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Journal articles on the topic 'Rotational systems'

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Author: Grafiati

Published: 10 December 2022

Last updated: 19 February 2023

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1

Pani, John R., and Davido Dupree. "Spatial Reference Systems in the Comprehension of Rotational Motion." Perception 23, no. 8 (August 1994): 929–46. http://dx.doi.org/10.1068/p230929.

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In certain simple rotations of objects, the orientation of the axis and planes of rotation can determine whether people are able to visualize the motion or perceive it as simple and coherent. This finding affords the opportunity to investigate the spatial reference systems used to define the orientation of the axis and planes of rotation. The results of two experiments suggest that the permanent environment is the primary reference system, apart from the rotating object, used for this purpose. Subjects also were able to use a local spatial environment to determine the orientation of the motion; some subjects were particularly adept at this. The viewer perspective, in contrast, was irrelevant as a reference system in these experiments. These results argue strongly for the primacy of environmental reference systems in the perception and imagination of orientation and extend the set of findings common between the comprehension of rotational motion and orientation-sensitive form perception.

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2

Pani, John R. "Limits on the Comprehension of Rotational Motion: Mental Imagery of Rotations with Oblique Components." Perception 22, no. 7 (July 1993): 785–808. http://dx.doi.org/10.1068/p220785.

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Mental imagery of rotational motion across variation in the orientation of a square to an axis of rotation, the orientation of the axis to the environment/viewer, and the starting orientation of the rotation were investigated in three experiments. The experimental method included specifying the particular rotations that subjects should consider and obtaining exact predictions of the outcomes of the rotations. When the square was normal to the axis and the axis was normal to the environment/viewer, performance was excellent. When either of these relationships was oblique, performance was quite good. When both of these relationships were oblique, nearly every subject made large errors on every problem. The difficulty of the double-oblique rotations was reduced when the initial orientation of the square was not canonical. Current views of the comprehension of rotational motion are discussed. It appears that the comprehension of rotational motion can be understood as an organization of the symmetric space traced out by the motion. People succeed in organizing this space when it is aligned with a principal spatial reference system.

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3

Painter, K. M., D. L. Young, D. M. Granatstein, and D. J. Mulla. "Combining alternative and conventional systems for environmental gains." American Journal of Alternative Agriculture 10, no. 2 (June 1995): 88–96. http://dx.doi.org/10.1017/s0889189300006214.

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AbstractTwo conventional cropping systems (winter wheat/dry peas and winter wheat/spring barley/dry peas) in the dryland grain region of southeastern Washington were compared with several alternative systems regarding profitability and environmental impacts. Two of the alternative systems use green manure crops and have low fertilizer and pesticide requirements. The remaining two are otherwise conventional rotations modified to include soil-building crops, bluegrass seed and rapeseed.Estimates of annual off-site erosion damage ranged from $6.56 to $20.50 per rotational acre, while on-site damage estimates ranged from $0.50 to $1.55 per rotational acre. Estimated leaching losses of pesticides to a water table 3.6 feet deep were negligible, but significant leaching losses of nitrate-N were predicted to occur from fall-applied inorganic fertilizer.Including bluegrass in a conventional grain rotation increased estimated net returns over variable costs by 16% and decreased soil loss by 33% compared with the most profitable conventional rotation. The next most profitable alternative system, rapeseed plus a conventional grain rotation, had slightly higher net returns over variable costs than the second most profitable conventional rotation, with slightly less soil loss. When fixed costs of machinery depreciation and land are included, the alternative systems fared relatively better. An experimental wheat/pea/medic system had higher projected net returns over total costs than the most profitable conventional rotation, while averaging just one-third as much soil loss per year. A wheat/barley/sweetclover green manure rotation was similar in profitability to the less profitable conventional rotation, but had only two-thirds as much soil loss.We constructed a mixed-integer linear programming model to determine the profitmaximizing combination of conventional and alternative rotations under 1990 farm bill provisions. Planting all or nearly all land to the bluegrass plus conventional grain rotation maximized returns over total costs for high, medium, and low program crop price scenarios. Farmers maximized profit by participating in both the wheat and barley programs under the low price scenario, only in the wheat program with moderate prices, and in neither the wheat nor the barley program under the high price scenario.

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4

Casdagli, Martin. "Rotational chaos in dissipative systems." Physica D: Nonlinear Phenomena 29, no. 3 (January 1988): 365–86. http://dx.doi.org/10.1016/0167-2789(88)90036-x.

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5

Mazurov, B. T. "Geodynamic systems (qualitative research rotational movements)." Geodesy and Cartography 919, no. 1 (February 20, 2017): 35–39. http://dx.doi.org/10.22389/0016-7126-2017-919-1-35-39.

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Geodetic data and their subsequent statistical analysis enable mathematical modeling and identifying the stress-deformed state of geodynamic systems in concern to the aspect of natural and man-made disasters prediction. Geodetic monitoring geodynamic processes is necessary for solving a number of scientific and practical tasks of geodesy i.e. expanding and maintaining the national geodetic network, studying changes in gravity field in time, using GNSS technology. Most important extension of research is mathematical modelling of geodynamic systems in a predictive order. To study the complex (nonlinear) geodynamic processes the appropriate mathematical framework should be selected. Here are theoretical foundations for studying rotation movements of the earth’s surface. A mathematical model of rotary circular structures of the Earth was mentioned. There are mathematical models explaining the nature of sudden global, regional and some local geodynamic processes. They are based on differences in temporal and spatial scales, of geodynamic systems. Theoretical bases of description rotational motions on a plane by a system of differential equations were considered. Some examples of integral curves were given. They can be qualitative characteristics of geodynamic systems. In many cases, a similar trajectory corresponds to the rotational horizontal movements of the earth’s surface.

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6

Afaunov, A. A., K. K. Takhmazyan, M. L. Mukhanov, I. V. Basankin, and M. Yu Ageyev. "Rotational stability of thoracolumbar junction fixation systems." Innovative Medicine of Kuban, no. 2 (June 20, 2021): 21–28. http://dx.doi.org/10.35401/2500-0268-2021-22-2-21-28.

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Objective To compare the rotational stability of fusion constructs using bisegmental fixation of Th12-L2 vertebrae with anterior stabilization or pedicle screw fixation.Material and Methods The strength, rigidity and limit of elasticity in the “injured vertebral motion segments (VMS) – bisegmental anterior stabilization” system under dislocating rotational loads were estimated. The data obtained were compared with the similar characteristics of the “injured VMS – bisegmental 4-screw transpedicular metal construction” system and intact spine segments.Results Under rotational loads the limits of elasticity of injured spine segments of Th12-L2 with anterior stabilization and transpedicular screw fixation (TSF) is 45.5 and 41.7%, respectively, and the general strength is 66.4% and 80%, respectively, as compared with those intact VMS. Rigidity parameters of anterior-stabilized and pedicle screw fixated VMS with unstable damage of L1 are 60.2 and 93.9%, accordingly, in comparison with those intact VMS.Conclusion No significant differences were observed between bisegmental anterior stabilization and bisegmental pedicle screw fixation of thoracolumbar junction in terms of the key mechanical properties. When treating patients with unstable thoracolumbar spine injuries using bisegmental anterior stabilization or transpedicular fixation with 4-screw spinal system possible rotation motion amplitude of operated segments must not exceed 50% of maximum physiological limits.

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7

Badgery, W., G. Millar, K. Broadfoot, J. Martin, D. Pottie, A. Simmons, and P. Cranney. "Better management of intensive rotational grazing systems maintains pastures and improves animal performance." Crop and Pasture Science 68, no. 12 (2017): 1131. http://dx.doi.org/10.1071/cp16396.

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Grazing management has been identified as a means of increasing livestock production and improving the composition of perennial pastures. The benefits of intensive rotational grazing have been the subject of much debate, but few studies have evaluated contrasting management of intensive rotational systems. A grazing management experiment was established on a pasture with cocksfoot (Dactylis glomerata L., varieties Porto and Kara) as the dominant species, to investigate different stocking rates, paddock numbers and rotation speeds, and a flexible treatment that adjusted grazing time, rest periods and stock numbers for optimal pasture utilisation. Data were collected on pasture composition and diet quality assessed by using faecal analysis, animal weight changes and pasture characteristics. Animal production per hectare was greatest for fast rotations (56 days’ rest) at high stocking rates (HStR, 13.6 dry sheep equivalents (DSE) ha–1), but continuous grazing (CG) was equally productive. Although flexible grazing based on the 3–4-leaf stage was proposed as the best balance between pasture production and quality, this treatment had lower stocking rates (9.2 DSE ha–1) and was not as productive. No treatment negatively affected pasture composition over the 4-year period. Area of bare ground was highest for the HStR CG treatment; however, the 30-paddock rotations were able to limit bare ground at the same stocking rate. The results indicated that intensive rotational grazing could be effectively managed by using green herbage allowance. In spring, green herbage allowance needed to be 1–1.5 kg green dry matter (DM) DSE–1 day–1, which increased to 5 kg green DM DSE–1 day–1 as the quality of green DM decreased, to allow selective grazing to enhance diet quality.

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8

Ramanathan, Jayakumar. "The Existence and Structure of Rotational Systems in the Circle." Abstract and Applied Analysis 2018 (June 3, 2018): 1–11. http://dx.doi.org/10.1155/2018/8752012.

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By a rotational system, we mean a closed subset X of the circle, T=R/Z, together with a continuous transformation f:X→X with the requirements that the dynamical system (X,f) be minimal and that f respect the standard orientation of T. We show that infinite rotational systems (X,f), with the property that map f has finite preimages, are extensions of irrational rotations of the circle. Such systems have been studied when they arise as invariant subsets of certain specific mappings, F:T→T. Because our main result makes no explicit mention of a global transformation on T, we show that such a structure theorem holds for rotational systems that arise as invariant sets of any continuous transformation F:T→T with finite preimages. In particular, there are no explicit conditions on the degree of F. We then give a development of known results in the case where Fθ=d·θmod⁡1 for an integer d>1. The paper concludes with a construction of infinite rotational sets for mappings of the unit circle of degree larger than one whose lift to the universal cover is monotonic.

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9

Soong, C. Y. "Thermal Buoyancy Effects in Rotating Non-Isothermal Flows." International Journal of Rotating Machinery 7, no. 6 (2001): 435–46. http://dx.doi.org/10.1155/s1023621x01000380.

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The present paper is concerned with the non-isothermal flow mechanisms in rotating systems with emphasis on the rotation-induced thermal buoyancy effects stemming from the coexistence of rotational body forces and the nonuniformity of the fluid temperature field. Non-isothermal flow in rotating ducts of radial and parallel modes and rotating cylindrical configurations, including rotating cylinders and disk systems, are considered. Previous investigations closely related to the rotational buoyancy are surveyed. The mechanisms of the rotation-induced buoyancy are manifested by the author's recent theoretical results and scaling analyses pertaining to the rotation-induced buoyancy in rotating ducts and two-disk systems. Finally, the open issues for future researches in this area are proposed.

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10

Tautges, Nicole E., Ian C. Burke, Kristy Borrelli, and E. Patrick Fuerst. "Competitive ability of rotational crops with weeds in dryland organic wheat production systems." Renewable Agriculture and Food Systems 32, no. 1 (February 1, 2016): 57–68. http://dx.doi.org/10.1017/s1742170516000028.

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AbstractWhile demand continues to grow and prices for organic grains have remained almost double those of conventional grains, few growers in the dryland wheat production region of Eastern Washington produce organic grain. Growers have cited weed control constraints as a top factor preventing adoption of organic production practices. In organic systems, inherent competitive ability of crops is very important in managing and preventing weed infestations. The objective of this study was to identify crop species that could reduce weed pressure and compete with perennial weeds in a wheat (Triticum aestivum) rotation. To assess weed suppressive ability of alternative rotational crops, relative total weed biomass and relative biomass of two perennial and three annual weed species were examined over 4 years in three organic cropping systems where winter wheat was in rotation with alternative crops, as part of a long-term study examining dryland organic wheat production. Three years of continuous alfalfa (Medicago sativa) production reduced Canada thistle (Cirsium arvense) biomass during the alfalfa production phase, and reduced Canada thistle biomass in winter wheat following alfalfa, compared with wheat following winter pea (Pisum sativum). Alfalfa was competitive with wild oat (Avena fatua), though it competed poorly with winter annual grass weeds. Spring barley (Hordeum vulgare), when established successfully, suppressed jointed goatgrass (Aegilops cylindrica) more than winter triticale (xTriticosecale), winter wheat, and spring wheat, and demonstrated some competitiveness toward field bindweed (Convolvulus arvensis). Winter triticale competed poorly with field bindweed, but suppressed Canada thistle and downy brome (Bromus tectorum). All alternative rotational crops contained lower weed biomass than winter pea, the crop typically rotated with wheat in the region. Organic and conventional growers could gain benefits in perennial and winter annual weed suppression by incorporating alternative rotational crops into wheat rotations.

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11

Sigalov, Mark, Vladimir Lokshin, Nina Larina, and Vladimir Khodorkovsky. "Hindered rotational barriers in conjugated donor–acceptor substituted systems: calculations vs. experiments." Physical Chemistry Chemical Physics 22, no. 3 (2020): 1214–21. http://dx.doi.org/10.1039/c9cp06234c.

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12

Azevedo, George Oliveira de Araújo, Bruno José Torres Fernandes, Leandro Honorato de Souza Silva, Agostinho Freire, Rogério Pontes de Araújo, and Francisco Cruz. "Event-Based Angular Speed Measurement and Movement Monitoring." Sensors 22, no. 20 (October 19, 2022): 7963. http://dx.doi.org/10.3390/s22207963.

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Computer vision techniques can monitor the rotational speed of rotating equipment or machines to understand their working conditions and prevent failures. Such techniques are highly precise, contactless, and potentially suitable for applications without massive setup changes. However, traditional vision sensors collect a significant amount of data to process and measure the rotation of high-speed systems, and they are susceptible to motion blur. This work proposes a new method for measuring rotational speed processing event-based data applied to high-speed systems using a neuromorphic sensor. This sensor produces event-based data and is designed to work with high temporal resolution and high dynamic range. The main advantages of the Event-based Angular Speed Measurement (EB-ASM) method are the high dynamic range, the absence of motion blurring, and the possibility of measuring multiple rotations simultaneously with a single device. The proposed method uses the time difference between spikes in a Kernel or Window selected in the sensor frame range. It is evaluated in two experimental scenarios by measuring a fan rotational speed and a Router Computer Numerical Control (CNC) spindle. The results compare measurements with a calibrated digital photo-tachometer. Based on the performed tests, the EB-ASM can measure the rotational speed with a mean absolute error of less than 0.2% for both scenarios.

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13

Bougaev, Anton A. "Rotational Vibration Measurements In Computer Systems." Journal of the Acoustical Society of America 129, no. 6 (2011): 4094. http://dx.doi.org/10.1121/1.3600941.

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14

Brunson, Mark W., and Elizabeth A. Burritt. "Behavioral Factors in Rotational Grazing Systems." Rangelands 31, no. 5 (October 2009): 20–25. http://dx.doi.org/10.2111/1551-501x-31.5.20.

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15

Estr�n, D. A., F. M. Fern�ndez, and E. A. Castro. "Alternative treatment of rotational quantum systems." Zeitschrift f�r Physik D Atoms, Molecules and Clusters 14, no. 1 (March 1989): 51–55. http://dx.doi.org/10.1007/bf01401343.

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16

Gardner, Robert, Biagio Micale, Mario Pennisi, and Rebecca Zijlstra. "Cyclic and rotational hybrid triple systems." Discrete Mathematics 171, no. 1-3 (June 1997): 121–39. http://dx.doi.org/10.1016/s0012-365x(96)00036-2.

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17

Gardner, Robert, Biagio Micale, Mario Pennisi, and Rebecca Zijlstra. "Cyclic and rotational hybrid triple systems." Discrete Mathematics 175, no. 1-3 (October 1997): 143–61. http://dx.doi.org/10.1016/s0012-365x(96)00148-3.

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18

Tkhai, V. N. "The rotational motions of mechanical systems." Journal of Applied Mathematics and Mechanics 63, no. 2 (January 1999): 173–88. http://dx.doi.org/10.1016/s0021-8928(99)00025-8.

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19

Balantekin, A. B., and W. A. Friedman. "Rotational bands in near-vibrational systems." Physical Review C 36, no. 1 (July 1, 1987): 311–15. http://dx.doi.org/10.1103/physrevc.36.311.

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20

Feng, Tao, Yanxun Chang, and Lijun Ji. "Constructions for rotational Steiner quadruple systems." Journal of Combinatorial Designs 17, no. 5 (September 2009): 353–68. http://dx.doi.org/10.1002/jcd.20202.

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21

Gooden, D. T., H. D. Skipper, J. H. Kim, and K. Xiong. "Diversity of Root Bacteria from Peanut Cropping Systems." Peanut Science 31, no. 2 (July 1, 2004): 86–91. http://dx.doi.org/10.3146/pnut.31.2.0005.

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Abstract Rhizobacteria play an important role in sustainable agriculture via plant growth and biological control of pests in a number of ecosystems. Understanding the interactions of crop rotation and rhizobacteria on peanut production is a critical research need. Development of a database on the rhizobacteria obtained from continuous and rotational fields of peanut was initiated in 1997 and terminated in 2000. Peanut was planted in monoculture for 4 yr. In rotational plots, peanut, cotton, corn, and peanut were planted in sequence. Rhizobacteria were isolated from the roots of crop plants grown in a Norfolk soil near Florence, SC. These isolates were identified by composition of fatty acids from gas chromatography analysis (GC/FAME). Arthrobacter and Bacillus were the major genera from non-rhizosphere soils. At initiation of this study in July 1997, the plots selected for continuous peanut had more diversity in rhizobacteria than those plots selected for rotation. In July 2000, rhizobacteria diversity was greater from peanut roots in the rotation cropping system than continuous peanut. Even though rhizobacteria diversity was greater in the rotation system, higher peanut yields were recorded in the continuous peanut system in 2000. Burkholderia spp. were always isolated from the peanut and other crop rhizospheres at each sampling date.

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22

Beikmann, R. S., N. C. Perkins, and A. G. Ulsoy. "Nonlinear Coupled Vibration Response of Serpentine Belt Drive Systems." Journal of Vibration and Acoustics 118, no. 4 (October 1, 1996): 567–74. http://dx.doi.org/10.1115/1.2888336.

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This theoretical and experimental study identifies a key nonlinear mechanism that promotes strongly coupled dynamics of serpentine belt drive systems. Attention is focused on a prototypical three-pulley system that contains the essential features of automotive serpentine drives having automatic (spring-loaded) tensioners. A theoretical model is presented that describes pulley and tensioner arm rotations, and longitudinal and transverse belt vibration response. A recent investigation demonstrates that infinitesimal belt stretching creates a linear mechanism that couples transverse belt vibration to tensioner arm rotation. Here, it is further demonstrated that finite belt stretching creates a nonlinear mechanism that may lead to strong coupling between pulley/tensioner arm rotation and transverse belt vibration, in the presence of an internal resonance. Theoretical and experimental results confirm the existence of this nonlinear coupling mechanism. In particular, it is shown that very large transverse belt vibrations can result from small resonant torque pulses applied to the crankshaft or accessory pulleys. These large amplitude transverse vibrations are particularly sensitive to seemingly small changes in the rotational mode characteristics.

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23

Carnevale, Arianna, Ilaria Mannocchi, Mohamed Saifeddine Hadj Sassi, Marco Carli, Giovanna De De Luca, Umile Giuseppe Longo, Vincenzo Denaro, and Emiliano Schena. "Virtual Reality for Shoulder Rehabilitation: Accuracy Evaluation of Oculus Quest 2." Sensors 22, no. 15 (July 23, 2022): 5511. http://dx.doi.org/10.3390/s22155511.

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Virtual reality (VR) systems are becoming increasingly attractive as joint kinematics monitoring systems during rehabilitation. This study aimed to evaluate the accuracy of the Oculus Quest 2 in measuring translational and rotational displacements. As the Oculus Quest 2 was chosen for future applications in shoulder rehabilitation, the translation range (minimum: ~200 mm, maximum: ~700 mm) corresponded to the forearm length of the 5th percentile female and the upper limb length of the 95th percentile male. The controller was moved on two structures designed to allow different translational displacements and rotations in the range 0–180°, to cover the range of motion of the upper limb. The controller measures were compared with those of a Qualisys optical capture system. The results showed a mean absolute error of 13.52 ± 6.57 mm at a distance of 500 mm from the head-mounted display along the x-direction. The maximum mean absolute error for rotational displacements was found to be 1.11 ± 0.37° for a rotation of 40° around the z-axis. Oculus Quest 2 is a promising VR tool for monitoring shoulder kinematics during rehabilitation. The inside-out movement tracking makes Oculus Quest 2 a viable alternative to traditional motion analysis systems.

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24

Farbiash, N., and R. Steinitz. "Spin Correlation in Binary Systems." International Astronomical Union Colloquium 191 (August 2004): 15–19. http://dx.doi.org/10.1017/s0252921100008368.

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AbstractWe examine the correlation of projected rotational velocities in binary systems. It is an extension of previous work (Steinitz and Pyper, 1970; Levato, 1974). An enlarged data basis and new tests enable us to conclude that there is indeed correlation between the projected rotational velocities of components of binaries. In fact we suggest that spins are already correlated.

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25

Angelaki, Dora E., and J. David Dickman. "Gravity or translation: Central processing of vestibular signals to detect motion or tilt." Journal of Vestibular Research 13, no. 4-6 (December 28, 2003): 245–53. http://dx.doi.org/10.3233/ves-2003-134-609.

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The processing and detection of tilts relative to gravity from actual motion (translational accelerations) is one of the most fundamental issues for understanding vestibular sensorimotor control in altered gravity environments. In order to better understand the nature of multisensory signals in detecting motion and tilt, we summarize here our recent studies regarding the central processing of vestibular signals during multi-axis rotational and translational stimuli. Approximately one fourth of the cells in the vestibular nuclei exclusively encoded rotational movements (Canal-Only neurons) and were unresponsive to translation. The Canal-Only central neurons encoded head rotation in canal afferent coordinates, exhibited no orthogonal canal convergence and were characterized by significantly higher sensitivities to rotation as compared to canal afferents. Another fourth of the neurons modulated their firing rates during translation (Otolith-Only cells). During rotations, these neurons typically only responded when the axis of rotation was earth-horizontal and the head was changing orientation relative to gravity. The remaining cells (approximately half of total population) were sensitive to both rotations and translations (Otolith+Canal neurons). Maximum sensitivity vectors to rotation were distributed throughout the 3D space, suggesting strong convergence from multiple semicircular canals. Only a small subpopulation (approximately one third) of these Otolith+Canal neurons seems to encode a true estimate of the translational component of the imposed passive head and body movement. These results provide the first step in further understanding multisensory convergence in normal gravity, as this task is fundamental to our appreciation of neurovestibular adaptation to altered gravity.

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26

Klioner, S. A., E. Gerlach, and M. H. Soffel. "Relativistic aspects of rotational motion of celestial bodies." Proceedings of the International Astronomical Union 5, S261 (April 2009): 112–23. http://dx.doi.org/10.1017/s174392130999024x.

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AbstractRelativistic modelling of rotational motion of extended bodies represents one of the most complicated problems of Applied Relativity. The relativistic reference systems of IAU (2000) give a suitable theoretical framework for such a modelling. Recent developments in the post-Newtonian theory of Earth rotation in the limit of rigidly rotating multipoles are reported below. All components of the theory are summarized and the results are demonstrated. The experience with the relativistic Earth rotation theory can be directly applied to model the rotational motion of other celestial bodies. The high-precision theories of rotation of the Moon, Mars and Mercury can be expected to be of interest in the near future.

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Wagner, Andrew R., Megan J. Kobel, and Daniel M. Merfeld. "Impacts of Rotation Axis and Frequency on Vestibular Perceptual Thresholds." Multisensory Research 35, no. 3 (January 5, 2022): 259–87. http://dx.doi.org/10.1163/22134808-bja10069.

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Abstract In an effort to characterize the factors influencing the perception of self-motion rotational cues, vestibular self-motion perceptual thresholds were measured in 14 subjects for rotations in the roll and pitch planes, as well as in the planes aligned with the anatomic orientation of the vertical semicircular canals (i.e., left anterior, right posterior; LARP, and right anterior, left posterior; RALP). To determine the multisensory influence of concurrent otolith cues, within each plane of motion, thresholds were measured at four discrete frequencies for rotations about earth-horizontal (i.e., tilts; EH) and earth-vertical axes (i.e., head positioned in the plane of the rotation; EV). We found that the perception of rotations, stimulating primarily the vertical canals, was consistent with the behavior of a high-pass filter for all planes of motion, with velocity thresholds increasing at lower frequencies of rotation. In contrast, tilt (i.e, EH rotation) velocity thresholds, stimulating both the canals and otoliths (i.e., multisensory integration), decreased at lower frequencies and were significantly lower than earth-vertical rotation thresholds at each frequency below 2 Hz. These data suggest that multisensory integration of otolithic gravity cues with semicircular canal rotation cues enhances perceptual precision for tilt motions at frequencies below 2 Hz. We also showed that rotation thresholds, at least partially, were dependent on the orientation of the rotation plane relative to the anatomical alignment of the vertical canals. Collectively these data provide the first comprehensive report of how frequency and axis of rotation influence perception of rotational self-motion cues stimulating the vertical canals.

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Mustafayev, Zh S., A. A. Sagaev, Y. N. Alimbaev, and V. V. Pchelkin. "BASIC CONSTRUCTION PRINCIPLES FOR MULTI-FUNCTIONAL HYDRO AGROLANDSCAPE SYSTEMS." REPORTS 6, no. 334 (December 15, 2020): 115–23. http://dx.doi.org/10.32014/2020.2518-1483.144.

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Based on the principles of natural analogies, the necessary diversity, the ability of soil formation and the integration of knowledge, multifunctional hydroagrolandscape systems have been developed, including multifunctional systems (crop rotation fields and irrigation technique), which ensure the fulfillment of the ecological and economic functions of the soils of hydroagrolandscape systems. Multifunctional hydro-agrolandscape systems for the purposeful regulation of the soil-forming process on irrigated crop rotation fields by designing crop rotation and an irrigation system on irrigated lands (hydro-agricultural landscape system) with the linkage of agricultural crops to irrigation equipment and technology, which move along with agricultural crops according to the rotational scheme, adopted in the crop rotation, ensure the maximum possible use of solar energy for the soil-forming process in specific natural and climatic conditions. The environment-forming functions of a multifunctional hydro-agrolandscape system are provided on the basis of the use of integral criteria to ensure the agroecological sustainability of irrigated crop rotations (hydroagrolandscapes), taking into account geoecological restrictions, that is, the weighted average irrigation rate (water demand deficit) of agricultural crops in the crop rotation should not exceed the deficit of the ecological water requirement of agricultural land systems. Thus, the design of highly productive hydrolandscape systems requires ensuring compliance with not only the principles of the necessary diversity and natural analogies, based on the creation of se-rotations with mobile irrigation techniques to control and regulate soil-forming processes, that is, the soil as an object of influence (reclamation) performing an ecological function , and agricultural crops as a subject perform an economic function, requires the need, on the basis of the principle of knowledge integration, to form ways of regulating the natural process that provide targeted regulation and control of soil-forming processes as environment-forming systems.

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29

Miyanaga, Norifumi, and Jun Tomioka. "Development of Herringbon-Grooved Aerodynamic Journal Bearing Systems for Ultra-High-Speed Rotations." Key Engineering Materials 656-657 (July 2015): 652–57. http://dx.doi.org/10.4028/www.scientific.net/kem.656-657.652.

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It is absolutely important for ultra-compact rotational machineries to achieve sable shaft rotation at ultra-high-speed. This paper discussed herringbone-grooved aerodynamic journal bearing systems developed for the purpose. In this system, the bearings are supported by rubber-O-rings for accurate and stable operations. To grasp the possibility for stabilization, two types of O-rings with different stiffness and damping properties under bearing supporting were tested in the experiment. As the results, the bearing system demonstrated the maximum rotational speed over 460,000 rpm without unstable phenomenon called whirl. However, the difference in rubber O-rings definitely affected the stability of the bearing system.

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30

Peixoto, Luciano T. "Perturbation theory approach to rotational tunneling systems." Brazilian Journal of Physics 30, no. 1 (March 2000): 163–71. http://dx.doi.org/10.1590/s0103-97332000000100017.

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31

Wu, Rui, Yi Cheng, and Ravi P. Agarwal. "Rotational periodic solutions for fractional iterative systems." AIMS Mathematics 6, no. 10 (2021): 11233–45. http://dx.doi.org/10.3934/math.2021651.

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<abstract><p>In this paper, we devoted to deal with the rotational periodic problem of some fractional iterative systems in the sense of Caputo fractional derivative. Under one sided-Lipschtiz condition on nonlinear term, the existence and uniqueness of solution for a fractional iterative equation is proved by applying the Leray-Schauder fixed point theorem and topological degree theory. Furthermore, the well posedness for a nonlinear control system with iteration term and a multivalued disturbance is established by using set-valued theory. The existence of solutions for a iterative neural network system is demonstrated at the end.</p></abstract>

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32

Wang, S. M., and F. O. Eke. "Rotational Dynamics of Axisymmetric Variable Mass Systems." Journal of Applied Mechanics 62, no. 4 (December 1, 1995): 970–74. http://dx.doi.org/10.1115/1.2896031.

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This paper studies the attitude dynamics of variable mass systems that have axisymmetric mass distribution and that are subjected to continuous mass variation while in motion. The equations of rotational motion for such systems are solved analytically under the assumption of zero external torque. It is found that such systems can spin up or spin down in free motion, and that the transverse angular velocity magnitude can increase or decrease with time. The analytical conditions for growth or decay of spin rate and lateral angular speed are presented, and these conditions are related to practical design criteria for rocket-type systems.

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Barioni, L. G., C. K. G. Dake, and W. J. Parker. "Optimizing rotational grazing in sheep management systems." Environment International 25, no. 6-7 (September 1999): 819–25. http://dx.doi.org/10.1016/s0160-4120(99)00051-3.

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Diezemann, Gregor, and Wolfgang Häusler. "Symmetry species exchange in rotational tunnelling systems." Physica B: Condensed Matter 226, no. 1-3 (August 1996): 189–93. http://dx.doi.org/10.1016/0921-4526(96)00300-6.

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35

Gardner, Robert B. "Steiner triple systems with near-rotational automorphisms." Journal of Combinatorial Theory, Series A 61, no. 2 (November 1992): 322–27. http://dx.doi.org/10.1016/0097-3165(92)90030-x.

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36

Thomsen, M., and E. Jakubowitz. "Rotational stability of different hip revision systems." Traumatology and Orthopedics of Russia, no. 4 (January 1, 2014): 57–61. http://dx.doi.org/10.21823/2311-2905-2014-0-4-57-61.

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Colbourn, Charles J., and Zhike Jiang. "The spectrum for rotational Steiner triple systems." Journal of Combinatorial Designs 4, no. 3 (1996): 205–17. http://dx.doi.org/10.1002/(sici)1520-6610(1996)4:3<205::aid-jcd4>3.0.co;2-j.

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38

Khan, Mahbub H., and G. Charles Clifton. "Proposed development of a damage-resisting Eccentrically Braced Frame with rotational active links." Bulletin of the New Zealand Society for Earthquake Engineering 44, no. 2 (June 30, 2011): 99–107. http://dx.doi.org/10.5459/bnzsee.44.2.99-107.

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Eccentrically Braced Frames (EBFs) are widely used seismic-resisting systems, as they allow both strength and stiffness to be optimised while providing good ductility capacity. However, in theory they have a low damage threshold in severe earthquakes and post-earthquake repair of conventional EBFs will be difficult and expensive. This paper presents the Numerical Integration Time-History (NITH) analysis of two ten storey EBF buildings; one with a conventional active link and the other with a new form of low damage active link based on rotational sliding bolted plates. The low damage active link can be designed to allow rotation only, or to allow both rotation and axial extension. The conventional active link response in terms of displacement, rotation and inelastic demand was well within the range of the rotational active links under the records considered. The analysis shows that average maximum displacement of the building and rotation of the link for both the rotational and the rotational+extension active links was almost identical. The extension of the rotational active link permitting axial extension was less than 1.5 mm. Axial load demands on the collector beams and braces were similar in the case all three active links. It can be concluded from the analysis that the rotational active link with extension is not required, as the lateral extensions can be accommodated within the rotational plates with nominal clearances in the bolt holes to accommodate the lateral extension.

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39

Chapman, D. F., M. R. McCaskill, P. E. Quigley, A. N. Thompson, J. F. Graham, D.Borg, J. Lamb, G. Kearney, G. R. Saul, and S. G. Clark. "Effects of grazing method and fertiliser inputs on the productivity andsustainability of phalaris-based pastures in Western Victoria." Australian Journal of Experimental Agriculture 43, no. 8 (2003): 785. http://dx.doi.org/10.1071/ea02198.

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The effects of combinations of different fertiliser rates and grazing methods applied to phalaris-based pastures on an acid, saline, yellow sodosol on the Dundas Tablelands of western Victoria (mean annual rainfall 623�mm) were measured from 1997 to 2000. The objective was to help identify management systems that improve phalaris growth and persistence, water use, and animal production, and thereby the productivity and sustainability of grazing systems. Pastures were either set stocked with low [mean 6.4 kg phosphorus (P)/ha.year] or high (mean 25 kg P/ha.year) fertiliser rates, or rotationally grazed with high fertiliser (mean 25 kg P/ha.year). Rotational grazing was implemented as either a simple '4-paddock' system (fixed rotation length), or a more intensive system where rotation length varied with pasture growth rate. Unreplicated paddocks of volunteer pasture (dominated by onion grass and annual grass weeds) receiving an average of 8 kg P/ha.year were also monitored. All treatments were stocked with spring-lambing Merino ewes. Stocking rate was an emergent property of each treatment, and was driven by pasture quality and availability. Total pasture herbage accumulation ranged from 7150 to 9750 kg DM/ha.year and was significantly lower on the set-stocked, low-fertility treatment than on all other treatments. A significant treatment.day effect in the spline analysis of herbage mass was explained by a trend toward higher pasture mass in the rotationally grazed treatments than set-stocked treatments from the break of season until mid-spring. Rotational grazing led to significantly higher phalaris herbage accumulation than set stocking (mean 3680 v. 2120 kg DM/ha.year), but significantly lower subterranean clover herbage accumulation (1440 v. 2490 kg DM/ha.year). Despite the stronger growth of deep-rooted phalaris in the rotationally grazed treatments, maximum soil water deficits at the end of summer differed only slightly between treatments, with the difference between driest and wettest treatments amounting to only 14 mm. Summer growth of phalaris was apparently insufficient to generate significant differences in soil water extraction at depth, even when phalaris content was increased by rotational grazing, and re-wetting of the soil profile occurred at a similar rate for all treatments. Rotationally grazed treatments supported higher stocking rates than set-stocked treatments at high fertiliser rates (mean 14.9 v. 13.7 ewes/ha), but apparent losses in pasture feeding value due to lower legume content under rotational grazing meant that there were few significant differences between treatments in lamb production per hectare. The experiment showed that grazing method can have a substantial and rapid effect on pasture botanical composition. There are clear opportunities for producers to use temporal and spatial combinations of set stocking and rotational grazing to manipulate herbage mass and pasture composition within broad target ranges for achieving both animal production (e.g. high per-head animal performance) and sustainability (e.g. persistence of perennial grasses) objectives. Rigid application of either set stocking or rotational grazing imposes limitations on both pasture and animal production, and neither grazing method will optimise system performance under all conditions. The experiment also demonstrated that management and land-use changes that have much greater potential to increase water use than those examined here will be needed to ensure the sustainability of pasture systems in the high rainfall zone of western Victoria.

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Dip, Goswami, and Vadakkepat Prahlad. "Rotational Stability Index (RSI) point: postural stability in planar bipeds." Robotica 29, no. 5 (October 12, 2010): 705–15. http://dx.doi.org/10.1017/s0263574710000597.

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SUMMARYThe postural stability of bipedal robots is investigated in perspective of foot-rotation during locomotion. With foot already rotated, the biped is modeled as an underactuated kinematic structure. The stability of such biped robots is analyzed by introducing the concept of rotational stability. The rotational stability investigates whether a biped would lead to a flat-foot posture or the biped would topple over. The rotational stability is quantified as a ground reference point named “rotational stability index (RSI)” point. Conditions are established to achieve rotational stability during biped locomotion using the concept of the RSI point. The applicability of the RSI point is illustrated through experimentation for the landing stability analysis of the bipedal jumping gaits.The traditional stability criteria such as zero-moment point (ZMP) [M. Vukobratovic and B. Borovac, “Zero-moment point – thirty five years of its life,” Int. J. Humanoid Robot. 1(1), 157–173 (2004)] and foot-rotation indicator (FRI) [A. Goswami, “Postural stability of biped robots and the foot-rotation indicator (FRI) point,” Int. J. Robot. Res. 18(6), 523–533 (1999)] are not applicable to analyze biped's postural stability when foot is already rotated. The RSI point is established as a stability criteria for planar bipedal locomotion in presence of foot rotation.

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Wang, Tao, Bicong Wang, Yufeng Luo, Hengyu Li, Jinjun Rao, Zhizheng Wu, and Mei Liu. "Accurate Measurements of the Rotational Velocities of Brushless Direct-Current Motors by Using an Ultrasensitive Magnetoimpedance Sensing System." Micromachines 10, no. 12 (December 6, 2019): 859. http://dx.doi.org/10.3390/mi10120859.

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Reports on measurements of the rotational velocity by using giant magnetoimpedance (GMI) sensors are rarely seen. In this study, a rotational-velocity sensing system based on GMI effect was established to measure rotational velocities of brushless direct-current motors. Square waves and sawtooth waves were observed due to the rotation of the shaft. We also found that the square waves gradually became sawtooth waves with increasing the measurement distance and rotational velocity. The GMI-based rotational-velocity measurement results (1000–4300 r/min) were further confirmed using the Hall sensor. This GMI sensor is capable of measuring ultrahigh rotational velocity of 84,000 r/min with a large voltage response of 5 V, even when setting a large measurement distance of 9 cm. Accordingly, the GMI sensor is very useful for sensitive measurements of high rotational velocity.

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42

Delate, Kathleen, Michael Duffy, Craig Chase, Ann Holste, Heather Friedrich, and Noreen Wantate. "An economic comparison of organic and conventional grain crops in a long-term agroecological research (LTAR) site in lowa." American Journal of Alternative Agriculture 18, no. 2 (June 2003): 59–69. http://dx.doi.org/10.1079/ajaa200235.

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AbstractBased on the interest of organic and conventional farmers in Iowa in long-term analysis of organic systems, the Neely-Kinyon Long-Term Agroecological Research (LTAR) site was established in 1998 to examine the agronomic and economic performance of conventional and organic systems, using certified organic production practices. We report the results of the economic analysis from 3 years of production (1999–2001). Using organic price premiums for organic crops, returns for corn within the organic corn-soybean-oat and corn-soybean-oat-alfalfa rotations were significantly greater than conventional corn-soybean rotation returns (US$126 ha−1). Com returns were not significantly different between the two organic rotations, at US$655 ha−1 and US$674 ha−1, respectively. Returns for soybean within the organic corn-soybean-oat and com-soybean-oat-alfalfa rotations were not significantly different, at US$1233 ha−1 and US$1326 ha−1, respectively. Organic soybean returns were significantly greater than conventional soybean crop returns (US$235 ha−1) in the corn-soybean rotation. Rotational 3-year average returns were US$180 ha−1 for the conventional corn-soybean rotation, compared to US$734 ha−1 for the organic corn-soybean-oat and US$739 ha−1 for the organic com-soybean-oat-alfalfa rotation.

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Eby, David W., Jack M. Loomis, and Eric M. Solomon. "Perceptual Linkage of Multiple Objects Rotating in Depth." Perception 18, no. 4 (August 1989): 427–44. http://dx.doi.org/10.1068/p180427.

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When multiple objects rotate in depth, they are frequently perceived to rotate in the same direction even when perspective information signals counterrotation. Three experiments are reported on this tendency to recover the rotation directions of multiple objects in a nonindependent fashion (termed rotational linkage). Rotational linkage was strongly affected by slant in depth of the objects, image perspective, and relative starting phase of the objects. Linkage was found not to vary as a function of the relative rotation speed of the objects or the relative alignment of their rotation axes. Rotational linkage is interpreted as a tendency of the visual system to assign signed depths to objects based on a communality of image point direction.

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Pietrosemoli, Silvana, James T. Green, and Maria Jesús Villamide. "A Comparison of Stocking Methods for Pasture-Based Growing-Finishing Pig Production Systems." Animals 10, no. 10 (October 15, 2020): 1885. http://dx.doi.org/10.3390/ani10101885.

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Two alternative stocking methods (rotational and strip-grazing) were compared to continuous stocking at a stocking rate of 47 pigs ha−1 in tall fescue pastures. The research was conducted during two twelve-weeks grazing periods in North Carolina (USA). In total 144 (females and castrated males, 17.5 and 29.1 kg initial body weight) crossbred Yorkshire X Berkshire, Yorkshire/Landrace X Hampshire and Yorkshire/Landrace X Duroc pigs without nose rings were used. Greater soil bulk density and soil concentrations of NO3−, P, K, Mn, Zn and Cu were observed in paddocks managed continuously, while greater final ground cover (+22%) was recorded in paddocks managed with rotational and strip-grazing stocking methods. No differences were detected in botanical composition of the paddocks. Greater weight gains (+8.5%) were registered for rotationally managed pigs. Feed efficiency was better (+8%) for rotationally than for continuously stocked pigs, while strip-grazed pigs presented intermediate values. The results indicated the potential of both alternative stocking methods to be implemented in sustainable pasture-based pig production systems.

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Plagányi, Éva Elizabeth, Timothy Skewes, Nicole Murphy, Ricardo Pascual, and Mibu Fischer. "Crop rotations in the sea: Increasing returns and reducing risk of collapse in sea cucumber fisheries." Proceedings of the National Academy of Sciences 112, no. 21 (May 11, 2015): 6760–65. http://dx.doi.org/10.1073/pnas.1406689112.

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Rotational harvesting is one of the oldest management strategies applied to terrestrial and marine natural resources, with crop rotations dating back to the time of the Roman Empire. The efficacy of this strategy for sessile marine species is of considerable interest given that these resources are vital to underpin food security and maintain the social and economic wellbeing of small-scale and commercial fishers globally. We modeled the rotational zone strategy applied to the multispecies sea cucumber fishery in Australia’s Great Barrier Reef Marine Park and show a substantial reduction in the risk of localized depletion, higher long-term yields, and improved economic performance. We evaluated the performance of rotation cycles of different length and show an improvement in biological and economic performance with increasing time between harvests up to 6 y. As sea cucumber fisheries throughout the world succumb to overexploitation driven by rising demand, there has been an increasing demand for robust assessments of fishery sustainability and a need to address local depletion concerns. Our results provide motivation for increased use of relatively low-information, low-cost, comanagement rotational harvest approaches in coastal and reef systems globally.

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Molski, Marcin, and Jerzy Konarski. "Modified Dunham potential for rovibrational diatomic systems." Canadian Journal of Physics 73, no. 1-2 (January 1, 1995): 59–62. http://dx.doi.org/10.1139/p95-010.

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A modified Dunham potential with parameters depending on the rotational quantum number is employed to describe the rovibrational states of diatomic molecules. This approach, applied to H81Br, 115InD, 7LiH, and 40Ar2, gives satisfactory reproduction of the observed transitions using fewer Dunham parameters than in the standard method. The results obtained indicate the possibility of introducing the local internal potentials, which, in contradiction to the global ones usually used, depend on the rotational states of a rotating–vibrating molecule. Such a J dependence may be a result of rovibronic interactions, in particular, Coriolis-type nonadiabatic interactions coupling other electronic states through the rotational angular momentum.

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Császár, Attila G., Irén Simkó, Tamás Szidarovszky, Gerrit C. Groenenboom, Tijs Karman, and Ad van der Avoird. "Rotational–vibrational resonance states." Physical Chemistry Chemical Physics 22, no. 27 (2020): 15081–104. http://dx.doi.org/10.1039/d0cp00960a.

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All molecular systems possess a significant number of rovibrational resonance states accessible via spectroscopic and scattering experiments, which can also be computed and rationalized by a variety of first-principles quantum-chemical techniques.

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48

Gurusinghe, Saliya, K. M. Shamsul Haque, Paul A. Weston, William B. Brown, and Leslie A. Weston. "Impact of Rotational Sequence Selection on Weed Seedbank Composition in Australian Broadacre Crops." Agronomy 12, no. 2 (February 1, 2022): 375. http://dx.doi.org/10.3390/agronomy12020375.

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The use of competitive crops in successional rotations has been shown to reduce the growth and establishment of annual weeds by the depletion of the weed seedbank in broadacre cropping systems. However, the impact of specific crop rotational sequences contributing to weed seedbank density has not been quantified in the Riverina region of southern Australia. Trials were established in two locations in 2014–2018 to quantify the impact of selected annual rotations featuring grain, pulse, and pasture crops on weed infestation and seedbank dynamics with a focus on winter and summer annual weeds. The weed seedbank dynamics were evaluated by a twice-annual soil sampling regime (at planting and harvest), followed by soil sample screening for weed propagule germination and seedling establishment in a subsequent controlled-environment screening performed from 2014–2020. The weed seedling density decreased in the cereal rotations in years experiencing average to above-average rainfall, as crops established a dense canopy leading to reduced weed establishment and fecundity. Several rotational treatments were effective in suppressing the weed propagule numbers over time, including those using dual-purpose cereals only or a canola break-crop along with the cereals. Rotational selection can be an important and cost-effective tool in integrated weed management systems when applied over multiple growing seasons.

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Sikorski, Jakub, and Witold Pawłowski. "Innovative designs of angular contact ball bearings systems preload mechanisms." Mechanik 91, no. 2 (February 12, 2018): 138–40. http://dx.doi.org/10.17814/mechanik.2018.2.29.

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Presented are two mechanisms to simplify preloading operations in angular contact ball bearings systems supporting rotating machines’ shafts. The proposed systems also significantly improve its later adjustment during machine exploitation. In the presented solutions, the tensioning force of the bearing comes from a system of appropriately shaped elements with rotational-wedge surfaces, rotation of which makes them mutually extend and consequently obtain the tensioning force for the angular contact ball bearings.

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Harkin-Jones, E., and R. J. Crawford. "Rotational Moulding of Liquid Polymers." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 210, no. 5 (October 1996): 437–47. http://dx.doi.org/10.1243/pime_proc_1996_210_141_02.

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The vast majority of rotationally moulded articles are produced from powdered polymers. However, the moulding process developed originally from the use of liquid polymers and nowadays there is a renewed interest in such systems because of some unique advantages that they offer. This paper compares the behaviour of three different liquid polymer systems—nylon 6 by ring-opening caprolactam, polyvinyl chloride plastisol and polyurethane. The flow behaviour of each material is examined with particular reference to wall thickness distributions and bubble formation in the product. On the basis of this, criteria for the production of fault-free mouldings have been established. The interrelationships between mould shape and resin viscosity are also examined and an ideal viscosity—time—temperature profile is proposed for liquid polymer systems. Finally, a general comparison of the materials is made with regard to material handling, safety, cycle times, etc.

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