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Sample records for leaf rolling angle

  1. Critical rolling angle of microparticles

    NASA Astrophysics Data System (ADS)

    Farzi, Bahman; Vallabh, Chaitanya K. P.; Stephens, James D.; Cetinkaya, Cetin

    2016-03-01

    At the micrometer-scale and below, particle adhesion becomes particularly relevant as van der Waals force often dominates volume and surface proportional forces. The rolling resistance of microparticles and their critical rolling angles prior to the initiation of free-rolling and/or complete detachment are critical in numerous industrial processes and natural phenomenon involving particle adhesion and granular dynamics. The current work describes a non-contact measurement approach for determining the critical rolling angle of a single microparticle under the influence of a contact-point base-excitation generated by a transient displacement field of a prescribed surface acoustic wave pulse and reports the critical rolling angle data for a set of polystyrene latex microparticles.

  2. Tree branch angle: maximizing effective leaf area.

    PubMed

    Honda, H; Fisher, J B

    1978-02-24

    In a computer simulation of branching pattern and leaf cluster in Terminalia catappa, right and left branch angles were varied, and the effective leaf surface areas were calculated. Theoretical branch angles that result in maximum effective leaf area are close to the values observed in nature. PMID:17757590

  3. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation.

    PubMed

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-04-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe asrl2(semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function.SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1(SLL1)/ROLLED LEAF9(RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation. PMID:26873975

  4. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation

    PubMed Central

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-01-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe a srl2 (semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function. SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1 (SLL1)/ROLLED LEAF9 (RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation. PMID:26873975

  5. Characterization of Rolled and Erect Leaf 1 in regulating leave morphology in rice

    PubMed Central

    Chen, Qiaoling; Xie, Qingjun; Gao, Ju; Wang, Wenyi; Sun, Bo; Liu, Bohan; Zhu, Haitao; Peng, Haifeng; Zhao, Haibing; Liu, Changhong; Wang, Jiang; Zhang, Jingliu; Zhang, Guiquan; Zhang, Zemin

    2015-01-01

    Leaf morphology, particularly in crop, is one of the most important agronomic traits because it influences the yield through the manipulation of photosynthetic capacity and transpiration. To understand the regulatory mechanism of leaf morphogenesis, an Oryza sativa dominant mutant, rolled and erect leaf 1 (rel1) has been characterized. This mutant has a predominant rolled leaf, increased leaf angle, and reduced plant height phenotype that results in a reduction in grain yield. Electron microscope observations indicated that the leaf incurvations of rel1 dominant mutants result from the alteration of the size and number of bulliform cells. Molecular cloning revealed that the rel1 dominant mutant phenotype is caused by the activation of the REL1 gene, which encodes a novel unknown protein, despite its high degree of conservation among monocot plants. Moreover, the downregulation of the REL1 gene in the rel1 dominant mutant restored the phenotype of this dominant mutant. Alternatively, overexpression of REL1 in wild-type plants induced a phenotype similar to that of the dominant rel1 mutant, indicating that REL1 plays a positive role in leaf rolling and bending. Consistent with the observed rel1 phenotype, the REL1 gene was predominantly expressed in the meristem of various tissues during plant growth and development. Nevertheless, the responsiveness of both rel1 dominant mutants and REL1-overexpressing plants to exogenous brassinosteroid (BR) was reduced. Moreover, transcript levels of BR response genes in the rel1 dominant mutants and REL1-overexpressing lines were significantly altered. Additionally, seven REL1-interacting proteins were also identified from a yeast two-hybrid screen. Taken together, these findings suggest that REL1 regulates leaf morphology, particularly in leaf rolling and bending, through the coordination of BR signalling transduction. PMID:26142419

  6. Predicting Roll Angle Of A Spinning Spacecraft

    NASA Technical Reports Server (NTRS)

    Smith, M. A.; Dyer, J. W.

    1988-01-01

    Data for corrections of attitude derived on Earth from secondary measurements. Paper describes how attitude of Pioneer 10 spacecraft controlled since spacecraft lost signal from Sun-sensor signal. Roll calculations in paper yields insight into environment of solar system at great distances.

  7. Roll angle measurement using a polarization scanning reference source

    NASA Astrophysics Data System (ADS)

    Dhadwal, Harbans S.; Rastegar, Jahangir; Kankipati, Varun

    2014-06-01

    On board measurement of attitude position, for example roll angle, of autonomous vehicles is critical to the execution of a successful mission. This paper describes a real-time technique, which combines a polarization scanning reference source and a priori knowledge of the scanning pattern. Measurements in an anechoic chamber, as well as, field tests in a busy parking lot, verify the efficacy of the technique, for both line of sight and non-line of sight capability.

  8. Light airplane crash tests at three roll angles

    NASA Technical Reports Server (NTRS)

    Castle, C. B.; Alfaro-Bou, E.

    1979-01-01

    Three similar twin engine general aviation airplanes were crash tested at the Langley impact dynamics research facility at 27 m/sec and at nominal roll angles of 0 deg, -15 deg, and -30 deg. Other flight parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  9. A study of roll attractor and wing rock of delta wings at high angles of attack

    NASA Technical Reports Server (NTRS)

    Niranjana, T.; Rao, D. M.; Pamadi, Bandu N.

    1993-01-01

    Wing rock is a high angle of attack dynamic phenomenon of limited cycle motion predominantly in roll. The wing rock is one of the limitations to combat effectiveness of the fighter aircraft. Roll Attractor is the steady state or equilibrium trim angle (phi(sub trim)) attained by the free-to-roll model, held at some angle of attack, and released form rest at a given initial roll (bank) angle (phi(sub O)). Multiple roll attractors are attained at different trim angles depending on initial roll angle. The test facility (Vigyan's low speed wind tunnel) and experimental work is presented here along with mathematical modelling of roll attractor phenomenon and analysis and comparison of predictions with experimental data.

  10. SHALLOT-LIKE1 is a KANADI transcription factor that modulates rice leaf rolling by regulating leaf abaxial cell development.

    PubMed

    Zhang, Guang-Heng; Xu, Qian; Zhu, Xu-Dong; Qian, Qian; Xue, Hong-Wei

    2009-03-01

    As an important agronomic trait, rice (Oryza sativa L.) leaf rolling has attracted much attention from plant biologists and breeders. Moderate leaf rolling increases the photosynthesis of cultivars and hence raises grain yield. However, the relevant molecular mechanism remains unclear. Here, we show the isolation and functional characterization of SHALLOT-LIKE1 (SLL1), a key gene controlling rice leaf rolling. sll1 mutant plants have extremely incurved leaves due to the defective development of sclerenchymatous cells on the abaxial side. Defective development can be functionally rescued by expression of SLL1. SLL1 is transcribed in various tissues and accumulates in the abaxial epidermis throughout leaf development. SLL1 encodes a SHAQKYF class MYB family transcription factor belonging to the KANADI family. SLL1 deficiency leads to defective programmed cell death of abaxial mesophyll cells and suppresses the development of abaxial features. By contrast, enhanced SLL1 expression stimulates phloem development on the abaxial side and suppresses bulliform cell and sclerenchyma development on the adaxial side. Additionally, SLL1 deficiency results in increased chlorophyll and photosynthesis. Our findings identify the role of SLL1 in the modulation of leaf abaxial cell development and in sustaining abaxial characteristics during leaf development. These results should facilitate attempts to use molecular breeding to increase the photosynthetic capacity of rice, as well as other crops, by modulating leaf development and rolling. PMID:19304938

  11. Mycangial fungus benefits the development of a leaf-rolling weevil, Euops chinesis.

    PubMed

    Li, Xiaoqiong; Guo, Wenfeng; Ding, Jianqing

    2012-06-01

    While a wide array of insects form symbiotic relationships with microbes, the underlying mechanisms of these relationships are various and complex. In this study, we investigated the role that the mycangial fungus Penicillium herquei plays in the development of the leaf-rolling weevil Euops chinesis, which feeds on the knotweed Fallopia japonica. The weevil inoculates the fungus during oviposition into a leaf-roll that it creates for its larvae. We found that removal of P. herquei inocula from leaf-rolls significantly decreased the weevil's survival rate especially in the larval stage. Although inoculation with P. herquei had no effect on the plant's lignin content, it significantly decreased the cellulose content of the knotweed leaves. P. herquei also showed antibiotic properties against two fungi (Rhizopus sp.) that attack the weevil's leaf-rolls. Our results suggest that the mycangial fungus may help alter leaf chemical components and protect against pathogens thus improve leaf-rolls for the development of E. chinesis. PMID:22465740

  12. Coherent optical determination of the leaf angle distribution of corn

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T. (Principal Investigator); Pihlman, M.

    1981-01-01

    A coherent optical technique for the diffraction analysis of an image is presented. Developments in radar remote sensing shows a need to understand plant geometry and its relationship to plant moisture, soil moisture, and the radar backscattering coefficient. A corn plant changes its leaf angle distribution, as a function of time, from a uniform distribution to one that is strongly vertical. It is shown that plant and soil moisture may have an effect on plant geometry.

  13. Real-time estimation of projectile roll angle using magnetometers: in-lab experimental validation

    NASA Astrophysics Data System (ADS)

    Changey, S.; Pecheur, E.; Wey, P.; Sommer, E.

    2013-12-01

    The knowledge of the roll angle of a projectile is decisive to apply guidance and control law. For example, the goal of ISL's project GSP (Guided Supersonic Projectile) is to change the flight path of an airdefence projectile in order to correct the aim error due to the target manoeuvres. The originality of the concept is based on pyrotechnical actuators and onboard sensors which control the angular motion of the projectile. First of all, the control of the actuators requires the precise control of the roll angle of the projectile. To estimate the roll angle of the projectile, two magnetometers are embedded in the projectile to measure the projection of the Earth magnetic field along radial axes of the projectiles. Then, an extended Kalman filter (EKF) is used to compute the roll angle estimation. As the rolling frequency of the GSP is about 22 Hz, it was easy to test the navigation algorithm in laboratory. In a previous paper [1], the In-Lab demonstration of this concept showed that the roll angle estimation was possible with an accuracy of about 1◦ . In this paper, the demonstration is extended to high-speed roll rate, up to 1000 Hz. Thus, two magnetometers, a DSP (Digital Signal Processor) and a LED (Light Eminent Diode), are rotated using a pneumatic motor; the DSP runs an EKF and a guidance algorithm to compute the trigger times of the LED. By using a high-speed camera, the accuracy of the method can be observed and improved.

  14. Determination of the Nip Angle in Roller Compactors With Serrated Rolls.

    PubMed

    Tan, Bernice Mei Jin; Chan, Lai Wah; Heng, Paul Wan Sia

    2016-06-01

    In roller compaction, the nip angle defines the critical transition interface between the slip and nip regions which is used to model material densification behavior and the properties of compacted ribbons. Current methods to determine the nip angle require either sophisticated instrumentation on smooth rolls or input parameters that are difficult to obtain experimentally. In this study, a practical method to determine nip angles for serrated rolls was developed based on mass balance considerations established around the nip region. Experimental input relating to roll geometry, powder density, and mass output from the compactor were required and they could be obtained reliably. The calculated nip angles were validated against those obtained from physical measurements during actual roll compaction. These nip angles were in agreement for various powder formulations containing plastic and brittle materials. The nip angles ranged from 4° to 12° and decreased significantly when the proportion of brittle material increased. Nip angles were also calculated using the widely used Johanson model. However, wall friction measurement on serrated roll surfaces could be impractical. The Johanson model-derived nip angles could differ by 3°-8° just by altering the roughness of the reference wall and this had compromised their reliability. PMID:27238494

  15. Characterization of R genes involved in resistance to Cherry leaf roll virus in paradox hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A single dominant ‘R’ gene (clrvR), in black walnuts (Juglans hindsii) or ‘paradox’ hybrids (J. hindsii x J. regia) confers resistance to Cherry leaf roll virus (CLRV), the causal agent of blackline disease. The identification and cloning of the ‘R’ gene is expected to aid the walnut breeding progra...

  16. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Potato Leaf Roll Virus Resistance Gene... REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.513 Potato Leaf Roll... protectant Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene) in or on all...

  17. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Potato Leaf Roll Virus Resistance Gene... REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.513 Potato Leaf Roll... protectant Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene) in or on all...

  18. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Potato Leaf Roll Virus Resistance Gene... REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.513 Potato Leaf Roll... protectant Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene) in or on all...

  19. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Potato Leaf Roll Virus Resistance Gene... REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.513 Potato Leaf Roll... protectant Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene) in or on all...

  20. 40 CFR 174.513 - Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene); exemption from the...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Potato Leaf Roll Virus Resistance Gene... REQUIREMENTS FOR PLANT-INCORPORATED PROTECTANTS Tolerances and Tolerance Exemptions § 174.513 Potato Leaf Roll... protectant Potato Leaf Roll Virus Resistance Gene (also known as orf1/orf2 gene) in or on all...

  1. Photosystem II functionality and antioxidant system changes during leaf rolling in post-stress emerging Ctenanthe setosa exposed to drought.

    PubMed

    Terzi, Rabiye; Saruhan, Neslihan; Sağlam, A; Nar, Hatice; Kadioğlu, A

    2009-12-01

    We studied the changes in antioxidant system and chlorophyll fluorescence parameters in post-stress emerging Ctenanthe setosa (Rosc.) Eichler (Marantaceae) plants (PSE plants) having reduced leaf area under drought stress causing leaf rolling and re-watering. PSE plants were compared to primary stressed plants (PS) in previous studies. The parameters were measured at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others is intermediate form). Water potentials and stomatal conductance of leaves were gradually decreased during leaf rolling. Similarly, maximum quantum efficiency of open PS II center and quantum yield of PS II decreased during the rolling period. Non-photochemical quenching of chlorophyll fluorescence decreased at score 2 then increased while photochemical quenching did not change during leaf rolling. Electron transport rate decreased only at score 4 but approximately reached to score 1 level after re-watering. Superoxide dismutase activity was not constant at all leaf rolling scores. Ascorbate peroxidase, catalase and glutathione reductase activities generally tended to increase during leaf rolling. Lipid peroxidation and H 2 O 2 content increased at score 2 but decreased at the later scores. On the other hand, O 2 .- production increased during the rolling period. After re-watering of the plants having score 4 of leaf rolling, antioxidant enzyme activities were lower than those of score 1. Other physiological parameters also tended to reach the value of score 1. The results indicated that PSE plants gained drought tolerance by reducing leaf area effectively induced their antioxidant systems and protected the photosynthesis under drought stress similar to PS plants. PMID:20015833

  2. Notes on the ecology of rolled-leaf hispines (Chrysomelidae, Cassidinae) at La Gamba (Costa Rica).

    PubMed

    Schmitt, Michael; Frank, Meike

    2013-01-01

    A total of 301 adult hispine beetles of the genera Cephaloleia and Chelobasis were found in rolled leaves of plants of 17 species of Zingiberales (families Costaceae, Heliconiaceae, Maranthaceae, Musaceae, and Zingiberaceae) during a field study at La Gamba, Golfito region, Costa Rica. Of these beetles, Cephaloleia belti was recorded from 12 potential host plant species, C. distincta from 7, C. dilaticollis from 5, C., Chelobasis bicolor, C. championi, and C. histrionica from 3, Chelobasis perplexa and C. instabilis from 2, whereas C. trivittata from only one. Of the plant species, Heliconia latispatha had 7 beetle species in its leaf rolls, Calathea lutea had 5, H. imbricata and H. rostrata had 4, H. stricta and Musa paradisiaca had 3, H. wagneriana had 2, while on H. vaginalis, H. danielsiana, H. densiflora, H. longiflora, Calathea crotalifera, C. platystachya, Goeppertia lasiophylla, Alpinia purpurata, Costus pulverulentus and Costus barbatus, H. densiflora, H. vaginalis, and H. danielsana only hispines of one species were found. Cephaloleia belti occurred together with beetles of six other hispine species, whereas Cephaloleia trivittata never shared a leaf roll with another hispine species. The remaining beetle species aggregated with one to four other hispines. Adults of C. belti and C. championi were frequently seen, occasionally also with C. dilaticollis, C. histrionica, and Chelobasis perplexa, to co-occur with the carabid Calophaena ligata in the same leaf roll without any sign of interspecific aggression. A comparison of host choices and the phylogeny of the hispines and of their host plants revealed no signs that beetles used species level phylogenetic relationships within the Zingiberales to select food plants. Obviously, within this plant order, rolled-leaf hispines choose their plant hosts in a nearly opportunistic manner. Seemingly, they use differences among plants at higher taxonomic levels but within the Zingiberales, the availability of young

  3. Modified bubble level senses pitch and roll angles over wide range

    NASA Technical Reports Server (NTRS)

    Mattson, E. J.; Mcnally, P. F.

    1971-01-01

    Bubble level sensor with fiber-optic field flattener is simple, rugged, small, and impervious to temperature and vibration effects. Pitch angles from -15 deg to +40 deg and roll angles of +30 deg are determined within 0.5 deg.

  4. Simulations of Seasonal and Latitudinal Variations in Leaf Inclination Angle Distribution: Implications for Remote Sensing

    NASA Technical Reports Server (NTRS)

    Huemmrich, Karl F.

    2013-01-01

    The leaf inclination angle distribution (LAD) is an important characteristic of vegetation canopy structure affecting light interception within the canopy. However, LADs are difficult and time consuming to measure. To examine possible global patterns of LAD and their implications in remote sensing, a model was developed to predict leaf angles within canopies. Canopies were simulated using the SAIL radiative transfer model combined with a simple photosynthesis model. This model calculated leaf inclination angles for horizontal layers of leaves within the canopy by choosing the leaf inclination angle that maximized production over a day in each layer. LADs were calculated for five latitude bands for spring and summer solar declinations. Three distinct LAD types emerged: tropical, boreal, and an intermediate temperate distribution. In tropical LAD, the upper layers have a leaf angle around 35 with the lower layers having horizontal inclination angles. While the boreal LAD has vertical leaf inclination angles throughout the canopy. The latitude bands where each LAD type occurred changed with the seasons. The different LADs affected the fraction of absorbed photosynthetically active radiation (fAPAR) and Normalized Difference Vegetation Index (NDVI) with similar relationships between fAPAR and leaf area index (LAI), but different relationships between NDVI and LAI for the different LAD types. These differences resulted in significantly different relationships between NDVI and fAPAR for each LAD type. Since leaf inclination angles affect light interception, variations in LAD also affect the estimation of leaf area based on transmittance of light or lidar returns.

  5. Rolling-leaf14 is a 2OG-Fe (II) oxygenase family protein that modulates rice leaf rolling by affecting secondary cell wall formation in leaves.

    PubMed

    Fang, Likui; Zhao, Fangming; Cong, Yunfei; Sang, Xianchun; Du, Qing; Wang, Dezhong; Li, Yunfeng; Ling, Yinghua; Yang, Zhenglin; He, Guanghua

    2012-06-01

    As an important agronomic trait, leaf rolling in rice (Oryza sativa L.) has attracted much attention from plant biologists and breeders. Moderate leaf rolling increases the amount of photosynthesis in cultivars and hence raises grain yield. Here, we describe the map-based cloning of the gene RL14, which was found to encode a 2OG-Fe (II) oxygenase of unknown function. rl14 mutant plants had incurved leaves because of the shrinkage of bulliform cells on the adaxial side. In addition, rl14 mutant plants displayed smaller stomatal complexes and decreased transpiration rates, as compared with the wild type. Defective development could be rescued functionally by the expression of wild-type RL14. RL14 was transcribed in sclerenchymatous cells in leaves that remained wrapped inside the sheath. In mature leaves, RL14 accumulated mainly in the mesophyll cells that surround the vasculature. Expression of genes related to secondary cell wall formation was affected in rl14-1 mutants, and cellulose and lignin content were altered in rl14-1 leaves. These results reveal that the RL14 gene affects water transport in leaves by affecting the composition of the secondary cell wall. This change in water transport results in water deficiency, which is the major reason for the abnormal shape of the bulliform cells. PMID:22329407

  6. Angle Measurement System (AMS) for Establishing Model Pitch and Roll Zero, and Performing Single Axis Angle Comparisons

    NASA Technical Reports Server (NTRS)

    Crawford, Bradley L.

    2007-01-01

    The angle measurement system (AMS) developed at NASA Langley Research Center (LaRC) is a system for many uses. It was originally developed to check taper fits in the wind tunnel model support system. The system was further developed to measure simultaneous pitch and roll angles using 3 orthogonally mounted accelerometers (3-axis). This 3-axis arrangement is used as a transfer standard from the calibration standard to the wind tunnel facility. It is generally used to establish model pitch and roll zero and performs the in-situ calibration on model attitude devices. The AMS originally used a laptop computer running DOS based software but has recently been upgraded to operate in a windows environment. Other improvements have also been made to the software to enhance its accuracy and add features. This paper will discuss the accuracy and calibration methodologies used in this system and some of the features that have contributed to its popularity.

  7. Computer programs for calculation of sting pitch and roll angles required to obtain angles of attack and sideslip on wind tunnel models

    NASA Technical Reports Server (NTRS)

    Peterson, John B., Jr.

    1988-01-01

    Two programs have been developed to calculate the pitch and roll angles of a wind-tunnel sting drive system that will position a model at the desired angle of attack and and angle of sideslip in the wind tunnel. These programs account for the effects of sting offset angles, sting bending angles and wind-tunnel stream flow angles. In addition, the second program incorporates inputs from on-board accelerometers that measure model pitch and roll with respect to gravity. The programs are presented in the report and a description of the numerical operation of the programs with a definition of the variables used in the programs is given.

  8. Roll-yaw control at high angle of attack by forebody tangential blowing

    NASA Technical Reports Server (NTRS)

    Pedreiro, N.; Rock, S. M.; Celik, Z. Z.; Roberts, L.

    1995-01-01

    The feasibility of using forebody tangential blowing to control the roll-yaw motion of a wind tunnel model is experimentally demonstrated. An unsteady model of the aerodynamics is developed based on the fundamental physics of the flow. Data from dynamic experiments is used to validate the aerodynamic model. A unique apparatus is designed and built that allows the wind tunnel model two degrees of freedom, roll and yaw. Dynamic experiments conducted at 45 degrees angle of attack reveal the system to be unstable. The natural motion is divergent. The aerodynamic model is incorporated into the equations of motion of the system and used for the design of closed loop control laws that make the system stable. These laws are proven through dynamic experiments in the wind tunnel using blowing as the only actuator. It is shown that asymmetric blowing is a highly non-linear effector that can be linearized by superimposing symmetric blowing. The effects of forebody tangential blowing and roll and yaw angles on the flow structure are determined through flow visualization experiments. The transient response of roll and yaw moments to a step input blowing are determined. Differences on the roll and yaw moment dependence on blowing are explained based on the physics of the phenomena.

  9. Roll-Yaw control at high angle of attack by forebody tangential blowing

    NASA Technical Reports Server (NTRS)

    Pedreiro, N.; Rock, S. M.; Celik, Z. Z.; Roberts, L.

    1995-01-01

    The feasibility of using forebody tangential blowing to control the roll-yaw motion of a wind tunnel model is experimentally demonstrated. An unsteady model of the aerodynamics is developed based on the fundamental physics of the flow. Data from dynamic experiments is used to validate the aerodynamic model. A unique apparatus is designed and built that allows the wind tunnel model two degrees of freedom, roll and yaw. Dynamic experiments conducted at 45 degrees angle of attack reveal the system to be unstable. The natural motion is divergent. The aerodynamic model is incorporated into the equations of motion of the system and used for the design of closed loop control laws that make the system stable. These laws are proven through dynamic experiments in the wind tunnel using blowing as the only actuator. It is shown that asymmetric blowing is a highly non-linear effector that can be linearized by superimposing symmetric blowing. The effects of forebody tangential blowing and roll and yaw angles on the flow structure are determined through flow visualization experiments. The transient response of roll and yaw moments to a step input blowing are determined. Differences on the roll and yaw moment dependence on blowing are explained based on the physics of the phenomena.

  10. Functional and evolutionary correlations of steep leaf angles in the mexical shrubland.

    PubMed

    Valiente-Banuet, Alfonso; Verdú, Miguel; Valladares, Fernando; García-Fayos, Patricio

    2010-05-01

    In the evergreen shrubland vegetation of Mexico (mexical), most of the species are sclerophyllous woody plants with steep leaf angles. This architectural pattern has been interpreted as a strategy to cope with water shortages and high radiation. However, the current association between evergreenness and steep leaf angles across mexical plant species could be the result of an adaptive association achieved through correlated evolutionary change between both traits or, alternatively, may be the result of common evolutionary ancestry. In this study, we quantified leaf angle in 28 dominant species under a phylogenetic framework and evaluated the functional implications of the observed range of leaf angles in terms of leaf temperature, water potentials and transpiration by combining manipulative experiments restraining leaves horizontally with microclimatic and stomatal conductance measurements in selected species and energy balance calculations. Horizontally restrained leaves exhibited reduced water potentials and stomatal conductances, and significantly increased temperatures and transpiration rates. Steeply inclined leaves operated near air temperatures and could sustain relatively high stomatal conductances during the dry season since they were associated with low transpiration rates. Phylogenetic analyses showed that steep leaf angles evolved in a correlated fashion in evergreen species. The functional consequences of leaf angle together with the phylogenetic analysis indicate the adaptive nature of this trait which allows the evergreen species to cope with arid conditions and therefore to persist within the mexical community. PMID:19956973

  11. Influence of the angle between cold rolling direction and hot rolling direction on the texture evolution of non-oriented electrical steels

    NASA Astrophysics Data System (ADS)

    He, Y.; Hilinski, E.; Attard, M.; Bibby, D.; Santos, R.; Zavadil, R.

    2015-04-01

    In processing non-oriented electrical steel sheets using conventional rolling schemes, the most common texture components obtained after final annealing are the magnetically unfavourable <111>//ND (γ) and <110>//RD (α) fibres. A lot of researches have been carried out trying to optimize the processes to produce the favourable <001>//ND (θ) fibre. However, since the final texture is formed through a series of texture evolution steps during the solidification, hot rolling, cold rolling and annealing processes, it is quite challenging to tailor the texture of the final product. In this study, a new rolling scheme was examined, in which the cold rolling direction (CRD) was inclined to the hot rolling direction (HRD) at an angle from 0° to 90° (with a 15° increment). This was intended to alter the texture commonly produced by cold rolling along the HRD, and to optimize the final recrystallization texture. The cold rolling and recrystallization textures of two non-oriented electrical steels with 0.9% and 2.8% Si were measured. It was found that the inclination of CRD to HRD has a substantial effect on the cold rolling texture for both steels, but only in the low Si steel, does it lead to significantly different recrystallization textures. A strong cube texture was produced at an inclination angle of 60°, and the <111>//ND (γ) fibre was significantly weakened or essentially disappeared. The core losses of these steels were measured by Epstein frame method and the results showed a ∼10% difference among strips cold rolled at different angles. A minimum core loss occurred at a 45° inclination angle in the low Si steel.

  12. SU-E-T-195: Gantry Angle Dependency of MLC Leaf Position Error

    SciTech Connect

    Ju, S; Hong, C; Kim, M; Chung, K; Kim, J; Han, Y; Ahn, S; Chung, S; Shin, E; Shin, J; Kim, H; Kim, D; Choi, D

    2014-06-01

    Purpose: The aim of this study was to investigate the gantry angle dependency of the multileaf collimator (MLC) leaf position error. Methods: An automatic MLC quality assurance system (AutoMLCQA) was developed to evaluate the gantry angle dependency of the MLC leaf position error using an electronic portal imaging device (EPID). To eliminate the EPID position error due to gantry rotation, we designed a reference maker (RM) that could be inserted into the wedge mount. After setting up the EPID, a reference image was taken of the RM using an open field. Next, an EPID-based picket-fence test (PFT) was performed without the RM. These procedures were repeated at every 45° intervals of the gantry angle. A total of eight reference images and PFT image sets were analyzed using in-house software. The average MLC leaf position error was calculated at five pickets (-10, -5, 0, 5, and 10 cm) in accordance with general PFT guidelines using in-house software. This test was carried out for four linear accelerators. Results: The average MLC leaf position errors were within the set criterion of <1 mm (actual errors ranged from -0.7 to 0.8 mm) for all gantry angles, but significant gantry angle dependency was observed in all machines. The error was smaller at a gantry angle of 0° but increased toward the positive direction with gantry angle increments in the clockwise direction. The error reached a maximum value at a gantry angle of 90° and then gradually decreased until 180°. In the counter-clockwise rotation of the gantry, the same pattern of error was observed but the error increased in the negative direction. Conclusion: The AutoMLCQA system was useful to evaluate the MLC leaf position error for various gantry angles without the EPID position error. The Gantry angle dependency should be considered during MLC leaf position error analysis.

  13. Note: Optimal choice of the reflector by phase analysis for heterodyne interferometric roll angle measurement

    NASA Astrophysics Data System (ADS)

    Tang, Shanzhi; Wang, Zhao; Li, Ming; Gao, Junxiang; Jiang, Yongcheng; Zhang, Yao

    2016-02-01

    The choice of an actual reflector instead of an ideal or perfect reflector has to be dealt with for heterodyne-interferometric roll angle measurement methods. The candidates of regular reflectors such as corner cube prism and right angle prism are analyzed by the homogeneous coordinate transformation method, which provides a theoretical basis for the determination of the actual reflector. Furthermore, the influences of the phase loss of the determined reflector are strictly argued due to non-perfect or natural characteristics itself. Several tactics are considered to solve this problem by phase analysis. By contrast, it is an optimal choice that mirrors-based right angle prism can improve evidently the phase loss by experiment.

  14. Joint Mapping and Allele Mining of the Rolled Leaf Trait in Rice (Oryza sativa L.)

    PubMed Central

    Wang, Chunchao; Nafisah; Joseph, Charles; Zhang, Wenzhong; Xu, Jianlong; Li, Zhikang

    2016-01-01

    The rolled leaf trait, long considered to be a key component of plant architecture, represents an important target trait for improving plant architecture at the population level. We therefore performed linkage mapping using a set of 262 highly variable RILs from two rice cultivars (Minghui 63 and 02428) with minor differences in leaf rolling index (LRI) in conjunction with GWAS mapping of a random subset of the 1127 germplasms from the 3K Rice Genomes Project (3K Rice). A total of seven main-effect loci were found to underlie the transgressive segregation of progenies from parents with minor differences in LRI. Five of these loci were previously identified and two (qRl7b and qRl9b) are newly reported with additional evidence from GWAS mapping for qRl7b. A total of 18 QTLs were identified by GWAS, including four newly identified QTLs. Six QTLs were confirmed by linkage mapping with the above RIL population, and 83.3% were found to be consistent with previously reported loci based on comparative mapping. We also performed allele mining with representative SNPs and identified the elite germplasms for the improvement of rolled leaf trait. Most favorable alleles at the detected loci were contributed by various 3K Rice germplasms. By a re-scanning of the candidate region with more saturated SNP markers, we dissected the region harboring gRl4-2 into three subregions, in which the average effect on LRI was 3.5% with a range from 2.4 to 4.1% in the third subregion, suggesting the presence of a new locus or loci within this region. The representative SNPs for favorable alleles in the reliable QTLs which were consistently identified in both bi-parental mapping and GWAS, such as qRl4, qRl5, qRl6, qRl7a, and qRl7b will be useful for future molecular breeding programs for ideal plant type in rice. PMID:27441398

  15. Is the spherical leaf inclination angle distribution a valid assumption for temperate and boreal tree and shrub species?

    NASA Astrophysics Data System (ADS)

    Pisek, J.

    2012-12-01

    Directional distribution of leaves is one primary parameter for determining the radiation transmission through the canopy. When inverting canopy transmittance measurements for estimating the leaf area index or foliage clumping, incorrect assumptions on leaf angles may lead to considerable errors. Often spherical distribution of leaf normals is assumed, i.e. leaf normals are assumed to have no preferred direction in situations where no measurement data are available. The goal of this study is to examine if a spherical leaf angle distribution and the resulting isotropic G-function (G≡0.5) is indeed a valid assumption for temperate and boreal tree and shrub species. Leaf angle distributions were measured for over 80 deciduous broadleaf species commonly found in temperate and boreal ecoclimatic regions. The leaf inclination angles were obtained by sampling the complete vertical extent of trees and shrubs using a recently introduced technique based on digital photography. It is found a spherical leaf angle distribution is not a valid assumption for both tree and shrub species in temperate and boreal ecoclimatic regions. Given the influence of leaf angle distribution on inverting clumping and LAI estimates from canopy transmittance measurements, it is recommended to use planophile or plagiophile leaf angle distribution as more appropriate for modeling radiation transmission in temperate and boreal ecoclimatic regions when no actual leaf inclination angle measurements are available.

  16. Notes on the ecology of rolled-leaf hispines (Chrysomelidae, Cassidinae) at La Gamba (Costa Rica)1

    PubMed Central

    Schmitt, Michael; Frank, Meike

    2013-01-01

    Abstract A total of 301 adult hispine beetles of the genera Cephaloleia and Chelobasis were found in rolled leaves of plants of 17 species of Zingiberales (families Costaceae, Heliconiaceae, Maranthaceae, Musaceae, and Zingiberaceae) during a field study at La Gamba, Golfito region, Costa Rica. Of these beetles, Cephaloleia belti was recorded from 12 potential host plant species, C. distincta from 7, C. dilaticollis from 5, C., Chelobasis bicolor, C. championi, and C. histrionica from 3, Chelobasis perplexa and C. instabilis from 2, whereas C. trivittata from only one. Of the plant species, Heliconia latispatha had 7 beetle species in its leaf rolls, Calathea lutea had 5, H. imbricata and H. rostrata had 4, H. stricta and Musa paradisiaca had 3, H. wagneriana had 2, while on H. vaginalis, H. danielsiana, H. densiflora, H. longiflora, Calathea crotalifera, C. platystachya, Goeppertia lasiophylla, Alpinia purpurata, Costus pulverulentus and Costus barbatus, H. densiflora, H. vaginalis, and H. danielsana only hispines of one species were found. Cephaloleia belti occurred together with beetles of six other hispine species, whereas Cephaloleia trivittata never shared a leaf roll with another hispine species. The remaining beetle species aggregated with one to four other hispines. Adults of C. belti and C. championi were frequently seen, occasionally also with C. dilaticollis, C. histrionica, and Chelobasis perplexa, to co-occur with the carabid Calophaena ligata in the same leaf roll without any sign of interspecific aggression. A comparison of host choices and the phylogeny of the hispines and of their host plants revealed no signs that beetles used species level phylogenetic relationships within the Zingiberales to select food plants. Obviously, within this plant order, rolled-leaf hispines choose their plant hosts in a nearly opportunistic manner. Seemingly, they use differences among plants at higher taxonomic levels but within the Zingiberales, the availability of

  17. A detailed analysis of the leaf rolling mutant sll2 reveals complex nature in regulation of bulliform cell development in rice (Oryza sativa L.).

    PubMed

    Zhang, J-J; Wu, S-Y; Jiang, L; Wang, J-L; Zhang, X; Guo, X-P; Wu, C-Y; Wan, J-M

    2015-03-01

    Bulliform cells are large, thin-walled and highly vacuolated cells, and play an important role in controlling leaf rolling in response to drought and high temperature. However, the molecular mechanisms regulating bulliform cell development have not been well documented. Here, we report isolation and characterisation of a rice leaf-rolling mutant, named shallot-like 2 (sll2). The sll2 plants exhibit adaxially rolled leaves, starting from the sixth leaf stage, accompanied by increased photosynthesis and reduced plant height and tiller number. Histological analyses showed shrinkage of bulliform cells, resulting in inward-curved leaves. The mutant is recessive and revertible at a rate of 9%. The leaf rolling is caused by a T-DNA insertion. Cloning of the insertion using TAIL-PCR revealed that the T-DNA was inserted in the promoter region of LOC_Os07 g38664. Unexpectedly, the enhanced expression of LOC_Os07 g38664 by the 35S enhancer in the T-DNA is not responsible for the leaf rolling phenotype. Further, the enhancer also exerted a long-distance effect, including up-regulation of several bulliform cell-related genes. sll2 suppressed the outward leaf rolling of oul1 in the sll2oul1 double mutant. We conclude that leaf rolling in sll2 could be a result of the combined effect of multi-genes, implying a complex network in regulation of bulliform cell development. PMID:25213398

  18. A Sensor Fusion Method Based on an Integrated Neural Network and Kalman Filter for Vehicle Roll Angle Estimation.

    PubMed

    Vargas-Meléndez, Leandro; Boada, Beatriz L; Boada, María Jesús L; Gauchía, Antonio; Díaz, Vicente

    2016-01-01

    This article presents a novel estimator based on sensor fusion, which combines the Neural Network (NN) with a Kalman filter in order to estimate the vehicle roll angle. The NN estimates a "pseudo-roll angle" through variables that are easily measured from Inertial Measurement Unit (IMU) sensors. An IMU is a device that is commonly used for vehicle motion detection, and its cost has decreased during recent years. The pseudo-roll angle is introduced in the Kalman filter in order to filter noise and minimize the variance of the norm and maximum errors' estimation. The NN has been trained for J-turn maneuvers, double lane change maneuvers and lane change maneuvers at different speeds and road friction coefficients. The proposed method takes into account the vehicle non-linearities, thus yielding good roll angle estimation. Finally, the proposed estimator has been compared with one that uses the suspension deflections to obtain the pseudo-roll angle. Experimental results show the effectiveness of the proposed NN and Kalman filter-based estimator. PMID:27589763

  19. Simplified expressions for radiation scattering through canopies with ellipsoidal leaf angle distributions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to simulate the surface energy balance and microclimate within a plant canopy is contingent upon accurate simulation of radiation exchange within the canopy. Accurate radiation simulations require some assumption of leaf angle distribution to compute transmissivity, reflection and scatte...

  20. Note: Enhancing the sensitivity of roll-angle measurement with a novel interferometric configuration based on waveplates and folding mirror

    NASA Astrophysics Data System (ADS)

    Qi, J.; Wang, Z.; Huang, J. H.; Yu, B.; Gao, J.; Donati, S.

    2016-03-01

    A novel method for very high resolution measurement of roll angle on a transparent plate is developed theoretically and tested experimentally. The new optical configuration is based on the interferometric readout of phase shift accumulated on the double passage through half wave plate, together with a careful control of polarization state by means of quarter wave plate, and optimizing the tilt of the folding mirror. Sensitivity to roll angle is greatly enhanced and a gain coefficient exceeding 700 is found theoretically, based on Jones' matrix analysis, with a 6-fold increase respect to previous results. In the experimental setup, at the optimum 36° incidence to retroreflector, we measured a gain coefficient of 340. Correspondingly, with an interferometer phase meter resolving 0.01°, a roll-angle resolution 0.1-arc sec is attained.

  1. The transient roll moment response due to forebody tangential blowing at high angles of attack

    NASA Astrophysics Data System (ADS)

    Chow, Jonathan Kwokching

    The sustained ability for controlled flight at high angles of attack is desirable for future aircraft. For combat aircraft, enhancing maneuverability is important to increasing its survivability. For future supersonic commercial aircraft, an increase in lift at high angles of attack leads to improved performance during take-offs and landing, and a reduction in noise pollution. However, nonlinear and unsteady phenomena, such as flow separation and vortex shedding dominate the aerodynamics in the high angle of attack regime. These phenomena cause the onset of lateral loads and decrease the effectiveness of conventional control surfaces. For conventional aircraft, controlled flight at high angle of attack is difficult or unfeasible without augmented means of control and a good understanding of their impact on vehicle characteristics and dynamics. The injection of thin sheets of air tangentially to the forebody of the vehicle has been found to be an extremely promising method for augmenting the control of a flight vehicle at high angles of attack. Forebody Tangential Blowing (FTB) allows the flow structure to be altered in a rational manner and increase the controllability of the vehicle under these flight conditions. The feasibility of using FTB to control the roll-yaw motion of flight vehicles has been demonstrated. Existing knowledge of FTB's nonlinear impact on the aerodynamic moment responses is limited. Currently available dynamic models predict the general trends in the behavior but do not capture important transient effects that dominate the responses when small amounts of blowing is used. These transients can be large in comparison to the steady-state values. This thesis summarizes the experimental and theoretical results of an investigation into the transient effects of Forebody Tangential Blowing. The relationship between the aerodynamic roll moment, vortical flowfield, and blowing strength is examined to obtain a fundamental understanding of the physics of

  2. Effect of Variation of Chord and Span of Ailerons on Rolling and Yawing Moments at Several Angles of Pitch

    NASA Technical Reports Server (NTRS)

    Heald, R H; Strother, D H; Monish, B H

    1931-01-01

    This report presents the results of an extension to higher angles of attack of the investigation of the rolling and yawing moments due to ailerons of various chords and spans on two airfoils having the Clark Y and U. S. A. 27 wings. The measurements were made at various angles of pitch but at zero angle of roll and yaw, the wing chord being set at an angle of +4 degrees to the fuselage axis. In the case of the Clark Y airfoil the measurements have been extended to a pitch angle of 40 degrees, using ailerons of span equal to 67 per cent of the wing semispan and chord equal to 20 and 30 per cent of the wing chord. The work was conducted on wing models of 60-inch span and 10-inch chord.

  3. Light interacts with auxin during leaf elongation and leaf angle development in young corn seedlings.

    PubMed

    Fellner, Martin; Horton, Lindsey A; Cocke, Allison E; Stephens, Nicholas R; Ford, E David; Van Volkenburgh, Elizabeth

    2003-01-01

    Modern corn ( Zea mays L.) varieties have been selected for their ability to maintain productivity in dense plantings. We have tested the possibility that the physiological consequence of the selection of the modern hybrid, 3394, for increased crop yield includes changes in responsiveness to auxin and light. Etiolated seedlings in the modern line are shorter than in an older hybrid, 307, since they produce shorter coleoptile, mesocotyl, and leaves (blade as well as sheath). Etiolated 3394 seedlings, as well as isolated mesocotyl and sheath segments, were less responsive to auxin and an inhibitor of polar auxin transport, N-1-naphthylphthalamic acid (NPA). Reduced response of 3394 to auxin was associated with less reduction of elongation growth by light (white, red, far-red, blue) than in 307, whereas the activity of polar auxin transport (PAT) and its reduction by red or far-red light was similar in both genotypes. NPA reduced PAT in etiolated 3394 seedlings much less than in 307. A characteristic feature of 3394 plants is more erect leaves. In both hybrids, light (white, red, blue) increases leaf declination from the vertical, whereas NPA reduces leaf declination in 307, but not in 3394. Our results support findings that auxin and PAT are involved in elongation growth of corn seedlings, and we show that light interacts with auxin or PAT in regulation of leaf declination. We hypothesize that, relative to 307, more erect leaves in the modern hybrid may be primarily a consequence of a reduced amount of auxin receptor(s) and reduced responsiveness to light in etiolated 3394 plants. The more erect leaves in 3394 may contribute to the tolerance of the modern corn hybrid to dense planting. PMID:12520327

  4. The relationship between leaf rolling and ascorbate-glutathione cycle enzymes in apoplastic and symplastic areas of Ctenanthe setosa subjected to drought stress.

    PubMed

    Saruhan, Neslihan; Terzi, Rabiye; Saglam, Aykut; Kadioglu, Asim

    2009-01-01

    The ascorbate-glutathione (ASC-GSH) cycle has an important role in defensive processes against oxidative damage generated by drought stress. In this study, the changes that take place in apoplastic and symplastic ASC-GSH cycle enzymes of the leaf and petiole were investigated under drought stress causing leaf rolling in Ctenanthe setosa (Rose.) Eichler (Marantaceae). Apoplastic and symplastic extractions of leaf and petiole were performed at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others are intermediate forms). Glutathione reductase (GR), a key enzyme in the GSH regeneration cycle, and ascorbate (ASC) were present in apoplastic spaces of the leaf and petiole, whereas dehydroascorbate reductase (DHAR), which uses glutathione as reductant, monodehydroascorbate reductase (MDHAR), which uses NAD(P)H as reductant, and glutathione were absent. GR, DHAR and MDHAR activities increased in the symplastic and apoplastic areas of the leaf. Apoplastic and symplastic ASC and dehydroascorbate (DHA), the oxidized form of ascorbate, rose at all scores except score 4 of symplastic ASC in the leaf. On the other hand, while reduced glutathione (GSH) content was enhanced, oxidized glutathione (GSSG) content decreased in the leaf during rolling. As for the petiole, GR activity increased in the apoplastic area but decreased in the symplastic area. DHAR and MDHAR activities increased throughout all scores, but decreased to the score 1 level at score 4. The ASC content of the apoplast increased during leaf rolling. Conversely, symplastic ASC content increased at score 2, however decreased at the later scores. While the apoplastic DHA content declined, symplastic DHA rose at score 2, but later was down to the level of score 1. While GSH content enhanced during leaf rolling, GSSG content did not change except at score 2. As well, there were good correlations between leaf rolling and ASC-GSH cycle enzyme activities in the leaf (GR and DHAR

  5. Response properties of gerbil otolith afferents to small angle pitch and roll tilts

    NASA Technical Reports Server (NTRS)

    Dickman, J. D.; Angelaki, D. E.; Correia, M. J.

    1991-01-01

    The responses from isolated single otolith afferent fibers were obtained to small angle sinusoidal pitch and roll tilts in anesthetized gerbils. The stimulus directions that produced the maximum (response vector) and minimum response sensitivities were determined for each otolith afferent, with response vectors for the units being spread throughout the horizontal plane, similar to those reported for other species. A breadth of tuning measure was derived, with narrowly tuned neurons responding maximally to stimulation in one direction and minimally along an orthogonal ('null') direction. Most (approximately 80%) otolith afferents are narrowly tuned, however, some fibers were broadly tuned responding significantly to stimulations in any direction in the horizontal plane. The number of broadly tuned otolith afferents (approximately 20%) differs significantly from the more substantial number of broadly tuned vestibular nuclei neurons (88%) recently reported in rats.

  6. Leaf-rolling sawflies (Hymenoptera, Pamphiliidae, Pamphiliinae) of Tianmushan Mountains, Zhejiang Province, China.

    PubMed

    Shinohara, Akihiko; Wei, Mei-Cai

    2016-01-01

    Two species of Neurotoma, six species of Onycholyda, and five species of Pamphilius are recorded from Tianmushan, Zhejiang Province, China, and a key is given to these three genera and 13 species. Three new species, Onycholyda atra Shinohara & Wei, sp. nov. from Zhejiang Province, O. fulvicornis Shinohara, sp. nov. from Shaanxi Province and Zhejiang Province, and Pamphilius padus Shinohara, sp. nov. from Zhejiang Province, are described. New distribution records are: Onycholyda shaanxiana Shinohara, 1999, from Hubei Province, Zhejiang Province and Guangxi Zhuang Autonomous Region, O. subquadrata (Maa, 1944) from Zhejiang Province, O. tianmushana Shinohara & Xiao, 2006, from Hunan Province and Jiangxi Province, Pamphilius palliceps Shinohara & Xiao, 2006, from Anhui Province, P. lizejiani Shinohara in Shinohara & Wei, 2012, from Zhejiang Province, P. shengi Wei in Wei & Xiao, 1999, from Hubei Province and Zhejiang Province, and P. qinlingicus Wei in Wu & Wei, 2010, from Zhejiang Province. The larva of P. padus feeds on Padus obtusata (Rosaceae) and that of P. palliceps feeds on Rosa multiflora (Rosaceae), both singly making a leaf-roll. Rubus peltatus (Rosaceae) is recorded as a host plant of O. atra based on the observation of oviposition. PMID:27395926

  7. Flight Investigation of a Roll-stabilized Missile Configuration at Varying Angles of Attack at Mach Numbers Between 0.8 and 1.79

    NASA Technical Reports Server (NTRS)

    Zarovsky, Jacob; Gardiner, Robert A

    1957-01-01

    A missile research model was flown at supersonic speed to determine the quality of automatic roll stabilization at varying angles of attack. Aerodynamic rolling and pitching derivatives were determined from the flight record. It was concluded that the combination of the gyro-actuated automatic pilot with wing-tip ailerons provided adequate roll stabilization under conditions encountered in flight.

  8. Polarization Methods of Measuring the Roll Angle of an Object in Motion in Radio Beacon Navigation Systems

    NASA Astrophysics Data System (ADS)

    Gulko, V. L.; Mescheryakov, A. A.

    2016-06-01

    Polarization methods of measuring the roll angle of an object in motion with the help of radio beacon systems are considered. The polarization properties of the beacon signals received on board the object and amplitude-phase processing of their orthogonal polarized components are used to accomplish this goal.

  9. Genomic Dissection of Leaf Angle in Maize (Zea mays L.) Using a Four-Way Cross Mapping Population

    PubMed Central

    Li, Xiantang; Li, Yongming; Cheng, Hongliang; Huang, Rongrong; Zhou, Bo; Li, Zhimin; Wang, Jiankang; Wu, Jianyu

    2015-01-01

    Increasing grain yield by the selection for optimal plant architecture has been the key focus in modern maize breeding. As a result, leaf angle, an important determinant of plant architecture, has been significantly improved to adapt to the ever-increasing plant density in maize production over the past several decades. To extend our understanding on the genetic mechanisms of leaf angle in maize, we developed the first four-way cross mapping population, consisting of 277 lines derived from four maize inbred lines with varied leaf angles. The four-way cross mapping population together with the four parental lines were evaluated for leaf angle in two environments. In this study, we reported linkage maps built in the population and quantitative trait loci (QTL) on leaf angle detected by inclusive composite interval mapping (ICIM). ICIM applies a two-step strategy to effectively separate the cofactor selection from the interval mapping, which controls the background additive and dominant effects at the same time. A total of 14 leaf angle QTL were identified, four of which were further validated in near-isogenic lines (NILs). Seven of the 14 leaf angle QTL were found to overlap with the published leaf angle QTL or genes, and the remaining QTL were unique to the four-way population. This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize. PMID:26509792

  10. Genomic Dissection of Leaf Angle in Maize (Zea mays L.) Using a Four-Way Cross Mapping Population.

    PubMed

    Ding, Junqiang; Zhang, Luyan; Chen, Jiafa; Li, Xiantang; Li, Yongming; Cheng, Hongliang; Huang, Rongrong; Zhou, Bo; Li, Zhimin; Wang, Jiankang; Wu, Jianyu

    2015-01-01

    Increasing grain yield by the selection for optimal plant architecture has been the key focus in modern maize breeding. As a result, leaf angle, an important determinant of plant architecture, has been significantly improved to adapt to the ever-increasing plant density in maize production over the past several decades. To extend our understanding on the genetic mechanisms of leaf angle in maize, we developed the first four-way cross mapping population, consisting of 277 lines derived from four maize inbred lines with varied leaf angles. The four-way cross mapping population together with the four parental lines were evaluated for leaf angle in two environments. In this study, we reported linkage maps built in the population and quantitative trait loci (QTL) on leaf angle detected by inclusive composite interval mapping (ICIM). ICIM applies a two-step strategy to effectively separate the cofactor selection from the interval mapping, which controls the background additive and dominant effects at the same time. A total of 14 leaf angle QTL were identified, four of which were further validated in near-isogenic lines (NILs). Seven of the 14 leaf angle QTL were found to overlap with the published leaf angle QTL or genes, and the remaining QTL were unique to the four-way population. This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize. PMID:26509792

  11. Seasonal and vertical changes in leaf angle distribution for selected deciduous broadleaf tree species common to Europe

    NASA Astrophysics Data System (ADS)

    Raabe, Kairi; Pisek, Jan; Sonnentag, Oliver; Annuk, Kalju

    2014-05-01

    Leaf inclination angle distribution is a key parameter in determining the transmission and reflection of radiation by vegetation canopies. It has been previously observed that leaf inclination angle might change gradually from more vertical in the upper canopy and in high light habitats to more horizontal in the lower canopy and in low light habitats [1]. Despite its importance, relatively few measurements on actual leaf angle distributions have been reported for different tree species. Even smaller number of studies have dealt with the possible seasonal changes in leaf angle distribution [2]. In this study the variation of leaf inclination angle distributions was examined both temporally throughout the growing season and vertically at different heights of trees. We report on leaf inclination angle distributions for five deciduous broadleaf species found commonly in several parts of Europe: grey alder (Alnus incana), Silver birch (Betula pendula Roth), chestnut (Castanea), Norway maple (Acer platanoides), and aspen (Populus tremula). The angles were measured using the leveled camera method [3], with the data collected at several separate heights and four times during the period of May-September 2013. The results generally indicate the greatest change in leaf inclination angles for spring, with the changes usually being the most pronounced at the top of the canopy. It should also be noted, however, that whereas the temporal variation proved to be rather consistent for different species, the vertical variation differed more between species. The leveled camera method was additionally tested in terms of sensitivity to different users. Ten people were asked to measure the leaf angles for four different species. The results indicate the method is quite robust in providing coinciding distributions irrespective of the user and level of previous experience with the method. However, certain caution must be exercised when measuring long narrow leaves. References [1] G.G. Mc

  12. Rolling element bearing defect diagnosis under variable speed operation through angle synchronous averaging of wavelet de-noised estimate

    NASA Astrophysics Data System (ADS)

    Mishra, C.; Samantaray, A. K.; Chakraborty, G.

    2016-05-01

    Rolling element bearings are widely used in rotating machines and their faults can lead to excessive vibration levels and/or complete seizure of the machine. Under special operating conditions such as non-uniform or low speed shaft rotation, the available fault diagnosis methods cannot be applied for bearing fault diagnosis with full confidence. Fault symptoms in such operating conditions cannot be easily extracted through usual measurement and signal processing techniques. A typical example is a bearing in heavy rolling mill with variable load and disturbance from other sources. In extremely slow speed operation, variation in speed due to speed controller transients or external disturbances (e.g., varying load) can be relatively high. To account for speed variation, instantaneous angular position instead of time is used as the base variable of signals for signal processing purposes. Even with time synchronous averaging (TSA) and well-established methods like envelope order analysis, rolling element faults in rolling element bearings cannot be easily identified during such operating conditions. In this article we propose to use order tracking on the envelope of the wavelet de-noised estimate of the short-duration angle synchronous averaged signal to diagnose faults in rolling element bearing operating under the stated special conditions. The proposed four-stage sequential signal processing method eliminates uncorrelated content, avoids signal smearing and exposes only the fault frequencies and its harmonics in the spectrum. We use experimental data1

  13. Modeling and Analysis of Phase Fluctuation in a High-Precision Roll Angle Measurement Based on a Heterodyne Interferometer.

    PubMed

    Huang, Junhui; Wang, Zhao; Gao, Jianmin; Yu, Bao

    2016-01-01

    Heterodyne interferometry is a high-precision method applied in roll angle measurements. Phase metering is essential for high precision. During a high-precision measurement, a phase fluctuation appears even when the roll angle does not vary, which has never been analyzed before. Herein, the reason for the phase fluctuation is revealed, which results from the frequency-difference fluctuation and time difference between measurement and reference beams. A mathematical model of that phase-fluctuation mechanism is established, and that model provides a theoretical basis for analyzing and reducing the phase fluctuation. The impact that the main factors have on the phase metering is analyzed quantitatively, and experiments are carried out to validate the model. Finally, the phase fluctuation decreases to 0.02° by frequency reduction, which conversely verifies the theoretical model. PMID:27490552

  14. SLG controls grain size and leaf angle by modulating brassinosteroid homeostasis in rice.

    PubMed

    Feng, Zhiming; Wu, Chuanyin; Wang, Chunming; Roh, Jeehee; Zhang, Long; Chen, Jun; Zhang, Shengzhong; Zhang, Huan; Yang, Chunyan; Hu, Jinlong; You, Xiaoman; Liu, Xi; Yang, Xiaoming; Guo, Xiuping; Zhang, Xin; Wu, Fuqing; Terzaghi, William; Kim, Seong-Ki; Jiang, Ling; Wan, Jianmin

    2016-07-01

    Grain size and leaf angle are two important traits determining grain yield in rice. However, the mechanisms regulating the two traits remain largely unknown. Here, we characterized a rice gain-of-function mutant, slender grain Dominant (slg-D), which exhibited longer and narrower grains and larger leaf angles, similar to plants with elevated brassinosteroid (BR) levels or strengthened BR signaling. The increased cell length is responsible for the mutant phenotypes in slg-D We demonstrated that the phenotype of slg-D is caused by enhanced expression of SLG, a BAHD acyltransferase-like protein gene. SLG is preferentially expressed in young panicles and lamina joints, implying its role in controlling cell growth in those two tissues. slg-D was restored to wild type by treatment with brassinazole, an inhibitor of BR biosynthesis. Overexpression of SLG in d11-2 (deficient in BR synthesis) and d61-1 (deficient in BR signaling) did not change the existing phenotypes. The slg-D plants had elevated BR contents and, accordingly, expression of BR-related genes was changed in a manner similar to BR treatment. Moreover, SLG RNAi plants displayed mild BR-deficient phenotypes including shorter grains, smaller leaf angles, and compact semi-dwarf plant types. The in vitro biochemical assays and transgenic approaches collectively demonstrated that SLG functions as homomers. Taken together, we conclude that SLG is an important regulator in BR homeostasis and that manipulation of SLG expression to an optimal level may provide a way to develop an ideal plant type. PMID:27252468

  15. Genetic Control of the Leaf Angle and Leaf Orientation Value as Revealed by Ultra-High Density Maps in Three Connected Maize Populations

    PubMed Central

    Li, Chunhui; Li, Yongxiang; Shi, Yunsu; Song, Yanchun; Zhang, Dengfeng; Buckler, Edward S.; Zhang, Zhiwu; Wang, Tianyu; Li, Yu

    2015-01-01

    Plant architecture is a key factor for high productivity maize because ideal plant architecture with an erect leaf angle and optimum leaf orientation value allow for more efficient light capture during photosynthesis and better wind circulation under dense planting conditions. To extend our understanding of the genetic mechanisms involved in leaf-related traits, three connected recombination inbred line (RIL) populations including 538 RILs were genotyped by genotyping-by-sequencing (GBS) method and phenotyped for the leaf angle and related traits in six environments. We conducted single population quantitative trait locus (QTL) mapping and joint linkage analysis based on high-density recombination bin maps constructed from GBS genotype data. A total of 45 QTLs with phenotypic effects ranging from 1.2% to 29.2% were detected for four leaf architecture traits by using joint linkage mapping across the three populations. All the QTLs identified for each trait could explain approximately 60% of the phenotypic variance. Four QTLs were located on small genomic regions where candidate genes were found. Genomic predictions from a genomic best linear unbiased prediction (GBLUP) model explained 45±9% to 68±8% of the variation in the remaining RILs for the four traits. These results extend our understanding of the genetics of leaf traits and can be used in genomic prediction to accelerate plant architecture improvement. PMID:25807369

  16. A leaf-rolling weevil benefits from general saprophytic fungi in polysaccharide degradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insects form symbiosis with fungi widely, especially those feeding on leaf litter. As dead plant tissues provide poor quality diets which contain relatively high levels of indigestible lignin and cellulose, saprophytic fungi may increase nutrient availability by polysaccharide degradation. Although ...

  17. Investigation on Stability in Roll of Square Section Missile at High Angle of Attack

    NASA Astrophysics Data System (ADS)

    Tao, Yang; Fan, Zhaolin; Wu, Jifei; Wu, Wenhua

    An experimental investigation of the stability in roll of a square section missile at high incidence was conducted in FL-23 wind tunnel. Dynamic motions were obtained on a square section missile that is free to rotate about its longitudinal axis. Different dynamic rolling motions were observed depending on the incidence of the model sting. These dynamic regimes include damped oscillations, quasi-limit-cycle wing-rock motion, and constant rolling. A coupling numerical method was established by solving the fluid dynamics equations and the rigid-body dynamics equations synchronously in order to predict the onset and the development of uncommented motions and then explore the unsteady movement characteristics of the aircraft. The study indicates that the aircraft loss stability at high incidence is caused by the asymmetric vertex on the level fin tip liftoff and attach alternately. The computation results are in line with the experiment results.

  18. Epigenetic Mutation of RAV6 Affects Leaf Angle and Seed Size in Rice.

    PubMed

    Zhang, Xiangqian; Sun, Jing; Cao, Xiaofeng; Song, Xianwei

    2015-11-01

    Heritable epigenetic variants of genes, termed epialleles, can broaden genetic and phenotypic diversity in eukaryotes. Epialleles may also provide a new source of beneficial traits for crop breeding, but very few epialleles related to agricultural traits have been identified in crops. Here, we identified Epi-rav6, a gain-of-function epiallele of rice (Oryza sativa) RELATED TO ABSCISIC ACID INSENSITIVE3 (ABI3)/VIVIPAROUS1 (VP1) 6 (RAV6), which encodes a B3 DNA-binding domain-containing protein. The Epi-rav6 plants show larger lamina inclination and smaller grain size; these agronomically important phenotypes are inherited in a semidominant manner. We did not find nucleotide sequence variation of RAV6. Instead, we found hypomethylation in the promoter region of RAV6, which caused ectopic expression of RAV6 in Epi-rav6 plants. Bisulfite analysis revealed that cytosine methylation of four CG and two CNG loci within a continuous 96-bp region plays essential roles in regulating RAV6 expression; this region contains a conserved miniature inverted repeat transposable element transposon insertion in cultivated rice genomes. Overexpression of RAV6 in the wild type phenocopied the Epi-rav6 phenotype. The brassinosteroid (BR) receptor BR INSENSITIVE1 and BR biosynthetic genes EBISU DWARF, DWARF11, and BR-DEFICIENT DWARF1 were ectopically expressed in Epi-rav6 plants. Also, treatment with a BR biosynthesis inhibitor restored the leaf angle defects of Epi-rav6 plants. This indicates that RAV6 affects rice leaf angle by modulating BR homeostasis and demonstrates an essential regulatory role of epigenetic modification on a key gene controlling important agricultural traits. Thus, our work identifies a unique rice epiallele, which may represent a common phenomenon in complex crop genomes. PMID:26351308

  19. Self-rolling and light-trapping in flexible quantum well-embedded nanomembranes for wide-angle infrared photodetectors.

    PubMed

    Wang, Han; Zhen, Honglou; Li, Shilong; Jing, Youliang; Huang, Gaoshan; Mei, Yongfeng; Lu, Wei

    2016-08-01

    Three-dimensional (3D) design and manufacturing enable flexible nanomembranes to deliver unique properties and applications in flexible electronics, photovoltaics, and photonics. We demonstrate that a quantum well (QW)-embedded nanomembrane in a rolled-up geometry facilitates a 3D QW infrared photodetector (QWIP) device with enhanced responsivity and detectivity. Circular geometry of nanomembrane rolls provides the light coupling route; thus, there are no external light coupling structures, which are normally necessary for QWIPs. This 3D QWIP device under tube-based light-trapping mode presents broadband enhancement of coupling efficiency and omnidirectional detection under a wide incident angle (±70°), offering a unique solution to high-performance focal plane array. The winding number of these rolled-up QWIPs provides well-tunable blackbody photocurrents and responsivity. 3D self-assembly of functional nanomembranes offers a new path for high conversion efficiency between light and electricity in photodetectors, solar cells, and light-emitting diodes. PMID:27536723

  20. Self-rolling and light-trapping in flexible quantum well–embedded nanomembranes for wide-angle infrared photodetectors

    PubMed Central

    Wang, Han; Zhen, Honglou; Li, Shilong; Jing, Youliang; Huang, Gaoshan; Mei, Yongfeng; Lu, Wei

    2016-01-01

    Three-dimensional (3D) design and manufacturing enable flexible nanomembranes to deliver unique properties and applications in flexible electronics, photovoltaics, and photonics. We demonstrate that a quantum well (QW)–embedded nanomembrane in a rolled-up geometry facilitates a 3D QW infrared photodetector (QWIP) device with enhanced responsivity and detectivity. Circular geometry of nanomembrane rolls provides the light coupling route; thus, there are no external light coupling structures, which are normally necessary for QWIPs. This 3D QWIP device under tube-based light-trapping mode presents broadband enhancement of coupling efficiency and omnidirectional detection under a wide incident angle (±70°), offering a unique solution to high-performance focal plane array. The winding number of these rolled-up QWIPs provides well-tunable blackbody photocurrents and responsivity. 3D self-assembly of functional nanomembranes offers a new path for high conversion efficiency between light and electricity in photodetectors, solar cells, and light-emitting diodes. PMID:27536723

  1. Considerations involved in the design of a roll-angle computer for a bank-to-turn interceptor

    NASA Technical Reports Server (NTRS)

    Triplett, William C

    1955-01-01

    At the Ames Aeronautical Laboratory some flight and analog computer studies have been made on the final attack phase of automatic interceptions. The ultimate objective of these studies is to define the behavior of various types of automatic control systems as influenced by a wide range of aerodynamic characteristics. This is a continuing program still in its initial stages; however, it is felt that conclusions of general significance can be drawn from these preliminary studies. One point of particular importance is the necessity for including a gain charger or computer in the azimuth loop of any bank-to-turn airplane or missile. This device translates azimuth error signals into appropriate roll commands. The results to date have shown that the characteristics of this component have a predominant effect on the behavior of a automatic system. It is the purpose of this paper to discuss considerations of importance in the design of a suitable roll-angle computer. In this regard, the present paper complements the analytical work reported in NACA RM L54E27, 1954.

  2. Computer programs for the calculation of dual sting pitch and roll angles required for an articulated sting to obtain angles of attack and sideslip on wind-tunnel models

    NASA Technical Reports Server (NTRS)

    Peterson, John B., Jr.

    1991-01-01

    Two programs were developed to calculate the pitch and roll position of the conventional sting drive and the pitch of a high angle articulated sting to position a wind tunnel model at the desired angle of attack and sideslip and position the model as near as possible to the centerline of the tunnel. These programs account for the effects of sting offset angles, sting bending angles, and wind-tunnel stream flow angles. In addition, the second program incorporates inputs form on-board accelerometers that measure model pitch and roll with respect to gravity. The programs are presented and a description of the numerical operation of the programs with a definition of the variables used in the programs is given.

  3. Comparison of diagnostic techniques for the detection and differentiation of Cherry leaf roll virus strains for quarantine purposes.

    PubMed

    Lebas, B S M; Veerakone, S; Liefting, L W; Tang, J; Perez-Egusquiza, Z; von Bargen, S; Ward, L

    2016-08-01

    Some strains of Cherry leaf roll virus (CLRV) are considered as quarantine pests in New Zealand. CLRV was detected in seven plant host species: Actinidia chinensis, Hydrangea macrophylla, Malus domestica, Plantago major, Ribes rubrum, Rubus idaeus and Rumex sp. collected from New Zealand between 2005 and 2012. Biological, serological and molecular techniques were compared for the detection and differentiation of CLRV isolates. The biological analysis revealed differences in symptomatology and disease severity among the isolates. The five isolates tested by ELISA were serologically related to each other using polyclonal antisera with only one out of four commercially-available antisera successfully detecting all of them. The phylogenetic analysis of sequences obtained from parts of the coat protein, polymerase and 3'-untranslated regions revealed that the New Zealand CLRV isolates clustered into two closely related but distinct phylogenetic groups with some isolates grouping differently depending on the gene studied. The New Zealand CLRV isolates were clearly distinct to overseas isolates found in phylogenetic groups A, D and E. The conventional RT-PCR using primers targeting the CLRV coat protein coding region is recommended for determining sequence differences between strains. These findings will be useful in making regulatory decisions with regard to the testing requirements and the CLRV strains to be regulated in New Zealand. PMID:27129669

  4. PD Trafficking of Potato Leaf Roll Virus Movement Protein in Arabidopsis Depends on Site-specific Protein Phosphorylation

    PubMed Central

    Sonnewald, Uwe

    2011-01-01

    Many plant viruses encode for specialized movement proteins (MP) to facilitate passage of viral material to and through plasmodesmata (PD). To analyze intracellular trafficking of potato leaf roll virus (PLRV) movement protein (MP17) we performed GFP fusion experiments with distinct deletion variants of MP17. These studies revealed that the C-terminus of MP17 is essential but not sufficient for PD targeting. Interestingly, fusion of GFP to three C-terminal MP17 deletion variants resulted in the accumulation of GFP in chloroplasts. This indicates that MP17 harbors hidden plastid targeting sequences. Previous studies showed that posttranslational protein phosphorylation influences PD targeting of MP and virus spread. Analysis of MP17-derived phospho-peptides by mass spectrometry revealed four phosphorylated serine residues (S71, S79, S137, and S140). Site-directed mutagenesis of S71/S79 and S137/S140 showed that the C-terminal serine residues S137/S140 are dispensable for PD targeting. However, exchange of S71/S79 to A71/A79 abolished PD targeting of the mutated MP17 protein. To mimic phosphorylation of S71/S79 both amino acids were substituted by aspartic acid. The resulting D71/D79 variant of MP17 was efficiently targeted to PD. Further deletion analysis showed that PD targeting of MP17 is dependent on the C-terminus, phosphorylation of S71 and/or S79 and a N-terminal domain. PMID:22645527

  5. Estimates of leaf area index from spectral reflectance of wheat under different cultural practices and solar angle

    NASA Technical Reports Server (NTRS)

    Asrar, G.; Kanemasu, E. T.; Yoshida, M.

    1985-01-01

    The influence of management practices and solar illumination angle on the leaf area index (LAI) was estimated from measurements of wheat canopy reflectance evaluated by two methods, a regression formula and an indirect technique. The date of planting and the time of irrigation in relation to the stage of plant growth were found to have significant effects on the development of leaves in spring wheat. A reduction in soil moisture adversely affected both the duration and magnitude of the maximum LAI for late planting dates. In general, water stress during vegetative stages resulted in a reduction in maximum LAI, while water stress during the reproductive period shortened the duration of green LAI in spring wheat. Canopy geometry and solar angle also affected the spectral properties of the canopies, and hence the estimated LAI. Increase in solar zenith angles resulted in a general increase in estimated LAI obtained from both methods.

  6. Branching angles reflect a trade-off between reducing trail maintenance costs or travel distances in leaf-cutting ants.

    PubMed

    Farji-Brener, Alejandro Gustavo; Chinchilla, Federico; Umaña, María Natalia; Ocasio-Torres, Maríia Elena; Chauta-Mellizo, Alexander; Acosta-Rojas, Diana; Marinaro, Sofía; Curth, Mónica de Torres; Amador-Vargas, Sabrina

    2015-02-01

    The design of transport paths in consuming entities that use routes to access food should be under strong selective pressures to reduce costs and increase benefits. We studied the adaptive nature of branching angles in foraging trail networks of the two most abundant tropical leaf-cutting ant species. We mathematically assessed how these angles should reflect the relative weight of the pressure for reducing either trail maintenance effort or traveling distances. Bifurcation angles of ant foraging trails strongly differed depending on the location of the nests. Ant colonies in open areas showed more acute branching angles, which best shorten travel distances but create longer new trail sections to maintain than a perpendicular branch, suggesting that trail maintenance costs are smaller compared to the benefit of reduced traveling distance. Conversely, ant colonies in forest showed less acute branching angles, indicating that maintenance costs are of larger importance relative to the benefits of shortening travel distances. The trail pattern evident in forests may be attributable to huge amounts of litterfall that .increase trail maintenance costs, and the abundant canopy cover that reduces traveling costs by mitigating direct sunlight and rain. These results suggest that branching angles represent a trade-off between reducing maintenance work and shortening travel distances, illustrating how animal constructions can adjust to diverse environmental conditions. This idea may help to understand diverse networks systems, including urban travel networks. PMID:26240872

  7. OsMYB103L, an R2R3-MYB transcription factor, influences leaf rolling and mechanical strength in rice (Oryza sativa L.)

    PubMed Central

    2014-01-01

    Background The shape of grass leaves possesses great value in both agronomy and developmental biology research. Leaf rolling is one of the important traits in rice (Oryza sativa L.) breeding. MYB transcription factors are one of the largest gene families and have important roles in plant development, metabolism and stress responses. However, little is known about their functions in rice. Results In this study, we report the functional characterization of a rice gene, OsMYB103L, which encodes an R2R3-MYB transcription factor. OsMYB103L was localized in the nucleus with transactivation activity. Overexpression of OsMYB103L in rice resulted in a rolled leaf phenotype. Further analyses showed that expression levels of several cellulose synthase genes (CESAs) were significantly increased, as was the cellulose content in OsMYB103L overexpressing lines. Knockdown of OsMYB103L by RNA interference led to a decreased level of cellulose content and reduced mechanical strength in leaves. Meanwhile, the expression levels of several CESA genes were decreased in these knockdown lines. Conclusions These findings suggest that OsMYB103L may target CESA genes for regulation of cellulose synthesis and could potentially be engineered for desirable leaf shape and mechanical strength in rice. PMID:24906444

  8. Cherry leaf roll virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the blackberry cultivar Himalaya Giant naturally infected in England, CLRV is reported to cause chlorotic mottling and line patterning in leaves. Infected plants are stunted and may be killed. In three red raspberry cultivars naturally infected by CLRV in New Zealand, infected plants had stunted,...

  9. Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test.

    PubMed

    Vigotsky, Andrew D; Lehman, Gregory J; Contreras, Bret; Beardsley, Chris; Chung, Bryan; Feser, Erin H

    2015-01-01

    Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test. Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated. Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearson's r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = -1.39° (-5.53, +2.75); t(22) = -0.70; p = 0.4933; Cohen's d = - 0.15 (-0.58, 0.29)) or rectus femoris length (change = -0.005 (-0.013, +0.003); t(22) = -1.30; p = 0.2070; Cohen's d = - 0.27 (-0.70, 0.16)) were not due to chance alone. Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol. PMID:26421244

  10. Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test

    PubMed Central

    Lehman, Gregory J.; Contreras, Bret; Beardsley, Chris; Chung, Bryan; Feser, Erin H.

    2015-01-01

    Background. Foam rolling has been shown to acutely increase range of motion (ROM) during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test. Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg) performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated. Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61); z(22) = 2.08; p = 0.0372; Pearson’s r = 0.43 (0.02, 0.72)) was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = −1.39° (−5.53, +2.75); t(22) = −0.70; p = 0.4933; Cohen’s d = − 0.15 (−0.58, 0.29)) or rectus femoris length (change = −0.005 (−0.013, +0.003); t(22) = −1.30; p = 0.2070; Cohen’s d = − 0.27 (−0.70, 0.16)) were not due to chance alone. Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol. PMID:26421244

  11. Assessing the Impact of Central Appalachian Tree Species on Canopy Albedo via Measurement of Leaf Angles from Repeated Ground-based, Drone, and Hemispherical Photography

    NASA Astrophysics Data System (ADS)

    McNeil, B. E.; Erazo, D.; Heimerl, T.

    2014-12-01

    Satellite measurements of forest albedo are directly used in climate models, and could be used in models of the C and N cycles if we more fully understood the mechanism causing a strong correlation of forest albedo with canopy N and C assimilation. One attractive mechanism posits that tree species have evolved convergent leaf and canopy traits. While the leaf traits of tree species are known to drive variability in canopy N and C assimilation, linking tree species to variability in albedo is challenging because of the difficulty in measuring important canopy traits like leaf angle. To refine techniques for measuring leaf angle, and test the hypothesis that high albedo in the central Appalachians could be linked to the abundance of species with canopy traits of more horizontal leaf angles, we conducted four tests with ground-based, drone, and hemispherical photographs. First, we used a leveled camera on a steep slope to repeatedly, and directly measure the leaf angle of over 400 leaves within the canopies of oak, maple, and beech trees. Across all 21 repetitions (3 times a day on 7 dates between May and July), we observed consistent species differences in mean leaf angle (MLA), with maple always being the most horizontal (MLA = 14-18°) and oak the most vertical (MLA = 19-28°). Second, we again found highly significant species differences in MLA when we used a hexacopter drone with a camera on a self-leveling gimbal to make over 1020 direct measurements of leaf angle from six tree species in three broadleaf deciduous forest plots. Third, to measure MLA of a whole multi-species canopy, we compared a species abundance-weighted plot average of the drone-measured MLA values with an indirect, ground-based hemispherical photograph method. The strong agreement of these direct and indirect plot-level methods finally led us to compare a broader set of 61 plot-level hemispherical photo MLA measurements with canopy albedo measured by AVIRIS in broadleaf deciduous forests. In

  12. Molecular phylogenetics and evolution of host plant use in the Neotropical rolled leaf 'hispine' beetle genus Cephaloleia (Chevrolat) (Chrysomelidae: Cassidinae).

    PubMed

    McKenna, Duane D; Farrell, Brian D

    2005-10-01

    Here, we report the results of a species level phylogenetic study of Cephaloleia beetles designed to clarify relationships and patterns of host plant taxon and tissue use among species. Our study is based on up to 2088bp of mtDNA sequence data. Maximum parsimony, maximum likelihood, and Bayesian methods of phylogenetic inference consistently recover a monophyletic Cephaloleia outside of a basal clade of primarily palm feeding species (the 'Arecaceae-feeding clade'), and C. irregularis. In all three analyses, the 'Arecaceae-feeding clade' includes Cephaloleia spp. with unusual morphological features, and a few species currently placed in other cassidine genera and tribes. All three analyses also recover a clade that includes all Zingiberales feeding Cephaloleia and most Cephaloleia species (the 'Zingiberales-feeding clade'). Two notable clades are found within the 'Zingiberales-feeding clade.' One is comprised of beetles that normally feed only on the young rolled leaves of plants in the families Heliconiaceae and Marantaceae (the 'Heliconiaceae & Marantaceae-feeding clade'). The other is comprised of relative host tissue generalist, primarily Zingiberales feeding species (the 'generalist-feeding clade'). A few species in the 'generalist-feeding clade' utilize Cyperaceae or Poaceae as hosts. Overall, relatively basal Cephaloleia (e.g., the 'Arecaceae clade') feed on relatively basal monocots (e.g., Cyclanthaceae and Arecaceae), and relatively derived Cephaloleia (e.g., the 'Zingiberales-feeding clade') feed on relatively derived monocots (mostly in the order Zingiberales). Zingiberales feeding and specialization on young rolled Zingiberales leaves have each apparently evolved just once in Cephaloleia. PMID:16054400

  13. Leaf Rolling and Stem Fasciation in Grass Pea (Lathyrus sativus L.) Mutant Are Mediated through Glutathione-Dependent Cellular and Metabolic Changes and Associated with a Metabolic Diversion through Cysteine during Phenotypic Reversal

    PubMed Central

    Talukdar, Dibyendu; Talukdar, Tulika

    2014-01-01

    A Lathyrus sativus L. mutant isolated in ethylmethane sulfonate-treated M2 progeny of mother variety BioL-212 and designated as rlfL-1 was characterized by inwardly rolled-leaf and stem and bud fasciations. The mutant exhibited karyomorphological peculiarities in both mitosis and meiosis with origin of aneuploidy. The mitosis was vigorous with high frequency of divisional cells and their quick turnover presumably steered cell proliferations. Significant transcriptional upregulations of cysteine and glutathione synthesis and concomitant stimulations of glutathione-mediated antioxidant defense helped rlfL-1 mutant to maintain balanced reactive oxygen species (ROS) metabolisms, as deduced by ROS-imaging study. Glutathione synthesis was shut down in buthionine sulfoximine- (BSO-) treated mother plant and mutant, and leaf-rolling and stems/buds fasciations in the mutant were reversed, accompanied by normalization of mitotic cell division process. Antioxidant defense was downregulated under low glutathione-redox but cysteine-desulfurations and photorespiratory glycolate oxidase transcripts were markedly overexpressed, preventing cysteine overaccumulation but resulted in excess H2O2 in BSO-treated mutant. This led to oxidative damage in proliferating cells, manifested by severe necrosis in rolled-leaf and fasciated stems. Results indicated vital role of glutathione in maintaining abnormal proliferations in plant organs, and its deficiency triggered phenotypic reversal through metabolic diversions of cysteine and concomitant cellular and metabolic modulations. PMID:24987684

  14. Calibration and validation of DEM rolling and sliding friction coefficients in angle of repose and shear measurements

    NASA Astrophysics Data System (ADS)

    Frankowski, Piotr; Morgeneyer, Martin

    2013-06-01

    Pile formation and rotating drum experiments followed by DEM simulations using glass beads (1.5 and 3.0 mm diameter) and polyamide spheres (3.0 mm diameter) were conducted. A wide range of rotation velocities was tested (from 1 to 90 rpm), the drum fill degree was set to 50%. The material inclination angles obtained in pile formation experiments were comparable with low speed rotating drum tests. The experimentally obtained results were used to determine DEM friction coefficients. Both, good qualitative and good quantitative agreements between experiments and simulations were found for rotation speeds up to 5 rpm, whereas for higher rotation speeds small discrepancies were observed.

  15. Cross-directional interlocking of rolls in an air press of a papermaking machine

    DOEpatents

    Beck, David A.; Gorshe, Thomas

    2003-05-13

    An air press for pressing a paper web is composed of a plurality of rolls including at least a first roll and a second roll. The first roll and the second roll are positioned adjacent one another and form a first nip therebetween. Further, the first roll and the second roll each have a roll end, the roll end of the first roll adjoining the roll end of the second roll. A bevel plate is attached to the roll end of the first roll, the bevel plate having at least a first angled plate face. A seal ring is positioned adjacent the roll end of the second roll, the seal ring being juxtaposed to the bevel plate. The seal ring has at least a first angled ring face, and the first angled ring face mates with the first angled plate face.

  16. Video Analysis of Rolling Cylinders

    ERIC Educational Resources Information Center

    Phommarach, S.; Wattanakasiwich, P.; Johnston, I.

    2012-01-01

    In this work, we studied the rolling motion of solid and hollow cylinders down an inclined plane at different angles. The motions were captured on video at 300 frames s[superscript -1], and the videos were analyzed frame by frame using video analysis software. Data from the real motion were compared with the theory of rolling down an inclined…

  17. Computational Analysis of Ares I Roll Control System Jet Interaction Effects on Rolling Moment

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Pao, S. Paul; Abdol-Hamid, Khaled S.

    2011-01-01

    The computational flow solver USM3D was used to investigate the jet interaction effects from the roll control system on the rolling moment of the Ares I full protuberance configuration at wind tunnel Reynolds numbers. Solutions were computed at freestream Mach numbers from M = 0.5 to M = 5 at the angle of attack 0deg, at the angle of attack 3.5deg for a roll angle of 120deg, and at the angle of attack 7deg for roll angles of 120deg and 210deg. Results indicate that the RoCS housing provided a beneficial jet interaction effect on vehicle rolling moment for M > or = 0.9. Most of the components downstream of the roll control system housing contributed to jet interaction penalties on vehicle rolling moment.

  18. Metal rolling - Asymmetrical rolling process

    NASA Astrophysics Data System (ADS)

    Alexa, V.; Raţiu, S.; Kiss, I.

    2016-02-01

    The development of theory and practice related to the asymmetric longitudinal rolling process is based on the general theory of metalworking by pressure and symmetric rolling theory, to which a large number of scientists brought their contribution. The rolling of metal materials was a serious problem throughout history, either economically or technically, because the plating technologies enabled the consumption of raw materials (scarce and expensive) to be reduced, while improving the mechanical properties. Knowing the force parameters related to asymmetric rolling leads to the optimization of energy and raw material consumption. This paper presents data on symmetric rolling process, in order to comparatively highlight the particularities of the asymmetric process.

  19. How to pattern a leaf

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf development presents a tremendous resource for tackling the question of patterning in biology. Leaves can be simple or highly dissected. They may have elaborated parts such as the tendrils of a pea leaf or the rolled blade of a carnivorous pitcher plant. Despite the variation in size, shape, an...

  20. Rolling Reloaded

    ERIC Educational Resources Information Center

    Jones, Simon A.; Nieminen, John M.

    2008-01-01

    Not so long ago a new observation about rolling motion was described: for a rolling wheel, there is a set of points with instantaneous velocities directed at or away from the centre of the wheel; these points form a circle whose diameter connects the centre of the wheel to the wheel's point of contact with the ground (Sharma 1996 "Eur. J. Phys."…

  1. 14 CFR 23.157 - Rate of roll.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rate of roll. 23.157 Section 23.157... Maneuverability § 23.157 Rate of roll. (a) Takeoff. It must be possible, using a favorable combination of controls, to roll the airplane from a steady 30-degree banked turn through an angle of 60 degrees, so as...

  2. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  3. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  4. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  5. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  6. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  7. Effect of temper rolling on final shape defects in a V-section roll forming process

    NASA Astrophysics Data System (ADS)

    Abvabi, Akbar; Rolfe, Bernard; Hodgson, Peter D.; Weiss, Matthias

    2013-12-01

    Roll forming is a continuous process in which a flat strip is shaped to the desired profile by sequential bending in a series of roll stands. Because of the large variety of applications of roll forming in the industry, Finite Element Analysis (FEA) is increasingly utilized for roll forming process design. Bending is the dominant deformation mode in roll forming. Sheet materials used in this process are generally temper rolled, roller- or tension- leveled. These processes introduce residual stresses into the material, and recent studies have shown that those affect the material behavior in bending. In this study a numerical model of the temper rolling (skin passing) process was used to determine a residual stress distribution in a dual phase, DP780, steel strip. A 5-stand roll forming process for the forming of a V-section was modeled, and the effect of various thickness reduction levels in the temper rolling process on the final shape defects was analyzed. The results show that a small thickness reduction in the temper rolling process decreases the maximum bow height but the final springback angle increases. It is also shown that reasonable model accuracy can be achieved by including the residual stress information due to temper rolling as initial condition in the numerical modeling of a roll forming process.

  8. Rolling Moments Due to Rolling and Yaw for Four Wing Models in Rotation

    NASA Technical Reports Server (NTRS)

    Knight, Montgomery; Wenzinger, Carl J

    1932-01-01

    This report presents the results of a series of autorotation and torque tests on four different rotating wing systems at various rates of roll and at several angles of yaw. The investigation covered an angle of attack range up to 90 degrees and angles of yaw of 0 degree, 5 degrees, 10 degrees, and 20 degrees. The tests were made in a 5-foot, closed-throat atmospheric wind tunnel. The object of the tests was primarily to determine the effects of various angles of yaw on the rolling moments of the rotating wings up to large angles of attack. It was found that at angles of attack above that of maximum lift the rolling moments on the wings due to yaw (or side slip) from 5 degrees to 20 degrees were roughly of the same magnitude as those due to rolling. There was a wide variation in magnitude of the rolling moment due to yaw angle. The rates and ranges of stable autorotation for the monoplane models were considerably increased by yaw, whereas for an unstaggered biplane they were little affected. The immediate cause of the rolling moment due to yaw is apparently the building up of large loads on the forward wing tip and the reduction of loads on the rearward wing tip.

  9. CONTROL FOR ROLLING MILL

    DOEpatents

    Shuck, A.B.; Shaw, W.C.

    1961-06-20

    A plutonium-rolling apparatus is patented that has two sets of feed rolls, shaping rolls between the feed rolls, and grippers beyond the feed rolls, which ready a workpiece for a new pass through the shaping rolls by angularly shifting the workpiece about its axis or transversely moving it on a line parallel to the axes of the shaping rolls. Actuation of each gripper for gripping or releasing the workpiece is produced by the relative positions assumed by the feed rolls adjacent to the gripper as the workpiece enters or leaves the feed rolls.

  10. Silk gland gene expression during larval-pupal transitionin the cotton leaf roller Sylepta derogate (Lepidoptera: pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cotton leaf roller, Sylepta derogata, is a silk-producing insect pest. While young larvae feed on the underside of leaves, the older ones roll cotton leaves and feed on the leaf edges, which defoliates cotton plants. The larvae produce silk to stabilize the rolled leaf and to balloon from used t...

  11. Rolling process for producing biaxially textured substrates

    DOEpatents

    Goyal, Amit

    2004-05-25

    A method of preparing a biaxially textured article includes the steps of: rolling a metal preform while applying shear force thereto to form as-rolled biaxially textured substrate having an a rotated cube texture wherein a (100) cube face thereof is parallel to a surface of said substrate, and wherein a [100] direction thereof is at an angle of at least 30.degree. relative to the rolling direction; and depositing onto the surface of the biaxially textured substrate at least one epitaxial layer of another material to form a biaxially textured article.

  12. Rolling-Element Bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1983-01-01

    Rolling element bearings are a precision, yet simple, machine element of great utility. A brief history of rolling element bearings is reviewed and the type of rolling element bearings, their geometry and kinematics, as well as the materials they are made from and the manufacturing processes they involve are described. Unloaded and unlubricated rolling element bearings, loaded but unlubricated rolling element bearings and loaded and lubricated rolling element bearings are considered. The recognition and understanding of elastohydrodynamic lubrication covered, represents one of the major development in rolling element bearings.

  13. Measurements of canard-induced roll oscillations

    NASA Technical Reports Server (NTRS)

    Katz, J.; Levin, D.

    1985-01-01

    A small canard wing was installed in front of a delta wing which was mounted on a free-to-roll sting balance in a low-speed wind tunnel. The leading edge vortices, originating from the canard, enhanced self-induced roll oscillations at test conditions for which the basic delta wing would otherwise have been stable. Time-dependent roll angle, and normal and side force data recorded during these oscillations are presented along with their phase relations. It was found that the canard increased the range of angle of attack at which self-induced oscillations occurred. Also, at an angle of attack of about 46 deg asymmetric oscillations are observed.

  14. Texture Evolution of a Non-oriented Electrical Steel Cold Rolled at Directions Different from the Hot Rolling Direction

    NASA Astrophysics Data System (ADS)

    He, Youliang; Hilinski, Erik; Li, Jian

    2015-11-01

    With the objective of optimizing the crystallographic texture of non-oriented electrical steel, i.e., reducing the <111>//ND and <110>//RD fibers and promoting the <001>//ND texture, a new rolling scheme was proposed and tested, in which the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) in order to change the orientation flow paths during cold rolling and alter the final texture of the annealed sheets. A non-oriented electrical steel containing 0.88 wt pct Si was hot rolled using conventional routes and annealed, and a number of rectangular plates were cut from the hot band with the longitudinal directions inclined at various angles, i.e., 0, 15, 30, 45, 60, 75, and 90 deg, to the HRD. These plates were then cold rolled along the longitudinal directions with a thickness reduction of 72 pct. The cold-rolled samples were annealed, temper rolled and annealed again (final annealing). The texture evolution during hot rolling, hot band annealing, cold rolling, and final annealing was characterized by electron backscatter diffraction and X-ray diffraction techniques. By changing the CRD with respect to the HRD, the initial texture and the orientation flow paths were altered, which resulted in apparent differences in the textures as compared to conventional cold rolling. After temper rolling and final annealing, the recrystallization textures consisted of mainly a <001>//ND fiber and there was almost no <111>//ND fiber. The sample cold rolled at an angle of 60 deg to the HRD had the strongest texture (intensity almost 2× of conventional rolling) with a maximum at the cube {001}<100> orientation—a magnetically favorable orientation for non-oriented electrical steels.

  15. Comparison of half and full-leaf shape feature extraction for leaf classification

    NASA Astrophysics Data System (ADS)

    Sainin, Mohd Shamrie; Ahmad, Faudziah; Alfred, Rayner

    2016-08-01

    Shape is the main information for leaf feature that most of the current literatures in leaf identification utilize the whole leaf for feature extraction and to be used in the leaf identification process. In this paper, study of half-leaf features extraction for leaf identification is carried out and the results are compared with the results obtained from the leaf identification based on a full-leaf features extraction. Identification and classification is based on shape features that are represented as cosines and sinus angles. Six single classifiers obtained from WEKA and seven ensemble methods are used to compare their performance accuracies over this data. The classifiers were trained using 65 leaves in order to classify 5 different species of preliminary collection of Malaysian medicinal plants. The result shows that half-leaf features extraction can be used for leaf identification without decreasing the predictive accuracy.

  16. 4. ROLL LATHE OF THE MAIN ROLL SHOP. THE LATHE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. ROLL LATHE OF THE MAIN ROLL SHOP. THE LATHE WAS CLOSED WITH TWO ROLLS IN PLACE, AND THE LOWER ROLL WAS TURNED TO MATCH THE UPPER ROLL. - U.S. Steel Homestead Works, Main Roll Shop, Along Monongahela River, Homestead, Allegheny County, PA

  17. Effect of herbivore damage on broad leaf motion in wind

    NASA Astrophysics Data System (ADS)

    Burnett, Nicholas; Kothari, Adit

    2015-11-01

    Terrestrial plants regularly experience wind that imposes aerodynamic forces on the plants' leaves. Passive leaf motion (e.g. fluttering) and reconfiguration (e.g. rolling into a cone shape) in wind can affect the drag on the leaf. In the study of passive leaf motion in wind, little attention has been given to the effect of herbivory. Herbivores may alter leaf motion in wind by making holes in the leaf. Also, a small herbivore (e.g. snail) on a leaf can act as a point mass, thereby affecting the leaf's motion in wind. Conversely, accelerations imposed on an herbivore sitting on a leaf by the moving leaf may serve as a defense by dislodging the herbivore. In the present study, we investigated how point masses (>1 g) and holes in leaves of the tuliptree affected passive leaf motion in turbulent winds of 1 and 5 m s-1. Leaf motion was unaffected by holes in the leaf surface (about 10% of leaf area), but an herbivore's mass significantly damped the accelerations of fluttering leaves. These results suggest that an herbivore's mass, but not the damage it inflicts, can affect leaf motion in the wind. Furthermore, the damping of leaf fluttering from an herbivore's mass may prevent passive leaf motions from being an effective herbivore defense.

  18. Leaf Angle, Light Interception, and Water Relations.

    ERIC Educational Resources Information Center

    Knapp, Alan K.; Smith, Dixie L.

    1997-01-01

    Presents an exercise that demonstrates how plants cope with multiple resource limitations in the field. Stimulates students to think about interactions among multiple limited resources and the challenges plants as immobile organisms face when characteristics that increase the capture of one resource negatively impact the availability of another.…

  19. Facility No. 175, interior detail showing rolling doors, trusses, and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Facility No. 175, interior detail showing rolling doors, trusses, and angled monitor roof - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

  20. Internal roll compression system

    DOEpatents

    Anderson, Graydon E.

    1985-01-01

    This invention is a machine for squeezing water out of peat or other material of low tensile strength; the machine including an inner roll eccentrically positioned inside a tubular outer roll, so as to form a gradually increasing pinch area at one point therebetween, so that, as the rolls rotate, the material is placed between the rolls, and gets wrung out when passing through the pinch area.

  1. Rolling Friction on a Wheeled Laboratory Cart

    ERIC Educational Resources Information Center

    Mungan, Carl E.

    2012-01-01

    A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

  2. Measurement method for roll angular displacement with a high resolution by using diffraction gratings and a heterodyne interferometer

    SciTech Connect

    Tang, Shanzhi; Wang, Zhao; Gao, Jianmin; Guo, Junjie

    2014-04-15

    The roll angle measurement is difficult to be achieved directly using a typical commercial interferometer due to its low sensitivity in axial direction, where the axial direction is orthogonal to the plane of the roll angular displacement. A roll angle measurement method combined diffraction gratings with a laser heterodyne interferometer is discussed in this paper. The diffraction grating placed in the plane of a roll angular displacement and the interferometer arranged in the plane's orthogonal direction, constitute the measurement pattern for the roll angle with high resolution. The roll angular displacement, considered as the linear, can be tested precisely when the corresponding angle is very small. Using the proposed method, the angle roll measurement obtains the high resolution of 0.002{sup ″}. Experiment has proved its feasibility and practicability.

  3. The Effects of Forming Parameters on Conical Ring Rolling Process

    PubMed Central

    Meng, Wen; Zhao, Guoqun; Guan, Yanjin

    2014-01-01

    The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the “obtuse angle zone” of ring's cross-section are higher than those at “acute angle zone”; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained. PMID:25202716

  4. 'Magic Angle Precession'

    SciTech Connect

    Binder, Bernd

    2008-01-21

    An advanced and exact geometric description of nonlinear precession dynamics modeling very accurately natural and artificial couplings showing Lorentz symmetry is derived. In the linear description it is usually ignored that the geometric phase of relativistic motion couples back to the orbital motion providing for a non-linear recursive precession dynamics. The high coupling strength in the nonlinear case is found to be a gravitomagnetic charge proportional to the precession angle and angular velocity generated by geometric phases, which are induced by high-speed relativistic rotations and are relevant to propulsion technologies but also to basic interactions. In the quantum range some magic precession angles indicating strong coupling in a phase-locked chaotic system are identified, emerging from a discrete time dynamical system known as the cosine map showing bifurcations at special precession angles relevant to heavy nuclei stability. The 'Magic Angle Precession' (MAP) dynamics can be simulated and visualized by cones rolling in or on each other, where the apex and precession angles are indexed by spin, charge or precession quantum numbers, and corresponding magic angles. The most extreme relativistic warping and twisting effect is given by the Dirac spinor half spin constellation with 'Hyperdiamond' MAP, which resembles quark confinement.

  5. Multilayer roll bonded aluminium foil: processing, microstructure and flow stress

    SciTech Connect

    Barlow, C.Y.; Nielsen, P.; Hansen, N

    2004-08-02

    Bulk aluminium has been produced by warm-rolling followed by cold-rolling of commercial purity (99% purity) aluminium foil. The bonding appeared perfect from observation with the naked eye, light and transmission electron microscopy. By comparison with bulk aluminium of similar purity (AA1200) rolled to a similar strain (90%RA), the roll-bonded metal showed a much higher density of high-angle grain boundaries, similar strength and improved thermal stability. This study has implications for a number of applications in relation to the processing of aluminium. Roll bonding is of interest as a method for grain size refinement; oxide-containing materials have increased strength, enhanced work-hardening behaviour, and exhibit alterations in recrystallisation behaviour. The behaviour of the hard oxide film is of interest in aluminium processing, and has been investigated by characterising the size and distribution of oxide particles in the roll-bonded samples.

  6. TECHNICAL NOTE: Multiple-degrees-of-freedom electroelastomer roll actuators

    NASA Astrophysics Data System (ADS)

    Pei, Qibing; Rosenthal, Marcus; Stanford, Scott; Prahlad, Harsha; Pelrine, Ron

    2004-10-01

    Electroelastomers (electroactive elastomers) such as the 3M VHB 4910 acrylic adhesive films have exhibited up to 380% strain in area expansion at 5 6 kV when they are highly prestrained. By rolling highly prestrained electroelastomer films around a compression spring, we have demonstrated multifunctional electroelastomer rolls (MERs, or spring rolls) that combine load bearing, actuation, and sensing functions. We extended the design to two-degree-of-freedom (2-DOF) and 3-DOF spring rolls by patterning the electrodes to align radially on two and four circumferential spans of the rolls, respectively. Multiple-DOF spring rolls retain the linear actuation of 1-DOF spring rolls with additional bending actuation. Mathematical equations are derived to correlate the bending angle and lateral force of the rolls with the actuated stroke in one of the electroded spans. Two-DOF spring rolls with a 1.4 cm outside diameter, 6.8 cm axial length, and 11 g weight have been fabricated; these rolls have a 90° maximum actuation bending angle, 0.7 N maximum lateral force, and up to 15 N blocked axial force. Three-DOF spring rolls with a 2.3 cm outside diameter, 9.0 cm axial length, and 29 g weight exhibit a 35° maximum bending angle and 1.0 N maximum lateral force. These specifications can be modified by variations in roll parameters according to the equations. Multi-DOF spring rolls are easy to fabricate, compact, multifunctional, and mechanically robust. They represent a radically new actuation technology and may enable a number of unique applications. We have demonstrated a small walking robot, MERbot, with one 2-DOF spring roll as each of its six legs. The robot's speed is as high as 13.6 cm s-1 or two-thirds of its length per second. 'Sushi rolls' have also been fabricated: these consist of six 2-DOF springs connected in series and monolithic in structure. The sushi rolls can be driven so as to generate wavelike or serpentine motion.

  7. Kinematics and aerodynamics of the velocity vector roll

    NASA Technical Reports Server (NTRS)

    Durham, Wayne C.; Lutze, Frederick H.; Mason, W.

    1993-01-01

    The velocity vector roll is an angular rotation of an aircraft about its instantaneous velocity vector, constrained to be performed at constant angle-of-attack (AOA), no sideslip, and constant velocity. Consideration of the aerodynamic force equations leads to requirements for body-axis yawing and pitching rotations that satisfy these constraints. Here, the body axis rotations, and the constraints, are used in the moment equations to determine the aerodynamic moments required to perform the velocity vector roll. For representative tactical aircraft, the conditions for maximum pitching moment are a function of orientation, occurring at about 90 deg of bank in a level trajectory. Maximum required pitching moment occurs at peak roll rate, and is achieved at AOA above 45 deg. The conditions for maximum rolling moment depend on the value of the roll mode time constant. For a small time constant (fast response) the maximum rolling moment occurs at maximum roll acceleration and zero AOA, largely independent of aircraft orientation; for a large time constant, maximum required rolling moment occurs at maximum roll rate, at maximum AOA, and at 180 deg of bank in level flight. Maximum yawing moment occurs at maximum roll acceleration, maximum AOA, and is largely independent of airplane orientation.

  8. How to pattern a leaf.

    PubMed

    Bolduc, N; O'Connor, D; Moon, J; Lewis, M; Hake, S

    2012-01-01

    Leaf development presents a tremendous resource for tackling the question of patterning in biology. Leaves can be simple or highly dissected. They may have elaborated parts such as the tendrils of a pea leaf or the rolled blade of a carnivorous pitcher plant. Despite the variation in size, shape, and function, all leaves initiate in the same manner: from the flanks of a meristem. The maize leaf is useful for analysis of patterning due to the wealth of mutants and the distinct tissues along the proximal distal axis. The blade is distal, the sheath is proximal, and the ligule forms at the blade/sheath boundary. Establishment of this boundary involves the transcription factors LIGULELESS1 and LIGULELESS2 and the kinase LIGULELESS NARROW. The meristem-specific protein KNOTTED1 (KN1) binds and modulates the lg2 gene. Given the localization of KN1 at the proximal end of the leaf from the time of inception, we hypothesize that KN1 has a role in establishing the very proximal end of the leaf, whereas an auxin maximum guides the growing distal tip. PMID:23174765

  9. Conical Euler analysis and active roll suppression for unsteady vortical flows about rolling delta wings

    NASA Technical Reports Server (NTRS)

    Lee-Rausch, Elizabeth M.; Batina, John T.

    1993-01-01

    A conical Euler code was developed to study unsteady vortex-dominated flows about rolling, highly swept delta wings undergoing either forced motions or free-to-roll motions that include active roll suppression. The flow solver of the code involves a multistage, Runge-Kutta time-stepping scheme that uses a cell-centered, finite-volume, spatial discretization of the Euler equations on an unstructured grid of triangles. The code allows for the additional analysis of the free to-roll case by simultaneously integrating in time the rigid-body equation of motion with the governing flow equations. Results are presented for a delta wing with a 75 deg swept, sharp leading edge at a free-stream Mach number of 1.2 and at 10 deg, 20 deg, and 30 deg angle of attack alpha. At the lower angles of attack (10 and 20 deg), forced-harmonic analyses indicate that the rolling-moment coefficients provide a positive damping, which is verified by free-to-roll calculations. In contrast, at the higher angle of attack (30 deg), a forced-harmonic analysis indicates that the rolling-moment coefficient provides negative damping at the small roll amplitudes. A free-to-roll calculation for this case produces an initially divergent response, but as the amplitude of motion grows with time, the response transitions to a wing-rock type of limit cycle oscillation, which is characteristic of highly swept delta wings. This limit cycle oscillation may be actively suppressed through the use of a rate-feedback control law and antisymmetrically deflected leading-edge flaps. Descriptions of the conical Euler flow solver and the free-to roll analysis are included in this report. Results are presented that demonstrate how the systematic analysis of the forced response of the delta wing can be used to predict the stable, neutrally stable, and unstable free response of the delta wing. These results also give insight into the flow physics associated with unsteady vortical flows about delta wings undergoing forced

  10. One pot synthesis of opposing 'rose petal' and 'lotus leaf' superhydrophobic materials with zinc oxide nanorods.

    PubMed

    Myint, Myo Tay Zar; Hornyak, Gabor L; Dutta, Joydeep

    2014-02-01

    The synthesis in one pot(1) of opposing 'rose petal' and 'lotus leaf' superhydrophobic materials from commercially available superhydrophilic cloth substrates of varying texture is described for the first time. Surfaces of 'rough' textured cloth and 'smooth' textured cloth were simultaneously rendered superhydrophobic by growing zinc oxide (ZnO) nanorods by a hydrothermal process in the same chemical bath. Contact angle hysteresis and water pendant drop tests revealed strong water adhesion to ZnO microrod-treated rough cloth. The combination of water contact angle >150° and strong adhesion is indicative of the 'rose petal effect' with potential for water pinning. Smooth cloth with ZnO nanorods exhibited no adhesion to water droplets with facilitative roll-off. The combination of water contact angle >150° and weak to no adhesion with water is indicative of the 'lotus leaf effect' with potential for self-cleaning. Pendant water drop tests indicated cohesive failure of water on rough cloth coated with ZnO nanorods. Natural rose petals demonstrated adhesive failure between the petal surface and water droplet. A parsimonious explanation is presented. We also describe the development of superhydrophobic clothes without the need for special conditions or further chemical modification. PMID:24267327

  11. Detail of east rolling segment showing track girder, rolling panels ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of east rolling segment showing track girder, rolling panels and counter weights. View west - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  12. Leaf Development

    PubMed Central

    2013-01-01

    Leaves are the most important organs for plants. Without leaves, plants cannot capture light energy or synthesize organic compounds via photosynthesis. Without leaves, plants would be unable perceive diverse environmental conditions, particularly those relating to light quality/quantity. Without leaves, plants would not be able to flower because all floral organs are modified leaves. Arabidopsis thaliana is a good model system for analyzing mechanisms of eudicotyledonous, simple-leaf development. The first section of this review provides a brief history of studies on development in Arabidopsis leaves. This history largely coincides with a general history of advancement in understanding of the genetic mechanisms operating during simple-leaf development in angiosperms. In the second section, I outline events in Arabidopsis leaf development, with emphasis on genetic controls. Current knowledge of six important components in these developmental events is summarized in detail, followed by concluding remarks and perspectives. PMID:23864837

  13. Controlling roll perturbations in fruit flies.

    PubMed

    Beatus, Tsevi; Guckenheimer, John M; Cohen, Itai

    2015-04-01

    Owing to aerodynamic instabilities, stable flapping flight requires ever-present fast corrective actions. Here, we investigate how flies control perturbations along their body roll angle, which is unstable and their most sensitive degree of freedom. We glue a magnet to each fly and apply a short magnetic pulse that rolls it in mid-air. Fast video shows flies correct perturbations up to 100° within 30 ± 7 ms by applying a stroke-amplitude asymmetry that is well described by a linear proportional-integral controller. For more aggressive perturbations, we show evidence for nonlinear and hierarchical control mechanisms. Flies respond to roll perturbations within 5 ms, making this correction reflex one of the fastest in the animal kingdom. PMID:25762650

  14. Controlling roll perturbations in fruit flies

    PubMed Central

    Beatus, Tsevi; Guckenheimer, John M.; Cohen, Itai

    2015-01-01

    Owing to aerodynamic instabilities, stable flapping flight requires ever-present fast corrective actions. Here, we investigate how flies control perturbations along their body roll angle, which is unstable and their most sensitive degree of freedom. We glue a magnet to each fly and apply a short magnetic pulse that rolls it in mid-air. Fast video shows flies correct perturbations up to 100° within 30 ± 7 ms by applying a stroke-amplitude asymmetry that is well described by a linear proportional–integral controller. For more aggressive perturbations, we show evidence for nonlinear and hierarchical control mechanisms. Flies respond to roll perturbations within 5 ms, making this correction reflex one of the fastest in the animal kingdom. PMID:25762650

  15. Leaf Shape Recognition using Centroid Contour Distance

    NASA Astrophysics Data System (ADS)

    Hasim, Abdurrasyid; Herdiyeni, Yeni; Douady, Stephane

    2016-01-01

    This research recognizes the leaf shape using Centroid Contour Distance (CCD) as shape descriptor. CCD is an algorithm of shape representation contour-based approach which only exploits boundary information. CCD calculates the distance between the midpoint and the points on the edge corresponding to interval angle. Leaf shapes that included in this study are ellips, cordate, ovate, and lanceolate. We analyzed 200 leaf images of tropical plant. Each class consists of 50 images. The best accuracy is obtained by 96.67%. We used Probabilistic Neural Network to classify the leaf shape. Experimental results demonstrated the effectiveness of the proposed approach for shape recognition with high accuracy.

  16. Understanding Rolle's Theorem

    ERIC Educational Resources Information Center

    Parameswaran, Revathy

    2009-01-01

    This paper reports on an experiment studying twelfth grade students' understanding of Rolle's Theorem. In particular, we study the influence of different concept images that students employ when solving reasoning tasks related to Rolle's Theorem. We argue that students' "container schema" and "motion schema" allow for rich concept images.…

  17. OsLBD3-7 Overexpression Induced Adaxially Rolled Leaves in Rice

    PubMed Central

    Zhang, Chunyu; Shao, Qinghao; Liu, Jun; Liu, Bin; Li, Hongyu

    2016-01-01

    Appropriate leaf rolling enhances erect-leaf habits and photosynthetic efficiency, which consequently improves grain yield. Here, we reported the novel lateral organ boundaries domain (LBD) gene OsLBD3-7, which is involved in the regulation of leaf rolling. OsLBD3-7 works as a transcription activator and its protein is located on the plasma membrane and in the nucleus. Overexpression of OsLBD3-7 leads to narrow and adaxially rolled leaves. Microscopy of flag leaf cross-sections indicated that overexpression of OsLBD3-7 led to a decrease in both bulliform cell size and number. Transcriptional analysis showed that key genes that had been reported to be negative regulators of bulliform cell development were up-regulated in transgenic plants. These results indicated that OsLBD3-7 might acts as an upstream regulatory gene of bulliform cell development to regulate leaf rolling, which will give more insights on the leaf rolling regulation mechanism. PMID:27258066

  18. Thermomechanical Behavior of Work Rolls During Warm Strip Rolling

    NASA Astrophysics Data System (ADS)

    Khalili, L.; Serajzadeh, S.; Koohbor, B.

    2012-12-01

    A mathematical model was developed to assess thermomechanical behavior of work rolls during warm rolling processes. A combined finite element analysis-slab method was first developed to determine thermal and mechanical responses of the strip being rolled under steady-state conditions, and then, the calculated roll pressure and temperature field were utilized as the governing boundary conditions for the thermomechanical problem of the work roll. Finally, the thermomechanical stresses within the work rolls were predicted by a thermoelastic finite element approach. The results of the model indicate that, in warm strip rolling, thermal and mechanical stresses developed in the work rolls are comparable, and thus, both thermal and mechanical aspects of the problem should be considered in such a problem. Besides, the model was shown to be capable of determining the effects of various rolling parameters on the thermomechanical behavior of the work rolls during warm rolling process.

  19. What's Your Angle on Angles?

    ERIC Educational Resources Information Center

    Browning, Christine A.; Garza-Kling, Gina; Sundling, Elizabeth Hill

    2007-01-01

    Although the nature of the research varies, as do concepts of angle, research in general supports the supposition that angle is a complex idea, best understood from a variety of perspectives. In fact, the concept of angle tends to be threefold, consisting of: (1) the traditional, static notion of two rays meeting at a common vertex; (2) the idea…

  20. Wind-tunnel investigation at supersonic speeds of a canard-controlled missile with fixed and free-rolling tail fins

    NASA Technical Reports Server (NTRS)

    Blair, A. B., Jr.

    1978-01-01

    A wind tunnel investigation was made at free stream Mach numbers from 1.70 to 2.86 to determine the effects of fixed and free rolling tail fin afterbodies on the static longitudinal and lateral aerodynamic characteristics of a cruciform canard controlled missile model. The effect of small canard roll and yaw control deflections was also examined. The results indicate that the fixed and free rolling tail configurations have about the same lift curve slope and longitudinal stability level at low angles of attack. For the free rolling tail configuration, the canards provide conventional roll control with no roll control reversal at low angles of attack. The free rolling tail configuration reduced induced roll due to model roll angle and canard yaw control.

  1. Scavenging of reactive oxygen species in apoplastic and symplastic areas of rolled leaves in Ctenanthe setosa under drought stress.

    PubMed

    Saruhan, Neslihan; Terzi, Rabiye; Sağlam, Aykut; Kadioğlu, Asim

    2010-09-01

    The correspondence among apoplastic and symplastic antioxidant status, stomatal conductance and water potential was investigated during leaf rolling in Ctenanthe setosa (Rosc.) Eichler (Marantaceae) under drought stress. Apoplastic and symplastic extractions of leaf and petiole were performed at different visual leaf rolling scores from 1 to 4 (1 is unrolled, 4 is tightly rolled and the others are intermediate form). In the leaf symplast, the highest changes were found in catalase (CAT) and guaiacol peroxidase (GPX) activities when compared to score 1 during leaf rolling. No significant change was observed in superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities in the symplast of leaf during the rolling. The same phenomenon was also present in the symplast of petiole except APX activity. In the leaf apoplast, the highest increase occurred in APX and GPX activities, whilst a slight increase in CAT and SOD activities. In the apoplast of petiole, the highest increment was found only in GPX activity, while there were small increases in SOD, APX and CAT activities. Hydrogen peroxide content increased up to score 3 in the apoplast and symplast of leaf and petiole but then slightly decreased. Also, superoxide production increased in the leaf and petiole apoplast but its quantity in the apoplast was much more than that of the symplast. On the other hand, NAD(P)H oxidase activity increased in the leaf but no change was observed in the petiole. In conclusion, as a result of water deficit during leaf rolling antioxidant enzymes are induced to scavenging of ROS produced in symplast and apoplast. PMID:20724275

  2. Roll-to-roll embossing of optical linear Fresnel lens polymer film for solar concentration.

    PubMed

    Zhang, XinQuan; Liu, Kui; Shan, Xuechuan; Liu, Yuchan

    2014-12-15

    Roll-to-roll manufacturing has been proven to be a high-throughput and low-cost technology for continuous fabrication of functional optical polymer films. In this paper, we have firstly studied a complete manufacturing cycle of linear Fresnel lens polymer film for solar concentration in the aspects of ultra-precision diamond machining of metal roller mold, roll-to-roll embossing, and measurement on film profile and functionality. A metal roller mold patterned with linear Fresnel lenses is obtained using single point diamond turning technique. The roller mold is installed onto a self-developed roll-to-roll UV embossing system to realize continuous manufacturing of linear Fresnel lens film. Profile measurement of the machined roller mold and the embossed polymer film, which is conducted using a stylus profilometer, shows good agreement between measured facet angles with designed ones. Functionality test is conducted on a solar simulation system with a reference solar cell, and results show that strong light concentration is realized. PMID:25607497

  3. Effect of Roll Material on Surface Quality of Rolled Aluminum

    NASA Astrophysics Data System (ADS)

    Zhao, Qi

    The surface defects of aluminum alloys that have undergone hot rolling were studied. The effects of different roll materials, of the number of rolling passes and of lubrication on surface defects of hot rolled aluminum alloys were investigated by laboratory hot rolling. Two different aluminum alloys, Al-Mn and Al-Mg, were each rolled against three different steel alloy rolls, AISI 52100, AISI 440C and AISI D2. The results showed that different roll materials do affect the morphology of the mating aluminum alloy surface with apparent surface defects, which included magnesium and oxygen rich dark regions on both alloys. The carbide protrusions in 440C and D2 steel rolls are confirmed to be responsible for the dark, rich magnesium and oxygen regions on both the rolled Al-Mn and Al-Mg alloy surfaces. As the number of passes increases, Mg and O deposit in the form of patches and grain boundaries near the surface area.

  4. Correcting Quadrupole Roll in Magnetic Lenses with Skew Quadrupoles

    SciTech Connect

    Walstrom, Peter Lowell

    2014-11-10

    Quadrupole rolls (i.e. rotation around the magnet axis) are known to be a significant source of image blurring in magnetic quadrupole lenses. These rolls may be caused by errors in mechanical mounting of quadrupoles, by uneven radiation-induced demagnetization of permanent-magnet quadrupoles, etc. Here a four-quadrupole ×10 lens with so-called ”Russian” or A -B B-A symmetry is used as a model problem. Existing SLAC 1/2 in. bore high-gradient quadrupoles are used in the design. The dominant quadrupole roll effect is changes in the first-order part of the transfer map (the R matrix) from the object to the image plane (Note effects on the R matrix can be of first order in rotation angle for some R-matrix elements and second order in rotation angle for other elements, as shown below). It is possible to correct roll-induced image blur by mechanically adjusting the roll angle of one or more of the quadrupoles. Usually, rotation of one quadrupole is sufficient to correct most of the combined effect of rolls in all four quadrupoles. There are drawbacks to this approach, however, since mechanical roll correction requires multiple entries into experimental area to make the adjustments, which are made according to their effect on images. An alternative is to use a single electromagnetic skew quadrupole corrector placed either between two of the quadrupoles or after the fourth quadrupole (so-called “non-local” correction). The basic feasibility of skew quadrupole correction of quadrupole roll effects is demonstrated here. Rolls of the third lens quadrupole of up to about 1 milliradian can be corrected with a 15 cm long skew quadrupole with a gradient of up to 1 T/m. Since the effect of rolls of the remaining three lens quadrupoles are lower, a weaker skew quadrupole can be used to correct them. Non-local correction of quadrupole roll effects by skew quadrupoles is shown to be about one-half as effective as local correction (i.e. rotating individual quadrupoles to zero

  5. Biomechanics of leukocyte rolling.

    PubMed

    Sundd, Prithu; Pospieszalska, Maria K; Cheung, Luthur Siu-Lun; Konstantopoulos, Konstantinos; Ley, Klaus

    2011-01-01

    Leukocyte rolling on endothelial cells and other P-selectin substrates is mediated by P-selectin binding to P-selectin glycoprotein ligand-1 expressed on the tips of leukocyte microvilli. Leukocyte rolling is a result of rapid, yet balanced formation and dissociation of selectin-ligand bonds in the presence of hydrodynamic shear forces. The hydrodynamic forces acting on the bonds may either increase (catch bonds) or decrease (slip bonds) their lifetimes. The force-dependent 'catch-slip' bond kinetics are explained using the 'two pathway model' for bond dissociation. Both the 'sliding-rebinding' and the 'allosteric' mechanisms attribute 'catch-slip' bond behavior to the force-induced conformational changes in the lectin-EGF domain hinge of selectins. Below a threshold shear stress, selectins cannot mediate rolling. This 'shear-threshold' phenomenon is a consequence of shear-enhanced tethering and catch bond-enhanced rolling. Quantitative dynamic footprinting microscopy has revealed that leukocytes rolling at venular shear stresses (>0.6 Pa) undergo cellular deformation (large footprint) and form long tethers. The hydrodynamic shear force and torque acting on the rolling cell are thought to be synergistically balanced by the forces acting on tethers and stressed microvilli, however, their relative contribution remains to be determined. Thus, improvement beyond the current understanding requires in silico models that can predict both cellular and microvillus deformation and experiments that allow measurement of forces acting on individual microvilli and tethers. PMID:21515934

  6. Unsteady Aerodynamics of ``Roll-Tacking'' in Olympic Class Sailboats

    NASA Astrophysics Data System (ADS)

    Schutt, Riley; Williamson, Chk

    2015-11-01

    When tacking a sailboat (turning a boat through the wind during upwind sailing), racers employ a ``roll-tacking'' technique. During a roll-tack, sailors use body weight movements to roll the boat through extreme angles of heel. This contrasts with a flat-tack, where the boat remains upright throughout the turn. The dynamic heeling motion of a roll-tack causes the sail to vigorously sweep through the air, resulting in large-scale vortex shedding and increased propulsion. In this research, we use a characteristic roll-tack motion derived from on-the-water data. On-the-water data is collected from a full-scale Olympic racing boat sailed by a national champion in the Laser sailboat class. Using this data, we run a series of representative experiments in the laboratory. Two dimensional flexible sail extrusions are built using rapid-prototyping and are tested in a three degree-of-freedom (X, Y, and theta) towing tank. Particle Image Velocimetry and force measurements are used to compare vortex dynamics and propulsive forces generated by roll-tacks versus flat-tacks. An increase in thrust observed during roll-tack tests agrees with on-the-water experiments, which show a racing advantage greater than one boatlength when a roll-tack is performed relative to a flat tack.

  7. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  8. Studies on the influence of surface morphology of ZnO nail beds on easy roll off of water droplets

    NASA Astrophysics Data System (ADS)

    Sutha, S.; Vanithakumari, S. C.; George, R. P.; Mudali, U. Kamachi; Raj, Baldev; Ravi, K. R.

    2015-08-01

    A ZnO nanorods based superhydrophobic surface with extremely low roll-off angle is fabricated using a two-step solution based approach-Successive Ionic Layer Adsorption and Reaction (SILAR) and Chemical Bath Deposition (CBD). The grown ZnO nanorods have average diameter of 285 nm with a predominant growth direction of [002]. The static contact angle of ZnO nanorods superhydrophobic surface is 155°, and the dynamic contact angles contact angle hysteresis and roll-off angle is 2° and 1°, respectively. Furthermore, to comprehend the mechanism governing the extremely low roll-off angle of ZnO nanorods based superhydrophobic surface, an analytical model has been developed by incorporating the topographical (diameter, density of nanorods and solid area fraction) and droplet parameters (surface tension, mass and volume). The theoretically calculated roll-off angle closely matches with the experimental results and reported results.

  9. Subsonic roll damping of a model with swept-back and swept-forward wings

    NASA Technical Reports Server (NTRS)

    Boyden, R. P.

    1978-01-01

    The aerodynamic roll damping and the yawing moment due to roll rate characteristics were investigated at subsonic speeds for a model with either sweptback or swept forward wings. The tests were made in the Langley high speed 7 by 10 foot tunnel for Mach numbers between 0.3 and 0.7. The configuration with a 60 deg sweptback wing had positive damping in roll up to the maximum test angle of attack of almost 20 deg. The 32 deg swept forward wing configuration had positive damping in roll at the lower angles of attack, but there was a decrease in damping and negative damping in roll was measured at the highest angles of attack.

  10. Sliding and Rolling: The Physics of a Rolling Ball.

    ERIC Educational Resources Information Center

    Hierrezuelo, J.; Carnero, C.

    1995-01-01

    Presents an approach that provides a simple and adequate procedure for introducing the concept of rolling friction. Discusses some aspects related to rolling motion that are the source of students' misconceptions. Presents several didactic suggestions. (JRH)

  11. Roll Utilization of an F-100A Airplane During Service Operational Flying

    NASA Technical Reports Server (NTRS)

    Matranga, Gene J.

    1959-01-01

    As a means of evaluating the roll utilization of a fighter airplane capable of supersonic speeds, an instrumented North American F-100A fighter airplane was flown by U.S. Air Force pilots at Nellis Air Force Base, NV, during 20 hours of service operational flying. Mach numbers up to 1.22 and altitudes up to 50,000 feet were realized in this investigation. Results of the study showed that except for high g barrel rolls performed as evasive maneuvers and rolls performed in acrobatic flying, rolling was utilized primarily as a means of changing heading. Acrobatic and air combat maneuvering produced the largest bank angles (1,200 deg), roll velocities (3.3 radians/sec), rolling accelerations (8 radians/sq sec) and sideslip angles (10.8 deg). Full aileron deflections were utilized on numerous occasions. Although high rolling velocities and accelerations also were experienced during several air-to-air gunnery missions, generally, air-to-air gunnery and air-to-ground gunnery and bombing required only two-thirds of maximum aileron deflection. The air-to-air gunnery and air combat maneuvers initiated from supersonic speeds utilized up to two-thirds aileron deflection and bank angles of less than 18 deg and resulted in rolling velocities and accelerations of 2 radians per second and 4.6 radians/sq sec, respectively. Rolling maneuvers were often initiated from high levels of normal acceleration, but from levels of negative normal acceleration only once.

  12. Texture comparison between cold rolled and cryogenically rolled pure copper

    NASA Astrophysics Data System (ADS)

    Lapeire, L.; Sidor, J.; Martinez Lombardia, E.; Verbeken, K.; De Graeve, I.; Terryn, H.; Kestens, L. A. I.

    2015-04-01

    Nowadays, there is a considerable scientific interest in bulk ultrafine grained materials, due to their potential for superior mechanical properties. One of the possible formation methods of nano-grained materials is cryogenic rolling. The influence of rolling at cryogenic temperatures has been investigated. Significant differences in the textures and the microstructures can be observed between the cryogenically rolled copper and conventionally cold rolled copper, reduced to the same thickness.

  13. METHOD OF ROLLING URANIUM

    DOEpatents

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  14. Angular and Linear Accelerations of a Rolling Cylinder Acted by an External Force

    ERIC Educational Resources Information Center

    Oliveira, V.

    2011-01-01

    The dynamics of a cylinder rolling on a horizontal plane acted on by an external force applied at an arbitrary angle is studied with emphasis on the directions of the acceleration of the centre-of-mass and the angular acceleration of the body. If rolling occurs without slipping, there is a relationship between the directions of these…

  15. Research on work roll thermal crown in cold rolling mill

    NASA Astrophysics Data System (ADS)

    Song, Lei; Shen, Mingang; Chen, Xuebo; Wang, Junsheng

    2013-05-01

    The factors which have influence on the work roll thermal crown in cold strip rolling are discussed. The heat transferring in three directions (radial axis and circumference) were considered for calculating the work roll thermal deformation. Therefore, it is a three dimensions unstable system for the work roll temperature calculation. The plastic deformation work and friction heat are calculated by the divided element and digital integration method. The simplified calculation model is built for the heat transferring along work roll. There are four zones for work roll heat transferring: roll gap zone air cooling zone emulsion zone rolls contact zone. The heat transferring between the zones is decided by the temperature difference. The inter temperature field and thermal deformation of work roll can be calculated by two-dimension finite difference method. The work roll temperature and thermal crown of actual application cold rolling mill are analyzed by the model. By the comparison between calculated values and measured values, the work roll thermal calculation model can meet the accuracy requirement of on-line control.

  16. Rocking and rolling: A can that appears to rock might actually roll

    NASA Astrophysics Data System (ADS)

    Srinivasan, Manoj; Ruina, Andy

    2008-12-01

    A beer bottle or soda can on a table, when slightly tipped and released, falls to an upright position and then rocks up to a somewhat opposite tilt. Superficially this rocking motion involves a collision when the flat circular base of the container slaps the table before rocking up to the opposite tilt. A keen eye notices that the after-slap rising tilt is not generally just diametrically opposite the initial tilt but is veered to one side or the other. Cushman and Duistermaat [Regular Chaotic Dyn. 11, 31 (2006)] recently noticed such veering when a flat disk with rolling boundary conditions is dropped nearly flat. Here, we generalize these rolling disk results to arbitrary axi-symmetric bodies and to frictionless sliding. More specifically, we study motions that almost but do not quite involve a face-down collision of the round container’s bottom with the tabletop. These motions involve a sudden rapid motion of the contact point around the circular base. Surprisingly, similar to the rolling disk, the net angle of motion of this contact point is nearly independent of initial conditions. This angle of turn depends simply on the geometry and mass distribution but not on the moment of inertia about the symmetry axis. We derive simple asymptotic formulas for this “angle of turn” of the contact point and check the result with numerics and with simple experiments. For tall containers (height much bigger than radius) the angle of turn is just over π and the sudden rolling motion superficially appears as a nearly symmetric collision leading to leaning on an almost diametrically opposite point on the bottom rim.

  17. Rocking and rolling: a can that appears to rock might actually roll.

    PubMed

    Srinivasan, Manoj; Ruina, Andy

    2008-12-01

    A beer bottle or soda can on a table, when slightly tipped and released, falls to an upright position and then rocks up to a somewhat opposite tilt. Superficially this rocking motion involves a collision when the flat circular base of the container slaps the table before rocking up to the opposite tilt. A keen eye notices that the after-slap rising tilt is not generally just diametrically opposite the initial tilt but is veered to one side or the other. Cushman and Duistermaat [Regular Chaotic Dyn. 11, 31 (2006)] recently noticed such veering when a flat disk with rolling boundary conditions is dropped nearly flat. Here, we generalize these rolling disk results to arbitrary axi-symmetric bodies and to frictionless sliding. More specifically, we study motions that almost but do not quite involve a face-down collision of the round container's bottom with the tabletop. These motions involve a sudden rapid motion of the contact point around the circular base. Surprisingly, similar to the rolling disk, the net angle of motion of this contact point is nearly independent of initial conditions. This angle of turn depends simply on the geometry and mass distribution but not on the moment of inertia about the symmetry axis. We derive simple asymptotic formulas for this "angle of turn" of the contact point and check the result with numerics and with simple experiments. For tall containers (height much bigger than radius) the angle of turn is just over pi and the sudden rolling motion superficially appears as a nearly symmetric collision leading to leaning on an almost diametrically opposite point on the bottom rim. PMID:19256970

  18. Explicit Nonlinear Finite Element Geometric Analysis of Parabolic Leaf Springs under Various Loads

    PubMed Central

    Kong, Y. S.; Omar, M. Z.; Chua, L. B.; Abdullah, S.

    2013-01-01

    This study describes the effects of bounce, brake, and roll behavior of a bus toward its leaf spring suspension systems. Parabolic leaf springs are designed based on vertical deflection and stress; however, loads are practically derived from various modes especially under harsh road drives or emergency braking. Parabolic leaf springs must sustain these loads without failing to ensure bus and passenger safety. In this study, the explicit nonlinear dynamic finite element (FE) method is implemented because of the complexity of experimental testing A series of load cases; namely, vertical push, wind-up, and suspension roll are introduced for the simulations. The vertical stiffness of the parabolic leaf springs is related to the vehicle load-carrying capability, whereas the wind-up stiffness is associated with vehicle braking. The roll stiffness of the parabolic leaf springs is correlated with the vehicle roll stability. To obtain a better bus performance, two new parabolic leaf spring designs are proposed and simulated. The stress level during the loadings is observed and compared with its design limit. Results indicate that the newly designed high vertical stiffness parabolic spring provides the bus a greater roll stability and a lower stress value compared with the original design. Bus safety and stability is promoted, as well as the load carrying capability. PMID:24298209

  19. Ocimum sanctum leaf extract induces drought stress tolerance in rice.

    PubMed

    Pandey, Veena; Ansari, M W; Tula, Suresh; Sahoo, R K; Bains, Gurdeep; Kumar, J; Tuteja, Narendra; Shukla, Alok

    2016-05-01

    Ocimum leaves are highly enriched in antioxidant components. Thus, its leaf extract, if applied in plants, is believed to efficiently scavenge ROS, thereby preventing oxidative damage under drought stress. Thus, the present study was performed in kharif 2013 and rabi 2014 season to evaluate the effect of aqueous leaf extract of Ocimum sanctum against drought stress in 2 rice genotype under glass house conditions. Here we show that various morpho- physiological (chlorophyll fluorescence, leaf rolling score, leaf tip burn, number of senesced leaves and total dry matter) and biochemical parameters (proline, malondialdehyde and superoxide dismutase content) were amended by Ocimum treatment in both the seasons. Application of Ocimum extract increased expression of dehydrin genes, while reducing expression of aquaporin genes in drought stressed rice plant. Thus, application of Ocimum leaf extract under drought stress can be suggested as a promising strategy to mitigate drought stress in economical, accessible and ecofriendly manner. PMID:26890603

  20. A comparative study of roll compaction of free-flowing and cohesive pharmaceutical powders.

    PubMed

    Yu, Shen; Gururajan, Bindhu; Reynolds, Gavin; Roberts, Ron; Adams, Michael J; Wu, Chuan-Yu

    2012-05-30

    Roll compaction is widely adopted as a dry granulation method in the pharmaceutical industry. The roll compaction behaviour of feed powders is primarily governed by two parameters: the maximum pressure and the nip angle. Although the maximum pressure can be measured directly using pressure sensors fitted in the rolls, it is not a trivial task to determine the nip angle, which is a measure of the size of the compaction zone and hence the degree of compression. Thus a robust approach based upon the calculation of the pressure gradient, which can be obtained directly from experiments using an instrumented roll compactor, was developed. It has been shown that the resulting nip angles are comparable to those obtained using the methods reported in literature. Nevertheless, the proposed approach has distinctive advantages including (1) it is based on the intrinsic features of slip and no-slip interactions between the powder and roll surface and (2) it is not necessary to carry out wall friction measurements that involve plates that may not be representative of the roll compactor in terms of the surface topography and surface energy. The method was evaluated by investigating the effect of roll speed for two pharmaceutical excipients with distinctive material properties: microcrystalline cellulose (MCC) and di-calcium phosphate dihydrate (DCPD). It was found that the maximum pressure and nip angle for DCPD, which is a cohesive powder, decrease sharply with increasing roll speed whereas they are essentially independent of roll speed for MCC, which is an easy flowing powder. The roll compaction behaviour of MCC-DCPD mixtures with various compositions was also investigated in order to evaluate the effect of flowability. It was found that the nip angle and maximum pressure generally increased with improved flowability of the feed powders. PMID:22402475

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

    ERIC Educational Resources Information Center

    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…

  2. 9. COMPLETED ROLLING CAMERA CAR ON RAILROAD TRACK AND BRIDGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. COMPLETED ROLLING CAMERA CAR ON RAILROAD TRACK AND BRIDGE LOOKING WEST, APRIL 26, 1948. (ORIGINAL PHOTOGRAPH IN POSSESSION OF DAVE WILLIS, SAN DIEGO, CALIFORNIA.) - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  3. Angle detector

    NASA Technical Reports Server (NTRS)

    Parra, G. T. (Inventor)

    1978-01-01

    An angle detector for determining a transducer's angular disposition to a capacitive pickup element is described. The transducer comprises a pendulum mounted inductive element moving past the capacitive pickup element. The capacitive pickup element divides the inductive element into two parts L sub 1 and L sub 2 which form the arms of one side of an a-c bridge. Two networks R sub 1 and R sub 2 having a plurality of binary weighted resistors and an equal number of digitally controlled switches for removing resistors from the networks form the arms of the other side of the a-c bridge. A binary counter, controlled by a phase detector, balances the bridge by adjusting the resistance of R sub 1 and R sub 2. The binary output of the counter is representative of the angle.

  4. GRCop-84 Rolling Parameter Study

    NASA Technical Reports Server (NTRS)

    Loewenthal, William S.; Ellis, David L.

    2008-01-01

    This report is a section of the final report on the GRCop-84 task of the Constellation Program and incorporates the results obtained between October 2000 and September 2005, when the program ended. NASA Glenn Research Center (GRC) has developed a new copper alloy, GRCop-84 (Cu-8 at.% Cr-4 at.% Nb), for rocket engine main combustion chamber components that will improve rocket engine life and performance. This work examines the sensitivity of GRCop-84 mechanical properties to rolling parameters as a means to better define rolling parameters for commercial warm rolling. Experiment variables studied were total reduction, rolling temperature, rolling speed, and post rolling annealing heat treatment. The responses were tensile properties measured at 23 and 500 C, hardness, and creep at three stress-temperature combinations. Understanding these relationships will better define boundaries for a robust commercial warm rolling process. The four processing parameters were varied within limits consistent with typical commercial production processes. Testing revealed that the rolling-related variables selected have a minimal influence on tensile, hardness, and creep properties over the range of values tested. Annealing had the expected result of lowering room temperature hardness and strength while increasing room temperature elongations with 600 C (1112 F) having the most effect. These results indicate that the process conditions to warm roll plate and sheet for these variables can range over wide levels without negatively impacting mechanical properties. Incorporating broader process ranges in future rolling campaigns should lower commercial rolling costs through increased productivity.

  5. Polarized and specular reflectance variation with leaf surface features

    NASA Technical Reports Server (NTRS)

    Grant, Lois; Daughtry, C. S. T.; Vanderbilt, V. C.

    1993-01-01

    The linearly polarized reflectance from a leaf depends on the characteristics of the leaf surface. In the present study the leaf reflectance of a number of plant species with varying surface characteristics was measured at the Brewster angle with a polarization photometer having 5 visible and near-infrared wavelength bands. We found that all leaf surfaces polarized incident light. Differences among species could be explained by variation in surface features. The results support our hypothesis that the polarized light is reflected by the leaf surface, not by its interior. Two mechanisms appeared responsible for the linearly polarized reflectance: (1) specular reflectance and (2) surface particle scattering. In most cases, large values of linearly polarized reflectance could be attributed to specular reflectance from the leaf surface. Attribution required knowledge of the optical dimensions of features on the leaf surface.

  6. Walk and roll robot

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A mobile robotic unit features a main body, a plurality of legs for supporting the main body on and moving the main body in forward and reverse directions about a base surface, and a drive assembly. According to an exemplary embodiment each leg includes a respective pivotal hip joint, a pivotal knee joint, and a wheeled foot adapted to roll along the base surface. Also according to an exemplary embodiments the drive assembly includes a motor operatively associated with the hip and knee joints and the wheeled foot for independently driving pivotal movement of the hip joint and the knee joint and rolling motion of the wheeled foot. The hip joint may include a ball-and-socket-type joint interconnecting top portion of the leg to the main body, such that the hip joint is adapted to pivot said leg in a direction transverse to a forward-and-reverse direction.

  7. Influence of head orientation on visually induced pitch and roll sensation

    NASA Technical Reports Server (NTRS)

    Young, L. R.; Oman, C. M.; Dichgans, J. M.

    1975-01-01

    Observers viewing rotating scenes in their periphery frequently experience self-motion in the opposite direction. A full field flight simulator projection system was used to investigate the sensations resulting from pitch, roll, and yaw stimuli at various head orientations. Steady yaw rate (circularvection) and development of a constant roll tilt angle, for the head erect and constant velocity yaw and roll stimuli, confirmed previous reports. Pitch stimuli also were found to produce a sensation of tilting to a steady pitch angle, which was much stronger for pitch forward than backward. Pitch and roll effects were strongly dependent on head position, increasing for the head rolled 90 deg to the side or inverted, and decreasing for the head pitched 25 deg forward. These results support a hypothesis that visually induced tilt is limited by conflict with otolith information.

  8. Mach 6 experimental and theoretical stability and performance of a cruciform missile at angles of attack up to 65 degrees

    NASA Technical Reports Server (NTRS)

    Hartman, Edward R.; Johnston, Patrick J.

    1987-01-01

    An experimental and theoretical investigation of the longitudinal and lateral-directional stability and control of an axisymmetric cruciform-finned missile has been conducted at Mach 6. The angle-of-attack range extended from 20 to 65 deg to encompass maximum lift. Longitudinal stability, performance, and trim could be accurately predicted with the fins at a fin roll angle of 0 deg but not when the fins were at a fin roll angle of 45 deg. At this roll angle, windward fin choking occurred at angles of attack above 50 deg and reduced the effectiveness of the fins and caused pitch-up.

  9. Roll-to-Roll production of carbon nanotubes based supercapacitors

    NASA Astrophysics Data System (ADS)

    Zhu, Jingyi; Childress, Anthony; Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Podila, Ramakrishna; Rao, Apparao

    2014-03-01

    Carbon nanomaterials provide an excellent platform for electrochemical double layer capacitors (EDLCs). However, current industrial methods for producing carbon nanotubes are expensive and thereby increase the costs of energy storage to more than 10 Wh/kg. In this regard, we developed a facile roll-to-roll production technology for scalable manufacturing of multi-walled carbon nanotubes (MWNTs) with variable density on run-of-the-mill kitchen Al foils. Our method produces MWNTs with diameter (heights) between 50-100 nm (10-100 μm), and a specific capacitance as high as ~ 100 F/g in non-aqueous electrolytes. In this talk, the fundamental challenges involved in EDLC-suitable MWNT growth, roll-to-roll production, and device manufacturing will be discussed along with electrochemical characteristics of roll-to-roll MWNTs. Research supported by NSF CMMI Grant1246800.

  10. Reflectance model of a plant leaf

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L.

    1973-01-01

    A light ray, incident at 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's Equations and Snell's Law. The optical mediums of the leaf considered for ray tracing are: air, cell sap, chloroplast, and cell wall. The above ray is also drawn through the same leaf cross section considering cell wall and air as the only optical mediums. The values of the reflection and transmission found from ray tracing agree closely with the experimental results obtained using a Beckman DK-2A Spectroreflectometer. Similarly a light ray, incident at about 60 deg to the normal, is drawn through the palisade cells of a soybean leaf to illustrate the pathway of light, incident at an oblique angle, through the palisade cells.

  11. A hotspot model for leaf canopies

    NASA Technical Reports Server (NTRS)

    Jupp, David L. B.; Strahler, Alan H.

    1991-01-01

    The hotspot effect, which provides important information about canopy structure, is modeled using general principles of environmental physics as driven by parameters of interest in remote sensing, such as leaf size, leaf shape, leaf area index, and leaf angle distribution. Specific examples are derived for canopies of horizontal leaves. The hotspot effect is implemented within the framework of the model developed by Suits (1972) for a canopy of leaves to illustrate what might occur in an agricultural crop. Because the hotspot effect arises from very basic geometrical principles and is scale-free, it occurs similarly in woodlands, forests, crops, rough soil surfaces, and clouds. The scaling principles advanced are also significant factors in the production of image spatial and angular variance and covariance which can be used to assess land cover structure through remote sensing.

  12. The evaluation of the rolling moments induced by wraparound fins

    NASA Technical Reports Server (NTRS)

    Seginer, A.; Bar-Haim, B.

    1983-01-01

    A possible reason is suggested for the induced rolling moments occurring on wraparound-fin configurations in subsonic flight at zero angle of attack. The subsonic potential flow over the configuration at zero incidence is solved numerically. The body is simulated by a distribution of sources along its axis, and the fins are described by a vortex-lattice method. It is shown that rolling moments can be induced on the antisymmetric fins by the radial flow generated at the base of the configuration, either over the converging separated wake, or over the diverging plume of a rocket motor.

  13. Supersonic aerodynamic characteristics of a maneuvering canard-controlled missile with fixed and free-rolling tail fins

    NASA Technical Reports Server (NTRS)

    Blair, A. B., Jr.

    1990-01-01

    Wind tunnel investigations were conducted on a generic cruciform canard-controlled missile configuration. The model featured fixed or free-rolling tail-fin afterbodies to provide an expanded aerodynamic data base with particular emphasis on alleviating large induced rolling moments and/or for providing canard roll control throughout the entire test angle-of-attack range. The tests were conducted in the NASA Langley Unitary Plan Wind Tunnel at Mach numbers from 2.50 to 3.50 at a constant Reynolds number per foot of 2.00 x 10 to the 6th. Selected test results are presented to show the effects of a fixed or free-rolling tail-fin afterbody on the static longitudinal and lateral-directional aerodynamic characteristics of a canard-controlled missile with pitch, yaw, and roll control at model roll angles of 0 deg and 45 deg.

  14. Accuracy of System Step Response Roll Magnitude Estimation from Central and Peripheral Visual Displays and Simulator Cockpit Motion

    NASA Technical Reports Server (NTRS)

    Hosman, R. J. A. W.; Vandervaart, J. C.

    1984-01-01

    An experiment to investigate visual roll attitude and roll rate perception is described. The experiment was also designed to assess the improvements of perception due to cockpit motion. After the onset of the motion, subjects were to make accurate and quick estimates of the final magnitude of the roll angle step response by pressing the appropriate button of a keyboard device. The differing time-histories of roll angle, roll rate and roll acceleration caused by a step response stimulate the different perception processes related the central visual field, peripheral visual field and vestibular organs in different, yet exactly known ways. Experiments with either of the visual displays or cockpit motion and some combinations of these were run to asses the roles of the different perception processes. Results show that the differences in response time are much more pronounced than the differences in perception accuracy.

  15. Deformation and Vibration of a Platanus Acerifolia Tree Leaf in Wind

    NASA Astrophysics Data System (ADS)

    Shao, C. P.; Chen, Y. J.

    2011-09-01

    The behavior of a twig-connected leaf in wind was investigated. With the variation of wind speed in the range of 0.7-11.5 m/s, the leaf experienced different patterns of deformation or vibration, and abrupt changes from one pattern to another occurred at critical wind speeds. For the case of the back side facing high speed wind stream, the leaf rolled up into conical shapes to reduce resistance and vibration. When the front side facing high wind, however, the leaf vibrated fiercely and no "reconfiguration" phenomenon observed.

  16. Rolling cuff flexible bellows

    DOEpatents

    Lambert, Donald R.

    1985-01-01

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  17. Rolling cuff flexible bellows

    SciTech Connect

    Lambert, D. R.

    1985-09-10

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  18. Microstructure and Texture Evolution During Symmetric and Asymmetric Rolling of a Martensitic Ti-6Al-4V Alloy

    NASA Astrophysics Data System (ADS)

    Chao, Qi; Hodgson, Peter D.; Beladi, Hossein

    2016-01-01

    In the current study, the effect of deformation mode ( i.e., symmetric vs asymmetric rolling) on the extent of grain refinement and texture development in Ti-6Al-4V was examined through warm rolling of a martensitic starting microstructure. During rolling, the initial martensitic lath structure was progressively fragmented, primarily through continuous dynamic recrystallization. This eventually led to an ultrafine-grained (UFG) microstructure composed of equiaxed grains with a mean size of 180 to 230 nm, mostly surrounded by high-angle grain boundaries. Depending on the rolling reduction and deformation mode (symmetric and asymmetric), the rolled specimens displayed different layer morphologies throughout the specimen thickness: a fully UFG surface layer, a partial UFG transition layer, and a partially fragmented lath interior layer. Due to a higher level of effective strain and continuous rotation of the principle axis, asymmetric rolling resulted in a greater extent of grain refinement compared with symmetric rolling at a given thermomechanical condition. A bulk UFG structure was successfully obtained using 70 pct asymmetric rolling. In addition, the rolling texture exhibited various characteristics throughout the thickness due to a different combination of shear and compressive strains. Principally, the basal texture component was displaced from the normal toward rolling direction during asymmetric rolling, differing from the symmetric rolling textures.

  19. VIEW OF HANDOPERATED ROLLING MILLS ROLLING STANDS FROM LEFT TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF HAND-OPERATED ROLLING MILLS ROLLING STANDS FROM LEFT TO RIGHT: THREE HIGH; THREE HIGH; THREE HIGH; THREE HIGH (OPERATED AS A TWO-HIGH); TWO HIGH TWO HIGH MANUFACTURED BY BLAW-KNOX THREE HIGH MANUFACTURED BY LEWIS FOUNDRY AND MACHINE CO. - Cambria Iron Company, Gautier Works, 12" Mill, Clinton Street & Little Conemaugh River, Johnstown, Cambria County, PA

  20. Influence of Water Relations and Temperature on Leaf Movements of Rhododendron Species 1

    PubMed Central

    Nilsen, Erik Tallak

    1987-01-01

    Rhododendron maximum L. and R. Catawbiense L. are subcanopy evergreen shrubs of the eastern United States deciduous forest. Field measurements of climate factors and leaf movements of these species indicated a high correlation between leaf temperature and leaf curling; and between leaf water potential and leaf angle. Laboratory experiments were performed to isolate the influence of temperature and cellular water relations on leaf movements. Significant differences were found between the patterns of temperature induction of leaf curling in the two species. Leaves of the species which curled at higher temperatures (R. catawbiense) also froze at higher leaf temperatures. However, in both cases leaf curling occurred at leaf temperatures two to three degrees above the leaf freezing point. Pressure volume curves indicated that cellular turgor loss was associated with a maximum of 45% curling while 100% or more curling occurred in field leaves which still had positive cell turgor. Moisture release curves indicated that 70% curling requires a loss of greater than 60% of symplastic water which corresponds to leaf water potentials far below those experienced in field situations. Conversely, most laboratory induced changes in leaf angle could be related to leaf cell turgor loss. PMID:16665296

  1. Rolling vs. Sliding: The inclusion of non-conservative work in the classic comparison

    NASA Astrophysics Data System (ADS)

    Chediak, Alex; Buehler, Terry

    2010-03-01

    A semester-long mechanics course typically covers moment of inertia, angular velocity, and rolling. A classic comparison is made between rolling without slipping and sliding without friction. In either case, no non-conservation work is performed---all the gravitational potential energy that the rolling or sliding object possesses at the top of the incline plane is converted into kinetic energy. In the case of the sliding object, the kinetic energy term is simply .5ex1 -.1em/ -.15em.25ex2 mv^2. In the case of the rolling object, the kinetic energy term is .5ex1 -.1em/ -.15em.25ex2 mv^2 + .5ex1 -.1em/ -.15em.25ex2 Iφ^2. The friction here is static not kinetic, so it does no mechanical work. Since the sliding object has no angular velocity, its linear velocity is greater than that of the rolling object, and it reaches the bottom of the track faster. But if a rolling and sliding object, each of the same material, were to race down an incline plane, which would win? The answer depends on the effective coefficient of friction, C. If C > μs, which will occur at angles approaching 90^o, the rolling object slips. And if C < μk, the rolling object has a greater linear acceleration and wins the race to the bottom. Experimental results to verify a theoretical model (including the dependency on incline angle) will also be presented.

  2. Roll waves in mud

    NASA Astrophysics Data System (ADS)

    Balmforth, N. J.; Liu, J. J.

    2004-11-01

    The stability of a viscoplastic fluid film falling down an inclined plane is explored, with the aim of determining the critical Reynolds number for the onset of roll waves. The Herschel Bulkley constitutive law is adopted and the fluid is assumed two-dimensional and incompressible. The linear stability problem is described for an equilibrium in the form of a uniform sheet flow, when perturbed by introducing an infinitesimal stress perturbation. This flow is stable for very high Reynolds numbers because the rigid plug riding atop the fluid layer cannot be deformed and the free surface remains flat. If the flow is perturbed by allowing arbitrarily small strain rates, on the other hand, the plug is immediately replaced by a weakly yielded ‘pseudo-plug’ that can deform and reshape the free surface. This situation is modelled by lubrication theory at zero Reynolds number, and it is shown how the fluid exhibits free-surface instabilities at order-one Reynolds numbers. Simpler models based on vertical averages of the fluid equations are evaluated, and one particular model is identified that correctly predicts the onset of instability. That model is used to describe nonlinear roll waves.

  3. Roll back malaria update.

    PubMed

    1999-10-01

    This article presents the activities under WHO's Roll Back Malaria (RBM) program in Asia, particularly in Nepal, Indonesia, India, Bangladesh, Sri Lanka and the Philippines. In India, the RBM program will start in 5 districts with a major malaria problem. A national committee has been formed by researchers, which will be able to provide operational and strategic support and research expertise in relation to malaria. In Bangladesh, the RBM program was initiated in the sparsely populated hill tract areas of Banderban and Chittagong where access to health care is very poor. At the district level, effective partnerships with private practitioners, politicians, community leaders, school teachers, the press and district Ministry of Health officials are operating to plan for rolling back malaria. In Myanmar, Cambodia, Lao People's Democratic Republic, Yunnan province of China, Vietnam, and Thailand, the focus of the RBM program was to move health care closer to the malaria-infected communities. WHO¿s Global Health Leadership Fellowship Programme, supported by the UN Foundation and Rockefeller Foundation, enables potential leaders to experience the work of UN agencies and contribute to the work of the organization for 2 years. Three out of four persons appointed to the RBM program received prestigious awards: Dr. Paola Marchesini of Brazil; Dr. Tieman Diarra of Mali; and Dr. Bob Taylor of the UK. PMID:12295474

  4. Roll Back Malaria.

    PubMed

    Nabarro, D

    1999-09-01

    Roll Back Malaria is an initiative intended to halve the suffering caused by this disease by 2010. The initiative is being developed as a social movement. Action is directed by national authorities backed by a global partnership which consists of development agencies, banks, private sector groups and researchers. The World Health Organization, the World Bank, UNICEF and UNDP founded the partnership in October 1998. The WHO has established a new Cabinet Project, and a WHO-wide strategy and workplan, to support the partnership. High quality, practical, consistent and relevant technical advice is made available through networks of experts based in research, academic, and disease control institutions, particularly those in endemic countries. The initiative also supports research and development of new products and tools to control malaria. Implementation of Roll Back Malaria began with a series of in-country consultations in 1998, followed by sub-regional consensus building and inception meetings. The current period is one of momentum building at country level during which national authorities are developing their own strategies with the global partners. It is anticipated that, during the year 2000, RBM movements will become active in at least 30 countries. PMID:10697910

  5. Rolling Beam Umbilical System

    NASA Technical Reports Server (NTRS)

    Tatem, B. C., Jr.

    1983-01-01

    The decision to make the Centaur Vehicle a Space Transportation System (STS) payload meant that new ground support equipment provisions at Launch Pads Pads 39A and 39B were required. These new equipment provisions were needed to service the Centaur vehicle while it was installed in the Orbiter's payload bay prior to launch. This paper describes the design of a new rolling beam umbilical syste (RBUS) being added to the pad fixed service structure (FSS) in order to provide the primary functions of liquid hydrogen (LH2) fill, drain, and vent. The carrier plate itself is a Government-furnished equipment item and of necessity became a T-O disconnect. This permits quick offloading in the event of an abort prior to lift-off. In addition to the rolling beam structure, mechanisms, and fluid lines, it was necessary to design and build a carrier plate simulator to support early development testing of the mast at the Launch Equipment Test Facility at Kennedy Space Center. The RBUS is designed to be compatible with the rotating service structure (RSS) to the extent that the umbilical may be deployed with the RSS mated with the vehicle. It is also designed to clear the RSS as the RSS rotates back out of the way. Accessibility to the Orbiter aft compartment via the 50-1 door had to be maintained.

  6. Heat generation in Aircraft tires under yawed rolling conditions

    NASA Technical Reports Server (NTRS)

    Dodge, Richard N.; Clark, Samuel K.

    1987-01-01

    An analytical model was developed for approximating the internal temperature distribution in an aircraft tire operating under conditions of yawed rolling. The model employs an assembly of elements to represent the tire cross section and treats the heat generated within the tire as a function of the change in strain energy associated with predicted tire flexure. Special contact scrubbing terms are superimposed on the symmetrical free rolling model to account for the slip during yawed rolling. An extensive experimental program was conducted to verify temperatures predicted from the analytical model. Data from this program were compared with calculation over a range of operating conditions, namely, vertical deflection, inflation pressure, yaw angle, and direction of yaw. Generally the analytical model predicted overall trends well and correlated reasonably well with individual measurements at locations throughout the cross section.

  7. Lubrication of rolling element bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1980-01-01

    This paper is a broad survey of the lubrication of rolling-element bearings. Emphasis is on the critical design aspects related to speed, temperature, and ambient pressure environment. Types of lubrication including grease, jets, mist, wick, and through-the-race are discussed. The paper covers the historical development, present state of technology, and the future problems of rolling-element bearing lubrication.

  8. Photosynthetic responses to leaf surface wetness in tropical plant species of Costa Rica with varying leaf traits

    NASA Astrophysics Data System (ADS)

    Aparecido, L. M. T.; Moore, G. W.; Miller, G. R.; Cahill, A. T.

    2015-12-01

    Wet tropical forests are some of the environments with the greatest annual precipitation, but are also considered as the world's major carbon sink; however, literature postulates that phothsynthesis rates are inhibited while leaves are wet. Yet measurements of photosynthesis during wet conditions are challenging to obtain due to equipment limitations and the extreme complexity of canopy-atmosphere interactions in tropical environments. The objective of this study was to evaluate tropical species reactions to simulated leaf wetness and test the hypothesis that leaf wetness reduces rates of photosynthesis. In a central Costa Rica site with an average 4200 mm annual rainfall, we selected six tropical species with distinct leaf traits in which five sun-exposed leaf replicates from each species were subjected to gas exchange measurements using a LI-6400 IRGA (LICOR Inc., Lincoln, NE) under dry and wet/misted leaf conditions. Relationships between photosynthesis (As) and stomatal conductance (gs) with leaf to air temperature difference (DT), VPD, and relative humidity were evaluated using linear regression analysis. We found that the responses varied greatly among species, but all plants maintained a baseline of activity under wet leaf conditions, suggesting that abaxial leaf As was a significant percentage of total leaf As. Stachytarpheta jamaicens had an 18.7% reduction in As, while others, like Zamia skinneri, had a 7% increase in As. Tibouchina heteromalla showed a rapid stomatal recovery of 2 mins, while Carapa guianensis was slower with 7 mins. This variability between species suggests that leaf traits, such as presence or absence of trichomes, water repellency, vein distribution and size and leaf angle variation, may be critical for optimizing photosynthesis under wet conditions. Relative humidity and leaf temperature were the strongest secondary influences on As and gs under wet leaf conditions. While tropical vegetation-atmosphere interactions are complex, such

  9. Towards identifying the roll motion parameters of a motorcycle simulator.

    PubMed

    Shahar, Amit; Dagonneau, Virginie; Caro, Séphane; Israël, Isabelle; Lobjois, Régis

    2014-05-01

    This study aimed at identifying the roll motion parameters of a motorcycle simulator prototype. Experienced motorcyclists tuned the angular physical movement of the mock-up and that of the visual scene to achieve an optimal riding experience during curves. The participants exceeded the rolling angles that would be required in real-world riding, while avoiding leaning the mock-up beyond 10°. In addition, they were more influenced by the speed of the virtual motorcycle than by road curvature, especially in a wide field of view. Heterogeneity was found in the roll applied to the visual scene. The overall patterns suggest that at least when washout is not applied to remove the side forces that in real-world riding are compensated by a centrifugal force, greater roll of the visual at the expense of the mock-up is mandatory to avoid performance biases that might be enhanced due to fear of falling off the simulator. Future roll motion models must take into consideration factors such as riding postures, which might not only influence the forces operating on the rider-motorcycle system, but also how motorcyclists perceive the visual world. PMID:24140244

  10. Assessing soybean leaf area and leaf biomass by spectral measurements

    NASA Technical Reports Server (NTRS)

    Holben, B. N.; Tucker, C. J.; Fan, C. J.

    1979-01-01

    Red and photographic infrared spectral radiances were correlated with soybean total leaf area index, green leaf area index, chlorotic leaf area index, green leaf biomass, chlorotic leaf biomass, and total biomass. The most significant correlations were found to exist between the IR/red radiance ratio data and green leaf area index and/or green leaf biomass (r squared equals 0.85 and 0.86, respectively). These findings demonstrate that remote sensing data can supply information basic to soybean canopy growth, development, and status by nondestructive determination of the green leaf area or green leaf biomass.

  11. Dynamics of a viscous ball rolling down on a rigid staircase

    NASA Astrophysics Data System (ADS)

    Yan, Hua; Shi, Qingfan; Huang, Decai; Sun, Gang

    2007-02-01

    We theoretically investigate the motion of a ball rolling down on a periodical staircase. Our research is restricted in the case of completely inelastic collision when the ball falls down on the surface of the stairs. The ball is accelerated when it rolls cross the edge of the stair, while it is decelerated when it rolls on the horizontal surface due to the rolling friction. The competition between them causes two different regimes according to the parameters of the system. One is the steady moving regime in which the ball keeps moving forever, and the other is the still regime in which the ball finally stops after rolling on a finite number of stairs. The diagram of these two regimes is given in the reduced parameter space. The tendency that smaller scale of the staircase can keep moving on smaller inclined angle is found.

  12. Human Ocular Counter-Rolling and Roll Tilt Perception during Off-Vertical Axis Rotation after Spaceflight

    NASA Technical Reports Server (NTRS)

    Clement, Gilles; Denise, Pierre; Reschke, Millard; Wood, Scott J.

    2007-01-01

    Ocular counter-rolling (OCR) induced by whole body tilt in roll has been explored after spaceflight as an indicator of the adaptation of the otolith function to microgravity. It has been claimed that the overall pattern of OCR responses during static body tilt after spaceflight is indicative of a decreased role of the otolith function, but the results of these studies have not been consistent, mostly due to large variations in the OCR within and across individuals. By contrast with static head tilt, off-vertical axis rotation (OVAR) presents the advantage of generating a sinusoidal modulation of OCR, allowing averaged measurements over several cycles, thus improving measurement accuracy. Accordingly, OCR and the sense of roll tilt were evaluated in seven astronauts before and after spaceflight during OVAR at 45 /s in darkness at two angles of tilt (10 and 20 ). There was no significant difference in OCR during OVAR immediately after landing compared to preflight. However, the amplitude of the perceived roll tilt during OVAR was significantly larger immediately postflight, and then returned to control values in the following days. Since the OCR response is predominantly attributed to the shearing force exerted on the utricular macula, the absence of change in OCR postflight suggests that the peripheral otolith organs function normally after short-term spaceflight. However, the increased sense of roll tilt indicates an adaptation in the central processing of gravitational input, presumably related to a re-weigthing of the internal representation of gravitational vertical as a result of adaptation to microgravity.

  13. Manufacturing Demonstration Facility: Roll-to-Roll Processing

    SciTech Connect

    Datskos, Panos G; Joshi, Pooran C; List III, Frederick Alyious; Duty, Chad E; Armstrong, Beth L; Ivanov, Ilia N; Jacobs, Christopher B; Graham, David E; Moon, Ji Won

    2015-08-01

    This Manufacturing Demonstration Facility (MDF)e roll-to-roll processing effort described in this report provided an excellent opportunity to investigate a number of advanced manufacturing approaches to achieve a path for low cost devices and sensors. Critical to this effort is the ability to deposit thin films at low temperatures using nanomaterials derived from nanofermentation. The overarching goal of this project was to develop roll-to-roll manufacturing processes of thin film deposition on low-cost flexible substrates for electronics and sensor applications. This project utilized ORNL s unique Pulse Thermal Processing (PTP) technologies coupled with non-vacuum low temperature deposition techniques, ORNL s clean room facility, slot dye coating, drop casting, spin coating, screen printing and several other equipment including a Dimatix ink jet printer and a large-scale Kyocera ink jet printer. The roll-to-roll processing project had three main tasks: 1) develop and demonstrate zinc-Zn based opto-electronic sensors using low cost nanoparticulate structures manufactured in a related MDF Project using nanofermentation techniques, 2) evaluate the use of silver based conductive inks developed by project partner NovaCentrix for electronic device fabrication, and 3) demonstrate a suite of low cost printed sensors developed using non-vacuum deposition techniques which involved the integration of metal and semiconductor layers to establish a diverse sensor platform technology.

  14. Rolling Process Modeling Report: Finite-Element Prediction of Roll Separating Force and Rolling Defects

    SciTech Connect

    Soulami, Ayoub; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas

    2014-04-23

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).

  15. Experimental pitch-, yaw-, and roll-damping characteristics of a shuttle orbiter at Mach number 8

    NASA Technical Reports Server (NTRS)

    Uselton, B. L.; Freeman, D. C., Jr.; Boyden, R. P.

    1975-01-01

    Wind tunnel tests were conducted to measure the pitch-, yaw-, and roll-damping characteristics of a modified 089B shuttle orbiter. These tests were conducted for NASA-Langley at the von Karman Gas Dynamics Facility of the Arnold Engineering Development Center. Data were obtained utilizing the small amplitude forced-oscillation technique at angles of attack of -4.9 to 26.5 deg at Reynolds numbers, based on model length, of 1,180,000 to 4,820,000. The orbiter was dynamically stable in pitch, yaw, and roll, and the pitch derivatives were dependent on Reynolds number, while the roll derivatives were independent of Reynolds number.

  16. Precision instrumentation for rolling element bearing characterization

    SciTech Connect

    Marsh, Eric R.; Vigliano, Vincent C.; Weiss, Jeffrey R.; Moerlein, Alex W.; Vallance, R. Ryan

    2007-03-15

    This article describes an instrument to measure the error motion of rolling element bearings. This challenge is met by simultaneously satisfying four requirements. First, an axial preload must be applied to seat the rolling elements in the bearing races. Second, one of the races must spin under the influence of an applied torque. Third, rotation of the remaining race must be prevented in a way that leaves the radial, axial/face, and tilt displacements free to move. Finally, the bearing must be fixtured and measured without introducing off-axis loading or other distorting influences. In the design presented here, an air bearing reference spindle with error motion of less than 10 nm rotates the inner race of the bearing under test. Noninfluencing couplings are used to prevent rotation of the bearing outer race and apply an axial preload without distorting the bearing or influencing the measurement. Capacitive displacement sensors with 2 nm resolution target the nonrotating outer race. The error motion measurement repeatability is shown to be less than 25 nm. The article closes with a discussion of how the instrument may be used to gather data with sufficient resolution to accurately estimate the contact angle of deep groove ball bearings.

  17. Reduced Blood Coagulation on Roll-to-Roll, Shrink-Induced Superhydrophobic Plastics.

    PubMed

    Nokes, Jolie M; Liedert, Ralph; Kim, Monica Y; Siddiqui, Ali; Chu, Michael; Lee, Eugene K; Khine, Michelle

    2016-03-01

    The unique antiwetting properties of superhydrophobic (SH) surfaces prevent the adhesion of water and bodily fluids, including blood, urine, and saliva. While typical manufacturable approaches to create SH surfaces rely on chemical and structural modifications, such approaches are expensive, require postprocessing, and are often not biocompatible. By contrast, it is demonstrated that purely structural SH features are easily formed using high throughput roll-to-roll (R2R) manufacturing by shrinking a prestressed thermoplastic with a thin, stiff layer of silver and calcium. These features are subsequently embossed into any commercially available and Food and Drug Administration (FDA)-approved plastic. The R2R SH surfaces have contact angles >150° and contact angle hysteresis <10°. Importantly, the surfaces minimize blood adhesion, leading to reduced blood coagulation without the need for anticoagulants. SH surfaces have >4200× reduction of blood residue area compared to the nonstructured controls of the same material. In addition, blood clotting is reduced >5× using whole blood directly from the patient. Furthermore, these surfaces can be easily configured into 3D shapes, as demonstrated with SH tubes. With the simple scale-up production and the eliminated need for anticoagulants to prevent clotting, the proposed conformable SH surfaces can be impactful for a wide range of medical tools, including catheters and microfluidic channels. PMID:26784916

  18. Drift prediction for a roll-stabilized inertial measurement system

    SciTech Connect

    Bateman, V.I.

    1983-01-01

    A roll-stabilized inertial measurement system is being developed by Sandia National Laboratories. This system will measure three orthogonal-body angular rates and three orthogonal-body accelerations and will calculate three Euler angles for attitude control of small rocket systems and/or large rocket payloads in flight. An analysis of the predicted drift in the Euler angles has been undertaken to aid in the definition of computational hardware characteristics (such as gyro resolution and gyro sample frequency) and to assess the performance of the system over typical trajectories. The method of analysis uses two different techniques to calculate Euler angles and to compare the results. The first technique results in a true Euler angle which is calculated by a Bortz equation (a method to relate vehicle body coordinates to earth coordinates). The second technique simulates the in-flight calculations by including effects of drift from the truncated Bortz algorithm, quantization, and random gyro drift. The comparison results in drift as a function of time for the three Euler angles, roll, pitch, and yaw. Examples of predicted drift over typical trajectories are presented.

  19. Pulvinus activity, leaf movement and leaf water-use efficiency of bush bean ( Phaseplus vulgaris L.) in a hot environment

    NASA Astrophysics Data System (ADS)

    Raeini-Sarjaz, Mahmoud; Chalavi, Vida

    2008-11-01

    Pulvinus activity of Phaseolus species in response to environmental stimuli plays an essential role in heliotropic leaf movement. The aims of this study were to monitor the continuous daily pulvinus movement and pulvinus temperature, and to evaluate the effects of leaf movements, on a hot day, on instantaneous leaf water-use efficiency (WUEi), leaf gas exchange, and leaf temperature. Potted plants of Phaseolus vulgaris L. var. Provider were grown in Chicot sandy loam soil under well-watered conditions in a greenhouse. When the second trifoliate leaf was completely extended, one plant was selected to measure pulvinus movement using a beta-ray gauging (BRG) meter with a point source of thallium-204 (204Tl). Leaf gas exchange measurements took place on similar leaflets of three plants at an air temperature interval of 33-42°C by a steady-state LI-6200 photosynthesis system. A copper-constantan thermocouple was used to monitor pulvinus temperature. Pulvinus bending followed the daily diurnal rhythm. Significant correlations were found between the leaf-incident angle and the stomatal conductance ( R 2 = 0.54; P < 0.01), and photosynthesis rate ( R 2 = 0.84; P < 0.01). With a reduction in leaf-incidence angle and increase in air temperature, WUEi was reduced. During the measurements, leaf temperature remained below air temperature and was a significant function of air temperature ( r = 0.92; P < 0.01). In conclusion, pulvinus bending followed both light intensity and air temperature and influenced leaf gas exchange.

  20. An experimental study on the aerodynamic feasibility of a roll-controllable sounding rocket

    NASA Astrophysics Data System (ADS)

    Shirouzu, M.; Soga, K.; Shibato, Y.

    1986-02-01

    The aerodynamic feasibility of a roll-controllable two-stage sounding rocket is investigated experimentally. The rocket has ailerons on front-fins to generate the rolling moment for the control and free-rolling tail-fins to prevent the induced rolling moment on the tail-fins from transmitting to the fuselage. Wind tunnel tests were made at free-stream Mach numbers ranging from 0.5 to 2.5 and alpha = 0 deg, 4 deg, and 8 deg varying the deflection angle of the ailerons for the models with fixed tail-fins, with free-rolling tail-fins and without tail-fins. Aerodynamic characteristics were measured by using a six-component balance. The effectiveness of the free-rolling tail-fins for the elimination of the influence of the induced rolling moment is confirmed. It is concluded that the characteristics of the rolling moment generated by the ailerons are desirable for the control, and the rotation of the tail-fins would not raise mechanical and other aerodynamic problems.

  1. Yellow leaf blotch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Yellow leaf blotch occurs worldwide in temperate climates. The disease is reported from countries in Asia, Australasia, Oceania, Europe, North America, Central America, the West Indies, and South America. In the northern Great Plains of North America, it is often the major leaf disease on alfalfa....

  2. Human perceptual overestimation of whole body roll tilt in hypergravity

    PubMed Central

    Newman, Michael C.; Oman, Charles M.; Merfeld, Daniel M.; Young, Laurence R.

    2014-01-01

    Hypergravity provides a unique environment to study human perception of orientation. We utilized a long-radius centrifuge to study perception of both static and dynamic whole body roll tilt in hypergravity, across a range of angles, frequencies, and net gravito-inertial levels (referred to as G levels). While studies of static tilt perception in hypergravity have been published, this is the first to measure dynamic tilt perception (i.e., with time-varying canal stimulation) in hypergravity using a continuous matching task. In complete darkness, subjects reported their orientation perception using a haptic task, whereby they attempted to align a hand-held bar with their perceived horizontal. Static roll tilt was overestimated in hypergravity, with more overestimation at larger angles and higher G levels, across the conditions tested (overestimated by ∼35% per additional G level, P < 0.001). As our primary contribution, we show that dynamic roll tilt was also consistently overestimated in hypergravity (P < 0.001) at all angles and frequencies tested, again with more overestimation at higher G levels. The overestimation was similar to that for static tilts at low angular velocities but decreased at higher angular velocities (P = 0.006), consistent with semicircular canal sensory integration. To match our findings, we propose a modification to a previous Observer-type canal-otolith interaction model. Specifically, our data were better modeled by including the hypothesis that the central nervous system treats otolith stimulation in the utricular plane differently than stimulation out of the utricular plane. This modified model was able to simulate quantitatively both the static and the dynamic roll tilt overestimation in hypergravity measured experimentally. PMID:25540216

  3. A model for leaf initiation

    PubMed Central

    Abraham-Shrauner, Barbara; Pickard, Barbara G

    2011-01-01

    A biophysical model is proposed for how leaf primordia are positioned on the shoot apical
    meristem in both spiral and whorl phyllotaxes. Primordia are initiated by signals that propagate
    in the epidermis in both azimuthal directions away from the cotyledons or the most recently
    specified primordia. The signals are linear waves as inferred from the spatial periodicity of the
    divergence angle and a temporal periodicity. The periods of the waves, which represent actively
    transported auxin, are much smaller than the plastochron interval. Where oppositely directed
    waves meet at one or more angular positions on the periphery of the generative circle, auxin
    concentration builds and as in most models this stimulates local movement of auxin to
    underlying cells, where it promotes polarized cell division and expansion. For higher order
    spirals the wave model requires asymmetric function of auxin transport; that is, opposite wave
    speeds differ. An algorithm for determination of the angular positions of leaves in common leaf
    phyllotaxic configurations is proposed. The number of turns in a pattern repeat, number of leaves
    per level and per pattern repeat, and divergence angle are related to speed of auxin transport and
    radius of the generative circle. The rule for composition of Fibonacci or Lucas numbers
    associated with some phyllotaxes is discussed. A subcellular model suggests how the shoot
    meristem might specify either symmetric or asymmetric transport of auxin away from the
    forming primordia that produce it. Biological tests that could make or break the mathematical
    and molecular hypotheses are proposed. PMID:22212121

  4. Roll-to-roll manufacturing of electronic devices

    NASA Astrophysics Data System (ADS)

    Morrison, N. A.; Stolley, T.; Hermanns, U.; Kroemer, U.; Reus, A.; Lopp, A.; Campo, M.; Landgraf, H.

    2012-03-01

    Roll-to-Roll (R2R) production of thin film based electronic devices (e.g. solar cells, activematrix TFT backplanes & touch screens) combine the advantages of the use of inexpensive, lightweight & flexible substrates with high throughput production. Significant cost reduction opportunities can also be found in terms of processing tool capital cost, utilized substrate area and process gas flow when compared with batch processing systems. Nevertheless, material handling, device patterning and yield issues have limited widespread utilization of R2R manufacturing within the electronics industry.

  5. Hot rolling of thick uranium molybdenum alloys

    DOEpatents

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  6. Leaf growth is conformal.

    PubMed

    Alim, Karen; Armon, Shahaf; Shraiman, Boris I; Boudaoud, Arezki

    2016-01-01

    Growth pattern dynamics lie at the heart of morphogenesis. Here, we investigate the growth of plant leaves. We compute the conformal transformation that maps the contour of a leaf at a given stage onto the contour of the same leaf at a later stage. Based on the mapping we predict the local displacement field in the leaf blade and find it to agree with the experimentally measured displacement field to 92%. This approach is applicable to any two-dimensional system with locally isotropic growth, enabling the deduction of the whole growth field just from observation of the tissue contour. PMID:27597439

  7. Do liquid drops roll or slide on inclined surfaces?

    PubMed

    Thampi, Sumesh P; Adhikari, Ronojoy; Govindarajan, Rama

    2013-03-12

    We study the motion of a two-dimensional droplet on an inclined surface, under the action of gravity, using a diffuse interface model which allows for arbitrary equilibrium contact angles. The kinematics of motion is analyzed by decomposing the gradient of the velocity inside the droplet into a shear and a residual flow. This decomposition helps in distinguishing sliding versus rolling motion of the drop. Our detailed study confirms intuition, in that rolling motion dominates as the droplet shape approaches a circle, and the viscosity contrast between the droplet and the ambient fluid becomes large. As a consequence of kinematics, the amount of rotation in a general droplet shape follows a universal curve characterized by geometry, and independent of Bond number, surface inclination and equilibrium contact angle, but determined by the slip length and viscosity contrast. Our results open the way toward a rational design of droplet-surface properties, both when rolling motion is desirable (as in self-cleaning hydrophobic droplets) and when it must be prevented (as in insecticide sprays on leaves). PMID:23414059

  8. Texture and magnetic properties of non-oriented electrical steels processed by an unconventional cold rolling scheme

    NASA Astrophysics Data System (ADS)

    He, Youliang; Hilinski, Erik J.

    2016-05-01

    Two non-oriented electrical steels containing 0.9 wt% and 2.8 wt% of silicon were processed using an unconventional cold rolling scheme, i.e. the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) so that the initial texture before cold rolling and the rotation paths of crystals during cold deformation were both altered as compared to conventional cold rolling along the original HRD. The cold-rolled steel strips were then annealed, skin-pass rolled and final annealed. The texture and microstructure of the materials were characterized by X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and optical microscopy, and considerable differences in average grain size and texture were observed at different inclination angles. The magnetic properties of the steel strips were measured at 400 Hz and 1.0 T/1.5 T using a specially designed Epstein frame, and apparent differences were also noticed at various angles. The magnetic quality of texture was evaluated using different texture factors/parameters and compared to the measured magnetic properties. Although apparent improvement on the magnetic quality of texture can be noted by inclining the CRD to HRD, the trend does not match the measured magnetic properties at 400 Hz, which may have been affected by other parameters in addition to crystallographic texture.

  9. Resistance to Rolling in the Adhesive Contact of Two Elastic Spheres

    NASA Technical Reports Server (NTRS)

    Dominik, C.; Tielens, A. G. G. M.

    1995-01-01

    For the stability of agglomerates of micron sized particles it is of considerable importance to study the effects of tangential forces on the contact of two particles. If the particles can slide or roll easily over each other, fractal structures of these agglomerates will not be stable. We use the description of contact forces by Johnson, Kendall and Roberts, along with arguments based on the atomic structure of the surfaces in contact, in order to calculate the resistance to rolling in such a contact. It is shown that the contact reacts elastically to torque forces up to a critical bending angle. Beyond that, irreversible rolling occurs. In the elastic regime, the moment opposing the attempt to roll is proportional to the bending angle and to the pull-off force P(sub c). Young's modulus of the involved materials has hardly any influence on the results. We show that agglomerates of sub-micron sized particles will in general be quite rigid and even long chains of particles cannot be bent easily. For very small particles, the contact will rather break than allow for rolling. We further discuss dynamic properties such as the possibility of vibrations in this degree of freedom and the typical amount of rolling during a collision of two particles.

  10. Roll-to-Roll Nanoimprint Lithography Simulations for Flexible Substrates

    NASA Astrophysics Data System (ADS)

    Spann, Andrew; Jain, Akhilesh; Bonnecaze, Roger

    2015-11-01

    UV roll-to-roll nanoimprint lithography enables the patterning of features onto a flexible substrate for bendable electronics in a continuous process. One of the most important design goals in this process is to make the residual layer thickness of the photoresist in unpatterned regions as thin and uniform as possible. Another important goal is to minimize the imprint time to maximize throughput. We develop a multi-scale model to simulate the spreading of photoresist drops as the template is pressed against the substrate. We include the effect of capillary pressure on the bending of the substrate and show how this distorts uniformity in the residual thickness layer. Our simulation code is parallelized and can simulate the flow and merging of thousands of drops. We investigate the effect of substrate tension and the initial arrangement of drops on the residual layer thickness and imprint time. We find that for a given volume of photoresist, distributing that volume to more drops initially decreases the imprint time. We conclude with recommendations for scale-up and optimal operations of roll-to-roll nanoimprint lithography systems. The authors acknowledge the Texas Advanced Computing Center at The University of Texas at Austin for providing high performance computing resources.

  11. Leaf Tissue Senescence

    PubMed Central

    Manos, Peter J.; Goldthwaite, Jonathan

    1975-01-01

    During winter, excised leaf tissue from Rumex obtusifolius degrades chlorophyll at twice the summer rate but the plant hormones, gibberellic acid and zeatin, inhibit the senescence rate by a constant percentage, regardless of season. PMID:16659225

  12. Rolling flow wind tunnel tests of F-18 aircraft

    NASA Technical Reports Server (NTRS)

    Lutze, F. H.

    1980-01-01

    The lateral directional characteristics of an F-18 aircraft was investigated. Aerodynamic derivatives associated with pure roll rate, or the 'p' derivatives were obtained. The model is described and the procedures used to obtain and correct the data, and a graphical presentation of the results are presented. These results include graphs of the lateral directional static stability derivatives versus angle of attack, and the lateral directional force and moment coefficients versus nondimensional roll rate. Results are presented for several configurations including complete, complete without vertical tails, complete without horizontal tails, fuselage wing and fuselage alone. Each of these configuations was tested with and without wing leading edge extensions. The basic control surfaces were deflected and the results were investigated.

  13. Visual field influence on manual roll and pitch stabilization

    NASA Technical Reports Server (NTRS)

    Huang, J.-K.; Young, L. R.

    1988-01-01

    Human control performance in nulling perceived tilt angles was investigated for combinations of pseudo-random vestibular disturbances and different waveforms of low frequency wide visual field motions. For both roll and pitch axes, subjects tilted the trainer in which they were seated in the direction of field rotation. This visual bias was much stronger for pitch backwards with upward field rotation. Frequency response analysis showed the dominance of visual cues at low frequencies (below 0.06 Hz) and the reliance on vestibular information in the high frequency range for both axes. Models suggest that operator balancing responses at high frequencies are mainly processed by the semicircular canals rather than the otolith organs. The results also suggest that the subject tends to rely less on the otolith organs for pitch perception than for roll.

  14. Analysis of the effects of wing interference on the tail contributions to the rolling derivatives

    NASA Technical Reports Server (NTRS)

    Michael, William H , Jr

    1952-01-01

    An analysis of the effects of wing interference on the tail contributions to the rolling stability derivatives of complete airplane configurations is made by calculating the angularity of the air stream at the vertical tail due to rolling and determining the resulting forces and moments. Some of the important factors which affect the resultant angularity on the vertical tail are wing aspect ratio and sweepback, vertical-tail span, and considerations associated with angle of attack and airplane geometry. Some calculated sidewash results for a limited range of plan forms and vertical-tail sizes are presented. Equations taking into account the sidewash results are given for determining the tail contributions to the rolling derivatives. Comparisons of estimated and experimental results indicate that a consideration of wing interference effects improves the estimated values of the tail contributions to the rolling derivatives and that fair agreement with available experimental data is obtained.

  15. The Selection of the Spray Deposition Rate during the Spray Rolling Process

    SciTech Connect

    Yaojun Lin; Kevin M. McHugh; Yizhang Zhou; Enrique J. Lavernia

    2004-11-01

    This article presents a detailed theoretical analysis of the selection of the maximum and minimum spray deposition rates under steady-state conditions during the spray-rolling process. The following predictions are made on the basis of the preceding theoretical analysis. First, the key factor that may control the minimum spray deposition rate is either the removal of porosity or the removal of prior droplet boundaries. With an increase in initial liquid fraction at the deposit/roll interfaces, the mechanism changes from the former to the latter. Second, the mechanism that controls the maximum spray deposition rate is related to either the drag-in angle or the distance between the nozzle and the deposited material’s surface. With an increase in roll diameter or a decrease in distance between the nozzle and the roll-axis plane, the controlling mechanism is changed from the former to the latter. Third, both the calculated maximum and minimum spray deposition rates markedly increase with an increase in roll diameter and roll rotational frequency. In addition, the present theoretical analysis suggests that spray rolling can be optimized to manufacture strips with a high production rate.

  16. Modeling Asymmetric Rolling Process of Mg alloys

    SciTech Connect

    Cho, Jaehyung; Kim, Hyung-Wuk; Kang, Suk-Bong

    2010-06-15

    Asymmetric deformation during rolling can arise in various ways: difference in the radii, speeds, frictions of the top and bottom rolls. Asymmetric warm rolling processes of magnesium alloys were modeled using a lagrangian incremental approach. A constitutive equation representing flow behaviors of AZ31 magnesium alloys during warm deformation was implemented to the modeling. Various roll speed ratios were introduced to investigate deformation behaviors of the magnesium alloys. Bending and texturing of the strips were examined.

  17. Modulation of internal estimates of gravity during and after prolonged roll-tilts.

    PubMed

    Tarnutzer, Alexander A; Bertolini, Giovanni; Bockisch, Christopher J; Straumann, Dominik; Marti, Sarah

    2013-01-01

    Perceived direction of gravity, as assessed by the subjective visual vertical (SVV), shows roll-angle dependent errors that drift over time and a bias upon return to upright. According to Bayesian observer theory, the estimated direction of gravity is derived from the posterior probability distribution by combining sensory input and prior knowledge about earth-vertical in a statistically optimal fashion. Here we aimed to further characterize the stability of SVV during and after prolonged roll-tilts. Specifically we asked whether the post-tilt bias is related to the drift pattern while roll-tilted. Twenty-nine healthy human subjects (23-56 yo) repetitively adjusted a luminous arrow to the SVV over periods of 5 min while upright, roll-tilted (± 45°, ± 90°), and immediately after returning to upright. Significant (p<0.05) drifts (median absolute drift-amplitude: 10°/5 min) were found in 71% (± 45°) and 78% (± 90°) of runs. At ± 90° roll-tilt significant increases in absolute adjustment errors were more likely (76%), whereas significant increases (56%) and decreases (44%) were about equally frequent at ± 45°. When returning to upright, an initial bias towards the previous roll-position followed by significant exponential decay (median time-constant: 71 sec) was noted in 47% of all runs (all subjects pooled). No significant correlations were found between the drift pattern during and immediately after prolonged roll-tilt. We conclude that the SVV is not stable during and after prolonged roll-tilt and that the direction and magnitude of drift are individually distinct and roll-angle-dependent. Likely sensory and central adaptation and random-walk processes contribute to drift while roll-tilted. Lack of correlation between the drift and the post-tilt bias suggests that it is not the inaccuracy of the SVV estimate while tilted that determines post-tilt bias, but rather the previous head-roll orientation relative to gravity. We therefore favor central

  18. Towing tank tests for surface combatant for coupled pitch and heave and free roll decay motions

    NASA Astrophysics Data System (ADS)

    Irvine, Martin, Jr.

    Towing-tank experiments are performed for an advancing surface combatant in free roll decay and coupled pitch and heave motions. For free roll decay experiments, results are presented for motions (surge, sway, heave, roll, pitch and yaw), forces (resistance, sway and heave), moments (pitch and yaw), phase-averaged velocities (U, V and W) for measurement region near bilge keel and free surface elevations. For coupled pitch and heave experiments, results are presented for pitch and heave transfer functions, and pitch and heave phase angles. The geometry of interest is DTMB model 5512, which is a 1/46.6 scale geosym of DTMB model 5415 (DDG-51), with L = 3.048 m. The experiments are performed in a 3 x 3 x 100m towing tank equipped with a plunger-type wavemaker. The measurement systems include Krypton contactless motion tracker, 4-component load cell, towed 2-D particle image velocimetry (PIV) system, and servo wave probes with 2-D traverse. Uncertainty assessment following standard procedures is used to evaluate the quality of the data. Pitch and heave transfer functions and phase angles collapse to a single value independent of wave steepness. Free roll decay results show the addition of bilge keels to a ship model increases roll period and roll damping. Results show non-linear roll decay for Fr ≤ 0.138, a transition region for 0.190 ≤ Fr ≤ 0.340, and linear roll decay for Fr ≥ 0.410 for both without and with bilge keels. Phase-averaged flow-field velocity results show the evolution and subsequent decay of the bilge keel vortex. The vortex trails the motion of the bilge keel rotating clockwise for counter-clockwise model rotation (rolling to port) and rotates counter-clockwise for clockwise model rotation (rolling to starboard). The phase-averaged wave-field resembles the steady wave pattern (Kelvin wave pattern) with a superimposed oscillation due to the rolling motion of the model. As the model rolls, alternating crests and troughs radiate from the hull

  19. Bidirectional reflectance, leaf optical and physiological properties of prairie vegetation

    NASA Technical Reports Server (NTRS)

    Walter-Shea, E. A.; Blad, B. L.; Starks, P. J; Hays, C. J.; Mesarch, M. A.; Middleton, E. M.

    1990-01-01

    A modular multiband radiometer is used to measure reflected radiation from the vegetative surface of a prairie. The data are compared to estimates of incoming radiation by measuring the reflection from a molded halon panel, and the bidirectional reflectance factors are measured at seven view-zenith angles and various incidence angles. The canopy-reflectance results are compared to leaf-optical and other vegetative physiological properties, and a direct relationship is reported.

  20. High performance rolling element bearing

    NASA Technical Reports Server (NTRS)

    Bursey, Jr., Roger W. (Inventor); Olinger, Jr., John B. (Inventor); Owen, Samuel S. (Inventor); Poole, William E. (Inventor); Haluck, David A. (Inventor)

    1993-01-01

    A high performance rolling element bearing (5) which is particularly suitable for use in a cryogenically cooled environment, comprises a composite cage (45) formed from glass fibers disposed in a solid lubricant matrix of a fluorocarbon polymer. The cage includes inserts (50) formed from a mixture of a soft metal and a solid lubricant such as a fluorocarbon polymer.

  1. 42 CFR 21.46 - Merit roll.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Merit roll. 21.46 Section 21.46 Public Health... Appointment § 21.46 Merit roll. Each board appointed pursuant to § 21.30 to consider the qualifications of... Secretary, and, if approved by the Secretary, the report shall constitute a merit roll from which...

  2. 33 CFR 159.107 - Rolling test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Rolling test. 159.107 Section 159... MARINE SANITATION DEVICES Design, Construction, and Testing § 159.107 Rolling test. (a) The device, with... manufacturer in § 159.57. (b) Eighty percent of the rolling action must be approximately 15 degrees on...

  3. Deer predation on leaf miners via leaf abscission

    NASA Astrophysics Data System (ADS)

    Yamazaki, Kazuo; Sugiura, Shinji

    2008-03-01

    The evergreen oak Quercus gilva Blume sheds leaves containing mines of the leaf miner Stigmella sp. (Lepidoptera: Nepticulidae) earlier than leaves with no mines in early spring in Nara, central Japan. The eclosion rates of the leaf miner in abscised and retained leaves were compared in the laboratory to clarify the effects of leaf abscission on leaf miner survival in the absence of deer. The leaf miner eclosed successfully from both fallen leaves and leaves retained on trees. However, sika deer ( Cervus nippon centralis Kishida) feed on the fallen mined leaves. Field observations showed that deer consume many fallen leaves under Q. gilva trees, suggesting considerable mortality of leaf miners due to deer predation via leaf abscission. This is a previously unreported relationship between a leaf miner and a mammalian herbivore via leaf abscission.

  4. Mixed convective/dynamic roll vortices and their effects on initial wind and temperature profiles

    NASA Technical Reports Server (NTRS)

    Haack, Tracy; Shirer, Hampton N.

    1991-01-01

    The onset and development of both dynamically and convectively forced boundary layer rolls are studied with linear and nonlinear analyses of a truncated spectral model of shallow Boussinesq flow. Emphasis is given here on the energetics of the dominant roll modes, on the magnitudes of the roll-induced modifications of the initial basic state wind and temperature profiles, and on the sensitivity of the linear stability results to the use of modified profiles as basic states. It is demonstrated that the roll circulations can produce substantial changes to the cross-roll component of the initial wind profile and that significant changes in orientation angle estimates can result from use of a roll-modified profile in the stability analysis. These results demonstrate that roll contributions must be removed from observed background wind profiles before using them to investigate the mechanisms underlying actual secondary flows in the boundary layer. The model is developed quite generally to accept arbitrary basic state wind profiles as dynamic forcing. An Ekman profile is chosen here merely to provide a means for easy comparison with other theoretical boundary layer studies; the ultimate application of the model is to study observed boundary layer profiles. Results of the analytic stability analysis are validated by comparing them with results from a larger linear model. For an appropriate Ekman depth, a complete set of transition curves is given in forcing parameter space for roll modes driven both thermally and dynamically. Preferred orientation angles, horizontal wavelengths and propagation frequencies, as well as energetics and wind profile modifications, are all shown to agree rather well with results from studies on Ekman layers as well as with studies on near-neutral and convective atmospheric boundary layers.

  5. Damping in Pitch and Roll of Triangular Wings at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Brown, Clinton E; Adams, Mac C

    1948-01-01

    A method is derived for calculating the damping coefficients in pitch and roll for a series of triangular wings and a restricted series of sweptback wings at supersonic speeds. The elementary "supersonic source" solution of the linearized equation of motion is used to find the potential function of a line of doublets, and the flows are obtained by surface distributions of these doublet lines. The damping derivatives for triangular wings are found to be a function of the ratio of the tangent of the apex angle to the tangent of the Mach angle. As this ratio becomes equal to and greater than 1.0 for triangular wings, the damping derivatives, in pitch and in roll, become constant. The damping derivative in roll becomes equal to one-half the value calculated for an infinite rectangular wing, and the damping derivative in pitch for pitching about the apex becomes equal to 3.375 times that of an infinite rectangular wing.

  6. Perception of Perspective Angles

    PubMed Central

    2015-01-01

    We perceive perspective angles, that is, angles that have an orientation in depth, differently from what they are in physical space. Extreme examples are angles between rails of a railway line or between lane dividers of a long and straight road. In this study, subjects judged perspective angles between bars lying on the floor of the laboratory. Perspective angles were also estimated from pictures taken from the same point of view. Converging and diverging angles were judged to test three models of visual space. Four subjects evaluated the perspective angles by matching them to nonperspective angles, that is, angles between the legs of a compass oriented in the frontal plane. All subjects judged both converging and diverging angles larger than the physical angle and smaller than the angles in the proximal stimuli. A model of shallow visual space describes the results. According to the model, lines parallel to visual lines, vanishing at infinity in physical space, converge to visual lines in visual space. The perceived shape of perspective angles is incompatible with the perceived length and width of the bars. The results have significance for models of visual perception and practical implications for driving and flying in poor visibility conditions. PMID:27433312

  7. Perception of Perspective Angles.

    PubMed

    Erkelens, Casper J

    2015-06-01

    We perceive perspective angles, that is, angles that have an orientation in depth, differently from what they are in physical space. Extreme examples are angles between rails of a railway line or between lane dividers of a long and straight road. In this study, subjects judged perspective angles between bars lying on the floor of the laboratory. Perspective angles were also estimated from pictures taken from the same point of view. Converging and diverging angles were judged to test three models of visual space. Four subjects evaluated the perspective angles by matching them to nonperspective angles, that is, angles between the legs of a compass oriented in the frontal plane. All subjects judged both converging and diverging angles larger than the physical angle and smaller than the angles in the proximal stimuli. A model of shallow visual space describes the results. According to the model, lines parallel to visual lines, vanishing at infinity in physical space, converge to visual lines in visual space. The perceived shape of perspective angles is incompatible with the perceived length and width of the bars. The results have significance for models of visual perception and practical implications for driving and flying in poor visibility conditions. PMID:27433312

  8. 46 CFR 170.295 - Special consideration for free surface of passive roll stabilization tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) The factor (K) must be calculated as follows: (1) Plot (I/d)tan T on Graph 170.295 where— (i) (I) is... the roll tank; and (iii) (T) is the angle of heel. (2) Plot the moments of transference of the...

  9. 46 CFR 170.295 - Special consideration for free surface of passive roll stabilization tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) The factor (K) must be calculated as follows: (1) Plot (I/d)tan T on Graph 170.295 where— (i) (I) is... the roll tank; and (iii) (T) is the angle of heel. (2) Plot the moments of transference of the...

  10. 46 CFR 170.295 - Special consideration for free surface of passive roll stabilization tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) The factor (K) must be calculated as follows: (1) Plot (I/d)tan T on Graph 170.295 where— (i) (I) is... the roll tank; and (iii) (T) is the angle of heel. (2) Plot the moments of transference of the...

  11. 46 CFR 170.295 - Special consideration for free surface of passive roll stabilization tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) The factor (K) must be calculated as follows: (1) Plot (I/d)tan T on Graph 170.295 where— (i) (I) is... the roll tank; and (iii) (T) is the angle of heel. (2) Plot the moments of transference of the...

  12. 46 CFR 170.295 - Special consideration for free surface of passive roll stabilization tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) The factor (K) must be calculated as follows: (1) Plot (I/d)tan T on Graph 170.295 where— (i) (I) is... the roll tank; and (iii) (T) is the angle of heel. (2) Plot the moments of transference of the...

  13. Wind-tunnel investigation at supersonic speeds of a remote-controlled canard missile with a free-rolling-tail brake torque system

    NASA Technical Reports Server (NTRS)

    Blair, A. B., Jr.

    1985-01-01

    Wind tunnel tests were conducted at Mach numbers 1.70, 2.16, and 2.86 to determine the static aerodynamic characteristics of a cruciform canard-controlled missile with fixed or free rolling tailfin afterbodies. Mechanical coupling effects of the free-rolling-tail afterbody were investigated by using an electronic electromagnetic brake system providing arbitrary tail-fin brake torques with continuous measurements of tail-to-mainframe torque and tail roll rate. Remote-controlled canards were deflected to provide pitch, yaw, and roll control. Results indicate that the induced rolling moment coefficients due to canard yaw control are reduced and linearized for the free-rolling-tail (free-tail) configuration. The canards of the latter provide conventional roll control for the entire angle-of-attack test range. For the free-tail configuration, the induced rolling moment coefficient due to canard yaw control increased and the canard roll control decreased with increases in brake torque, which simulated bearing friction torque. It appears that a compromise in regard to bearing friction, for example, low-cost bearings with some friction, may allow satisfactory free-tail aerodynamic characteristics that include reductions in adverse rolling-moment coefficients and lower tail roll rates.

  14. Gravitropic basis of leaf blade nastic curvatures

    NASA Technical Reports Server (NTRS)

    Hayes, A. B.

    1982-01-01

    The curvatures produced in leaf blades by auxin treatment have been described as nastic curvatures because the initial differential growth is always enhanced on the lower side, regardless of the side of application. It is now known, however, that blades can show differential growth of either the upper or the lower side depending on the conditions of treatment. The dorsiventrality of the blade therefore influences but does not limit the direction of curvature. The dorsiventral directionality of response to growth regulators and the response to changes in the orientation to gravity are seen as indicating that blade curvatures are analogous to negative or positive gravitropism. It is noted that neither blade hyponasty or epinasty can be accounted for by ethylene alone. Petiole responses, however, are not directional, and the leaf angle changes induced by rotation or auxin treatment can be accounted for by ethylene production.

  15. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false What are the rules for securing roll-on/roll-off... for securing roll-on/roll-off or hook lift containers? (a) Applicability. The rules in this section apply to the transportation of roll-on/roll-off or hook lift containers. (b) Securement of a...

  16. Damped leaf flexure hinge

    NASA Astrophysics Data System (ADS)

    Chen, Zhong; Chen, Guisheng; Zhang, Xianmin

    2015-05-01

    Flexure-based mechanism like compliant actuation system embeds complex dynamics that will reduce the control bandwidth and limits their dynamic positioning precision. This paper presents a theoretical model of a leaf flexure hinge with damping layers using strain energy method and Kelvin damping model. The modified loss factor of the damped leaf flexure hinge is derived, and the equivalent viscous damping coefficient of the damped leaf hinge is obtained, which could be used to improve the pseudo-rigid-model. The free vibration signals of the hinge in three different damping configurations are measured. The experimental modal analysis also is performed on the three kinds of damped leaf flexure hinges in order to evaluate their 1st order bending natural frequency and vibration-suppressing effects. The evaluation of modified loss factor model also is performed. The experimental results indicate that the constrained layer damping can enhance the structure damping of the hinge even if only single damping layer each side, the modified loss factor model can get good predicts of a damped leaf flexure hinge in the frequency range below 1st order natural frequency, and it is necessary that the dimensional parameters of the damping layers and basic layer of the hinge should be optimized for simplification at the mechanism's design stage.

  17. Damped leaf flexure hinge.

    PubMed

    Chen, Zhong; Chen, Guisheng; Zhang, Xianmin

    2015-05-01

    Flexure-based mechanism like compliant actuation system embeds complex dynamics that will reduce the control bandwidth and limits their dynamic positioning precision. This paper presents a theoretical model of a leaf flexure hinge with damping layers using strain energy method and Kelvin damping model. The modified loss factor of the damped leaf flexure hinge is derived, and the equivalent viscous damping coefficient of the damped leaf hinge is obtained, which could be used to improve the pseudo-rigid-model. The free vibration signals of the hinge in three different damping configurations are measured. The experimental modal analysis also is performed on the three kinds of damped leaf flexure hinges in order to evaluate their 1st order bending natural frequency and vibration-suppressing effects. The evaluation of modified loss factor model also is performed. The experimental results indicate that the constrained layer damping can enhance the structure damping of the hinge even if only single damping layer each side, the modified loss factor model can get good predicts of a damped leaf flexure hinge in the frequency range below 1st order natural frequency, and it is necessary that the dimensional parameters of the damping layers and basic layer of the hinge should be optimized for simplification at the mechanism's design stage. PMID:26026549

  18. High speed electrical measurement for roll-to-roll nanomanufacturing

    NASA Astrophysics Data System (ADS)

    Orloff, Nathan; Long, Christian; Obrzut, Jan; Maillaud, Laurent; Mirri, Francesca; Kole, Thomas; McMichael, Robert; Pasquali, Matteo; Stranick, Stephan; Liddle, J. Alexander

    2015-03-01

    Roll-to-roll processing of nanomaterials can produce high-quality coatings and filaments continuously, enabling materials applications for electronics, fabrics, and wires. These applications often require specific electrical properties that are correlated to the material's nanostructure. While several high-throughput structural characterizations techniques exist, there are relatively few contactless options for quantifying the electrical properties of materials for nanomanufacturing. Here, we demonstrate a microwave method for measuring complex permittivity (or geometry for samples of known dielectric properties) in a millisecond. The demonstrated measurement times are suitable for current industrial needs, allowing real-time materials characterization and in-line control of processing variables without disrupting production. Address correspondence to Dr. Stephan J. Stranick, and Dr. J. Alexander Liddle.

  19. A review of roll-to-roll nanoimprint lithography

    PubMed Central

    2014-01-01

    Since its introduction in 1995, nanoimprint lithography has been demonstrated in many researches as a simple, low-cost, and high-throughput process for replicating micro- and nanoscale patterns. Due to its advantages, the nanoimprint lithography method has been rapidly developed over the years as a promising alternative to conventional nanolithography processes to fulfill the demands generated from the recent developments in the semiconductor and flexible electronics industries, which results in variations of the process. Roll-to-roll (R2R) nanoimprint lithography (NIL) is the most demanded technique due to its high-throughput fulfilling industrial-scale application. In the present work, a general literature review on the various types of nanoimprint lithography processes especially R2R NIL and the methods commonly adapted to fabricate imprint molds are presented to provide a clear view and understanding on the nanoimprint lithography technique as well as its recent developments. PACS 81.16.Nd PMID:25024682

  20. A Heading and Flight-Path Angle Control of Aircraft Based on Required Acceleration Vector

    NASA Astrophysics Data System (ADS)

    Yoshitani, Naoharu

    This paper describes a control of heading and flight-path angles of aircraft to time-varying command angles. The controller first calculates an acceleration command vector (acV), which is vertical to the velocity vector. acV consists of two components; the one is feedforward acceleration obtained from the rates of command angles, and the other is feedback acceleration obtained from angle deviations by using PID control law. A bank angle command around the velocity vector and commands of pitch and yaw rates are then obtained to generate the required acceleration. A roll rate command is calculated from bank angle deviation. Roll, pitch and yaw rate commands are put into the attitude controller, which can be composed of any suitable control laws such as PID control. The control requires neither aerodynamic coefficients nor online calculation of the inverse dynamics of the aircraft. A numerical simulation illustrates the effects of the control.

  1. Towards roll-to-roll manufacturing of polymer photonic devices

    NASA Astrophysics Data System (ADS)

    Subbaraman, Harish; Lin, Xiaohui; Ling, Tao; Guo, L. Jay; Chen, Ray T.

    2014-03-01

    Traditionally, polymer photonic devices are fabricated using clean-room processes such as photolithography, e-beam lithography, reactive ion etching (RIE) and lift-off methods etc, which leads to long fabrication time, low throughput and high cost. We have utilized a novel process for fabricating polymer photonic devices using a combination of imprinting and ink jet printing methods, which provides high throughput on a variety of rigid and flexible substrates with low cost. We discuss the manufacturing challenges that need to be overcome in order to realize true implementation of roll-to-roll manufacturing of flexible polymer photonic systems. Several metrology and instrumentation challenges involved such as availability of particulate-free high quality substrate, development and implementation of high-speed in-line and off-line inspection and diagnostic tools with adaptive control for patterned and unpatterned material films, development of reliable hardware, etc need to be addressed and overcome in order to realize a successful manufacturing process. Due to extreme resolution requirements compared to print media, the burden of software and hardware tools on the throughput also needs to be carefully determined. Moreover, the effect of web wander and variations in web speed need to accurately be determined in the design of the system hardware and software. In this paper, we show the realization of solutions for few challenges, and utilizing these solutions for developing a high-rate R2R dual stage ink-jet printer that can provide alignment accuracy of <10μm at a web speed of 5m/min. The development of a roll-to-roll manufacturing system for polymer photonic systems opens limitless possibilities for the deployment of high performance components in a variety of applications including communication, sensing, medicine, agriculture, energy, lighting etc.

  2. Roll Casting of Al-25%Si

    SciTech Connect

    Haga, Toshio; Harada, Hideto; Watari, Hisaki

    2011-05-04

    Strip casting of Al-25%Si strip was tried using an unequal diameter twin roll caster. The diameter of the lower roll (large roll) was 1000 mm and the diameter of the upper roll (small roll) was 250 mm. Roll material was mild steel. The sound strip could be cast at the speeds ranging from 8 m/min to 12 m/min. The strip did not stick to the roll without the parting material. The primary Si, which existed at centre area of the thickness direction, was larger than that which existed at other area. The size of the primary Si was smaller than 0.2 mm. Eutectic Si was smaller 5 {mu}m. The as-cast strip was ranging from 2 mm to 3 mm thick and its width was 100 mm. The as-cast strip could be hot rolled down to 1 mm. The hot rolled strip was cold rolled. The primary Si became smaller and the pore occurred around the primary Si after the rolling.

  3. Circuitry for Angle Measurements

    NASA Technical Reports Server (NTRS)

    Currie, J. R.; Kissel, R. R.

    1983-01-01

    Angle resolver pulsed and read under microprocessor control. Pulse generator excites resolver windings with dual slope pulse. System sequentially reads sine and cosine windings. Microprocessor determines angle through which resolver shaft turned from reference angle. Suitable applications include rate tables, antenna direction controllers, and machine tools.

  4. Two blowing concepts for roll and lateral control of aircraft

    NASA Technical Reports Server (NTRS)

    Tavella, D. A.; Wood, N. J.; Lee, C. S.; Roberts, L.

    1986-01-01

    Two schemes to modulate aerodynamic forces for roll and lateral control of aircraft have been investigated. The first scheme, called the lateral blowing concept, consists of thin jets of air exiting spanwise, or at small angle with the spanwise direction, from slots at the tips of straight wings. For this scheme, in addition to experimental measurements, a theory was developed showing the analytical relationship between aerodynamic forces and jet and wing parameters. Experimental results confirmed the theoretically derived scaling laws. The second scheme, which was studied experimentally, is called the jet spoiler concept and consists of thin jets exiting normally to the wing surface from slots aligned with the spanwise direction.

  5. Aerodynamic characteristics of cruciform missiles at high angles of attack

    NASA Technical Reports Server (NTRS)

    Lesieutre, Daniel J.; Mendenhall, Michael R.; Nazario, Susana M.; Hemsch, Michael J.

    1987-01-01

    An aerodynamic prediction method for missile aerodynamic performance and preliminary design has been developed to utilize a newly available systematic fin data base and an improved equivalent angle of attack methodology. The method predicts total aerodynamic loads and individual fin forces and moments for body-tail (wing-body) and canard-body-tail configurations with cruciform fin arrangements. The data base and the prediction method are valid for angles of attack up to 45 deg, arbitrary roll angles, fin deflection angles between -40 deg and 40 deg, Mach numbers between 0.6 and 4.5, and fin aspect ratios between 0.25 and 4.0. The equivalent angle of attack concept is employed to include the effects of vorticity and geometric scaling.

  6. Tribological Testing of Anti-Adhesive coatings for Cold Rolling Mill Rolls--Application to TiN-Coated Rolls

    SciTech Connect

    Ould, Choumad; Montmitonnet, Pierre; Gachon, Yves; Badiche, Xavier

    2011-05-04

    Roll life is a major issue in cold strip rolling. Roll wear may result either in too low roll roughness, bringing friction below the minimum requested for strip entrainment; or it may degrade strip surface quality. On the contrary, adhesive wear and transfer (''roll coating'', ''pick up'') may form a thick metallic deposits on the roll which increases friction excessively and degrades strip surface again [1]. The roll surface, with the help of a materials-adapted lubricant, must therefore possess anti-wear and anti-adhesive properties. Thus, High Speed Steeel (HSS) rolls show superior properties compared with standard Cr-steel rolls due to their high carbide surface coverage. Another way to improve wear and adhesion properties of surfaces is to apply hard metallic (hard-Cr) or ceramic coatings. Chromium is renowned for its excellent anti-wear and anti-adhesive properties and may serve as a reference. Here, as a first step towards alternative, optimised coatings, a PVD TiN coating has been deposited on tool steels, as previous attempts have proved TiN to be rather successful in cold rolling experiments [2,3]. Different tribological tests are reported here, giving insight in both anti-adhesive properties and fatigue life improvement.

  7. Increased roll stability suspension system

    SciTech Connect

    Giese, L.

    1987-05-26

    A suspension system is described for suspending an elongated chassis of a vehicle, such as a heavy duty truck, above the front axle and rear axle of a transversely extending tandem axle combination. The suspension system comprises: means for locating the roll center of the vehicle at an elevation below the elevation of the axles; and a stabilizer unit for providing roll stability to the vehicle. The stabilizer unit is mounted to the vehicle chassis at a pivot point longitudinally intermediate the front axle and the rear axle of the tandem axle combination for rotation in a generally horizontal plane. The stabilizer unit includes a pair of linkage members, each linkage member extending generally longitudinally outward from the pivot point in a direction opposite from the other linkage member and toward a corresponding axle.

  8. Rolling-Friction Robotic Gripper

    NASA Technical Reports Server (NTRS)

    Vranish, John M.

    1992-01-01

    Robotic gripper using rolling-friction fingers closes in on object with interface designed to mate with rollers somewhat misaligned initially, aligns object with respect to itself, then holds object securely in uniquely determined position and orientation. Operation of gripper causes minimal wear and burring of gripper and object. Exerts minimal friction forces on object when grasping and releasing. Releases object easily and reliably even when side forces and torques are between itself and object.

  9. Rolling Contact Fatigue of Ceramics

    SciTech Connect

    Wereszczak, Andrew A; Wang, W.; Wang, Y.; Hadfield, M.; Kanematsu, W.; Kirkland, Timothy Philip; Jadaan, Osama M.

    2006-09-01

    High hardness, low coefficient of thermal expansion and high temperature capability are properties also suited to rolling element materials. Silicon nitride (Si{sub 3}N{sub 4}) has been found to have a good combination of properties suitable for these applications. However, much is still not known about rolling contact fatigue (RCF) behavior, which is fundamental information to assess the lifetime of the material. Additionally, there are several test techniques that are employed internationally whose measured RCF performances are often irreconcilable. Due to the lack of such information, some concern for the reliability of ceramic bearings still remains. This report surveys a variety of topics pertaining to RCF. Surface defects (cracks) in Si{sub 3}N{sub 4} and their propagation during RCF are discussed. Five methods to measure RCF are then briefly overviewed. Spalling, delamination, and rolling contact wear are discussed. Lastly, methods to destructively (e.g., C-sphere flexure strength testing) and non-destructively identify potential RCF-limiting flaws in Si{sub 3}N{sub 4} balls are described.

  10. Mechanisms of rolling contact spalling

    NASA Technical Reports Server (NTRS)

    Kumar, A. M.; Kulkarni, S. M.; Bhargava, V.; Hahn, G. T.; Rubin, C. A.

    1987-01-01

    The results of a study aimed at analyzing the mechanical material interactions responsible for rolling contact spalling of the 440 C steel, high pressure oxygen turbopump bearings are presented. A coupled temperature displacement finite element analysis of the effects of friction heating under the contact is presented. The contact is modelled as a stationary, heat generating, 2 dimensional indent in an elastic perfectly plastic half-space with heat fluxes up to 8.6 x 10000 KW/m sq comparable to those generated in the bearing. Local temperatures in excess of 1000 C are treated. The calculations reveal high levels of residual tension after the contact is unloaded and cools. Efforts to promote Mode 2/Mode 3 fatigue crack growth under cyclic torsion in hardened 440 C steel are described. Spalls produced on 440 C steel by a 3 ball/rod rolling contact testing machine were studied with scanning microscopy. The shapes of the cyclic, stress strain hysteresis loops displayed by hardened 440 C steel in cyclic torsion at room temperature are defined for the plastic strain amplitudes encountered in rolling/sliding contact. Results of these analyses are discussed in detail.

  11. Roller compaction process development and scale up using Johanson model calibrated with instrumented roll data.

    PubMed

    Nesarikar, Vishwas V; Patel, Chandrakant; Early, William; Vatsaraj, Nipa; Sprockel, Omar; Jerzweski, Robert

    2012-10-15

    Roller compaction is a dry granulation process used to convert powder blends into free flowing agglomerates. During scale up or transfer of roller compaction process, it is critical to maintain comparable ribbon densities at each scale in order to achieve similar tensile strengths and subsequently similar particle size distribution of milled material. Similar ribbon densities can be reached by maintaining analogous normal stress applied by the rolls on ribbon for a given gap between rolls. Johanson (1965) developed a model to predict normal stress based on material properties and roll diameter. However, the practical application of Johanson model to estimate normal stress on the ribbon is limited due to its requirement of accurate estimate of nip pressure i.e. pressure at the nip angle. Another weakness of Johanson model is the assumption of a fixed angle of wall friction that leads to use of a fixed nip angle in the model. To overcome the above mentioned limitations, we developed a novel approach using roll force equations based on a modified Johanson model in which the requirement of pressure value at nip angle was eliminated. An instrumented roll on WP120 roller compactor was used to collect normal stress data measured at three locations across the width of a roll (P1, P2, P3), as well as gap and nip angle data on ribbon for placebo and various active blends along with corresponding process parameters. The nip angles were estimated directly using experimental pressure profile data of each run. The roll force equation of Johanson model was validated using normal stress, gap, and nip angle data of the placebo runs. The calculated roll force values compared well with those determined from the roll force equation provided for the Alexanderwerk(®) WP120 roller compactor. Subsequently, the calculation was reversed to estimate normal stress and corresponding ribbon densities as a function of gap and RFU (roll force per unit roll width). A placebo model was developed

  12. Non-linear dynamics of inlet film thickness during unsteady rolling process

    NASA Astrophysics Data System (ADS)

    Fu, Kuo; Zang, Yong; Gao, Zhiying; Qin, Qin; Wu, Diping

    2016-05-01

    The inlet film thickness directly affects film and stress distribution of rolling interfaces. Unsteady factors, such as unsteady back tension, may disturb the inlet film thickness. However, the current models of unsteady inlet film thickness lack unsteady disturbance factors and do not take surface topography into consideration. In this paper, based on the hydrodynamic analysis of inlet zone an unsteady rolling film model which concerns the direction of surface topography is built up. Considering the small fluctuation of inlet angle, absolute reduction, reduction ratio, inlet strip thickness and roll radius as the input variables and the fluctuation of inlet film thickness as the output variable, the non-linear relationship between the input and output is discussed. The discussion results show that there is 180° phase difference between the inlet film thickness and the input variables, such as the fluctuant absolute reduction, the fluctuant reduction ratio and non-uniform inlet strip thickness, but there is no phase difference between unsteady roll radius and the output. The inlet angle, the steady roll radius and the direction of surface topography have significant influence on the fluctuant amplitude of unsteady inlet film thickness. This study proposes an analysis method for unsteady inlet film thickness which takes surface topography and new disturbance factors into consideration.

  13. Low-Speed Yawed-Rolling Characteristics of a Pair of 56-Inch-Diameter, 32-Ply-Rating, Type 7 Aircraft Tires

    NASA Technical Reports Server (NTRS)

    Thompson, Wilbur E.; Horne, Walter B.

    1959-01-01

    The low-speed (up to 4 miles per hour) yawed-rolling characteristics of two 56 x 16 32-ply-rating, type 7 aircraft tires under straight-yawed rolling were determined over a range of inflation pressures and yaw angles for a vertical load approximately equal to 75 percent of the rated vertical load. The quantities measured or determined included cornering force, drag force self-alining torque, pneumatic caster vertical tire deflection, yaw angle, and relaxation length. During straight-yawed rolling the normal force generally increased with increasing yaw angle within the test range. The self-alining torque increased to a maximum value and then decreased with increasing angle of yaw. The pneumatic caster tended to decrease with increasing yaw angle.

  14. Penetration of sunlight into a canopy - Explicit models based on vertical and horizontal leaf projections

    NASA Technical Reports Server (NTRS)

    Otterman, J.; Brakke, T.

    1986-01-01

    The projections of leaf areas onto a horizontal plane and onto a vertical plane are examined for their utility in characterizing canopies for sunlight penetration (direct beam only) models. These projections exactly specify the penetration if the projections on the principal plane of the normals to the top surfaces of the leaves are in the same quadrant as the sun. Inferring the total leaf area from these projections (and therefore the penetration as a function of the total leaf area) is possible only with a large uncertainty (up to + or - 32 percent) because the projections are a specific measure of the total leaf area only if the leaf angle distribution is known. It is expected that this uncertainty could be reduced to more acceptable levels by making an approximate assessment of whether the zenith angle distribution is that of an extremophile canopy.

  15. Mesomorphic Lamella Rolling of Au in Vacuum

    NASA Astrophysics Data System (ADS)

    Huang, Chang-Ning; Chen, Shuei-Yuan; Shen, Pouyan

    2009-11-01

    Lamellar nanocondensates in partial epitaxy with larger-sized multiply twinned particles (MTPs) or alternatively in the form of multiple-walled tubes (MWTs) having nothing to do with MTP were produced by the very energetic pulse laser ablation of Au target in vacuum under specified power density and pulses. Transmission electron microscopic observations revealed (111)-motif diffraction and low-angle scattering. They correspond to layer interspacing (0.241-0.192 nm) and the nearest neighbor distance (ca. 0.74-0.55 nm) of atom clusters within the layer, respectively, for the lamella, which shows interspacing contraction with decreasing particle size under the influence of surface stress and rolls up upon electron irradiation. The uncapped MWT has nearly concentric amorphous layers interspaced by 0.458-0.335 nm depending on dislocation distribution and becomes spherical onions for surface-area reduction upon electron dosage. Analogous to graphene-derived tubular materials, the lamella-derived MWT of Au could have pentagon-hexagon pair at its zig-zag junction and useful optoelectronic properties worthy of exploration.

  16. Mesomorphic Lamella Rolling of Au in Vacuum

    PubMed Central

    2009-01-01

    Lamellar nanocondensates in partial epitaxy with larger-sized multiply twinned particles (MTPs) or alternatively in the form of multiple-walled tubes (MWTs) having nothing to do with MTP were produced by the very energetic pulse laser ablation of Au target in vacuum under specified power density and pulses. Transmission electron microscopic observations revealed (111)-motif diffraction and low-angle scattering. They correspond to layer interspacing (0.241–0.192 nm) and the nearest neighbor distance (ca. 0.74–0.55 nm) of atom clusters within the layer, respectively, for the lamella, which shows interspacing contraction with decreasing particle size under the influence of surface stress and rolls up upon electron irradiation. The uncapped MWT has nearly concentric amorphous layers interspaced by 0.458–0.335 nm depending on dislocation distribution and becomes spherical onions for surface-area reduction upon electron dosage. Analogous to graphene-derived tubular materials, the lamella-derived MWT of Au could have pentagon–hexagon pair at its zig-zag junction and useful optoelectronic properties worthy of exploration. PMID:20628452

  17. Mesomorphic lamella rolling of au in vacuum.

    PubMed

    Huang, Chang-Ning; Chen, Shuei-Yuan; Shen, Pouyan

    2009-01-01

    Lamellar nanocondensates in partial epitaxy with larger-sized multiply twinned particles (MTPs) or alternatively in the form of multiple-walled tubes (MWTs) having nothing to do with MTP were produced by the very energetic pulse laser ablation of Au target in vacuum under specified power density and pulses. Transmission electron microscopic observations revealed (111)-motif diffraction and low-angle scattering. They correspond to layer interspacing (0.241-0.192 nm) and the nearest neighbor distance (ca. 0.74-0.55 nm) of atom clusters within the layer, respectively, for the lamella, which shows interspacing contraction with decreasing particle size under the influence of surface stress and rolls up upon electron irradiation. The uncapped MWT has nearly concentric amorphous layers interspaced by 0.458-0.335 nm depending on dislocation distribution and becomes spherical onions for surface-area reduction upon electron dosage. Analogous to graphene-derived tubular materials, the lamella-derived MWT of Au could have pentagon-hexagon pair at its zig-zag junction and useful optoelectronic properties worthy of exploration. PMID:20628452

  18. Effect of Dynamic Rolling Oscillations on Twin Tail Buffet Response

    NASA Technical Reports Server (NTRS)

    Sheta, Essam F.; Kandil, Osama A.

    1999-01-01

    The effect of dynamic rolling oscillations of delta-wing/twin-tail configuration on twin-tail buffet response is investigated. The computational model consists of a sharp-edged delta wing of aspect ratio one and swept-back flexible twin tail with taper ratio of 0.23. The configuration model is statically pitched at 30 deg. angle of attack and then forced to oscillate in roll around the symmetry axis at a constant amplitude of 4 deg. and reduced frequency of pi and 2(pi). The freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. This multidisciplinary problem is solved using three sets of equations on a dynamic multi-block grid structure. The first set is the unsteady, full Navier-Stokes equations, the second set is the aeroelastic equations for coupled bending and torsion vibrations of the tails, and the third set is the grid-displacement equations. The configuration is investigated for inboard position of the twin tails which corresponds to a separation distance between the twin tails of 33% wing span. The computed results are compared with the results of stationary configuration, which previously have been validated using experimental data. The results conclusively showed that the rolling oscillations of the configuration have led to higher loads, higher deflections, and higher excitation peaks than those of the stationary configuration. Moreover, increasing the reduced frequency has led to higher loads and excitation peaks and lower bending and torsion deflections and acceleration.

  19. Kinematics investigations of cylinders rolling down a ramp using tracker

    NASA Astrophysics Data System (ADS)

    Prima, Eka Cahya; Mawaddah, Menurseto; Winarno, Nanang; Sriwulan, Wiwin

    2016-02-01

    Nowadays, students' exploration as well as students' interaction in the application stage of learning cycle can be improved by directly model real-world objects based on Newton's Law using Open Source Physics (OSP) computer-modeling tools. In a case of studying an object rolling down a ramp, a traditional experiment method commonly uses a ticker tape sliding through a ticker timer. However, some kinematics parameters such as the instantaneous acceleration and the instantaneous speed of object cannot be investigated directly. By using the Tracker video analysis method, all kinematics parameters of cylinders rolling down a ramp can be investigated by direct visual inspection. The result shows that (1) there are no relations of cylinders' mass as well as cylinders' radius towards their kinetics parameters. (2) Excluding acceleration data, the speed and position as function of time follow the theory. (3) The acceleration data are in the random order, but their trend-lines closely fit the theory with 0.15% error. (4) The decrease of acceleration implicitly occurs due to the air friction acting on the cylinder during rolling down. (5) The cylinder's inertial moment constant has been obtained experimentally with 3.00% error. (6) The ramp angle linearly influences the cylinders' acceleration with 2.36% error. This research implied that the program can be further applied to physics educational purposes.

  20. Maple Leaf Outdoor Centre.

    ERIC Educational Resources Information Center

    Maguire, Molly; Gunton, Ric

    2000-01-01

    Maple Leaf Outdoor Centre (Ontario) has added year-round outdoor education facilities and programs to help support its summer camp for disadvantaged children. Schools, youth centers, religious groups, and athletic teams conduct their own programs, collaborate with staff, or use staff-developed programs emphasizing adventure education and personal…

  1. Raspberry leaf curl virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Raspberry leaf curl virus (RLCV) is limited to hosts in the genus Rubus and is transmitted persistently by the small raspberry aphid, Aphis rubicola Oestlund. It is found only in North America, principally in the northeastern United States and southeastern Canada and in the Rocky Mountain regions of...

  2. Bacterial leaf spot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial leaf spot has been reported in Australia (Queensland), Egypt, El Salvador, India, Japan, Nicaragua, Sudan, and the United States (Florida, Iowa, Kansas, Maryland, and Wisconsin). It occasionally causes locally severe defoliation and post-emergence damping-off and stunting. The disease is...

  3. Pressure Drop Correlations of Single-Phase and Two-Phase Flow in Rolling Tubes

    SciTech Connect

    Xia-xin Cao; Chang-qi Yan; Pu-zhen Gao; Zhong-ning Sun

    2006-07-01

    A series of experimental studies of frictional pressure drop for single phase and two-phase bubble flow in smooth rolling tubes were carried out. The tube inside diameters were 15 mm, 25 mm and 34.5 mm respectively, the rolling angles of tubes could be set as 10 deg. and 20 deg., and the rolling periods could be set as 5 s, 10 s and 15 s. Combining with the analysis of single-phase water motion, it was found that the traditional correlations for calculating single-phase frictional coefficient were not suitable for the rolling condition. Based on the experimental data, a new correlation for calculating single-phase frictional coefficient under rolling condition was presented, and the calculations not only agreed well with the experimental data, but also could display the periodically dynamic characteristics of frictional coefficients. Applying the new correlation to homogeneous flow model, two-phase frictional pressure drop of bubble flow in rolling tubes could be calculated, the results showed that the relative error between calculation and experimental data was less than {+-} 25%. (authors)

  4. Long term prediction of roll phase for an undisturbed spinning spacecraft

    NASA Technical Reports Server (NTRS)

    Smith, M. A.; Dyer, J. W.

    1987-01-01

    This paper describes the attitude control of the Pioneer 10 spacecraft since the loss of the sun-sensor signal in late 1983. It is necessary to control the attitude of the spin-stablized spacecraft so as to maintain communications with earth. Roll phase is calculated on earth using data from a science instrument on-board Pioneer 10, the imaging-photopolarimeter, which, along with its other functions, was designed to collect images of Jupiter during encounter in 1973. With calculation of instantaneous roll phase performed only once per week, the spacecraft roll angle can be predicted more than a week ahead for timing reorientation impulses. Attitude reorientation maneuvers based on roll phase predictions have been successfully executed for several years on Pioneer 10. Of 10 maneuvers analyzed in this paper, predictions were made for as many as 10 days in the future based on a roll-phase measurements spanning only 12 days of data. The average maneuver was planned by projecting the roll phase for 3 days (22,000 spacecraft revolutions) and resulted in a maneuver execution phase error of only 11 deg.

  5. Forced Rolling Oscillation of a 65 deg-Delta Wing in Transonic Vortex-Breakdown Flow

    NASA Technical Reports Server (NTRS)

    Menzies, Margaret A.; Kandil, Osama A.; Kandil, Hamdy A.

    1996-01-01

    Unsteady, transonic, vortex dominated flow over a 65 deg. sharp-edged, cropped-delta wing of zero thickness undergoing forced rolling oscillations is investigated computationally. The wing angle of attack is 20 deg. and the free stream Mach number and Reynolds number are 0.85 and 3.23 x 10(exp 6), respectively. The initial condition of the flow is characterized by a transverse terminating shock which induces vortex breakdown of the leading edge vortex cores. The computational investigation uses the time accurate solution of the laminar, unsteady, compressible, full Navier-Stokes equations with the implicit, upwind, Roe flux difference splitting, finite-volume scheme. While the maximum roll amplitude is kept constant at 4.0 deg., both Reynolds number and roll frequency are varied covering three cases of forced sinusoidal rolling. First, the Reynolds number is held at 3.23 x 10(exp 6) and the wing is forced to oscillate in roll around the axis of geometric symmetry at a reduced frequency of 2(pi). Second, the Reynolds number is reduced to 0.5 x 10(exp 6) to observe the effects of added viscosity on the vortex breakdown. Third, with the Reynolds number held at 0.5 x 10(exp 6), the roll frequency is reduced to 1(pi) to complete the study.

  6. Evaluation of two methods of predicting MLC leaf positions using EPID measurements

    SciTech Connect

    Parent, Laure; Seco, Joao; Evans, Phil M.; Dance, David R.; Fielding, Andrew

    2006-09-15

    In intensity modulated radiation treatments (IMRT), the position of the field edges and the modulation within the beam are often achieved with a multileaf collimator (MLC). During the MLC calibration process, due to the finite accuracy of leaf position measurements, a systematic error may be introduced to leaf positions. Thereafter leaf positions of the MLC depend on the systematic error introduced on each leaf during MLC calibration and on the accuracy of the leaf position control system (random errors). This study presents and evaluates two methods to predict the systematic errors on the leaf positions introduced during the MLC calibration. The two presented methods are based on a series of electronic portal imaging device (EPID) measurements. A comparison with film measurements showed that the EPID could be used to measure leaf positions without introducing any bias. The first method, referred to as the 'central leaf method', is based on the method currently used at this center for MLC leaf calibration. It mimics the manner in which leaf calibration parameters are specified in the MLC control system and consequently is also used by other centers. The second method, a new method proposed by the authors and referred to as the ''individual leaf method,'' involves the measurement of two positions for each leaf (-5 and +15 cm) and the interpolation and extrapolation from these two points to any other given position. The central leaf method and the individual leaf method predicted leaf positions at prescribed positions of -11, 0, 5, and 10 cm within 2.3 and 1.0 mm, respectively, with a standard deviation (SD) of 0.3 and 0.2 mm, respectively. The individual leaf method provided a better prediction of the leaf positions than the central leaf method. Reproducibility tests for leaf positions of -5 and +15 cm were performed. The reproducibility was within 0.4 mm on the same day and 0.4 mm six weeks later (1 SD). Measurements at gantry angles of 0 deg., 90 deg., and 270 deg

  7. In situ monitoring of structure formation in the active layer of polymer solar cells during roll-to-roll coating

    SciTech Connect

    Rossander, Lea H.; Zawacka, Natalia K.; Dam, Henrik F.; Krebs, Frederik C.; Andreasen, Jens W.

    2014-08-15

    The active layer crystallization during roll-to-roll coating of organic solar cells is studied in situ. We developed an X-ray setup where the coater unit is an integrated part of the small angle X-ray scattering instrument, making it possible to control the coating process while recording scattering measurements in situ, enabling us to follow the crystal formation during drying. By varying the distance between the coating head and the point where the X-ray beam hits the film, we obtained measurements of 4 different stages of drying. For each of those stages, the scattering from as long a foil as possible is summed together, with the distance from coating head to scattering point kept constant. The results are average crystallographic properties for the active layer coated on a 30 m long foil. With this insight into the dynamics of crystallization in a roll-coated polymer film, we find that the formation of textured and untextured crystallites seems uncorrelated, and happens at widely different rates. Untextured P3HT crystallites form later in the drying process than expected which may explain previous studies speculating that untextured crystallization depends on concentration. Textured crystallites, however, begin forming much earlier and steadily increases as the film dries, showing a development similar to other in situ studies of these materials.

  8. Effect of viscosity on rolling-element fatigue life at cryogenic temperature with fluorinated ether lubricants

    NASA Technical Reports Server (NTRS)

    Dietrich, M. W.; Zaretsky, E. V.

    1975-01-01

    Rolling-element fatigue tests were conducted with 12.7-mm-(1/2-in.-) diameter AISI 52100 steel balls in the NASA five-ball fatigue tester, with a maximum hertz stress of 5500 mN/m2 (800 000 psi), a shaft speed of 4750 rpm, lubricant temperature of 200 K (360 R), a contact angle of 20 deg, using four fluorinated ether lubricants of varying viscosities. No statistically significant differences in rolling-element fatigue life occurred using the four viscosity levels. Elastohydrodynamic calculations indicate that values of the lubricant film parameter were approximately 2 or greater.

  9. Some theoretical low-speed span loading characteristics of swept wings in roll and sideslip

    NASA Technical Reports Server (NTRS)

    Bird, John D

    1950-01-01

    The Weissinger method for determining additional span loading for incompressible flow is used to find the damping in roll, the lateral center of pressure of the rolling for wing plan forms of various aspect ratios, taper ratios, and sweep angles. In addition, the applicability of the method to the determination of certain other aerodynamic derivatives is investigated, and corrections for the first-order effects of compressibility are indicated. The agreement obtained between experimentally and theoretically determined values for the aerodynamic coefficients indicates that the method of Weissinger is well suited to the calculation of such resulting aerodynamic derivatives of wings as do not involve considerations of tip suction.

  10. Controlled-Shape, Ultrasonic-Angle-Beam Standard Reflector

    NASA Technical Reports Server (NTRS)

    Berry, J., Robertf.

    1986-01-01

    New ultrasonic angle-beam standard reflector uses impression of letter "l" steel-die stamp. NDE techniques and standard reflector apply to use of pulse-echo-type ultrasonic equipment for inspection of wrought metals including forgings and forging stock; rolled billet, bar or plate; and extruded bar, tube, and shapes. "l" reference standard reflector affords advantages of easy insertion in inspected item using common hand-tools and greatly reduced implementation time through elimination of machining operations.