United States)

    Zeng, Fanxue; Huang, Jianke; Meng, Chen; Zhu, Fachao; Chen, Jianpei; Li, Yuanguang

    2016-01-01

    The open raceway ponds are nowadays the most used large-scale reactors for microalgae culture. To avoid the stacking of microalgae, the paddle wheels are the most widely used to circulate and mix the culture medium. In this paper, a numerical simulation using computational fluid dynamics (CFD) was used to investigate the hydrodynamic characteristics of open raceway ponds with different types of paddle wheels (the traditional paddle wheels and the novel paddle wheels with specially inclined angle of the blades). The particle image velocimetry (PIV) was used to validate the reliability of the CFD model. The CFD simulation results showed that the novel raceway pond with 15° inclined angle of the blades had the best mixing efficiency under the same power consumption. Lastly, the results of microalgae culture experiments showed that the growth rates of Chlorella pyrenoidosa in the novel raceway pond with 15° inclined angle of the blades were higher than those in the traditional reactor. The results of the culture experiments and CFD simulations were identical with each other. Therefore, a novel paddle wheel with 15° inclined angle of the blades was obtained for better microalgae cultivation.

  3. A new dimension to cephalometry: DW plane

    Directory of Open Access Journals (Sweden)

    Shruti K Hatewar

    2015-01-01

    Full Text Available Context: An accurate jaw relationship is critically important in orthodontic diagnosis and treatment planning. Various angular and linear measurements that have been proposed can be erroneous because they depend on various factors. Aim: The purpose of this study is to establish a new cephalometric measurement to assess the skeletal jaw discrepancy using Walker's point. Settings and Design: Lateral cephalogram of 100 Indian subjects with age range (8–11, 12–18, 19-27 were obtained. Inclusion criteria were – clinically Class I occlusion; normal overjet and overbite; orthoganthic profile; competent lips and cephalometrically normal ANB; Wits appraisal; Rakosi Jarabak's angle of inclination and mandibular plane angle. Materials and Methods: Four skeletal landmarks: Point A, Point B, Walker's point (W and Wing point (w were used to indicate the severity and type of skeletal dysplasia. Double W (DW was constructed joining the Walker's and Wing point. Statistical Analysis Used: Analysis of variance test and Student's t-test was applied which showed significant results. Results: The difference between Walker's perpendicular to A Point and Walker's perpendicular to B Point gave the sagittal jaw discrepancy and was found to be 8.2 ± 0.9 mm. This measurement remained relatively constant throughout life. Conclusions: DW plane is an effective way to accurately establish the skeletal jaw relationship. It analyses the variance between linear measurements to determine the sagittal jaw relationship, linear measurements for vertical maxillary height and angular measurements to determine rotational jaw changes.

  4. Validation of Galileo orbits using SLR with a focus on satellites launched into incorrect orbital planes

    Science.gov (United States)

    Sośnica, Krzysztof; Prange, Lars; Kaźmierski, Kamil; Bury, Grzegorz; Drożdżewski, Mateusz; Zajdel, Radosław; Hadas, Tomasz

    2018-02-01

    The space segment of the European Global Navigation Satellite System (GNSS) Galileo consists of In-Orbit Validation (IOV) and Full Operational Capability (FOC) spacecraft. The first pair of FOC satellites was launched into an incorrect, highly eccentric orbital plane with a lower than nominal inclination angle. All Galileo satellites are equipped with satellite laser ranging (SLR) retroreflectors which allow, for example, for the assessment of the orbit quality or for the SLR-GNSS co-location in space. The number of SLR observations to Galileo satellites has been continuously increasing thanks to a series of intensive campaigns devoted to SLR tracking of GNSS satellites initiated by the International Laser Ranging Service. This paper assesses systematic effects and quality of Galileo orbits using SLR data with a main focus on Galileo satellites launched into incorrect orbits. We compare the SLR observations with respect to microwave-based Galileo orbits generated by the Center for Orbit Determination in Europe (CODE) in the framework of the International GNSS Service Multi-GNSS Experiment for the period 2014.0-2016.5. We analyze the SLR signature effect, which is characterized by the dependency of SLR residuals with respect to various incidence angles of laser beams for stations equipped with single-photon and multi-photon detectors. Surprisingly, the CODE orbit quality of satellites in the incorrect orbital planes is not worse than that of nominal FOC and IOV orbits. The RMS of SLR residuals is even lower by 5.0 and 1.5 mm for satellites in the incorrect orbital planes than for FOC and IOV satellites, respectively. The mean SLR offsets equal -44.9, -35.0, and -22.4 mm for IOV, FOC, and satellites in the incorrect orbital plane. Finally, we found that the empirical orbit models, which were originally designed for precise orbit determination of GNSS satellites in circular orbits, provide fully appropriate results also for highly eccentric orbits with variable linear

  5. Aqua/Aura Spring 2017 Inclination Adjust Maneuver Series

    Science.gov (United States)

    Noyes, Thomas; Stezelberger, Shane

    2017-01-01

    This will be presented at the International Earth Science Constellation Mission Operations Working Group meeting June 13-15, 2017 to discuss the AquaAura Spring 2017 Inclination Adjust Maneuver series.

  6. Brilliance and flux reduction in imperfect inclined crystals

    International Nuclear Information System (INIS)

    Lee, W.K.; Blasdell, R.C.; Fernandez, P.B.; Macrander, A.T.; Mills, D.M.

    1996-01-01

    The inclined crystal geometry has been suggested as a method of reducing the surface absorbed power density of high-heat-load monochromators for third-generation synchrotron radiation sources. Computer simulations have shown that if the crystals are perfectly aligned and have no strains then the diffraction properties of a pair of inclined crystals are very similar to a pair of conventional flat crystals with only subtle effects differentiating the two configurations. However, if the crystals are strained, these subtle differences in the behavior of inclined crystals can result in large beam divergences causing brilliance and flux losses. This manuscript elaborates on these issues and estimates potential brilliance and flux losses from strained inclined crystals at the APS

  7. Systems of pillarless working of adjacent, sloped and inclined seams

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1979-01-01

    An analysis is made (advantages and disadvantages) of existing and recommended (pillarless) systems of working adjacent, sloped, and inclined seams. The economic benefits, area and extent of those systems are indicated. 8 references, 4 figures.

  8. Role of Edge Inclination in an Optical Microdisk Resonator for Label-Free Sensing

    OpenAIRE

    Gandolfi, Davide; Ramiro-Manzano, Fernando; Rebollo, Francisco Javier Aparicio; Ghulinyan, Mher; Pucker, Georg; Pavesi, Lorenzo

    2015-01-01

    In this paper, we report on the measurement and modeling of enhanced optical refractometric sensors based on whispering gallery modes. The devices under test are optical microresonators made of silicon nitride on silicon oxide, which differ in their sidewall inclination angle. In our approach, these microresonators are vertically coupled to a buried waveguide with the aim of creating integrated and cost-effective devices. Device modeling shows that the optimization of the devic...

  9. Double Slip Plane Crack Model

    Science.gov (United States)

    1983-01-01

    sur une distance qui augmente a chaque cycle, et que la loi de croissance est une equation de Paris de degre quatre. Zusammenfassung—Ein einfaches...de la fissure, ä une distance r, deux plans de glissement paralleles au plan de la fissure. Nous supposons que le glissement ne peut se produire que...sur ces deux plans. Partout ailleurs. le materiau est elastique. Lorsque w egale zero, la fissure devient une fissure de Bilby, Cottrell el Swinden

  10. Psychosocial Determinants of Romantic Inclination Among Indian Youth

    OpenAIRE

    D. Barani Ganth; S. Kadhiravan

    2017-01-01

    The present study was conducted with the aim of understanding the psychosocial determinants of romantic inclination among youth in India. We involved 779 student participants from a large central university in south India in the age range of 18-24 years. The participants filled measures on romantic inclination, personality, attachment style, interpersonal attraction, and social influence on romantic relationship in addition to a questionnaire on demographic information and relationship histor...

  11. Trunk muscle activity with different sitting postures and pelvic inclination.

    Science.gov (United States)

    Watanabe, Masahiro; Kaneoka, Koji; Wada, Yusuke; Matsui, Yasushi; Miyakawa, Shumpei

    2014-01-01

    Sitting posture may often place large burden on trunk muscles, while trunk muscle activities in the sitting posture have not been well clarified. In this study, a difference in trunk muscle activity between two kinds of sitting postures was evaluated, focusing on low back pain induced by posture holding. An experiment was conducted on the subjects sitting on a stable-seat and on an unstable-seat, with the pelvis inclined forward, backward, rightward, and leftward. With the pelvis inclined forward, rightward and leftward, muscle activities were significantly increased in a stable-seat sitting posture. In contrast, no significant increase in muscle activity was observed with the pelvis inclined in every direction in an unstable-seat sitting posture. With the pelvis inclined in the stable-seat sitting posture, muscle activities were imbalanced, while with the pelvis inclined in the unstable-seat sitting posture, muscle activities were not imbalanced. Thus, it is suggested that with the pelvis inclined to the maximum extent in the stable-seat sitting posture, low back pain may be induced by imbalanced muscle activities.

  12. Thermo-economic performance of inclined solar water distillation systems

    Directory of Open Access Journals (Sweden)

    Agboola Phillips O.

    2015-01-01

    Full Text Available This study investigates the thermo-economic performance of different configurations of inclined solar water desalination for parameters such as daily production, efficiency, system cost and distilled water production cost. The four different configurations considered for this study are as follows; 1. Inclined solar water distillation with bare absorber plate (IISWD with daily production of 5.46 kg/m2 day and daily efficiency of 48.3%. 2. Inclined solar water distillation with wick on absorber plate (IISWDW with daily production of 6.41kg/m2 day and daily efficiency 50.3%. 3. Inclined solar water distillation with wire mesh on absorber plate (IISWDWM with daily production n of 3.03 kg/m2 day and daily efficiency 32.6%. 4. Inclined solar water distillation with bare absorber plate (ISWD. (Control System with daily production of 3.25 kg/m2 day and daily efficiency of 40.1%. The systems potable water cost price ranges from 0.03 $/L for IISWDW to 0.06$/L for IISWDWM System. All the systems are economically and technically feasible as a solar distillation system for potable water in Northern Cyprus. The price of potable water from water vendors/hawkers ranges from 0.11-0.16 $/L. It is more economically viable to have the rooftop inclined solar water desalination system than procuring potable water from vendors.`

  13. TRANSIT TIMING VARIATIONS FOR INCLINED AND RETROGRADE EXOPLANETARY SYSTEMS

    International Nuclear Information System (INIS)

    Payne, Matthew J.; Ford, Eric B.; Veras, Dimitri

    2010-01-01

    We perform numerical calculations of the expected transit timing variations (TTVs) induced on a hot-Jupiter by an Earth-mass perturber. Motivated by the recent discoveries of retrograde transiting planets, we concentrate on an investigation of the effect of varying relative planetary inclinations, up to and including completely retrograde systems. We find that planets in low-order (e.g., 2:1) mean-motion resonances (MMRs) retain approximately constant TTV amplitudes for 0 deg. 170 deg. Systems in higher order MMRs (e.g., 5:1) increase in TTV amplitude as inclinations increase toward 45 deg., becoming approximately constant for 45 deg. 135 deg. Planets away from resonance slowly decrease in TTV amplitude as inclinations increase from 0 deg. to 180 deg., whereas planets adjacent to resonances can exhibit a huge range of variability in TTV amplitude as a function of both eccentricity and inclination. For highly retrograde systems (135 deg. < i ≤ 180 deg.), TTV signals will be undetectable across almost the entirety of parameter space, with the exceptions occurring when the perturber has high eccentricity or is very close to an MMR. This high inclination decrease in TTV amplitude (on and away from resonance) is important for the analysis of the known retrograde and multi-planet transiting systems, as inclination effects need to be considered if TTVs are to be used to exclude the presence of any putative planetary companions: absence of evidence is not evidence of absence.

  14. Soret and Dufour effects on free convective heat and solute transfer in fluid saturated inclined porous cavity

    Directory of Open Access Journals (Sweden)

    Chandra Shekar Balla

    2015-12-01

    Full Text Available The present problem addresses double diffusive free convection in an inclined square cavity filled with fluid saturated porous medium under the influence of Soret and Dufour effects. The inclined cavity makes an angle with the horizontal plane. At the two horizontal walls of the cavity the heat and solute transverse gradients are applied and lateral walls of the cavity are being regarded insulated and impermeable. Using the appropriate dimensionless quantities, the governing equations with boundary conditions are transformed to non-dimensional form. The governing partial differential equations are solved by Finite element method of Galerkin weighted residual scheme. Numerical results are obtained for different values of the Rayleigh number, Lewis number, buoyancy ratio, Soret Number and Dufour number. The overall investigation of variation of streamlines, isotherms, iso-concentration, Nusselt number and Sherwood numbers are presented graphically. To examine the accuracy, the present results are compared with the available results.

  15. Testing correction for paleomagnetic inclination error in sedimentary rocks: a comparative approach

    Science.gov (United States)

    Tauxe, L.; Kodama, K. P.; Kent, D. V.

    2008-05-01

    Paleomagnetic inclinations in sedimentary formations are frequently suspected of being too shallow. Recognition and correction of shallow bias is therefore critical for paleogeographical reconstructions. The elongation/inclination (E/I) correction method of Tauxe and Kent (2004) relies on the twin assumptions that inclination flattening follows the empirical sedimentary flattening formula and that the distribution of paleomagnetic directions can be predicted from a paleosecular variation (PSV) model. We will test the reliability of the E/I correction method in several ways. First we consider the E/I trends predicted by various PSV models. The Giant Gaussian Process-type paleosecular variation models were all constrained by paleomagnetic data from lava flows of the last five million years. Therefore, to test whether the method can be used in more ancient times, we will compare model predictions of E/I trends with observations from four Large Igneous Provinces since the Jurassic (Yemen, Kerguelen, Faroe Islands, and Deccan basalts). All data are consistent at the 95% level of confidence with the elongation/inclination trends predicted by the paleosecular variation models. Then we will then discuss the geological implications of various applications of the E/I method. In general the E/I corrected data are more consistent with data from contemporaneous lavas, with predictions from the well constrained synthetic apparent polar wander paths, and other geological constraints. Finally, we will compare the E/I corrections with corrections from an entirely different method of inclination correction: the anisotropy of remanence method of Jackson et al. (1991) which relies on measurement of remanence and particle anisotropies of the sediments. In the two cases where a direct comparison can be made, the two methods give corrections that are consistent within error. In summary, it appears that the elongation/inclination method for recognizing and corrected the effects of

  16. Model of the initiation of signal transduction by ligands in a cell culture: Simulation of molecules near a plane membrane comprising receptors

    International Nuclear Information System (INIS)

    Plante, Ianik; Cucinotta, Francis A.

    2011-01-01

    Cell communication is a key mechanism in tissue responses to radiation. Several molecules are implicated in radiation-induced signaling between cells, but their contributions to radiation risk are poorly understood. Meanwhile, Green's functions for diffusion-influenced reactions have appeared in the literature, which are applied to describe the diffusion of molecules near a plane membrane comprising bound receptors with the possibility of reversible binding of a ligand and activation of signal transduction proteins by the ligand-receptor complex. We have developed Brownian dynamics algorithms to simulate particle histories in this system which can accurately reproduce the theoretical distribution of distances of a ligand from the membrane, the number of reversibly bound particles, and the number of receptor complexes activating signaling proteins as a function of time, regardless of the number of time steps used for the simulation. These simulations will be of great importance to model interactions at low doses where stochastic effects induced by a small number of molecules or interactions come into play.

  17. Accelerated Time-Domain Modeling of Electromagnetic Pulse Excitation of Finite-Length Dissipative Conductors over a Ground Plane via Function Fitting and Recursive Convolution

    Energy Technology Data Exchange (ETDEWEB)

    Campione, Salvatore [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Warne, Larry K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sainath, Kamalesh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Basilio, Lorena I. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    In this report we overview the fundamental concepts for a pair of techniques which together greatly hasten computational predictions of electromagnetic pulse (EMP) excitation of finite-length dissipative conductors over a ground plane. In a time- domain, transmission line (TL) model implementation, predictions are computationally bottlenecked time-wise, either for late-time predictions (about 100ns-10000ns range) or predictions concerning EMP excitation of long TLs (order of kilometers or more ). This is because the method requires a temporal convolution to account for the losses in the ground. Addressing this to facilitate practical simulation of EMP excitation of TLs, we first apply a technique to extract an (approximate) complex exponential function basis-fit to the ground/Earth's impedance function, followed by incorporating this into a recursion-based convolution acceleration technique. Because the recursion-based method only requires the evaluation of the most recent voltage history data (versus the entire history in a "brute-force" convolution evaluation), we achieve necessary time speed- ups across a variety of TL/Earth geometry/material scenarios. Intentionally Left Blank

  18. BKP plane partitions

    International Nuclear Information System (INIS)

    Foda, Omar; Wheeler, Michael

    2007-01-01

    Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another

  19. BKP plane partitions

    Energy Technology Data Exchange (ETDEWEB)

    Foda, Omar; Wheeler, Michael [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)

    2007-01-15

    Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another.

  20. Aerodynamics of wing-assisted incline running in birds.

    Science.gov (United States)

    Tobalske, Bret W; Dial, Kenneth P

    2007-05-01

    Wing-assisted incline running (WAIR) is a form of locomotion in which a bird flaps its wings to aid its hindlimbs in climbing a slope. WAIR is used for escape in ground birds, and the ontogeny of this behavior in precocial birds has been suggested to represent a model analogous to transitional adaptive states during the evolution of powered avian flight. To begin to reveal the aerodynamics of flap-running, we used digital particle image velocimetry (DPIV) and measured air velocity, vorticity, circulation and added mass in the wake of chukar partridge Alectoris chukar as they engaged in WAIR (incline 65-85 degrees; N=7 birds) and ascending flight (85 degrees, N=2). To estimate lift and impulse, we coupled our DPIV data with three-dimensional wing kinematics from a companion study. The ontogeny of lift production was evaluated using three age classes: baby birds incapable of flight [6-8 days post hatching (d.p.h.)] and volant juveniles (25-28 days) and adults (45+ days). All three age classes of birds, including baby birds with partially emerged, symmetrical wing feathers, generated circulation with their wings and exhibited a wake structure that consisted of discrete vortex rings shed once per downstroke. Impulse of the vortex rings during WAIR was directed 45+/-5 degrees relative to horizontal and 21+/-4 degrees relative to the substrate. Absolute values of circulation in vortex cores and induced velocity increased with increasing age. Normalized circulation was similar among all ages in WAIR but 67% greater in adults during flight compared with flap-running. Estimated lift during WAIR was 6.6% of body weight in babies and between 63 and 86% of body weight in juveniles and adults. During flight, average lift was 110% of body weight. Our results reveal for the first time that lift from the wings, rather than wing inertia or profile drag, is primarily responsible for accelerating the body toward the substrate during WAIR, and that partially developed wings, not yet

  1. Consistent lattice Boltzmann modeling of low-speed isothermal flows at finite Knudsen numbers in slip-flow regime: Application to plane boundaries.

    Science.gov (United States)

    Silva, Goncalo; Semiao, Viriato

    2017-07-01

    The first nonequilibrium effect experienced by gaseous flows in contact with solid surfaces is the slip-flow regime. While the classical hydrodynamic description holds valid in bulk, at boundaries the fluid-wall interactions must consider slip. In comparison to the standard no-slip Dirichlet condition, the case of slip formulates as a Robin-type condition for the fluid tangential velocity. This makes its numerical modeling a challenging task, particularly in complex geometries. In this work, this issue is handled with the lattice Boltzmann method (LBM), motivated by the similarities between the closure relations of the reflection-type boundary schemes equipping the LBM equation and the slip velocity condition established by slip-flow theory. Based on this analogy, we derive, as central result, the structure of the LBM boundary closure relation that is consistent with the second-order slip velocity condition, applicable to planar walls. Subsequently, three tasks are performed. First, we clarify the limitations of existing slip velocity LBM schemes, based on discrete analogs of kinetic theory fluid-wall interaction models. Second, we present improved slip velocity LBM boundary schemes, constructed directly at discrete level, by extending the multireflection framework to the slip-flow regime. Here, two classes of slip velocity LBM boundary schemes are considered: (i) linear slip schemes, which are local but retain some calibration requirements and/or operation limitations, (ii) parabolic slip schemes, which use a two-point implementation but guarantee the consistent prescription of the intended slip velocity condition, at arbitrary plane wall discretizations, further dispensing any numerical calibration procedure. Third and final, we verify the improvements of our proposed slip velocity LBM boundary schemes against existing ones. The numerical tests evaluate the ability of the slip schemes to exactly accommodate the steady Poiseuille channel flow solution, over

  2. Consistent lattice Boltzmann modeling of low-speed isothermal flows at finite Knudsen numbers in slip-flow regime: Application to plane boundaries

    Science.gov (United States)

    Silva, Goncalo; Semiao, Viriato

    2017-07-01

    The first nonequilibrium effect experienced by gaseous flows in contact with solid surfaces is the slip-flow regime. While the classical hydrodynamic description holds valid in bulk, at boundaries the fluid-wall interactions must consider slip. In comparison to the standard no-slip Dirichlet condition, the case of slip formulates as a Robin-type condition for the fluid tangential velocity. This makes its numerical modeling a challenging task, particularly in complex geometries. In this work, this issue is handled with the lattice Boltzmann method (LBM), motivated by the similarities between the closure relations of the reflection-type boundary schemes equipping the LBM equation and the slip velocity condition established by slip-flow theory. Based on this analogy, we derive, as central result, the structure of the LBM boundary closure relation that is consistent with the second-order slip velocity condition, applicable to planar walls. Subsequently, three tasks are performed. First, we clarify the limitations of existing slip velocity LBM schemes, based on discrete analogs of kinetic theory fluid-wall interaction models. Second, we present improved slip velocity LBM boundary schemes, constructed directly at discrete level, by extending the multireflection framework to the slip-flow regime. Here, two classes of slip velocity LBM boundary schemes are considered: (i) linear slip schemes, which are local but retain some calibration requirements and/or operation limitations, (ii) parabolic slip schemes, which use a two-point implementation but guarantee the consistent prescription of the intended slip velocity condition, at arbitrary plane wall discretizations, further dispensing any numerical calibration procedure. Third and final, we verify the improvements of our proposed slip velocity LBM boundary schemes against existing ones. The numerical tests evaluate the ability of the slip schemes to exactly accommodate the steady Poiseuille channel flow solution, over

  3. Evaluation of performance of veterinary in-clinic hematology analyzers.

    Science.gov (United States)

    Rishniw, Mark; Pion, Paul D

    2016-12-01

    A previous study provided information regarding the quality of in-clinic veterinary biochemistry testing. However, no similar studies for in-clinic veterinary hematology testing have been conducted. The objective of this study was to assess the quality of hematology testing in veterinary in-clinic laboratories using results obtained from testing 3 levels of canine EDTA blood samples. Clinicians prepared blood samples to achieve measurand concentrations within, below, and above their RIs and evaluated the samples in triplicate using their in-clinic analyzers. Quality was assessed by comparison of calculated total error with quality requirements, determination of sigma metrics, use of a quality goal index, and agreement between in-clinic and reference laboratory instruments. Suitability for statistical quality control was determined using adaptations from the computerized program, EZRules3. Evaluation of 10 veterinary in-clinic hematology analyzers showed that these instruments often fail to meet quality requirements. At least 60% of analyzers reasonably determined RBC, WBC, HCT, and HGB, when assessed by most quality goal criteria; platelets were less reliably measured, with 80% deemed suitable for low platelet counts, but only 30% for high platelet counts, and automated differential leukocyte counts were generally considered unsuitable for clinical use with fewer than 40% of analyzers meeting the least stringent quality goal requirements. Fewer than 50% of analyzers were able to meet requirements for statistical quality control for any measurand. These findings reflect the current status of in-clinic hematology analyzer performance and provide a basis for future evaluations of the quality of veterinary laboratory testing. © 2016 American Society for Veterinary Clinical Pathology.

  4. Stability of film boiling on inclined plates and spheres

    Science.gov (United States)

    Aursand, Eskil; Hammer, Morten; Munkejord, Svend Tollak; Müller, Bernhard; Ytrehus, Tor

    2017-11-01

    In film boiling, a continuous sub-millimeter vapor film forms between a liquid and a heated surface, insulating the two from each other. While quite accurate steady state solutions are readily obtained, the intermediate Reynolds numbers can make transient analysis challenging. The present work is a theoretical study of film boiling instabilities. We study the formation of travelling waves that are a combination of Kelvin-Helmholtz and the Rayleigh-Taylor instabilities. In particular, we study how the nature of this process depends on the Reynolds number, the Bond number, and the inclination of the submerged heated plate. In addition we extend the analysis to the case of a submerged heated sphere. Modelling of the transient dynamics of such films is important for answering practical questions such as how instabilities affect the overall heat transfer, and whether they can lead to complete film boiling collapse (Leidenfrost point). This work has been financed under the MAROFF program. We acknowledge the Research Council of Norway (244076/O80) and The Gas Technology Centre NTNU-SINTEF (GTS) for support.

  5. Role of edge inclination in an optical microdisk resonator for label-free sensing.

    Science.gov (United States)

    Gandolfi, Davide; Ramiro-Manzano, Fernando; Rebollo, Francisco Javier Aparicio; Ghulinyan, Mher; Pucker, Georg; Pavesi, Lorenzo

    2015-02-26

    In this paper, we report on the measurement and modeling of enhanced optical refractometric sensors based on whispering gallery modes. The devices under test are optical microresonators made of silicon nitride on silicon oxide, which differ in their sidewall inclination angle. In our approach, these microresonators are vertically coupled to a buried waveguide with the aim of creating integrated and cost-effective devices. Device modeling shows that the optimization of the device is a delicate balance of the resonance quality factor and evanescent field overlap with the surrounding environment to analyze. By numerical simulations, we show that the microdisk thickness is critical to yield a high figure of merit for the sensor and that edge inclination should be kept as high as possible. We also show that bulk-sensing figures of merit as high as 1600 RIU(-1) (refractive index unit) are feasible.

  6. Magnetohydrodynamics Carreau nanofluid flow over an inclined convective heated stretching cylinder with Joule heating

    Directory of Open Access Journals (Sweden)

    Imad Khan

    Full Text Available Current work highlights the computational aspects of MHD Carreau nanofluid flow over an inclined stretching cylinder with convective boundary conditions and Joule heating. The mathematical modeling of physical problem yields nonlinear set of partial differential equations. A suitable scaling group of variables is employed on modeled equations to convert them into non-dimensional form. The integration scheme Runge-Kutta-Fehlberg on the behalf of shooting technique is utilized to solve attained set of equations. The interesting aspects of physical problem (linear momentum, energy and nanoparticles concentration are elaborated under the different parametric conditions through graphical and tabular manners. Additionally, the quantities (local skin friction coefficient, local Nusselt number and local Sherwood number which are responsible to dig out the physical phenomena in the vicinity of stretched surface are computed and delineated by varying controlling flow parameters. Keywords: MHD, Carreau nanofluid, Inclined stretching cylinder, Joule heating, Shooting technique

  7. A novel method of microneedle array fabrication using inclined deep x-ray exposure

    International Nuclear Information System (INIS)

    Moon, Sang Jun; Jin, Chun Yan; Lee, Seung S

    2006-01-01

    We report a novel fabrication method for the microneedle array with a 3-dimensional feature and its replication method; 'Hot-pressing' process with bio-compatible material, PLLA (Poly L-LActide). Using inclined deep X-ray exposure technique, we fabricate a band type microneedle array with a single body on the same material basement. Since the single body feature does not make adhesion problem with the microneedle shank and basement during peel-off step of a mold, the PMMA (Poly-Methyl-MethAcrylate) microneedle array mold insert can be used for mold process which is used with the soft material mold, PDMS (Poly-Di- Methyl-Siloxane). The side inclined deep X-ray exposure also makes complex 3-dimensional features by the regions which are not exposed during twice successive exposure steps. In addition, the successive exposure does not need an additional mask alignment after the first side exposure. The fabricated band type microneedle array mold inserts are assembled for large area patch type out-of-plane microneedle array. The bio-compatible microneedle array can be fabricated to the laboratory scale mass production by the single body PMMA mold insert and 'Hot-pressing' process

  8. A novel method of microneedle array fabrication using inclined deep x-ray exposure

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sang Jun; Jin, Chun Yan; Lee, Seung S [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1, Guseong-dong, Yuseong-dong, Daejeon (Korea, Republic of)

    2006-04-01

    We report a novel fabrication method for the microneedle array with a 3-dimensional feature and its replication method; 'Hot-pressing' process with bio-compatible material, PLLA (Poly L-LActide). Using inclined deep X-ray exposure technique, we fabricate a band type microneedle array with a single body on the same material basement. Since the single body feature does not make adhesion problem with the microneedle shank and basement during peel-off step of a mold, the PMMA (Poly-Methyl-MethAcrylate) microneedle array mold insert can be used for mold process which is used with the soft material mold, PDMS (Poly-Di- Methyl-Siloxane). The side inclined deep X-ray exposure also makes complex 3-dimensional features by the regions which are not exposed during twice successive exposure steps. In addition, the successive exposure does not need an additional mask alignment after the first side exposure. The fabricated band type microneedle array mold inserts are assembled for large area patch type out-of-plane microneedle array. The bio-compatible microneedle array can be fabricated to the laboratory scale mass production by the single body PMMA mold insert and 'Hot-pressing' process.

  9. Error Analysis on Plane-to-Plane Linear Approximate Coordinate ...

    Indian Academy of Sciences (India)

    c Indian Academy of Sciences. Error Analysis on Plane-to-Plane Linear Approximate Coordinate. Transformation. Q. F. Zhang1,∗, Q. Y. Peng1 & J. H. Fan2 ... In astronomy, some tasks require performing the coordinate transformation between two tangent planes in ... Based on these parameters, we get maxi- mum errors in ...

  10. A highly precise frequency-based method for estimating the tension of an inclined cable with unknown boundary conditions

    Science.gov (United States)

    Ma, Lin

    2017-11-01

    This paper develops a method for precisely determining the tension of an inclined cable with unknown boundary conditions. First, the nonlinear motion equation of an inclined cable is derived, and a numerical model of the motion of the cable is proposed using the finite difference method. The proposed numerical model includes the sag-extensibility, flexural stiffness, inclination angle and rotational stiffness at two ends of the cable. Second, the influence of the dynamic parameters of the cable on its frequencies is discussed in detail, and a method for precisely determining the tension of an inclined cable is proposed based on the derivatives of the eigenvalues of the matrices. Finally, a multiparameter identification method is developed that can simultaneously identify multiple parameters, including the rotational stiffness at two ends. This scheme is applicable to inclined cables with varying sag, varying flexural stiffness and unknown boundary conditions. Numerical examples indicate that the method provides good precision. Because the parameters of cables other than tension (e.g., the flexural stiffness and rotational stiffness at the ends) are not accurately known in practical engineering, the multiparameter identification method could further improve the accuracy of cable tension measurements.

  11. Instability timescale for the inclination instability in the solar system

    Science.gov (United States)

    Zderic, Alexander; Madigan, Ann-Marie; Fleisig, Jacob

    2018-04-01

    The gravitational influence of small bodies is often neglected in the study of solar system dynamics. However, this is not always an appropriate assumption. For example, mutual secular torques between low mass particles on eccentric orbits can result in a self-gravity instability (`inclination instability'; Madigan & McCourt 2016). During the instability, inclinations increase exponentially, eccentricities decrease (detachment), and orbits cluster in argument of perihelion. In the solar system, the orbits of the most distant objects show all three of these characteristics (high inclination: Volk & Malhotra (2017), detachment: Delsanti & Jewitt (2006), and argument of perihelion clustering: Trujillo & Sheppard (2014)). The inclination instability is a natural explanation for these phenomena.Unfortunately, full N-body simulations of the solar system are unfeasible (N ≈ O(1012)), and the behavior of the instability depends on N, prohibiting the direct application of lower N simulations. Here we present the instability timescale's functional dependence on N, allowing us to extrapolate our simulation results to that appropriate for the solar system. We show that ~5 MEarth of small icy bodies in the Sedna region is sufficient for the inclination instability to occur in the outer solar system.

  12. The relationship between specific absorption rate and temperature elevation in anatomically based human body models for plane wave exposure from 30 MHz to 6 GHz

    Science.gov (United States)

    Hirata, Akimasa; Laakso, Ilkka; Oizumi, Takuya; Hanatani, Ryuto; Chan, Kwok Hung; Wiart, Joe

    2013-02-01

    According to the international safety guidelines/standard, the whole-body-averaged specific absorption rate (Poljak et al 2003 IEEE Trans. Electromagn. Compat. 45 141-5) and the peak spatial average SAR are used as metrics for human protection from whole-body and localized exposures, respectively. The IEEE standard (IEEE 2006 IEEE C95.1) indicates that the upper boundary frequency, over which the whole-body-averaged SAR is deemed to be the basic restriction, has been reduced from 6 to 3 GHz, because radio-wave energy is absorbed around the body surface when the frequency is increased. However, no quantitative discussion has been provided to support this description especially from the standpoint of temperature elevation. It is of interest to investigate the maximum temperature elevation in addition to the core temperature even for a whole-body exposure. In the present study, using anatomically based human models, we computed the SAR and the temperature elevation for a plane-wave exposure from 30 MHz to 6 GHz, taking into account the thermoregulatory response. As the primary result, we found that the ratio of the core temperature elevation to the whole-body-averaged SAR is almost frequency independent for frequencies below a few gigahertz; the ratio decreases above this frequency. At frequencies higher than a few gigahertz, core temperature elevation for the same whole-body averaged SAR becomes lower due to heat convection from the skin to air. This lower core temperature elevation is attributable to skin temperature elevation caused by the power absorption around the body surface. Then, core temperature elevation even for whole-body averaged SAR of 4 W kg-1 with the duration of 1 h was at most 0.8 °C, which is smaller than a threshold considered in the safety guidelines/standard. Further, the peak 10 g averaged SAR is correlated with the maximum body temperature elevations without extremities and pinna over the frequencies considered. These findings were confirmed

  13. Two- and three-dimensional transoesophageal echocardiography in large swine used as model for transcatheter heart valve therapies: standard planes and values.

    Science.gov (United States)

    Sündermann, Simon H; Cesarovic, Nikola; Falk, Volkmar; Bettex, Dominique

    2016-05-01

    Swine models are widely used to develop new techniques and materials for the treatment of heart valve disease like aortic valve and mitral valve transcatheter interventions and to train physicians in these techniques. Transoesophageal echocardiography (TOE) is crucial in these models. We defined standard planes of 2D and 3D TOE in healthy pigs undergoing transcatheter heart valve interventions. Twenty healthy pigs (weight 56-106 kg) underwent different mitral and aortic valve interventions (transcatheter aortic valve implantations, implantations of a mitral band, bicuspidization of the aortic valve, trans-septal punctures). For image guidance of the procedures, an adult TOE probe was introduced under direct vision in the oesophagus. Before the procedure itself was performed, a standardized protocol was used to determine normal values for anatomical and functional echocardiographic parameters. Positioning of the probe was possible in all animals and ideal when achieving a distance from the front teeth (incisors) of 40-60 cm. Anteflexion and lateroflexion of the probe was necessary to achieve optimal imaging quality. 2D visualization of all relevant cardiac structures was possible. The aortic annulus diameter was 24.1 ± 2.5 mm, the sinus of valsalva diameter was 30.6 ± 4 mm and the sinotubular junction diameter was 25.2 ± 4 mm. The ascending aorta had a diameter of 24 ± 4 mm and the descending aorta a diameter of 16 ± 5 mm. The mitral valve anterior-posterior diameter was 31.8 ± 4 mm and the commissure to commissure diameter was 40.5 ± 5 mm resulting in a mitral valve area of 10.7 ± 1.5 cm(2). 3D visualization was possible for the aortic and the mitral valve. None of the animals showed any pathology except one that had a dilated left ventricle and moderate mitral valve insufficiency. Left and right ventricular dimensions and the anatomy of the aortic-, mitral-, tricuspid and pulmonary valve as well as of the aorta were comparable with those of the human

  14. Dropwise condensation on inclined textured surfaces

    CERN Document Server

    Khandekar, Sameer

    2014-01-01

    Dropwise Condensation on Textured Surfaces presents a holistic framework for understanding dropwise condensation through mathematical modeling and meaningful experiments. The book presents a review of the subject required to build up models as well as to design experiments. Emphasis is placed on the effect of physical and chemical texturing and their effect on the bulk transport phenomena. Application of the model to metal vapor condensation is of special interest. The unique behavior of liquid metals, with their low Prandtl number and high surface tension, is also discussed. The model predicts instantaneous drop size distribution for a given level of substrate subcooling and derives local as well as spatio-temporally averaged heat transfer rates and wall shear stress.

  15. Oblique Wave-Induced Responses of A VLFS Edged with A Pair of Inclined Perforated Plates

    Science.gov (United States)

    Cheng, Yong; Ji, Chun-yan; Zhai, Gang-jun; Oleg, Gaidai

    2018-03-01

    This paper is concerned with the hydroelastic responses of a mat-like, rectangular very large floating structure (VLFS) edged with a pair of horizontal/inclined perforated anti-motion plates in the context of the direct coupling method. The updated Lagrangian formulae are applied to establish the equilibrium equations of the VLFS and the total potential formula is employed for fluids in the numerical model including the viscous effect of the perforated plates through the Darcy's law. The hybrid finite element-boundary element (FE-BE) method is implemented to determine the response reduction of VLFS with attached perforated plates under various oblique incident waves. Also, the numerical solutions are validated against a series of experimental tests. The effectiveness of the attached perforated plates in reducing the deflections of the VLFS can be significantly improved by selecting the proper design parameters such as the porous parameter, submergence depth, plate width and inclination angle for the given sea conditions.

  16. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    collaboration, The Pierre Augur

    2014-08-01

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.

  17. Spectrum of 100-kyr glacial cycle: Orbital inclination, not eccentricity

    Science.gov (United States)

    Muller, Richard A.; MacDonald, Gordon J.

    1997-01-01

    Spectral analysis of climate data shows a strong narrow peak with period ≈100 kyr, attributed by the Milankovitch theory to changes in the eccentricity of the earth’s orbit. The narrowness of the peak does suggest an astronomical origin; however the shape of the peak is incompatible with both linear and nonlinear models that attribute the cycle to eccentricity or (equivalently) to the envelope of the precession. In contrast, the orbital inclination parameter gives a good match to both the spectrum and bispectrum of the climate data. Extraterrestrial accretion from meteoroids or interplanetary dust is proposed as a mechanism that could link inclination to climate, and experimental tests are described that could prove or disprove this hypothesis. PMID:11607741

  18. Microscopic calculation of the sticking force for nanodrops on an inclined surface

    Science.gov (United States)

    Berim, Gersh O.; Ruckenstein, Eli

    2008-09-01

    A two-dimensional nanodrop on a vertical rough solid surface is examined using a nonlocal density functional theory in the presence of gravity. The roughness is modeled either as a chemical inhomogeneity of the solid or as a result of the decoration with pillars of a smooth homogeneous surface. From the obtained fluid density distribution, the sticking force, which opposes the drop motion along an inclined surface, and the contact angles on the lower and upper leading edges of the drop are calculated. On the basis of these results, it is shown that the macroscopically derived equation for a drop in equilibrium on an inclined surface is also applicable to nanodrops. The liquid-vapor surface tension involved in this equation was calculated for various specific cases, and the values obtained are of the same order of magnitude as those obtained in macroscopic experiments.

  19. Effect of occlusal plane on smile attractiveness.

    Science.gov (United States)

    Batwa, Waeil; Hunt, Nigel P; Petrie, Aviva; Gill, Daljit

    2012-03-01

    To determine the influence of the occlusal plane angle on smile attractiveness as perceived by a group of adult orthodontic patients and dentists. The first stage utilized a laboratory approach to record changes in vertical tooth position at different occlusal plane angles using a maxillary model mounted on an articulator. In the second stage, photographic manipulation was undertaken, using data from stage 1, to produce a computerized prediction of the appearance of the smile at differing occlusal plane angles (0, 5, 10, 15, and 20 degrees). Finally, the five developed photographs were assessed by participants. Alterations in the occlusal plane angle did affect relative smile attractiveness for both patients (n  =  66) and dentists (n  =  66). For patients, the 10 degree smile was rated better than the 0 and 20 degree smiles (P occlusal plane angle does affect relative smile attractiveness. However, patients were more tolerant of these changes than dentists. This suggests that large changes in the occlusal plane angle would affect relative smile attractiveness, and small changes are unlikely to affect smile attractiveness.

  20. Psychopathic Inclination Among Incarcerated Youth of Hazara Division Pakistan

    Directory of Open Access Journals (Sweden)

    Sher Dil

    2016-09-01

    Full Text Available Present study aimed at evaluating the psychopathic inclination among youth and finding the gender differences in psychopathy. An indigenously developed Psychopathy scale (Urdu has been used in this study. Alpha reliability of the scale was .90. The study was conducted on 100 males (50 criminals and 50 non-criminals and 100 females (26 criminals and 74 non-criminals using a convenient sampling technique from three districts of Hazara division: Haripur, Abbottabad, and Mansehra. Results confirmed that there is significant difference in psychopathic inclination of males and females; criminals differed significantly from the non-criminals. The study also paves way for further investigation in the field in Pakistan.

  1. Entrepreneurial Inclination Among Business Students: A Malaysian Study

    Directory of Open Access Journals (Sweden)

    Yet-Mee Lim

    2012-10-01

    Full Text Available Entrepreneurship has been the fundamental topics of discussion among the politicians, economists, and academics. Business creation is especially critical in developing countries to stimulate economic growth. The present study attempts to examine entrepreneurial inclination among students who are a potential source of entrepreneurs. The fi ndings of the present research study indicate that majority of our business students are not entrepreneurial-inclined. They do not seem to possess strong entrepreneurial characteristics and entrepreneurial skills, and they are not keen in starting a new business. The roles of higher institutes of education and the government in promoting entrepreneurship are discussed.

  2. The OBS control plane

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Ruepp, Sarah Renée

    2010-01-01

    . The applicability analysis carried out here focuses on the actual feasibility of the integration and the potential trade-offs which appear when two contradicting principles are combined. Taking advantage of the flexibility of the GMPLS control plane does not seem to be as easy and as straightforward as expected....... Thus, more than ten years later not many practical implementations of OBS networks with intelligent control can be found. The lack of active work in the ¯eld results in an incomplete set of proposals which address only few aspects of the integration challenge. Here, we analyze what is missing and why...... the existing solutions seem not to be able to provide the highly desirable strict QoS guarantees for the clients of the OBS networks....

  3. Calm Water Performance of Hard-Chine Vessels in Semi-Planing and Planing Regimes

    Directory of Open Access Journals (Sweden)

    Ghadimi Parviz

    2016-12-01

    Full Text Available In the current paper, a mathematical model is developed for performance prediction of hard-chin boats which can be used in both semi-planing and planing regimes. The proposed model bases on the 2D+T theory and implements pressure distributions over the length of the hull in order to compute the forces. To determine the forces in the semi-planing range, a function is proposed for the non-dimensional length at which the transom effect appears. Three drag components, which are: frictional drag, induced drag, and spray drag, are considered in the computations performed using an iterative method to satisfy two equilibrium equations. The validity of the proposed method is verified by comparing the predicted trim angle and resistance against the available experimental data. Based on this comparison, it is observed that the proposed method reveals satisfying accuracy in both semi-planing and planing regimes. The method is then used to study variation of hydrodynamic and hydrostatic forces as the hull makes a transition from the semi-planing regime to the planing regime. In addition, different components of the resistance are analyzed.

  4. Effects of heat transfer on peristaltic motion of Oldroyd fluid in the presence of inclined magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Afsar Khan, A. [Department of Mathematics and Statistics, FBAS, IIUI, Islamabad (Pakistan); Ellahi, R., E-mail: rahmatellahi@yahoo.com [Department of Mathematics and Statistics, FBAS, IIUI, Islamabad (Pakistan); Department of Mechanical Engineering, Bourns Hall, University of California Riverside, CA 92521 (United States); Mudassar Gulzar, M. [National University of Sciences and Technology, College of Electrical and Mechanical Engineering Islamabad (Pakistan); Sheikholeslami, Mohsen [Department of Mechanical Engineering, Babol University of Technology, Babol (Iran, Islamic Republic of)

    2014-12-15

    In this study the peristaltic motion of Oldroyd fluid in an asymmetric channel is investigated. Mathematical analysis has been carried out in the presence of an inclined magnetic field. Heat transfer is also taken into account. The physical problem is first modeled and then the analytical solutions of coupled equations are developed by regular perturbation method. Assumptions of long wavelength approximation are used. Effects of inclined magnetic field on the axial velocity and temperature are presented. Physical features of pertinent parameters such as wave number δ, Reynolds number Re, Weissenberg number Wi, Prandtl number Pr and Hartmann number M are also discussed graphically at the end of the paper. - Highlights: • This paper analyses heat transfer and inclined magnetic effects in peristaltic motion of Oldroyd fluid. • An asymmetric channel under long wavelength approximation is considered. • Regular perturbation method is used to find analytical solutions. • Effects of sundry parameters are presented through graphs.

  5. Heat and mass transfer of Williamson nanofluid flow yield by an inclined Lorentz force over a nonlinear stretching sheet

    Directory of Open Access Journals (Sweden)

    Mair Khan

    2018-03-01

    Full Text Available The present analysis is devoted to explore the computational solution of the problem addressing the variable viscosity and inclined Lorentz force effects on Williamson nanofluid over a stretching sheet. Variable viscosity is assumed to vary as a linear function of temperature. The basic mathematical modelled problem i.e. system of PDE’s is converted nonlinear into ODE’s via applying suitable transformations. Computational solutions of the problem is also achieved via efficient numerical technique shooting. Characteristics of controlling parameters i.e. stretching index, inclined angle, Hartmann number, Weissenberg number, variable viscosity parameter, mixed convention parameter, Brownian motion parameter, Prandtl number, Lewis number, thermophoresis parameter and chemical reactive species on concentration, temperature and velocity gradient. Additionally, friction factor coefficient, Nusselt number and Sherwood number are describe with the help of graphics as well as tables verses flow controlling parameters. Keywords: Williamson nanofluid, Temperature depended viscosity, Inclined magnetic field, Mixed convection, Chemical reactive species, Variable viscosity, Shooting method

  6. Quantifying skin motion artifact error of the hindfoot and forefoot marker clusters with the optical tracking of a multi-segment foot model using single-plane fluoroscopy.

    Science.gov (United States)

    Shultz, R; Kedgley, A E; Jenkyn, T R

    2011-05-01

    The trajectories of skin-mounted markers tracked with optical motion capture are assumed to be an adequate representation of the underlying bone motions. However, it is well known that soft tissue artifact (STA) exists between marker and bone. This study quantifies the STA associated with the hindfoot and midfoot marker clusters of a multi-segment foot model. To quantify STA of the hindfoot and midfoot marker clusters with respect to the calcaneus and navicular respectively, fluoroscopic images were collected on 27 subjects during four quasi-static positions, (1) quiet standing (non-weight bearing), (2) at heel strike (weight-bearing), (3) at midstance (weight-bearing) and (4) at toe-off (weight-bearing). The translation and rotation components of STA were calculated in the sagittal plane. Translational STA at the calcaneus varied from 5.9±7.3mm at heel-strike to 12.1±0.3mm at toe-off. For the navicular the translational STA ranged from 7.6±7.6mm at heel strike to 16.4±16.7mm at toe-off. Rotational STA was relatively smaller for both bones at all foot positions. For the calcaneus they varied between 0.1±2.2° at heel-strike to 0.2±0.6° at toe-off. For the navicular, the rotational STA ranged from 0.6±0.9° at heel-strike to 0.7±0.7° at toe-off. The largest translational STA found in this study (16mm for the navicular) was smaller than those reported in the literature for the thigh and the lower leg, but was larger than the STA of individual spherical markers affixed to the foot. The largest errors occurred at toe-off position for all subjects for both the hindfoot and midfoot clusters. Future studies are recommended to quantify true three-dimensional STA of the entire foot during gait. Copyright © 2011. Published by Elsevier B.V.

  7. Transition to turbulence in plane channel flow

    Science.gov (United States)

    Biringen, S.; Goglia, G. L.

    1983-01-01

    A numerical simulation of the final stages of transition to turbulence in plane channel flow is reported. Three dimensional, incompressible Navier-Stokes equations are numerically integrated to obtain the time-evolution of two and three dimensional finite amplitude disturbances. Computations are performed on the CYBER-203 vector processor for a 32x51x32 grid. Results are presented for no-slip boundary conditions at the solid walls as well as for periodic suction-blowing to simulate active control of transition by mass transfer. Solutions indicate that the method is capable of simulating the complex character of vorticity dynamics during the various stages of transition and final breakdown. In particular, evidence points to the formation of a lambda-shape vortex and the subsequent system of horseshoe vortices inclined to the main flow direction as the main elements of transition. Calculations involving suction-blowing indicate that interference with a wave of suitable phase and amplitude reduces the disturbance growth rates.

  8. Transition to turbulence in plane channel flows

    Science.gov (United States)

    Biringen, S.

    1984-01-01

    Results obtained from a numerical simulation of the final stages of transition to turbulence in plane channel flow are described. Three dimensional, incompressible Navier-Stokes equations are numerically integrated to obtain the time evolution of two and three dimensional finite amplitude disturbances. Computations are performed on CYBER-203 vector processor for a 32x51x32 grid. Results are presented for no-slip boundary conditions at the solid walls as well as for periodic suction blowing to simulate active control of transition by mass transfer. Solutions indicate that the method is capable of simulating the complex character of vorticity dynamics during the various stages of transition and final breakdown. In particular, evidence points to the formation of a lambda-shape vortex and the subsequent system of horseshoe vortices inclined to the main flow direction as the main elements of transition. Calculations involving periodic suction-blowing indicate that interference with a wave of suitable phase and amplitude reduces the disturbance growth rates.

  9. Aqua/Aura Inclination Adjust Maneuver Series Spring 2018 Planning

    Science.gov (United States)

    Trenholme, Elena; Boone, Spencer

    2017-01-01

    This will be presented at the International Earth Science Constellation Mission Operations Working Group meeting on December 6-8, 2017 to discuss the Aqua/Aura Spring 2018 Inclination Adjust Maneuver series planning. Presentation has been reviewed and approved by Eric Moyer, ESMO (Earth Science Mission Operations) Deputy Project Manager.

  10. MEASUREMENTS OF DUST EXTINCTION IN HIGHLY INCLINED SPIRAL GALAXIES

    NARCIS (Netherlands)

    JANSEN, RA; KNAPEN, JH; BECKMAN, JE; PELETIER, RF; HES, R

    1994-01-01

    We study the extinction properties of dust in the well-defined dust lanes of four highly inclined galaxies, using U-, B-, V-, R- and I-band CCD and J- and K'-band near-infrared array images. For three of these galaxies, we could use the symmetry of the underlying light profile to obtain absolute

  11. The effect of circular bridge piers with different inclination angles ...

    Indian Academy of Sciences (India)

    c Indian Academy of Sciences. The effect of circular bridge piers with different inclination angles toward downstream on scour. MOHAMMAD VAGHEFI1,∗, MASOUD GHODSIAN2 and. SAEID SALIMI3. 1Department of Civil Engineering, Persian Gulf University, Shahid Mahini Street, P.O. Box: 75169-13817,. Bushehr, Iran.

  12. The inter-relationships between angle of inclination, height and ...

    African Journals Online (AJOL)

    Experiments were conducted to investigate the dependence of number of sprouted teak (Tectona grandis Linn. F) stumps on the height above root collar and angle of inclination of planted teak stumps. The studies were aim-ed at developing suitable methods of converting teak seedlings into stumps and planting practices to ...

  13. Evidences of inclined transpression at the contact between ...

    Indian Academy of Sciences (India)

    zone may show different structures or dominance of certain type of structures, depending on whether that part is dominated by strike-slip, dip slip or compression. The present study finds evidences of inclined transpression at the contact between. Udayagiri and Vinjamuru group of NSB, which is the main focus of this paper.

  14. The relationship between specific absorption rate and temperature elevation in anatomically based human body models for plane wave exposure from 30 MHz to 6 GHz.

    Science.gov (United States)

    Hirata, Akimasa; Laakso, Ilkka; Oizumi, Takuya; Hanatani, Ryuto; Chan, Kwok Hung; Wiart, Joe

    2013-02-21

    According to the international safety guidelines/standard, the whole-body-averaged specific absorption rate (Poljak et al 2003 IEEE Trans. Electromagn. Compat. 45 141-5) and the peak spatial average SAR are used as metrics for human protection from whole-body and localized exposures, respectively. The IEEE standard (IEEE 2006 IEEE C95.1) indicates that the upper boundary frequency, over which the whole-body-averaged SAR is deemed to be the basic restriction, has been reduced from 6 to 3 GHz, because radio-wave energy is absorbed around the body surface when the frequency is increased. However, no quantitative discussion has been provided to support this description especially from the standpoint of temperature elevation. It is of interest to investigate the maximum temperature elevation in addition to the core temperature even for a whole-body exposure. In the present study, using anatomically based human models, we computed the SAR and the temperature elevation for a plane-wave exposure from 30 MHz to 6 GHz, taking into account the thermoregulatory response. As the primary result, we found that the ratio of the core temperature elevation to the whole-body-averaged SAR is almost frequency independent for frequencies below a few gigahertz; the ratio decreases above this frequency. At frequencies higher than a few gigahertz, core temperature elevation for the same whole-body averaged SAR becomes lower due to heat convection from the skin to air. This lower core temperature elevation is attributable to skin temperature elevation caused by the power absorption around the body surface. Then, core temperature elevation even for whole-body averaged SAR of 4 W kg(-1) with the duration of 1 h was at most 0.8 °C, which is smaller than a threshold considered in the safety guidelines/standard. Further, the peak 10 g averaged SAR is correlated with the maximum body temperature elevations without extremities and pinna over the frequencies considered. These findings

  15. The Canada–France Ecliptic Plane Survey (CFEPS)—High-latitude Component

    Energy Technology Data Exchange (ETDEWEB)

    Petit, J-M. [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besançon, BP 1615, F-25010 Besançon Cedex (France); Kavelaars, J. J. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Gladman, B. J.; Van Laerhoven, C.; Lawler, S. M. [Department of Physics and Astronomy, 6224 Agricultural Road, University of British Columbia, Vancouver, BC (Canada); Jones, R. L. [Department of Astronomy, University of Washington, Seattle, WA (United States); Parker, J. Wm.; Bieryla, A. [Planetary Science Directorate, Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Pike, R. E. [Department of Physics and Astronomy, University of Victoria, Victoria, BC (Canada); Nicholson, P. [Cornell University, Space Sciences Building, Ithaca, NY 14853 (United States); Ashby, M. L. N. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2017-05-01

    The High Ecliptic Latitude (HiLat) extension of the Canada–France Ecliptic Plane Survey (CFEPS), conducted from 2006 June to 2009 July, discovered a set of Trans-Neptunian objects (TNOs) that we report here. The HiLat component was designed to address one of the shortcomings of ecliptic surveys (like CFEPS), their low sensitivity to high-inclination objects. We searched 701 deg{sup 2} of sky ranging from 12° to 85° ecliptic latitude and discovered 24 TNOs, with inclinations between 15° and 104°. This survey places a very strong constraint on the inclination distribution of the hot component of the classical Kuiper Belt, ruling out any possibility of a large intrinsic fraction of highly inclined orbits. Using the parameterization of Brown, the HiLat sample combined with CFEPS imposes a width 14° ≤  σ  ≤ 15.°5, with a best match for σ  = 14.°5. HiLat discovered the first retrograde TNO, 2008 KV{sub 42}, with an almost polar orbit with inclination 104°, and (418993) = 2009 MS{sub 9}, a scattering object with perihelion in the region of Saturn’s influence, with a  ∼ 400 au and i  = 68°.

  16. Reduction in disk and fiber stresses by axial distraction is higher in cervical disk with fibers oriented toward the vertical rather than horizontal plane: a finite element model analysis.

    Science.gov (United States)

    Hussain, Mozammil; Gay, Ralph E; An, Kai-Nan

    2010-05-01

    The purpose of this study was to quantify the biomechanical changes that occur in a compressed cervical disk with the application of axial distraction when the annular fiber orientation angles are varied between the horizontal and vertical planes. A 3-dimensional finite element (FE) model of a cervical motion segment was developed. From this model, 3 FE models were developed and validated corresponding to 3 different fiber angles relative to the end plate-disk interface: +/-25 degrees (oriented toward the horizontal plane), +/-45 degrees (midway between the horizontal and vertical planes), and +/-65 degrees (oriented toward the vertical plane). Compression (50N), followed by an axial distraction (17N), was simulated. Annulus and nucleus stresses, von-Mises fiber stresses, annulus radial bulging, and nucleus radial displacement were computed. Hard tissue (cortical and cancellous bones and end plate) stresses were also quantified. With increasing fiber angle (toward vertical), axial segmental stiffness increased, whereas annulus and nucleus stresses, fiber stresses, annulus radial bulging, and nucleus radial displacement decreased. Similar outcomes were observed when axial distraction was applied to the compressed segment. Hard tissues were not affected with varying fiber angles; however, their mechanics changed when axial distraction was applied on the compressed segment. We noted lower disk stress in axial distraction than in compression. The results confirmed the hypothesis that fibers oriented toward the vertical plane reduce disk and fiber stresses and disk bulging. By aligning annular fibers toward the vertical plane axial distraction may help reduce disk and fiber stresses. Axial disk stresses decrease radially from outside to inside under compressive loading and that the anterior annulus is more stressed than the posterior-lateral annulus during both compression and distraction. Stresses decreased in both the annulus tissue matrix and fibers with increasing

  17. Effects of High Inclined and Eccentric Disturbers on the Dynamics of the Equator of an Axy-Simmetric Body

    Science.gov (United States)

    Yokoyama, Tadashi; Frouard, J. H.; Deienno, R.

    2013-05-01

    Abstract (2,250 Maximum Characters): In this work we consider the rotational long term dynamics of an axy-simmetric body under the action of a high inclined and eccentric disturber. The problem is written in terms of Andoyer canonical variables (L,G,H, l,g,h), with respect to an independent inertial frame. Since A=B (moments of inertia ), the l angle is an ignorable variable, so that spin-orbit resonance is ruled out. Therefore the Hamiltonian can be averaged in the mean anomaly of the orbital motion of the disturber. An extra average is still possible in g as it is a fast Andoyer variable. In order to have a first and rough idea of the real dynamics, the disturber is assumed in a simplified precessing keplerian motion (Henrard & Schwanen, 2004) . Then the Hamiltonian is reduced to a problem of one degree of freedom and the level curves show a gross idea of the basic dynamics. In particular the curves show interesting equilibrium points, some of them are related to Cassini’s second law. Depending on the mass and eccentricity or inclination of the disturber, a strong resonance between h and longitude of the node of the disturber can appear. This resonance can cause interesting variations of the inclination of the plane normal to the angular momentum of the perturbed body. Finally, numerical integrations of the complete averaged problem are performed. In particular, we study the possible cumulative effects of temporary satellites when they orbit their host planet in high inclined and eccentric orbit. These satellites ( planetesimals) might have existed during the planetary migration but due to Lidov-Kozai resonance they should have ejected after some time.

  18. Stability of a flow down an incline with respect to two-dimensional and three-dimensional disturbances for Newtonian and non-Newtonian fluids.

    Science.gov (United States)

    Allouche, M H; Millet, S; Botton, V; Henry, D; Ben Hadid, H; Rousset, F

    2015-12-01

    Squire's theorem, which states that the two-dimensional instabilities are more dangerous than the three-dimensional instabilities, is revisited here for a flow down an incline, making use of numerical stability analysis and Squire relationships when available. For flows down inclined planes, one of these Squire relationships involves the slopes of the inclines. This means that the Reynolds number associated with a two-dimensional wave can be shown to be smaller than that for an oblique wave, but this oblique wave being obtained for a larger slope. Physically speaking, this prevents the possibility to directly compare the thresholds at a given slope. The goal of the paper is then to reach a conclusion about the predominance or not of two-dimensional instabilities at a given slope, which is of practical interest for industrial or environmental applications. For a Newtonian fluid, it is shown that, for a given slope, oblique wave instabilities are never the dominant instabilities. Both the Squire relationships and the particular variations of the two-dimensional wave critical curve with regard to the inclination angle are involved in the proof of this result. For a generalized Newtonian fluid, a similar result can only be obtained for a reduced stability problem where some term connected to the perturbation of viscosity is neglected. For the general stability problem, however, no Squire relationships can be derived and the numerical stability results show that the thresholds for oblique waves can be smaller than the thresholds for two-dimensional waves at a given slope, particularly for large obliquity angles and strong shear-thinning behaviors. The conclusion is then completely different in that case: the dominant instability for a generalized Newtonian fluid flowing down an inclined plane with a given slope can be three dimensional.

  19. An inverse analysis of weak structural plane parameters for a limestone foundation pit based on critical stability

    Science.gov (United States)

    yan, LIU Jun; hua, SONG Xiang; Yan, LIU

    2017-11-01

    The article uses the Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D) to make an analysis of the deformation characteristics of the structural plane, which is based on a real rock foundation pit in Jinan city. It makes an inverse analysis of the strength of the surface structure and the occurrence of the parameters by Mohr-Coulomb strength criterion value criterion in the way of numerical simulation, which explores the change of stress field of x-z oblique section of pit wall and the relation between the exposed height of structural plane and the critical cohesion, the exposed height and critical inclination angle of the structure surface. We can find that when the foundation pit is in the critical stable state and the inclination angle of the structural plane is constant, the critical cohesive force of the structural plane increases with the increase of the exposed surface height. And when the foundation pit in the critical stability of the situation and the structural surface of the cohesive force is constant, the structural surface exposed height increases and the structural angle of inclination is declining. The conclusion can provide theoretical basis for the design and construction of the rock foundation pit with structural plane.

  20. Deontological and utilitarian inclinations in moral decision making: a process dissociation approach.

    Science.gov (United States)

    Conway, Paul; Gawronski, Bertram

    2013-02-01

    Dual-process theories of moral judgment suggest that responses to moral dilemmas are guided by two moral principles: the principle of deontology states that the morality of an action depends on the intrinsic nature of the action (e.g., harming others is wrong regardless of its consequences); the principle of utilitarianism implies that the morality of an action is determined by its consequences (e.g., harming others is acceptable if it increases the well-being of a greater number of people). Despite the proposed independence of the moral inclinations reflecting these principles, previous work has relied on operationalizations in which stronger inclinations of one kind imply weaker inclinations of the other kind. The current research applied Jacoby's (1991) process dissociation procedure to independently quantify the strength of deontological and utilitarian inclinations within individuals. Study 1 confirmed the usefulness of process dissociation for capturing individual differences in deontological and utilitarian inclinations, revealing positive correlations of both inclinations to moral identity. Moreover, deontological inclinations were uniquely related to empathic concern, perspective-taking, and religiosity, whereas utilitarian inclinations were uniquely related to need for cognition. Study 2 demonstrated that cognitive load selectively reduced utilitarian inclinations, with deontological inclinations being unaffected. In Study 3, a manipulation designed to enhance empathy increased deontological inclinations, with utilitarian inclinations being unaffected. These findings provide evidence for the independent contributions of deontological and utilitarian inclinations to moral judgments, resolving many theoretical ambiguities implied by previous research. (c) 2013 APA, all rights reserved.

  1. Calibration of the inclined contour planes formed on ESPI and optimization of ESPI optical system for contouring

    OpenAIRE

    Diao, Hongyan; Zou, Yunlu; Peng, Xiang; Tiziani, Hans J.; Chen, L.

    1992-01-01

    Es wird eine neue Konturing-Methode mit einer elektronischen Zweiwellenlängen-Speckle-Interferometrie (TWESPI) vorgeschlagen, bei der zwei Beleuchtungsstrahlen verwendet werden. Die optisch rauhe Oberfläche wird bei einer synthetischen längeren equivalenten Wellenlänge vermessen, so daß durch die Änderung der Wellenlängen eine variable Meßempfindlichkeit erhalten werden kann. Dadurch erweitert diese Technik den Meßbereich der Einwellen-Speckle-Interferometrie und erlaubt die Messung von Kontu...

  2. Entrepreneurial Inclination Among Business Students: A Malaysian Study

    Directory of Open Access Journals (Sweden)

    Yet-Mee Lim

    2012-11-01

    Full Text Available Normal 0 false false false IN X-NONE AR-SA MicrosoftInternetExplorer4 Entrepreneurship has been the fundamental topics of discussion among the politicians, economists, and academics. Business creation is especially critical in developing countries to stimulate economic growth. The present study attempts to examine entrepreneurial inclination among students who are a potential source of entrepreneurs. The fi ndings of the present research study indicate that majority of our business students are not entrepreneurial-inclined. They do not seem to possess strong entrepreneurial characteristics and entrepreneurial skills, and they are not keen in starting a new business. The roles of higher institutes of education and the government in promoting entrepreneurship are discussed.

  3. Microfiber inclination, crystallinity, and water wettability of microfibrous thin-film substrates of Parylene C in relation to the direction of the monomer vapor during fabrication

    Science.gov (United States)

    Chindam, Chandraprakash; Wonderling, Nichole M.; Lakhtakia, Akhlesh; Awadelkarim, Osama O.; Orfali, Wasim

    2015-08-01

    We experimentally determined the inclination of microfibers, crystallinity, and the water wettability of columnar microfibrous thin-film substrates (μFTFS) of Parylene C fabricated using a variant of conventional chemical vapor deposition, wherein a collimated vapor of reactive monomers is obliquely directed towards a planar wafer in a low-pressure chamber. The independent variable was the monomer deposition angle χv, which is the angle between the direction of the collimated vapor and the wafer plane. The dependence of the microfiber inclination angle χ on χv can be classified into four χv-regimes of two different types, and is reminiscent of the conversion of continuous rotation into intermittent rotary motion by a gear mechanism. X-ray diffraction (XRD) experiments indicate that the columnar μFTFS contain three crystal planes not evident in bulk Parylene-C films, the columnar μFTFS are less crystalline than bulk Parylene-C films, and the crystallinity of the columnar μFTFS reflects the four χv-regimes. Identical resonance frequencies in infrared absorbance spectra revealed that the atomic bonding is the same for all monomer deposition angles. The static hydrophobicity is more pronounced in the morphologically significant plane (MSP) of a columnar μFTFS than in the vertical plane orthogonal to the MSP, but the upper and lower limits of static hydrophobicity are almost isotropic. Both the static hydrophobicity as well as water adhesion can be maximized by a proper choice of χv.

  4. Origin of the Local Group satellite planes

    Science.gov (United States)

    Banik, Indranil; O'Ryan, David; Zhao, Hongsheng

    2018-04-01

    We attempt to understand the planes of satellite galaxies orbiting the Milky Way (MW) and M31 in the context of Modified Newtonian Dynamics (MOND), which implies a close MW-M31 flyby occurred ≈8 Gyr ago. Using the timing argument, we obtain MW-M31 trajectories consistent with cosmological initial conditions and present observations. We adjust the present M31 proper motion within its uncertainty in order to simulate a range of orbital geometries and closest approach distances. Treating the MW and M31 as point masses, we follow the trajectories of surrounding test particle disks, thereby mapping out the tidal debris distribution. Around each galaxy, the resulting tidal debris tends to cluster around a particular orbital pole. We find some models in which these preferred spin vectors align fairly well with those of the corresponding observed satellite planes. The radial distributions of material in the simulated satellite planes are similar to what we observe. Around the MW, our best-fitting model yields a significant fraction (0.22) of counter-rotating material, perhaps explaining why Sculptor counter-rotates within the MW satellite plane. In contrast, our model yields no counter-rotating material around M31. This is testable with proper motions of M31 satellites. In our best model, the MW disk is thickened by the flyby 7.65 Gyr ago to a root mean square height of 0.75 kpc. This is similar to the observed age and thickness of the Galactic thick disk. Thus, the MW thick disk may have formed together with the MW and M31 satellite planes during a past MW-M31 flyby.

  5. Graphs and matroids weighted in a bounded incline algebra.

    Science.gov (United States)

    Lu, Ling-Xia; Zhang, Bei

    2014-01-01

    Firstly, for a graph weighted in a bounded incline algebra (or called a dioid), a longest path problem (LPP, for short) is presented, which can be considered the uniform approach to the famous shortest path problem, the widest path problem, and the most reliable path problem. The solutions for LPP and related algorithms are given. Secondly, for a matroid weighted in a linear matroid, the maximum independent set problem is studied.

  6. Drop impact and rebound dynamics on an inclined superhydrophobic surface.

    Science.gov (United States)

    Yeong, Yong Han; Burton, James; Loth, Eric; Bayer, Ilker S

    2014-10-14

    Due to its potential in water-repelling applications, the impact and rebound dynamics of a water drop impinging perpendicular to a horizontal superhydrophobic surface have undergone extensive study. However, drops tend to strike a surface at an angle in applications. In such cases, the physics governing the effects of oblique impact are not well studied or understood. Therefore, the objective of this study was to conduct an experiment to investigate the impact and rebound dynamics of a drop at various liquid viscosities, in an isothermal environment, and on a nanocomposite superhydrophobic surface at normal and oblique impact conditions (tilted at 15°, 30°, 45°, and 60°). This study considered drops falling from various heights to create normal impact Weber numbers ranging from 6 to 110. In addition, drop viscosity was varied by decreasing the temperature for water drops and by utilizing water-glycerol mixtures, which have similar surface tension to water but higher viscosities. Results revealed that oblique and normal drop impact behaved similarly (in terms of maximum drop spread as well as rebound dynamics) at low normal Weber numbers. However, at higher Weber numbers, normal and oblique impact results diverged in terms of maximum spread, which could be related to asymmetry and more complex outcomes. These asymmetry effects became more pronounced as the inclination angle increased, to the point where they dominated the drop impact and rebound characteristics when the surface was inclined at 60°. The drop rebound characteristics on inclined surfaces could be classified into eight different outcomes driven primarily by normal Weber number and drop Ohnesorge numbers. However, it was found that these outcomes were also a function of the receding contact angle, whereby reduced receding angles yielded tail-like structures. Nevertheless, the contact times of the drops with the coating were found to be generally independent of surface inclination.

  7. Two Mechanisms of Sensorimotor Set Adaptation to Inclined Stance

    Directory of Open Access Journals (Sweden)

    Kyoung-Hyun Lee

    2017-10-01

    Full Text Available Orientation of posture relative to the environment depends on the contributions from the somatosensory, vestibular, and visual systems mixed in varying proportions to produce a sensorimotor set. Here, we probed the sensorimotor set composition using a postural adaptation task in which healthy adults stood on an inclined surface for 3 min. Upon returning to a horizontal surface, participants displayed a range of postural orientations – from an aftereffect that consisted of a large forward postural lean to an upright stance with little or no aftereffect. It has been hypothesized that the post-incline postural change depends on each individual’s sensorimotor set: whether the set was dominated by the somatosensory or vestibular system: Somatosensory dominance would cause the lean aftereffect whereas vestibular dominance should steer stance posture toward upright orientation. We investigated the individuals who displayed somatosensory dominance by manipulating their attention to spatial orientation. We introduced a distraction condition in which subjects concurrently performed a difficult arithmetic subtraction task. This manipulation altered the time course of their post-incline aftereffect. When not distracted, participants returned to upright stance within the 3-min period. However, they continued leaning forward when distracted. These results suggest that the mechanism of sensorimotor set adaptation to inclined stance comprises at least two components. The first component reflects the dominant contribution from the somatosensory system. Since the postural lean was observed among these subjects even when they were not distracted, it suggests that the aftereffect is difficult to overcome. The second component includes a covert attentional component which manifests as the dissipation of the aftereffect and the return of posture to upright orientation.

  8. Determination of angle of inclination for optimum power production ...

    African Journals Online (AJOL)

    This study evaluates the performance of the photovoltaic modules at different tilt angle (angle of inclination) from 5º to 90º. The solar panel of 45 Watts capacity was placed on the manual tracker between the hours of 7:00am and 6:15pm on the geographical location of latitude of 40 55' 58” North and longitude of 60 59' 55” ...

  9. Testing corrections for paleomagnetic inclination error in sedimentary rocks: A comparative approach

    Science.gov (United States)

    Tauxe, Lisa; Kodama, Kenneth P.; Kent, Dennis V.

    2008-08-01

    Paleomagnetic inclinations in sedimentary formations are frequently suspected of being too shallow. Recognition and correction of shallow bias is therefore critical for paleogeographical reconstructions. This paper tests the reliability of the elongation/inclination ( E/ I) correction method in several ways. First we consider the E/ I trends predicted by various PSV models. We explored the role of sample size on the reliability of the E/ I estimates and found that for data sets smaller than ˜100-150, the results were less reliable. The Giant Gaussian Process-type paleosecular variation models were all constrained by paleomagnetic data from lava flows of the last five million years. Therefore, to test whether the method can be used in more ancient times, we compare model predictions of E/ I trends with observations from five Large Igneous Provinces since the early Cretaceous (Yemen, Kerguelen, Faroe Islands, Deccan and Paraná basalts). All data are consistent at the 95% level of confidence with the E/ I trends predicted by the paleosecular variation models. The Paraná data set also illustrated the effect of unrecognized tilting and combining data over a large latitudinal spread on the E/ I estimates underscoring the necessity of adhering to the two principle assumptions of the method. Then we discuss the geological implications of various applications of the E/ I method. In general the E/ I corrected data are more consistent with data from contemporaneous lavas, with predictions from the well constrained synthetic apparent polar wander paths, and other geological constraints. Finally, we compare the E/ I corrections with corrections from an entirely different method of inclination correction: the anisotropy of remanence method of Jackson et al. [Jackson, M.J., Banerjee, S.K., Marvin, J.A., Lu, R., Gruber, W., 1991. Detrital remanence, inclination errors and anhysteretic remanence anisotropy: quantitative model and experimental results. Geophys. J. Int. 104, 95

  10. Impact on perceived root resorption based on the amount of incisal inclination as determined from conventional panoramic radiography.

    Science.gov (United States)

    Tieu, Long Dao; Normando, David; Toogood, Roger; Flores-Mir, Carlos

    2015-10-01

    Our objective was to measure the impact on perceived root resorption based on the amount of anteroposterior incisal inclination as determined in vitro from conventional panoramic radiography. A rapid prototyping model was created to mimic different maxillary and mandibular incisal anteroposterior inclinations. Two titanium beads were placed on the incisors at the apical and incisal edges. Panoramic radiographs were obtained, with the incisors changing relative inclination by 10° increments. The length was measured from the midpoint of the bead on the incisal edge to the midpoint of the bead on the apical edge. By using a length of wire of known size, this value was compared in all images to correct for image magnification. Changes to mandibular incisor anteroposterior inclinations, as either a theoretical proclination or retroclination, resulted in an increase of "apparent" root resorption on a panoramic radiograph. When the maxillary incisors were significantly and severely retroclined, they appeared larger than expected. When the maxillary incisors were mildly retroclined, the length was roughly similar to the theoretical model. When the maxillary incisors were mildly proclined, they appeared shorter than expected. The foreshortening or forelengthening of incisor root lengths because of incisor inclination vs root resorption cannot be reliably evaluated from panoramic images. The proposed theoretical model helps to understand the direction of the changes produced by the magnification factor. More severe scenarios where either the maxillary or the mandibular teeth are outside the focal trough have not been fully evaluated. The clinical impact of these changes is likely to be questionable. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  11. Casimir entropy for a ball in front of a plane

    Science.gov (United States)

    Bordag, M.; Pirozhenko, I. G.

    2010-12-01

    The violation of the third law of thermodynamics for metals described by the Drude model and for dielectrics with finite dc conductivity is one of the most interesting problems in the field of the Casimir effect. It manifests itself as a nonvanishing of the entropy for vanishing temperature. We review the relevant calculations for plane surfaces and calculate the corresponding contributions for a ball in front of a plane. In this geometry, these appear in much the same way as for parallel planes. We conclude that the violation of the 3rd law is not related to the infinite size of the planes.

  12. Properties of light transition radiation of 660 MeV proton inclined incidence (γ=1.7) on a thick nickel plate. II

    International Nuclear Information System (INIS)

    Zrelov, V.P.; Pavlovic, P.; Ruzicka, J.

    1975-01-01

    The basic properties of transition radiation in the visible fraction of the spectrum have been calculated for 660 MeV protons (γ=1.7) obliquely incident on a thick nickel plate in vacuum. The angular distributions of the summary radiation (i.e. the sums of radiations of various polarizations) both 'forward' and 'backward' for different azimuthal planes are presented in tables and diagrams for different particle inclination angles to the separation boundary. The examples of angular distributions of radiation having various polarizations (at the inclination angle of 45 0 ) show that they differ considerably. The spectra of summary radiation are of a monotonous character. The calculations have shown that in a relativistic case the forward radiation is concentrated near the direction of particle motion and backward radiation moves in an opposite direction with respect to that of the particle inclination. The dependence of the total yield of forward and backward transition radiations upon the particle inclination angle is approximately cos 2 psi. (Auth.)

  13. Iron-mineral-based magnetoreceptor in birds: polarity or inclination compass?

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Greiner, Walter

    2009-01-01

    In the present paper we demonstrate that the iron-mineral-based magnetoreceptor model can provide birds with a magnetic compass in addition to the generally believed "magnetic map". We show that the iron-mineral-based magnetoreceptor system possesses all properties of a polarity compass, which...... is extremely important for avian navigation. We study how parameters of the magnetoreceptor system influence on the properties of the compass and show that at certain conditions it acquires features of an inclination compass. In the present paper we address the question of avian magnetoreception theoretically...

  14. On the unsteady flow of two visco-elastic fluids between two inclined porous plates

    Directory of Open Access Journals (Sweden)

    P. R. Sengupta

    1992-01-01

    Full Text Available This study is concerned with both hydrodynamic and hydromagnetic unsteady slow flows of two immiscible visco-elastic fluids of Rivlin-Ericksen type between two porous parallel nonconducting plates inclined at a certain angle to the horizontal. The exact solutions for the velocity fields, skin frictions, and the interface velocity distributions are found for both fluid models. Numerical results are presented in graphs. A comparison is made between the hydrodynamic and hydromagnetic velocity profiles. It is shown that the velocity is diminished due to the presence of a transverse magnetic field.

  15. Phase Plane Analysis Method of Nonlinear Traffic Phenomena

    Directory of Open Access Journals (Sweden)

    Wenhuan Ai

    2015-01-01

    Full Text Available A new phase plane analysis method for analyzing the complex nonlinear traffic phenomena is presented in this paper. This method makes use of variable substitution to transform a traditional traffic flow model into a new model which is suitable for the analysis in phase plane. According to the new model, various traffic phenomena, such as the well-known shock waves, rarefaction waves, and stop-and-go waves, are analyzed in the phase plane. From the phase plane diagrams, we can see the relationship between traffic jams and system instability. So the problem of traffic flow could be converted into that of system stability. The results show that the traffic phenomena described by the new method is consistent with that described by traditional methods. Moreover, the phase plane analysis highlights the unstable traffic phenomena we are chiefly concerned about and describes the variation of density or velocity with time or sections more clearly.

  16. ESTIMATION OF TOTAL SOLAR RADIATION INCIDENT ON AN INCLINED SURFACE OF A SOUTH-FACING GREENHOUSE ROOF

    Directory of Open Access Journals (Sweden)

    RONOH E.K.

    2017-12-01

    Full Text Available Solar radiation is the driving force for the surface energy balance in buildings such as greenhouses. Greenhouses are generally tilted towards the sun in order to maximize the solar irradiance on the surfaces. Precise computation of the solar radiation received on these surfaces assumes an important role in the energy simulation. It is practical to calculate the total solar irradiance on inclined surfaces based on the solar global and diffuse radiation intensities on horizontal surfaces. This study focused on estimating the total solar radiation incident on inclined greenhouse roof surfaces. In this work, a south-facing thermal box inclined at 26.5° from the horizontal was used for solar radiation measurements. Additionally, recorded solar radiation data were retrieved for the study location and used to develop an empirical correlation. The conversion factors for the beam, the diffuse and the reflected solar radiation components were essential in the prediction of the total solar radiation incident on the tilted surface. The measured solar radiation data were then compared with the simulated data. The model performance was assessed using both graphical and statistical methods. Overall, locally calibrated data led to a satisfactory improvement in estimation of the total solar radiation on an inclined surface.

  17. Computational parametric study of a Richtmyer-Meshkov instability for an inclined interface.

    Science.gov (United States)

    McFarland, Jacob A; Greenough, Jeffrey A; Ranjan, Devesh

    2011-08-01

    A computational study of the Richtmyer-Meshkov instability for an inclined interface is presented. The study covers experiments to be performed in the Texas A&M University inclined shock tube facility. Incident shock wave Mach numbers from 1.2 to 2.5, inclination angles from 30° to 60°, and gas pair Atwood numbers of ∼0.67 and ∼0.95 are used in this parametric study containing 15 unique combinations of these parameters. Qualitative results are examined through a time series of density plots for multiple combinations of these parameters, and the qualitative effects of each of the parameters are discussed. Pressure, density, and vorticity fields are presented in animations available online to supplement the discussion of the qualitative results. These density plots show the evolution of two main regions in the flow field: a mixing region containing driver and test gas that is dominated by large vortical structures, and a more homogeneous region of unmixed fluid which can separate away from the mixing region in some cases. The interface mixing width is determined for various combinations of the parameters listed at the beginning of the Abstract. A scaling method for the mixing width is proposed using the interface geometry and wave velocities calculated using one-dimensional gas dynamic equations. This model uses the transmitted wave velocity for the characteristic velocity and an initial offset time based on the travel time of strong reflected waves. It is compared to an adapted Richtmyer impulsive model scaling and shown to scale the initial mixing width growth rate more effectively for fixed Atwood number.

  18. Continuous inclination record of the geomagnetic field from a Brazilian stalagmite

    Science.gov (United States)

    Jaqueto, P.; Trindade, R. I.; Hartmann, G. A.; Feinberg, J. M.; Novello, V. F.; Cruz, F. W.

    2013-12-01

    It is known that South America contributes with less than ~3% of the global database and some of these data (obtained decades ago) do not obey minimum quality criteria, such as standard deviations and age controls. In this sense, continuous full-vector records (direction and intensity) provide important high-resolution data on the spatial and temporal behavior of Earth's magnetic field of utmost importance to describe the evolution of major field features, such as the South Atlantic Magnetic Anomaly (SAMA). Here, we present results of magnetic inclination determined from a stalagmite collected in Pau d'Alho cave located at 14.8° S, 56.4° W (Mato Grosso, Brazil), where no previous geomagnetic record was available. The sample is a 23-cm-long stalagmite which grew continuously during most of the last 1400 years. The chronology based on high-quality U-Th dating ranges from 500 AD to 1900 AD and reveals a nearly constant growth rate of ~150 μm/yr. Remanence measurements of the stalagmite were performed continuously using a SQUID magnetometer with a spatial resolution of 0.5 cm. Magnetic values for each measured point were deconvolved using the singular value decomposition (SVD) method. Hysteresis and low-temperature magnetization analyses indicate a very homogeneous magnetic mineralogy with the presence of tiny concentrations of pure magnetite in the SD-PSD state. After stepwise alternating field demagnetization, inclination data show maximum angular deviation (MAD) for most samples below 5° (with anomalous MAD of up to 15° for the 1660 AD to 1690 AD period). In general, our magnetic inclination data are consistent with those predicted by geomagnetic field models, and will provide a firm observational anchor for future modeling efforts. In this way, continuous magnetic measurements on speleothems can provide important, high-quality information about the short term behavior of the geomagnetic field.

  19. GAPS IN PROTOPLANETARY DISKS AS SIGNATURES OF PLANETS. II. INCLINED DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Jang-Condell, Hannah [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Turner, Neal J. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2013-07-20

    We examine the observational appearance of partial gaps being opened by planets in protoplanetary disks, considering the effects of the inclination relative to the line of sight. We model the disks with static {alpha}-models with detailed radiative transfer, parameterizing the shape and size of the partially cleared gaps based on the results of hydrodynamic simulations. As in previous work, starlight falling across the gap leads to high surface brightness contrasts. The gap's trough is darkened by both shadowing and cooling, relative to the uninterrupted disk. The gap's outer wall is brightened by direct illumination and also by heating, which puffs it up so that it intercepts more starlight. In this paper, we examine the effects of inclination on resolved images of disks with and without gaps at a wide range of wavelengths. The scattering surface's offset from the disk midplane creates a brightness asymmetry along the axis of inclination, making the disk's near side appear brighter than the far side in scattered light. Finite disk thickness also causes the projected distances of equidistant points on the disk surface to be smaller on the near side of the disk as compared to the far side. Consequently, the gap shoulder on the near side of the disk should appear brighter and closer to the star than on the far side. However, if the angular resolution of the observation is coarser than the width of the brightened gap shoulder, then the gap shoulder on the far side may appear brighter because of its larger apparent size. We present a formula to recover the scale height and inclination angle of an imaged disk using simple geometric arguments and measuring disk asymmetries. Resolved images of circumstellar disks have revealed clearings and gaps, such as the transitional disk in LkCa 15. Models created using our synthetic imaging attempting to match the morphology of observed scattered light images of LkCa 15 indicate that the H-band flux deficit in

  20. Radioactivity in the galactic plane

    Science.gov (United States)

    Walraven, G. D.; Haymes, R. C.

    1976-01-01

    The paper reports the detection of a large concentration of interstellar radioactivity during balloon-altitude measurements of gamma-ray energy spectra in the band between 0.02 and 12.27 MeV from galactic and extragalactic sources. Enhanced counting rates were observed in three directions towards the plane of the Galaxy; a power-law energy spectrum is computed for one of these directions (designated B 10). A large statistical deviation from the power law in a 1.0-FWHM interval centered near 1.16 MeV is discussed, and the existence of a nuclear gamma-ray line at 1.15 MeV in B 10 is postulated. It is suggested that Ca-44, which emits gamma radiation at 1.156 MeV following the decay of radioactive Sc-44, is a likely candidate for this line, noting that Sc-44 arises from Ti-44 according to explosive models of supernova nucleosynthesis. The 1.16-MeV line flux inferred from the present data is shown to equal the predicted flux for a supernova at a distance of approximately 3 kpc and an age not exceeding about 100 years.

  1. Differential Quadrature Method Based Study of Vibrational Behaviour of Inclined Edge Cracked Beams

    Directory of Open Access Journals (Sweden)

    Srivastava Shivani

    2017-01-01

    Full Text Available The study of vibration behaviour of cracked system is an important area of research. In the present work we present a mathematical model to study the effect of inclination, location and size of the crack on the vibrational behavior of beam with different boundary conditions. The model is based on the assumption that the equivalent flexible rigidity of the cracked beam can be written in terms of the flexible rigidity of the uncracked beam, based on the energy approach as proposed by earlier researchers. In the present work the Differential Quadrature Method (DQM is used to solve equation of motion derived by using Euler’s beam theory. The primary interest of the paper is to study the effect of inclined crack on natural frequency. We have also studied the beam vibration with and without vertical edge crack as a special case to validate the model. The DQM results for the natural frequencies of cracked beams agree well with other literature values and ANSYS solutions.

  2. Inclined Pulsar Magnetospheres in General Relativity: Polar Caps for the Dipole, Quadrudipole, and Beyond

    Science.gov (United States)

    Gralla, Samuel E.; Lupsasca, Alexandru; Philippov, Alexander

    2017-12-01

    In the canonical model of a pulsar, rotational energy is transmitted through the surrounding plasma via two electrical circuits, each connecting to the star over a small region known as a “polar cap.” For a dipole-magnetized star, the polar caps coincide with the magnetic poles (hence the name), but in general, they can occur at any place and take any shape. In light of their crucial importance to most models of pulsar emission (from radio to X-ray to wind), we develop a general technique for determining polar cap properties. We consider a perfectly conducting star surrounded by a force-free magnetosphere and include the effects of general relativity. Using a combined numerical-analytical technique that leverages the rotation rate as a small parameter, we derive a general analytic formula for the polar cap shape and charge-current distribution as a function of the stellar mass, radius, rotation rate, moment of inertia, and magnetic field. We present results for dipole and quadrudipole fields (superposed dipole and quadrupole) inclined relative to the axis of rotation. The inclined dipole polar cap results are the first to include general relativity, and they confirm its essential role in the pulsar problem. The quadrudipole pulsar illustrates the phenomenon of thin annular polar caps. More generally, our method lays a foundation for detailed modeling of pulsar emission with realistic magnetic fields.

  3. Crack initiation under generalized plane strain conditions

    International Nuclear Information System (INIS)

    Shum, D.K.M.; Merkle, J.G.

    1991-01-01

    A method for estimating the decrease in crack-initiation toughness, from a reference plane strain value, due to positive straining along the crack front of a circumferential flaw in a reactor pressure vessel is presented in this study. This method relates crack initiation under generalized plane strain conditions with material failure at points within a distance of a few crack-tip-opening displacements ahead of a crack front, and involves the formulation of a micromechanical crack-initiation model. While this study is intended to address concerns regarding the effects of positive out-of- plane straining on ductile crack initiation, the approach adopted in this work can be extended in a straightforward fashion to examine conditions of macroscopic cleavage crack initiation. Provided single- parameter dominance of near-tip fields exists in the flawed structure, results from this study could be used to examine the appropriateness of applying plane strain fracture toughness to the evaluation of circumferential flaws, in particular to those in ring-forged vessels which have no longitudinal welds. In addition, results from this study could also be applied toward the analysis of the effects of thermal streaming on the fracture resistance of circumferentially oriented flaws in a pressure vessel. 37 refs., 8 figs., 1 tab

  4. Mining planing introduction

    International Nuclear Information System (INIS)

    Toledo, R.D.

    1985-01-01

    Basic concepts concerning mining parameters, plan establishment and typical procedure methods applied throughout the physical execution of mining operations are here determined, analyzed and discussed. Technological and economic aspects of the exploration phase are presented as well as general mathematical and statistical methods for estimating, analyzing and representing mineral deposits which are virtually essential for good mining project execution. The characterization of important mineral substances and the basic parameters of mining works are emphasized in conjunction with long, medium and short term mining planning. Finally, geological modelling, ore reserves calculations and final economic evaluations are considered using a hypothetical example in order to consolidate the main elaborated ideas. (D.J.M.) [pt

  5. MHD natural convection in open inclined square cavity with a heated circular cylinder

    Science.gov (United States)

    Hosain, Sheikh Anwar; Alim, M. A.; Saha, Satrajit Kumar

    2017-06-01

    MHD natural convection in open cavity becomes very important in many scientific and engineering problems, because of it's application in the design of electronic devices, solar thermal receivers, uncovered flat plate solar collectors having rows of vertical strips, geothermal reservoirs, etc. Several experiments and numerical investigations have been presented for describing the phenomenon of natural convection in open cavity for two decades. MHD natural convection and fluid flow in a two-dimensional open inclined square cavity with a heated circular cylinder was considered. The opposite wall to the opening side of the cavity was first kept to constant heat flux q, at the same time the surrounding fluid interacting with the aperture was maintained to an ambient temperature T∞. The top and bottom wall was kept to low and high temperature respectively. The fluid with different Prandtl numbers. The properties of the fluid are assumed to be constant. As a result a buoyancy force is created inside the cavity due to temperature difference and natural convection is formed inside the cavity. The Computational Fluid Dynamics (CFD) code are used to discretize the solution domain and represent the numerical result to graphical form.. Triangular meshes are used to obtain the solution of the problem. The streamlines and isotherms are produced, heat transfer parameter Nu are obtained. The results are presented in graphical as well as tabular form. The results show that heat flux decreases for increasing inclination of the cavity and the heat flux is a increasing function of Prandtl number Pr and decreasing function of Hartmann number Ha. It is observed that fluid moves counterclockwise around the cylinder in the cavity. Various recirculations are formed around the cylinder. The almost all isotherm lines are concentrated at the right lower corner of the cavity. The object of this work is to develop a Mathematical model regarding the effect of MHD natural convection flow around

  6. Molar heights and incisor inclinations in adults with Class II and Class III skeletal open-bite malocclusions.

    Science.gov (United States)

    Arriola-Guillén, Luis Ernesto; Flores-Mir, Carlos

    2014-03-01

    The aim of this research was to compare maxillary and mandibular molar heights and incisor inclinations in patients with skeletal open-bite Class II, patients with skeletal open-bite Class III, and an untreated control group. Pretreatment lateral cephalograms of 70 orthodontic patients (34 men, 36 women) between 16 and 40 years of age were examined. The sample was divided into 3 groups according to facial growth pattern and overbite. The control group (n = 25) included normodivergent Class I subjects with adequate overbite; the skeletal open-bite Class II group (n = 25) and the skeletal open-bite Class III group (n = 20) included hyperdivergent Class II or Class III subjects with negative overbite. Measurements considered were ANB angle, palatal and mandibular plane angles, maxillary incisor palatal plane angulation, and mandibular incisor mandibular plane angulation, as well as the distance from the palatal or the mandibular plane to the mesial cusp of the molars. Multivariate analysis of covariance and multivariate analysis of variance tests were used to determine the differences between the groups, followed by the Tukey post-hoc test. Additionally, the Mann-Whitney U test and Kruskall-Wallis test were performed. Significant differences in molar height were found (P open-bite and control groups was found. Mandibular molar height was greater in the skeletal open-bite Class II group (P open-bite Class III group by approximately 6°. Mandibular incisor to mandibular plane angulation was 10° more lingual in the skeletal open-bite Class III group (P open-bite groups had greater molar heights than did the control group. The skeletal open-bite Class II group had more eruption of the mandibular molars. The maxillary incisors were more proclined and the mandibular incisors were more lingual in the skeletal open-bite Class III group. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  7. The flare model for X-ray variability of NGC 4258

    Science.gov (United States)

    Trześniewski, T.; Czerny, B.; Karas, V.; Pecháček, T.; Dovčiak, M.; Goosmann, R.; Nikołajuk, M.

    2011-06-01

    Aims: We study the variability mechanism of active galactic nuclei (AGN) within the framework of the flare model. We examine the case of Seyfert/LINER galaxy NGC 4258, which is observed at high inclination angle and exhibits rapid fluctuations in its X-ray light curve. Methods: We construct a model light curve based on the assumption of magnetic flares localized in the equatorial plane and orbiting with Keplerian speed at each given radius. We calculate the level of variability as a function of the inclination of an observer, taking into account all effects of general relativity near a rotating supermassive black hole. Results: The variability level is a monotonic function of the source inclination. It rises more rapidly for larger values of the black hole spin (Kerr parameter a) and for steeper emissivity (index β of the radial profile). We compare the expected level of variability for the viewing angle 81.6 deg, as inferred for NGC 4258, with the case of moderate viewing angles of about 30 deg, which are typical of Seyfert type-1 galaxies. Conclusions: Highly inclined sources such as this one are particularly suitable to test the flare model because the orbital motion, Doppler boosting, and light bending are all expected to have maximum effect when the accretion disk is seen almost edge-on. The model is consistent with the NGC 4258 variability, where the obscuring material is thought to be localized mainly toward the equatorial plane rather than forming a geometrically thick torus. Once the intrinsic timescales of the flare duration are determined with higher precision, this kind of highly inclined objects with a precisely known mass of the black hole can be used to set independent constraints on the spin parameter.

  8. Sex Differences in Incline-Walking among Humans.

    Science.gov (United States)

    Wall-Scheffler, Cara M

    2015-12-01

    Previous research has shown that people tend to walk around the speed that minimizes energy consumption when traveling a given distance. It has further been shown that men and women have different speeds that minimize energy and that women will choose slower speeds when the activity itself is a high-rate activity (e.g. carrying a load). Here we investigate what men and women will do when given a high rate walking activity, namely walking on an inclined surface. Fourteen people (nine men and five women) walked at four speeds on a level treadmill and four speeds on an inclined treadmill while their metabolic rate, kinematics and core temperature were monitored. Following the data collection, participants were asked to identify their ‘preferred’ walking speed at each of the conditions. Cost of transport (CoT) curves were calculated for each individual, and the delta between the preferred and the ‘optimal’ speeds were calculated. People chose to walk at slightly slower speeds on the level; there was minimal change in the cost to walk at these slower speeds. Women walked at absolutely slower speeds on the incline than men (P=0.06) and had significantly larger speed deltas (P=0.02), thus choosing to walk at slower rate speeds. Women also showed a significant relationship between the rate of activity and core temperature, whereas men did not. This is consistent with other research showing that women choose behavioral strategies to minimize body temperature changes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  9. Flame spread over inclined electrical wires with AC electric fields

    KAUST Repository

    Lim, Seung J.

    2017-07-21

    Flame spread over polyethylene-insulated electrical wires was studied experimentally with applied alternating current (AC) by varying the inclination angle (θ), applied voltage (VAC), and frequency (fAC). For the baseline case with no electric field applied, the flame spread rate and the flame width of downwardly spreading flames (DSFs) decreased from the horizontal case for −20° ≤ θ < 0° and maintained near constant values for −90° ≤ θ < −20°, while the flame spread rate increased appreciably as the inclination angle of upwardly spreading flames (USFs) increased. When an AC electric field was applied, the behavior of flame spread rate in DSFs (USFs) could be classified into two (three) sub-regimes characterized by various functional dependences on VAC, fAC, and θ. In nearly all cases of DSFs, a globular molten polyethylene formed ahead of the spreading flame edge, occasionally dripping onto the ground. In these cases, an effective flame spread rate was defined to represent the burning rate by measuring the mass loss due to dripping. This effective spread rate was independent of AC frequency, while it decreased linearly with voltage and was independent of the inclination angle. In DSFs, when excessively high voltage and frequency were applied, the dripping led to flame extinction during propagation and the extinction frequency correlated well with applied voltage. In USFs, when high voltage and frequency were applied, multiple globular molten PEs formed at several locations, leading to ejections of multiple small flame segments from the main flame, thereby reducing the flame spread rate, which could be attributed to the electrospray phenomenon.

  10. Mining adjacent inclined coal seams of varying thickness

    Energy Technology Data Exchange (ETDEWEB)

    Batmanov, Yu.K.; Bakhtin, A.F.; Bulavka, E.I.

    1980-01-01

    In the Donbass coal basin a large number of thin coal seams located near other thicker coal seams are left. It is suggested that coal output from the Donbass could be increased by 100% and cost of mining could be lowered by 0.4-1.1 roubles per 1 ton of coal if thinner coal seams were also mined. Mining methods in the Donbass are analyzed from the point of view of reducing the cost of mining and increasing coal production. Recommendations on methods of mining thin inclined coal seams are given. (6 refs.) (In Russian)

  11. Influence of patient head positioning on measured axial tooth inclination in panoramic radiography.

    Science.gov (United States)

    Hardy, Timothy C; Suri, Lokesh; Stark, Paul

    2009-06-01

    Panoramic radiographs are routinely used to assess the mesiodistal axial inclination of teeth (MDAI) in orthodontic treatment. These radiographs are sensitive to minor deviations from standard head position that result in image distortions. The aim of this study is to measure and quantify the changes in MDAI on panoramic radiograph resulting from changes in patient head position. The testing devise was a human skull with guide wires placed on the facial surface of the teeth and alveolar process along the long axis of each tooth. Panoramic radiographs were captured digitally with the orientation of the skull in Frankfurt horizontal plane parallel to the floor and with 1 degrees , 2 degrees , 5 degrees , 7 degrees , and 10 degrees both superior and inferior rotations. The mesiodistal tooth angulations were determined using MIPAC software (DentalEye and LEAD Technologies, Inc. 2005). The more distal the position of the tooth in the arch the greater the change in MDAI with a change in vertical head position. A maximum change of approximately 10 degrees was observed in MDAI of both the maxillary and mandibular molars with a corresponding superior head tilt of 10 degrees. The Mandibular anteriors displayed significant inconsistencies in MDAI with both superior and inferior head tilt. A superior head tilt produced a greater change in mesiodistal angulation than did an inferior head tilt. Accurately taken panoramic radiographs can serve as a convenient tool for evaluating the MDAI before, during and after orthodontic treatment. Additional radiographs are recommended for the mandibular anteriors.

  12. Three-dimensional collimation of in-plane-propagating light using silicon micromachined mirror

    Science.gov (United States)

    Sabry, Yasser M.; Khalil, Diaa; Saadany, Bassam; Bourouina, Tarik

    2014-03-01

    We demonstrate light collimation of single-mode optical fibers using deeply-etched three-dimensional curved micromirror on silicon chip. The three-dimensional curvature of the mirror is controlled by a process combining deep reactive ion etching and isotropic etching of silicon. The produced surface is astigmatic with out-of-plane radius of curvature that is about one half the in-plane radius of curvature. Having a 300-μm in-plane radius and incident beam inplane inclined with an angle of 45 degrees with respect to the principal axis, the reflected beam is maintained stigmatic with about 4.25 times reduction in the beam expansion angle in free space and about 12-dB reduction in propagation losses, when received by a limited-aperture detector.

  13. Finite element analysis of inclined nozzle-plate junctions

    International Nuclear Information System (INIS)

    Dixit, K.B.; Seth, V.K.; Krishnan, A.; Ramamurthy, T.S.; Dattaguru, B.; Rao, A.K.

    1979-01-01

    Estimation of stress concentration at nozzle to plate or shell junctions is a significant problem in the stress analysis of nuclear reactors. The topic is a subject matter of extensive investigations and earlier considerable success has been reported on analysis for the cases when the nozzle is perpendicular to the plate or is radial to the shell. Analytical methods for the estimation of stress concentrations for the practical situations when the intersecting nozzle is inclined to the plate or is non-radial to the shell is rather scanty. Specific complications arise in dealing with the junction region when the nozzle with circular cross-section meets the non-circular cut-out on the plate or shell. In this paper a finite element analysis is developed for inclined nozzles and results are presented for nozzle-plate junctions. A method of analysis is developed with a view to achieving simultaneously accuracy of results and simplicity in the choice of elements and their connectivity. The circular nozzle is treated by axisymmetric conical shell elements. The nozzle portion in the region around the junction and the flat plate is dealt with by triangular flat shell elements. Special transition elements are developed for joining the flat shell elements with the axisymmetric elements under non-axisymmetric loading. A substructure method of analysis is adopted which achieves considerable economy in handling the structure and also conveniently combines the different types of elements in the structure. (orig.)

  14. An Experimental Investigation on Inclined Negatively Buoyant Jets

    Directory of Open Access Journals (Sweden)

    Raed Bashitialshaaer

    2012-09-01

    Full Text Available An experimental study was performed to investigate the behavior of inclined negatively buoyant jets. Such jets arise when brine is discharged from desalination plants. A turbulent jet with a specific salinity was discharged through a circular nozzle at an angle to the horizontal into a tank with fresh water and the spatial evolution of the jet was recorded. Four different initial jet parameters were changed, namely the nozzle diameter, the initial jet inclination, the jet density and the flow rate. Five geometric quantities describing the jet trajectory that are useful in the design of brine discharge systems were determined. Dimensional analysis demonstrated that the geometric jet quantities studied, if normalized with the jet exit diameter, could be related to the densimetric Froude number. Analysis of the collected data showed that this was the case for a Froude number less than 100, whereas for larger values of the Froude number the scatter in the data increased significantly. As has been observed in some previous investigations, the slope of the best-fit straight line through the data points was a function of the initial jet angle (θ, where the slope increased with θ for the maximum levels (Ym studied, but had a more complex behavior for horizontal distances.

  15. Simplification of rat intubation on inclined metal plate.

    Science.gov (United States)

    Kastl, Sigrid; Kotschenreuther, U; Hille, B; Schmidt, J; Gepp, H; Hohenberger, W

    2004-12-01

    Small-animal intubation is often necessary during inhalation anesthesia to allow steady-state conditions for large operations and in vivo experiments in all fields of experimental surgery. In rats, placing an orotracheal tube is technically difficult primarily because of the small size of the subject and the lack of equipment specifically designed for this task. We describe a simple rat intubation technique in which the animal is suspended in dorsal recumbency on an inclined metal plate. The animal, anesthetized with ether, is fixed to a 70 degrees-inclined metal plate in a dorsal position by means of a Mersilene ribbon hooked around the upper incisors. This method of positioning the animal is the most important step in the intubation process and further facilitates the technique already described by other authors. A human otoscope was used as a laryngoscope, intubation was performed using the Seldinger technique, and a 14-gauge intravenous catheter served as an endotracheal tube. This inexpensive technique is quickly learned and can be used in any laboratory. Safe and reliable airway management can thus be achieved, permitting in vivo examinations and operations.

  16. Non-dispersive traveling waves in inclined shallow water channels

    International Nuclear Information System (INIS)

    Didenkulova, Ira; Pelinovsky, Efim

    2009-01-01

    Existence of traveling waves propagating without internal reflection in inclined water channels of arbitrary slope is demonstrated. It is shown that traveling non-monochromatic waves exist in both linear and nonlinear shallow water theories in the case of a uniformly inclined channel with a parabolic cross-section. The properties of these waves are studied. It is shown that linear traveling waves should have a sign-variable shape. The amplitude of linear traveling waves in a channel satisfies the same Green's law, which is usually derived from the energy flux conservation for smoothly inhomogeneous media. Amplitudes of nonlinear traveling waves deviate from the linear Green's law, and the behavior of positive and negative amplitudes are different. Negative amplitude grows faster than positive amplitude in shallow water. The phase of nonlinear waves (travel time) is described well by the linear WKB approach. It is shown that nonlinear traveling waves of any amplitude always break near the shoreline if the boundary condition of the full absorption is applied.

  17. Breakdown of air pockets in downwardly inclined sewerage pressure mains.

    Science.gov (United States)

    Lubbers, C L; Clemens, F H L R

    2006-01-01

    In the Netherlands, wastewater is collected in municipal areas and transported to centralised WWTPs by an extensive system of pressure mains. Over the last decades these pressure mains did not receive much attention in terms of monitoring of performance or maintenance. A recent inventory showed that half of the pressure mains show an increased pressure loss for no directly obvious reason. One of the many causes that account for the reduction of the flow capacity is the occurrence of free gas in the pipeline. During dry weather periods with low flow velocities, gas may accumulate at high points in the system. Once the velocity increases during storm weather flow, the air pockets may be broken down and transported to the end of the system. A research study is started focussing on the description of the gas-water phenomena in wastewater pressure mains with respect to transportation of gas. An experimental facility is constructed for the study of multi-phase flow. This paper describes the preliminary results of experiments on breakdown rates of gas pockets as a function of inclination angle and water flow rate. The results show an increasing breakdown rate with increasing inclination angle.

  18. Regularized plane-wave least-squares Kirchhoff migration

    KAUST Repository

    Wang, Xin

    2013-09-22

    A Kirchhoff least-squares migration (LSM) is developed in the prestack plane-wave domain to increase the quality of migration images. A regularization term is included that accounts for mispositioning of reflectors due to errors in the velocity model. Both synthetic and field results show that: 1) LSM with a reflectivity model common for all the plane-wave gathers provides the best image when the migration velocity model is accurate, but it is more sensitive to the velocity errors, 2) the regularized plane-wave LSM is more robust in the presence of velocity errors, and 3) LSM achieves both computational and IO saving by plane-wave encoding compared to shot-domain LSM for the models tested.

  19. Error Analysis on Plane-to-Plane Linear Approximate Coordinate ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, the error analysis has been done for the linear approximate transformation between two tangent planes in celestial sphere in a simple case. The results demonstrate that the error from the linear transformation does not meet the requirement of high-precision astrometry under some conditions, so the ...

  20. Error Analysis on Plane-to-Plane Linear Approximate Coordinate ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In this paper, the error analysis has been done for the linear approximate transformation between two tangent planes in celestial sphere in a simple case. The results demonstrate that the error from the linear transformation does not meet the requirement of high-precision astrometry under some conditions, ...

  1. Testing of focal plane arrays

    International Nuclear Information System (INIS)

    Merriam, J.D.

    1988-01-01

    Problems associated with the testing of focal plane arrays are briefly examined with reference to the instrumentation and measurement procedures. In particular, the approach and instrumentation used as the Naval Ocean Systems Center is presented. Most of the measurements are made with flooded illumination on the focal plane array. The array is treated as an ensemble of individual pixels, data being taken on each pixel and array averages and standard deviations computed for the entire array. Data maps are generated, showing the pixel data in the proper spatial position on the array and the array statistics

  2. Algebraic Methods in Plane Geometry

    Indian Academy of Sciences (India)

    user

    a 6= 1, c 6= 1; then f ± g(z) = acz + ad + b. T he fact th a t jacj = 1,and the presence of z rath er th an z, ... alldisplacem ents in the plane;this is essentially the ad- ditive group of all vectors in the plane. In fact, D is ..... ro ta tio n s fa ;fb;fc as follow s: fa = R A ;® , fb = R B ;¯ , fc = R C ;° . A ssum e that the vertices of 4 A B C are ...

  3. Plane waves in noncommutative fluids

    Energy Technology Data Exchange (ETDEWEB)

    Abdalla, M.C.B., E-mail: mabdalla@ift.unesp.br [Instituto de Física Teórica, UNESP, Universidade Estadual Paulista, Rua Dr. Bento Teobaldo Ferraz 271, Bloco 2, Barra-Funda, Caixa Postal 70532-2, 01156-970, São Paulo, SP (Brazil); Holender, L., E-mail: holender@ufrrj.br [Grupo de Física Teórica e Matemática Física, Departamento de Física, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, BR 465 Km 7, 23890-000 Seropédica, RJ (Brazil); Santos, M.A., E-mail: masantos@cce.ufes.br [Departamento de Física e Química, Universidade Federal do Espírito Santo (UFES), Avenida Fernando Ferarri S/N, Goiabeiras, 29060-900 Vitória, ES (Brazil); Vancea, I.V., E-mail: ionvancea@ufrrj.br [Grupo de Física Teórica e Matemática Física, Departamento de Física, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Cx. Postal 23851, BR 465 Km 7, 23890-000 Seropédica, RJ (Brazil)

    2013-08-01

    We study the dynamics of the noncommutative fluid in the Snyder space perturbatively at the first order in powers of the noncommutative parameter. The linearized noncommutative fluid dynamics is described by a system of coupled linear partial differential equations in which the variables are the fluid density and the fluid potentials. We show that these equations admit a set of solutions that are monochromatic plane waves for the fluid density and two of the potentials and a linear function for the third potential. The energy–momentum tensor of the plane waves is calculated.

  4. Lower limb joint forces during walking on the level and slopes at different inclinations.

    Science.gov (United States)

    Alexander, Nathalie; Schwameder, Hermann

    2016-03-01

    Sloped walking is associated with an increase of lower extremity joint loading compared to level walking. Therefore, the aim of this study was to analyse lower limb joint compression forces as well as tibiofemoral joint shear forces during sloped walking at different inclinations. Eighteen healthy male participants (age: 27.0 ± 4.7 years, height: 1.80 ± 0.05 m, mass: 74.5 ± 8.2 kg) were asked to walk at a pre-set speed of 1.1m/s on a ramp (6 m × 1.5 m) at the slopes of -18°, -12°, -6°, 0°, 6°, 12° and 18°. Kinematic data were captured with a twelve-camera motion capture system (Vicon). Kinetic data were recorded with two force plates (AMTI) imbedded into a ramp. A musculoskeletal model (AnyBody) was used to compute lower limb joint forces. Results showed that downhill walking led to significantly increased hip, tibiofemoral and patellofemoral joint compression forces (pforces (pforces with increasing inclination (pforces did not increase with the gradient. Due to diverse tibiofemoral joint shear force patterns in the literature, results should be treated with caution in general. Finally, lower limb joint force analyses provided more insight in the structure loading conditions during sloped walking than joint moment analyses. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Signature of non-isotropic distribution of stellar rotation inclination angles in the Praesepe cluster

    Science.gov (United States)

    Kovacs, Geza

    2018-04-01

    The distribution of the stellar rotation axes of 113 main sequence stars in the open cluster Praesepe are examined by using current photometric rotation periods, spectroscopic rotation velocities, and estimated stellar radii. Three different samples of stellar rotation data on spotted stars from the Galactic field and two independent samples of planetary hosts are used as control samples to support the consistency of the analysis. Considering the high completeness of the Praesepe sample and the behavior of the control samples, we find that the main sequence F - K stars in this cluster are susceptible to rotational axis alignment. Using a cone model, the most likely inclination angle is 76° ± 14° with a half opening angle of 47° ± 24°. Non-isotropic distribution of the inclination angles is preferred over the isotropic distribution, except if the rotation velocities used in this work are systematically overestimated. We found no indication of this being the case on the basis of the currently available data. Data are only available at the CDS, together with the other two compiled datasets used in this paper, via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/L2

  6. Pelvic tilt and truncal inclination: two key radiographic parameters in the setting of adults with spinal deformity.

    Science.gov (United States)

    Lafage, Virginie; Schwab, Frank; Patel, Ashish; Hawkinson, Nicola; Farcy, Jean-Pierre

    2009-08-01

    Prospective radiographic and clinical analysis. Investigate the relationship between spino-pelvic parameters and patient self reported outcomes on adult subjects with spinal deformities. It is becoming increasingly recognized that the study of spinal alignment should include pelvic position. While pelvic incidence determines lumbar lordosis, pelvic tilt (PT) is a positional parameter reflecting compensation to spinal deformity. Correlation between plumbline offset (sagittal vertical axis [SVA]) and Health Related Quality of Life (HRQOL) measures has been demonstrated, but such a study is lacking for PT. This prospective study was carried out on 125 adult patients suffering from spinal deformity (mean age: 57 years). Full-length free-standing radiographs including the spine and pelvis were available for all patients. HRQOL instruments included: Oswestry Disability Index, Short Form-12, Scoliosis Research Society. Correlation analysis between radiographic spinopelvic parameters and HRQOL measures was pursued. Correlation analysis revealed no significance pertaining to coronal plane parameters. Significant sagittal plane correlations were identified. SVA and truncal inclination measured by T1 spinopelvic inclination (T1-SPI) (angle between T1-hip axis and vertical) correlated with: Scoliosis Research Society (appearance, activity, total score), Oswestry Disability Index, and Short Form-12 (physical component score). Correlation coefficients ranged from 0.42 < r < 0.55 (P < 0.0001). T1-SPI revealed greater correlation with HRQOL compared to SVA. PT showed correlation with HRQOL (0.28 < r < 0.42) and with SVA (r = 0.64, P < 0.0001). This study confirms that pelvic position measured via PT correlates with HRQOL in the setting of adult deformity. High values of PT express compensatory pelvic retroversion for sagittal spinal malalignment. This study also demonstrates significant T1-SPI correlation with HRQOL measures and outperforms SVA. This parameter carries the

  7. Plane-wave least-squares reverse-time migration

    KAUST Repository

    Dai, Wei

    2013-06-03

    A plane-wave least-squares reverse-time migration (LSRTM) is formulated with a new parameterization, where the migration image of each shot gather is updated separately and an ensemble of prestack images is produced along with common image gathers. The merits of plane-wave prestack LSRTM are the following: (1) plane-wave prestack LSRTM can sometimes offer stable convergence even when the migration velocity has bulk errors of up to 5%; (2) to significantly reduce computation cost, linear phase-shift encoding is applied to hundreds of shot gathers to produce dozens of plane waves. Unlike phase-shift encoding with random time shifts applied to each shot gather, plane-wave encoding can be effectively applied to data with a marine streamer geometry. (3) Plane-wave prestack LSRTM can provide higher-quality images than standard reverse-time migration. Numerical tests on the Marmousi2 model and a marine field data set are performed to illustrate the benefits of plane-wave LSRTM. Empirical results show that LSRTM in the plane-wave domain, compared to standard reversetime migration, produces images efficiently with fewer artifacts and better spatial resolution. Moreover, the prestack image ensemble accommodates more unknowns to makes it more robust than conventional least-squares migration in the presence of migration velocity errors. © 2013 Society of Exploration Geophysicists.

  8. Two-dimensional probabilistic inversion of plane-wave electromagnetic data: Methodology, model constraints and joint inversion with electrical resistivity data

    NARCIS (Netherlands)

    Rosas-Carbajal, M.; Linde, N.; Kalscheuer, T.; Vrugt, J.A.

    2014-01-01

    Probabilistic inversion methods based on Markov chain Monte Carlo (MCMC) simulation are well suited to quantify parameter and model uncertainty of nonlinear inverse problems. Yet, application of such methods to CPU-intensive forward models can be a daunting task, particularly if the parameter space

  9. Improvement in greenhouse solar drying using inclined north wall reflection

    Energy Technology Data Exchange (ETDEWEB)

    Sethi, V.P. [Department of Mechanical Engineering, Punjab Agricultural University, Ludhiana 141004, Punjab (India); Arora, Sadhna [Department of Processing and Food Engineering, Punjab Agricultural University, Ludhiana 141004, Punjab (India)

    2009-09-15

    A conventional greenhouse solar dryer of 6 m{sup 2} x 4 m{sup 2} floor area (east-west orientation) was improved for faster drying using inclined north wall reflection (INWR) under natural as well as forced convection mode. To increase the solar radiation availability onto the product (to be dried) during extreme summer months, a temporary inclined wall covered with aluminized reflector sheet (of 50 {mu}m thickness and reflectance 0.93) was raised inside the greenhouse just in front of the vertical transparent north wall. By doing so, product fully received the reflected beam radiation (which otherwise leaves through the north wall) in addition to the direct total solar radiation available on the horizontal surface during different hours of drying. The increment in total solar radiation input enhanced the drying rate of the product by increasing the inside air and crop temperature of the dryer. Inclination angle of the reflective north wall with vertical ({beta}) was optimized for various selective widths of the tray W (1.5, 2, 2.5 and 3 m) and for different realistic heights of existing vertical north wall (h) at 25 N, 30 N and 35 N latitudes (hot climatic zones). Experimental performance of the improved dryer was tested during the month of May 2008 at Ludhiana (30.56 N) climatic conditions, India by drying bitter gourd (Momordica charantia Linn) slices. Results showed that by using INWR under natural convection mode of drying, greenhouse air and crop temperature increased by 1-6.7 C and 1-4 C, respectively, during different drying hours as compared to, when INWR was not used and saved 13.13% of the total drying time. By using INWR under forced convection mode of drying, greenhouse air and crop temperature increased by 1-4.5 C and 1-3 C, respectively, during different drying hours as compared to, when INWR was not used and saved 16.67% of the total drying time. (author)

  10. Hydraulic shock waves in an inclined chute contraction

    Science.gov (United States)

    Jan, C.-D.; Chang, C.-J.

    2009-04-01

    A chute contraction is a common structure used in hydraulic engineering for typical reasons such as increase of bottom slope, transition from side channel intakes to tunnel spillways, reduction of chute width due to bridges, transition structures in flood diversion works, among others. One of the significant chute contractions in Taiwan is that used in the Yuanshantzu Flood Diversion Project of Keelung River. The diversion project is designed to divert flood water from upper Keelung River into East Sea with a capasity of 1,310 cubic meters per second for mitigating the flood damage of lower part of Keelung River basin in Northern Taiwan. An inclined chute contraction is used to connect Keelung River and a diversion turnel. The inlet and outlet works of the diversion project is located at Ruifang in the Taipei County of north Taiwan. The diameter of diversion tunnel is 12 meters and the total length of tunnel is 2,484 meters. The diversion project has been completed and successfully executed many times since 2004 to lower the water level of Keelung River in typhoon seasons for avioding flooding problems in the lower part of Keelung River basin. Flow in a chute contraction has complicated flow pattern due to the existence of shock waves in it. A simple and useful calculation procedure for the maximum height and its position of shock waves is essentially needed for the preliminary design stage of a chute contraction. Hydraulic shock waves in an inclined chute contraction were experimentally and numerically investigated in this study with the consideration of the effects of sidewall deflection angle, bottom inclination angle and Froude number of approaching flow. The flow pattern of hydraulic shock waves in a chute contraction was observed. The main issue of designing chute contraction is to estimate the height and position of maximum shock wave for the consideration of freeboards. Achieving this aim, the experimental data are adopted and analyzed for the shock angle

  11. Algebraic Methods in Plane Geometry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 10. Algebraic Methods in Plane Geometry - The Use of Conic Sections. Shailesh A Shirali. General Article Volume 13 Issue 10 October 2008 pp 916-928. Fulltext. Click here to view fulltext PDF. Permanent link:

  12. Distributed storage in the plane

    NARCIS (Netherlands)

    Altman, Eitan; Avrachenkov, Konstatin; Goseling, Jasper

    2013-01-01

    We consider storage devices located in the plane according to a general point process and specialize the results for the homogeneous Poisson process. A large data file is stored at the storage devices, which have limited storage capabilities. Hence, they can only store parts of the data. Clients can

  13. Force Lines in Plane Stress

    DEFF Research Database (Denmark)

    Rathkjen, Arne

    A state of plane stress is illustrated by means of two families of curves, each family representing constant values of a derivative of Airy's stress function. The two families of curves form a map giving in the first place an overall picture of regions of high and low stress, and in the second pl...

  14. Complex Numbers and Plane Geometry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 1. Complex Numbers and Plane Geometry. Anant R Shastri. General Article Volume 13 Issue 1 January 2008 pp 35-53. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/013/01/0035-0053. Keywords.

  15. A comparison study for control and stabilisation of inverted pendulum on inclined surface (IPIS using PID and fuzzy controllers

    Directory of Open Access Journals (Sweden)

    Ashwani Kharola

    2016-09-01

    Full Text Available Inverted pendulum on cart belongs to a class of highly non-linear, multivariable and complex system which is currently a keen area of interest for researchers in the field of control engineering and robotics. This paper considers stabilisation and control of inverted pendulum on cart moving on an inclined surface. The task of controlling inverted pendulum on inclined surface is much difficult as compared to that moving on horizontal surface. An offline control of the proposed system has been successfully achieved using proportional-integral-derivative (PID and fuzzy controllers. A Matlab-Simulink model of the proposed system has been built using mathematical equations derived from Newton's second law. The study compares the proposed techniques in terms of settling time, overshoot, undershoot and steady state error. The simulation results are illustrated with the help of graphs and tables which confirms the validity of the proposed techniques.

  16. Heat and mass transfer of Williamson nanofluid flow yield by an inclined Lorentz force over a nonlinear stretching sheet

    Science.gov (United States)

    Khan, Mair; Malik, M. Y.; Salahuddin, T.; Hussian, Arif.

    2018-03-01

    The present analysis is devoted to explore the computational solution of the problem addressing the variable viscosity and inclined Lorentz force effects on Williamson nanofluid over a stretching sheet. Variable viscosity is assumed to vary as a linear function of temperature. The basic mathematical modelled problem i.e. system of PDE's is converted nonlinear into ODE's via applying suitable transformations. Computational solutions of the problem is also achieved via efficient numerical technique shooting. Characteristics of controlling parameters i.e. stretching index, inclined angle, Hartmann number, Weissenberg number, variable viscosity parameter, mixed convention parameter, Brownian motion parameter, Prandtl number, Lewis number, thermophoresis parameter and chemical reactive species on concentration, temperature and velocity gradient. Additionally, friction factor coefficient, Nusselt number and Sherwood number are describe with the help of graphics as well as tables verses flow controlling parameters.

  17. Sagittal plane considerations and the pelvis in the adult patient.

    Science.gov (United States)

    Schwab, Frank; Lafage, Virginie; Patel, Ashish; Farcy, Jean-Pierre

    2009-08-01

    Research update, focused review. Identify the role of the pelvis in the setting of adults with spinal deformity. Sagittal plane alignment is increasingly recognized as a critical parameter in the setting of adult spinal deformity. Additionally, pelvic parameters reveal to be a key component in the regulation of sagittal alignment. Analysis of the pelvis in the sagittal plane is commonly assessed by 3 angular measurements: the pelvic incidence (morphologic parameter directly linked to sagittal morphotypes), the pelvic tilt (or pelvis retroversion used to maintain an upright posture in the setting of spinal deformity), and the sacral slope. Recent work using force plate technology has revealed that in the setting of anterior trunk inclination ("spinal imbalance"), the pelvis shifted posteriorly (toward the heels) in order to maintain a balanced mass distribution. The complex relationship between pelvic and spinal parameter were investigated in order to construct predictive formulas of postoperative spinopelvic alignment. It has emerged that pelvic tilt is highly correlated with patient self reported function (ODI, SF-12, and SRS). It has become evident that good clinical outcome in the treatment of spinal deformity requires proper alignment. Pelvis parameters play an essential role not only in terms of spine morphotypes but also in regulating standing balance and postoperative alignment. Thus, optimal treatment of a patient with spinal deformity requires integration of the pelvis in the preoperative evaluation and treatment plan.

  18. Virginia Base Mapping Program (VBMP) 2002; Digital Terrain Model developed for 1"=400' scale Digital Orthophotography for the North Zone of the Virginia State Plane Grid

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — These files contain rectified digital vector terrain model data. The vector files are uncompressed complete with coordinate information. The VBMP project encompasses...

  19. Virginia Base Mapping Program (VBMP) 2002; Digital Terrain Model developed for 1"=400' scale Digital Orthophotography for the South Zone of the Virginia State Plane Grid

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — These files contain rectified digital vector terrain model data. The vector files are uncompressed complete with coordinate information. The VBMP project encompasses...

  20. Quantitative plane-resolved crystal growth and dissolution kinetics by coupling in situ optical microscopy and diffusion models : the case of salicylic acid in aqueous solution

    OpenAIRE

    Perry, Amelia R.; Peruffo, Massimo; Unwin, Patrick R.

    2013-01-01

    The growth and dissolution kinetics of salicylic acid crystals are investigated in situ by focusing on individual microscale crystals. From a combination of optical microscopy and finite element method (FEM) modeling, it was possible to obtain a detailed quantitative picture of dissolution and growth dynamics for individual crystal faces. The approach uses real-time in situ growth and dissolution data (crystal size and shape as a function of time) to parametrize a FEM model incorporating surf...

  1. Inclined nanoimprinting lithography-based 3D nanofabrication

    Science.gov (United States)

    Liu, Zhan; Bucknall, David G.; Allen, Mark G.

    2011-06-01

    We report a 'top-down' 3D nanofabrication approach combining non-conventional inclined nanoimprint lithography (INIL) with reactive ion etching (RIE), contact molding and 3D metal nanotransfer printing (nTP). This integration of processes enables the production and conformal transfer of 3D polymer nanostructures of varying heights to a variety of other materials including a silicon-based substrate, a silicone stamp and a metal gold (Au) thin film. The process demonstrates the potential of reduced fabrication cost and complexity compared to existing methods. Various 3D nanostructures in technologically useful materials have been fabricated, including symmetric and asymmetric nanolines, nanocircles and nanosquares. Such 3D nanostructures have potential applications such as angle-resolved photonic crystals, plasmonic crystals and biomimicking anisotropic surfaces. This integrated INIL-based strategy shows great promise for 3D nanofabrication in the fields of photonics, plasmonics and surface tribology.

  2. Segregation in inclined flows of binary mixtures of spheres

    Directory of Open Access Journals (Sweden)

    Larcher Michele

    2017-01-01

    Full Text Available We outline the equations that govern the evolution of segregation of a binary mixture of spheres in flows down inclines. These equations result from the mass and momentum balances of a kinetic theory for dense flows of inelastic spheres that interact through collisions. The theory employed for segregation is appropriate for particles with relatively small differences in size and mass. The flow of the mixture is assumed to reach a fully developed state much more rapidly than does the concentrations of the two species. We illustrate the predictions of the theory for a mixture of spheres of the same diameter but different masses and for spheres of different diameters but nearly the same mass. We show the evolution of the profiles of the concentration fractions of the two types of spheres and the profiles in the final, steady state. The latter compare favourably with those obtained in discrete-element numerical simulations.

  3. Method and apparatus for logging inclined earth boreholes

    International Nuclear Information System (INIS)

    Youmans, A.H.

    1981-01-01

    An improved technique is provided for comparing the velocity of an elongated well logging instrument traversing an inclined earth borehole with the playout velocity of the well logging cable at the earth's surface to control both the cable hoist drum rotation and the rate of movement of the subsurface instrument and thus insure cable playout is in equilibrium with the logging instrument movement. Method and apparatus are described for detecting any reduction in movement of the logging instrument through the borehole and for reducing the velocity of the logging cable playout in response thereto by reducing drum rotation. Further, when the velocity of cable playout slows to a preselected value, a monitoring circuit generates control signals which actuate a means of power attached to or integral with the logging instrument which, upon initiation, apply a force to move the logging instrument upward or downward within the borehole

  4. Transient flow and heat transfer phenomena in inclined wavy films

    Energy Technology Data Exchange (ETDEWEB)

    Serifi, Katerina; Bontozoglou, Vasilis [Department of Mechanical and Industrial Engineering, University of Thessaly, 38334, Volos (Greece); Malamataris, Nikolaos A. [Department of Mechanical Engineering, Technological Educational Institution of Western Macedonia, 50100, Kila Kozani (Greece)

    2004-08-01

    A finite-element numerical scheme is used to study rigorously the flow of an inclined liquid film and the heat transfer from the constant-temperature wall. Regular inlet disturbances are predicted to evolve into periodic or solitary waves depending on the frequency of the forcing. At very low disturbance frequencies parasitic crests appear and the regularity of the wave-train is lost. The effect of a solitary wave-train on heat transfer from the wall is studied, and it is predicted that a stationary temperature distribution develops with periodic flux variation that follows the waves. The thinning of the substrate between successive humps combines with the effect of convection at the crest and tail of the solitary humps to produce heat transfer enhancement significantly above the conduction limit. (authors)

  5. Mathematica numerical simulation of peristaltic biophysical transport of a fractional viscoelastic fluid through an inclined cylindrical tube.

    Science.gov (United States)

    Tripathi, D; Anwar Bég, O

    2015-01-01

    This paper studies the peristaltic transport of a viscoelastic fluid (with the fractional second-grade model) through an inclined cylindrical tube. The wall of the tube is modelled as a sinusoidal wave. The flow analysis is presented under the assumptions of long wave length and low Reynolds number. Caputo's definition of fractional derivative is used to formulate the fractional differentiation. Analytical solutions are developed for the normalized momentum equations. Expressions are also derived for the pressure, frictional force, and the relationship between the flow rate and pressure gradient. Mathematica numerical computations are then performed. The results are plotted and analysed for different values of fractional parameter, material constant, inclination angle, Reynolds number, Froude number and peristaltic wave amplitude. It is found that fractional parameter and Froude number resist the flow pattern while material constant, Reynolds number, inclination of angle and amplitude aid the peristaltic flow. Furthermore, frictional force and pressure demonstrate the opposite behaviour under the influence of the relevant parameters emerging in the equations of motion. The study has applications in uretral biophysics, and also potential use in peristaltic pumping of petroleum viscoelastic bio-surfactants in chemical engineering and astronautical applications involving conveyance of non-Newtonian fluids (e.g. lubricants) against gravity and in conduits with deformable walls.

  6. Theoretical-experimental assesment of braking sistems for inclined lifts according to EN 81:22-2014

    Energy Technology Data Exchange (ETDEWEB)

    Valles Fernandez, B.; Martin Lopez, A.L.; Alcala, E.

    2016-07-01

    The inclined lifts, in case of emergency braking, can experience high longitudinal decelerations that can lead to passengers’ collisions with lift walls and interior elements. In 2014 the CEN/TC10 WG1 published the part 22 of the norm series 81 with regard to the construction elements and installation of electrical lifts with inclined trajectory. This norm stablishes, amongst other requirements, the maximum and minimum deceleration levels in both longitudinal and vertical directions. Both requirements, in opposite senses and the definition of the braking system, do not cause design difficulties in case of high slopes, but in case of lifts with the slope under a certain level they can be needed, to guarantee the fulfilment of the norm, elements that allow and additional relative displacement between the braking system and the cabin. To define the performances and the optimal behaviour of these systems it has been defined a simulation model of the dynamical behaviour of the lift under the conditions of the norm tests. Additionally, in this work it is presented a calculation methodology to define the cabin allowable weight corridor, for each braking effort made by each safety gear model, and the simulations have been validated with the results of tests with different braking efforts, weights and lift slopes. The present work has been performed in cooperation with Thyssen Krupp Elevadores with the aim of improving the knowledge of the brake dynamics of inclined lifts. (Author)

  7. Soil-structure interaction on inclined soil layers

    International Nuclear Information System (INIS)

    Massa, G.; De Stefano, R.

    1983-01-01

    The case history presented deals with a Category I building having two-thirds of its base founded on a wedge of hard material. This wedge is underlain by an inclined layer of softer material, which also directly supports the remaining one-third of the foundation. The inclined layer is underlain by a third material, possessing large stiffness and extending to great depth. This case is analyzed with the methodology described below: - Determination of the static soil compliances by discretizing the foundation area into a number of strips and taking the soil profile as horizontally layered under each strip. Lumped parameter soil compliances for the whole foundation are obtained by weighting the contributions to stiffness in proportion to the area of each strip. - Definition of the degree of coupling between modes. The soil compliances defined in the previous step include coupling between the vertical and rocking modes and the horizontal and torsional modes through the positioning of the corresponding soil springs. The degree of coupling is checked through a static finite element analysis. - Frequency correction of the static soil compliances taking into account the inhomogeneity of the foundation conditions. The correction is based on obtaining dynamic stiffness coefficients for extreme configurations of the soil profile. - Assessment of the sliding potential of the structure under earthquake loading, considering eccentricities of the dynamic forces and non-uniform friction resistance over the foundation area, accounting for the frictional capacity of the different bearing materials. It is concluded that the simplified technique can provide accurate soil compliances, coupling and frequency corrections for soil-structure interaction on sloping layers, and an appropriate assessment of the sliding potential. (orig./HP)

  8. Shell side numerical analysis of a shell and tube heat exchanger considering the effects of baffle inclination angle on fluid flow using CFD

    Directory of Open Access Journals (Sweden)

    Raj Karuppa Thundil R.

    2012-01-01

    Full Text Available In this present study, attempts were made to investigate the impacts of various baffle inclination angles on fluid flow and the heat transfer characteristics of a shell-and-tube heat exchanger for three different baffle inclination angles namely 0°,10° and 20°. The simulation results for various shell and tube heat exchangers, one with segmental baffles perpendicular to fluid flow and two with segmental baffles inclined to the direction of fluid flow are compared for their performance. The shell side design has been investigated numerically by modeling a small shell-and-tube heat exchanger. The study is concerned with a single shell and single side pass parallel flow heat exchanger. The flow and temperature fields inside the shell are studied using non-commercial CFD software tool ANSYS CFX 12.1. For a given baffle cut of 36 %, the heat exchanger performance is investigated by varying mass flow rate and baffle inclination angle. From the CFD simulation results, the shell side outlet temperature, pressure drop, recirculation near the baffles, optimal mass flow rate and the optimum baffle inclination angle for the given heat exchanger geometry are determined.

  9. Plane micropolar elasticity with surface flexural resistance

    Science.gov (United States)

    Gharahi, Alireza; Schiavone, Peter

    2018-03-01

    We propose a linear surface/interface model for plane deformations of a micropolar elastic solid based on a higher-order surface elasticity theory capable of incorporating bending and twisting effects. The surface/interface is modeled as a bending-resistant Kirchhoff micropolar thin shell perfectly bonded to the boundary of the solid. It is anticipated that by combining micropolar bulk and surface effects in this way, the enhanced model will most accurately capture the essential characteristics (in particular, size dependency) required in the modeling of materials with significant microstructure as well as in the modeling of classes of nanomaterials. The corresponding boundary value problems are particularly interesting in that they involve boundary conditions of order higher than that of the governing field equations. We illustrate our theory by analyzing the simple problem of a circular hole in a micropolar sheet noting, in particular, the extent to which surface effects and micropolar properties each contribute to the deformation of the sheet.

  10. Gas-liquid two-phase flow behavior in terrain-inclined pipelines for gathering transport system of wet natural gas

    DEFF Research Database (Denmark)

    Yang, Yan; Li, Jingbo; Wang, Shuli

    2018-01-01

    The Volume of Fluid method and Re-Normalisation Group (RNG) k-ε turbulence model were employed to predict the gas-liquid two-phase flow in a terrain-inclined pipeline with deposited liquids. The simulation was carried out in a 22.5 m terrain-inclined pipeline with a 150 mm internal diameter...... on the liquid level under the suction force which caused by the negative pressure around the elbow, and then it touched to the top of the pipe. When the liquid blocked the pipe, the pressure drop between the upstream and downstream of the elbow increased with the increase of the gas velocity. At larger gas...

  11. Hydrodynamics of planing monohull watercraft

    CERN Document Server

    Vorus, William S

    2017-01-01

    This book addresses the principles involved in the design and engineering of planing monohull power boats, with an emphasis on the theoretical fundamentals that readers need in order to be fully functional in marine design and engineering. Author William Vorus focuses on three topics: boat resistance, seaway response, and propulsion and explains the physical principles, mathematical details, and theoretical details that support physical understanding. In particular, he explains the approximations and simplifications in mathematics that lead to success in the applications of planing craft design engineering, and begins with the simplest configuration that embodies the basic physics. He leads readers, step-by-step, through the physical complications that occur, leading to a useful working knowledge of marine design and engineering. Included in the book are a wealth of examples that exemplify some of the most important naval architecture and marine engineering problems that challenge many of today’s engineers.

  12. Algebraic Methods in Plane Geometry

    Indian Academy of Sciences (India)

    Srimath

    the role ofm appings and transform ation groups in plane geom etry. 1. P arabola in a Triangle. W e ¯rst recall tw o results from the geom etry of the parabola. Let P denote a parabola w ith focus F and d irectrix `. For any point P 2 P , let tP denote the tangent to P at P . (i) T he im age ofF under re°ection in any ofthe tangents.

  13. Identification and Modelling of the In-Plane Reinforcement Orientation Variations in a CFRP Laminate Produced by Manual Lay-Up

    Science.gov (United States)

    Davila, Yves; Crouzeix, Laurent; Douchin, Bernard; Collombet, Francis; Grunevald, Yves-Henri

    2017-08-01

    Reinforcement angle orientation has a significant effect on the mechanical properties of composite materials. This work presents a methodology to introduce variable reinforcement angles into finite element (FE) models of composite structures. The study of reinforcement orientation variations uses meta-models to identify and control a continuous variation across the composite ply. First, the reinforcement angle is measured through image analysis techniques of the composite plies during the lay-up phase. Image analysis results show that variations in the mean ply orientations are between -0.5 and 0.5° with standard deviations ranging between 0.34 and 0.41°. An automatic post-treatment of the images determines the global and local angle variations yielding good agreements visually and numerically between the analysed images and the identified parameters. A composite plate analysed at the end of the cooling phase is presented as a case of study. Here, the variation in residual strains induced by the variability in the reinforcement orientation are up to 28% of the strain field of the homogeneous FE model. The proposed methodology has shown its capabilities to introduce material and geometrical variability into FE analysis of layered composite structures.

  14. Control by damping Injection of Electrodynamic Tether System in an Inclined Orbit

    DEFF Research Database (Denmark)

    Larsen, Martin Birkelund; Blanke, Mogens

    2009-01-01

    dynamical system. Based on this model, a nonlinear controller is designed that will make the system asymptotically stable around its open-loop equilibrium. The control scheme handles the time-varying nature of the system in a suitable manner resulting in a large operational region. The performance...... of the closed loop system is treated using Floquet theory, investigating the closed loop properties for their dependency of the controller gain and orbit inclination.......Control of a satellite system with an electrodynamic tether as actuator is a time-periodic and underactuated control problem. This paper considers the tethered satellite in a Hamiltonian framework and determines a port-controlled Hamiltonian formulation that adequately describes the nonlinear...

  15. Mixed convection heat and mass transfer in peristaltic flow with chemical reaction and inclined magnetic field

    Science.gov (United States)

    Noreen, S.; Hayat, T.; Alsaedi, A.; Qasim, M.

    2013-09-01

    A mathematical model is constructed to investigate the mixed convective heat and mass transfer effects on peristaltic flow of magnetohydrodynamic pseudoplastic fluid in a symmetric channel. An analysis has been carried out to examine the impact of an inclined magnetic field and chemical reaction in presence of heat sink/source. Mechanics of flow and heat/mass transfer described in terms of continuity, linear momentum, energy and concentration equations are predicted by using long wavelength and low Reynolds number. Expressions for stream function, temperature, concentration and pressure gradient are derived. Numerical simulation is performed for the rise in pressure per wave length. Effects of several physical parameters on the flow quantities are analyzed.

  16. Exploring the Strategic Inclinations of Japanese Environmental NPOs in Post-Fukushima Japan

    Directory of Open Access Journals (Sweden)

    Mark Heuer

    2018-03-01

    Full Text Available Following Sine and David’s research on the potential of environmental jolts shifting the status quo in U.S. energy policy, we focus on the potential for environmental non-profit organizations in Japan to shift the status quo through institutional entrepreneurial efforts following the environmental jolt from the Fukushima nuclear power catastrophe. We evaluate the institutionalization of energy policy in Japan both pre- and post-Fukushima as the context for examining the potential for change in Japan’s energy policy. We utilize mixed qualitative and quantitative research methods to evaluate the attitudes and strategic inclinations of privately funded Japanese environmental non-profit organizations. Following Dreiling and Wolf’s model of material–organizational dependencies versus ideological motivations of non-profit organizations, we develop a typology to identify which, if any, segments of environmental Japanese non-profit organizations might pursue institutional entrepreneurial (Levy and Scully opportunities in support of renewable energy policy.

  17. Influence of inclined Lorentz forces on boundary layer flow of Casson fluid over an impermeable stretching sheet with heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Abdul Hakeem, A.K., E-mail: abdulhakeem6@gmail.com [Department of Mathematics, Sri Ramakrishna Mission Vidyalaya, College of Arts and Science, Coimbatore 641 020 (India); Renuka, P. [Department of Mathematics, Erode Sengunthar Engineering college, Erode 638 057 (India); Vishnu Ganesh, N.; Kalaivanan, R. [Department of Mathematics, Sri Ramakrishna Mission Vidyalaya, College of Arts and Science, Coimbatore 641 020 (India); Ganga, B. [Department of Mathematics, Providence College for Women, Coonoor 643 104 (India)

    2016-03-01

    The inclined magnetic field effect on the boundary layer flow of a Casson model non-Newtonian fluid over a stretching sheet in the existence of thermal radiation and velocity slip boundary condition is investigated for both prescribed surface temperature and power law of surface heat flux cases. It is assumed that the magnetic field is applied with an aligned angle which varied from 0° to 90°. Both analytical and numerical solutions are obtained for the transformed non-dimensional ODE's using confluent hypergeometric function and fourth order Runge–Kutta method with shooting technique respectively. The combined effects of inclined magnetic field with other pertinent parameters such as Casson parameter, velocity slip parameter, radiation parameter and Prandtl number on velocity profile, temperature profile, local skin friction coefficient, local Nusselt number and non-dimensional wall temperature are discussed through graphs. It is found that the aligned angle plays a vital role in controlling the magnetic field strength on the Casson fluid flow region and the increasing values of aligned angle of the magnetic field lead to decrease the skin friction coefficient and the Nusselt number and increase the non-dimensional wall temperature. - Highlights: • Casson fluid flow in the presence of inclined magnetic field is investigated for the first time. • Aligned angle controls the magnetic field strength on the boundary layer flow region. • The direction of Lorentz force changes according to aligned angle. • An excellent agreement is observed between present analytical and numerical results.

  18. A measurement of the muon number in showers using inclined events detected at the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Rodriguez G.

    2013-06-01

    Full Text Available The average muon content of measured showers with zenith angles between 62∘ and 80∘ detected at the Pierre Auger Observatory is obtained as a function of shower energy using a reconstruction method specifically designed for inclined showers and the hybrid character of the detector. The reconstruction of inclined showers relies on a comparison between the measured signals at ground and reference patterns at ground level from which an overall normalization factor is obtained. Since inclined showers are dominated by muons this factor gives the relative muon size. It can be calibrated using a subsample of showers simultaneously recorded with the fluorescence detector (FD and the surface detector (SD which provides an independent calorimetric measurement of the energy. The muon size obtained for each shower becomes a measurement of the relative number of muons with respect to the reference distributions. The precision of the measurement is assessed using simulated events which are reconstructed using exactly the same procedure. We compare the relative number of muons versus energy as obtained to simulations. Proton simulations with QGSJETII show a factor of 2.13 ± 0.04(stat ± 0.11(sys at 1019eV without significant variations in the energy range explored between 4 × 1018eV to 7 × 1019eV. We find that none of the current shower models, neither for proton nor for iron primaries, are able to predict as many muons as are observed.

  19. Complex eigensolutions of coupled flexural and longitudinal modes in a beam with inclined elastic supports with non-proportional damping

    Science.gov (United States)

    Noll, Scott; Dreyer, Jason; Singh, Rajendra

    2014-02-01

    Structure borne vibration and noise in an automobile are often explained by representing the full vehicle as a system of elastically coupled beam structures representing the body, engine cradle and body subframe where the engine is often connected to the chassis via inclined viscoelastic supports. To understand more clearly the interactions between a beam structure and isolators, this article examines the flexural and longitudinal motions in an elastic beam with intentionally inclined mounts (viscoelastic end supports). A new analytical solution is derived for the boundary coupled Euler beam and wave equations resulting in complex eigensolutions. This system is demonstrated to be self-adjoint when the support stiffness matrices are symmetric; thus, the modal analysis is used to decouple the equations of motion and solve for the steady state, damped harmonic response. Experimental validation and computational verifications confirm the validity of the proposed formulation. New and interesting phenomena are presented including coupled rigid motions, modal properties for ideal angled roller boundaries, and relationships between coupling and system modal loss factors. The ideal roller boundary conditions when inclined are seen as a limiting case of coupled longitudinal and flexural motions. In particular, the coupled rigid body motions illustrate the influence of support stiffness coupling on the eigenvalues and eigenfunctions. The relative modal strain energy concept is used to distinguish the contribution of longitudinal and flexural deformation modes. Since the beam is assumed to be undamped, the system damping is derived from the viscoelastic supports. The support damping (for a given loss factor) is shown to be redistributed between the system modes due to the inclined coupling mechanisms. Finally, this article provides valuable insight by highlighting some technical issues a real-life designer faces when balancing modeling assumptions such as rigid or elastic

  20. Nanoscale effects in the characterization of viscoelastic materials with atomic force microscopy: coupling of a quasi-three-dimensional standard linear solid model with in-plane surface interactions.

    Science.gov (United States)

    Solares, Santiago D

    2016-01-01

    Significant progress has been accomplished in the development of experimental contact-mode and dynamic-mode atomic force microscopy (AFM) methods designed to measure surface material properties. However, current methods are based on one-dimensional (1D) descriptions of the tip-sample interaction forces, thus neglecting the intricacies involved in the material behavior of complex samples (such as soft viscoelastic materials) as well as the differences in material response between the surface and the bulk. In order to begin to address this gap, a computational study is presented where the sample is simulated using an enhanced version of a recently introduced model that treats the surface as a collection of standard-linear-solid viscoelastic elements. The enhanced model introduces in-plane surface elastic forces that can be approximately related to a two-dimensional (2D) Young's modulus. Relevant cases are discussed for single- and multifrequency intermittent-contact AFM imaging, with focus on the calculated surface indentation profiles and tip-sample interaction force curves, as well as their implications with regards to experimental interpretation. A variety of phenomena are examined in detail, which highlight the need for further development of more physically accurate sample models that are specifically designed for AFM simulation. A multifrequency AFM simulation tool based on the above sample model is provided as supporting information.