Academic literature on the topic 'Amplitude and height parameters'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Amplitude and height parameters.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Amplitude and height parameters"

1

Barányi, I., Á. Czifra, and Gabor Kalácska. "Height-independent topographic parameters of worn surfaces." International Journal Sustainable Construction & Design 2, no. 1 (November 6, 2011): 35–40. http://dx.doi.org/10.21825/scad.v2i1.20433.

Full text
Abstract:
Surface microtopography plays a dual role in the course of friction and wear processes. It affectsthe contact and temperature conditions, and it undergoes significant changes in accordance with the wearmechanism. Fractal dimension (Df), root mean square gradient (Sdq), surface area ratio (Sdr) and surfacekurtosis (Sku) parameters of microtopographies provides opportunities for understanding more deeply thewear processes independently from the amplitude of the roughness. Wear experiments and surfaceroughness measurements before and after wear were performed. Investigations extended to wear in thecourse of the non-lubricated ferrodo-steel material pairs, and lubricated camshaft-bushing pairs.
APA, Harvard, Vancouver, ISO, and other styles
2

Mofjeld, Harold O., Frank I. González, Vasily V. Titov, Angie J. Venturato, and Jean C. Newman. "Effects of Tides on Maximum Tsunami Wave Heights: Probability Distributions*." Journal of Atmospheric and Oceanic Technology 24, no. 1 (January 1, 2007): 117–23. http://dx.doi.org/10.1175/jtech1955.1.

Full text
Abstract:
Abstract A theoretical study was carried out to understand how the probability distribution for maximum wave heights (ηm) during tsunamis depends on the initial tsunami amplitude (A) and the tides. It was assumed that the total wave height is the linear sum of the tides and tsunami time series in which the latter is decaying exponentially in amplitude with an e-folding time of 2.0 days, based on the behavior of observed Pacific-wide tsunamis. Direct computations were made to determine the statistics of maximum height for a suite of different arrival times and initial tsunami amplitudes. Using predicted tides for 1992 when the lunar nodal f factors were near unity during the present National Tidal Datum Epoch 1983–2001, the results show that when A is small compared with the tidal range the probability density function (PDF) of the difference ηm − A is closely confined in height near mean higher high water (MHHW). The ηm − A PDF spreads in height and its mean height ηo − A decreases, approaching the PDF of the tides and MSL, respectively, when A becomes large compared with the tidal range. A Gaussian form is found to be a close approximation to the ηm − A PDF over much of the amplitude range; associated parameters for 30 coastal stations along the U.S. West Coast, Alaska, and Hawaii are given in the paper. The formula should prove useful in probabilistic mapping of coastal tsunami flooding.
APA, Harvard, Vancouver, ISO, and other styles
3

Wang, Hong Cai, and Yang Wang. "The Height Amplitudes of Surface Roughness Based on Area-Direction Character and Relative Assessed Indexes." Advanced Materials Research 482-484 (February 2012): 1150–54. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.1150.

Full text
Abstract:
To study the relationship among the height amplitude of surface roughness , assessed area and assessed direction, the height amplitudes SRa, SRq, SRsk and SRku based on area-direction character are defined in the paper. And on the foundation of these parameters, relative assessed area indexes, assessed direction indexes and assessed total indexes are established. SRa, SRq, SRsk and SRku are the natural extension of 2D height amplitudes Ra, Rq, Rsk and Rku. They are different from 3D height amplitudes Sa, Sq, Ssk and Sku. They provide an evidence to study the quantitative relationship among surface roughness, assessed area and assessed direction. Relative assessed area indexes, assessed direction indexes and assessed total indexes can be used to assess the distribution situation of height amplitudes of surface roughness related to area, direction and entireness.
APA, Harvard, Vancouver, ISO, and other styles
4

Didenkulova, I. "Nonlinear long-wave deformation and runup in a basin of varying depth." Nonlinear Processes in Geophysics 16, no. 1 (January 29, 2009): 23–32. http://dx.doi.org/10.5194/npg-16-23-2009.

Full text
Abstract:
Abstract. Nonlinear transformation and runup of long waves of finite amplitude in a basin of variable depth is analyzed in the framework of 1-D nonlinear shallow-water theory. The basin depth is slowly varied far offshore and joins a plane beach near the shore. A small-amplitude linear sinusoidal incident wave is assumed. The wave dynamics far offshore can be described with the use of asymptotic methods based on two parameters: bottom slope and wave amplitude. An analytical solution allows the calculation of increasing wave height, steepness and spectral amplitudes during wave propagation from the initial wave characteristics and bottom profile. Three special types of bottom profile (beach of constant slope, and convex and concave beach profiles) are considered in detail within this approach. The wave runup on a plane beach is described in the framework of the Carrier-Greenspan approach with initial data, which come from wave deformation in a basin of slowly varying depth. The dependence of the maximum runup height and the condition of a wave breaking are analyzed in relation to wave parameters in deep water.
APA, Harvard, Vancouver, ISO, and other styles
5

Gritsinskaya, V. L., V. P. Novikova, and A. I. Khavkin. "Variability of the dynamics of somatometric parameters in schoolchildren with different nutritional status (longitudinal study)." Voprosy praktičeskoj pediatrii 15, no. 5 (2020): 68–72. http://dx.doi.org/10.20953/1817-7646-2020-5-68-72.

Full text
Abstract:
Objective. To identify specific features of pubertal growth spurt in adolescents depending on their nutritional status in prepuberty. Patients and methods. We analyzed the dynamics of height and weight in 645 children (331 boys and 314 girls) aged between 8 and 16 years. All study participants were divided into three groups depending on whether their weight and height at the age of 8 years were within the normal limits given in the ‘WHO Growth Reference 2007’: children with physical development; underweight children; and overweight children. Results. The dynamics of somatometric parameters during pubertal growth spurt varied between children with different nutritional status. Underweight boys demonstrated prolonged and low-amplitude pubertal growth pattern; in boys with normal physical development, the growth spurt was usually shorter and had high amplitude. In overweight boys, the pubertal growth spurt started with higher annual increase in height, had a more pronounced amplitude, and was shorter than in peers (р < 0.001 ÷ р < 0.05). Both underweight girls and girls with normal physical development demonstrated low-amplitude pubertal growth spurt lasting for two years. Overweight girls had two peaks of pubertal growth spurt, which usually started earlier than in other girls (р < 0.001 ÷ р < 0.01). Conclusion. Our findings can be used as a guide for predicting pubertal spurt in children during medical examinations, determining adequate physical activity in physical education classes at school and in sports sections. Key words: children, nutritional status, pubertal growth spurt
APA, Harvard, Vancouver, ISO, and other styles
6

Gaile, Liga. "Analysis of Dynamic Parameters of Observation Towers in Latvia." Environment. Technology. Resources. Proceedings of the International Scientific and Practical Conference 2 (August 8, 2015): 57. http://dx.doi.org/10.17770/etr2013vol2.847.

Full text
Abstract:
The purpose of this research is to experimentally identify the performance of most of the light-weight observation towers open for public in Latvia. It analyzes the structure of towers, technical condition, dynamic parameters and dynamic response to human movement along the tower height. During the experiment there were measured and recorded the vibration accelerations of 18 observation towers’ upper platform. Further dynamic parameters were extracted using the spectral analysis. There was performed the sensitivity analysis to establish parameters that most influences the dynamic response amplitudes due to human movement. All experimentally obtained fundamental frequencies of the inspected towers are in the typical range of human walking frequencies. It is found that the main parameter that denotes the response level (acceleration amplitude) of the tower due to human movement is a tower self-weight.
APA, Harvard, Vancouver, ISO, and other styles
7

Noury, Ahmed Osman. "Normal neurophysiologic parameters of the sural nerve among adult healthy Sudanese population." Journal of Neurology & Stroke 11, no. 1 (January 22, 2021): 12–15. http://dx.doi.org/10.15406/jnsk.2021.11.00446.

Full text
Abstract:
Background: Nerve conduction studies (NCSs) are of central importance for the assessment of peripheral nervous system disorders. They help in the diagnosis, extent distribution of neural lesion as well as the prognosis of a disease process. The aim of this study is to establish normative NCS reference data of the sural nerve in Sudanese population for our EMG electrodiagnostic center; and to survey the effects of age, gender, height, weight and temperature on conduction Parameters. Methods: The study was conducted in Elmagzoub Neuroscience Electrodiagnostic Centre; supported by the Faculty of Medicine, National Ribat University, Khartoum, Sudan. NCSs were performed in 210 sural nerves of 105 adult healthy Sudanese subjects using standardized techniques. Results: The Right sural nerve SNAP parameters in the whole subjects were set as (mean ±standard deviation) for onset latency. peak latency, amplitude and conduction velocity. The values were 2.73±0.42 ms, 3.32±0.46 ms, 8.39±3.49 uV and 52.05±8.47 m/s, respectively. The Left sural nerve SNAP parameters in the whole study group were 2.71±0.50 ms, 3.29 ±0.52 ms, 8.54±4.56 uV and 52.66 ±8.95, respectively. Conclusion: The sural sensory nerve conduction parameters compared favorably with the existing literature. Age showed a positive correlation with latencies, and negative correlation with amplitude and velocity. Gender has conspicuous effect on all sural nerve conduction parameters. Height showed an effect on latency and conduction velocity whereas BMI revealed a negative correlation with amplitude and conduction velocity of sural nerve.
APA, Harvard, Vancouver, ISO, and other styles
8

Kozlova, E. S. "Investigation of the influence of amplitude spiral zone plate parameters on produced energy backflow." Computer Optics 43, no. 6 (December 2019): 1093–97. http://dx.doi.org/10.18287/2412-6179-2019-43-6-1093-1097.

Full text
Abstract:
Investigation of the influence of parameters of silver, aluminum, gold, and chromium spiral zone plates on the longitudinal component of Umov-Pointing vector in produced optical vortices by using the frequency-dependent finite-difference time-domain method is presented. It is shown that the aluminum spiral zone plate with a relief height of 50 nm gives an optical vortex with the smallest longitudinal component of Umov-Pointing vector on the optical axis. The gold spiral zone plate is the least effective for the formation of vortex beams with a reverse energy flow.
APA, Harvard, Vancouver, ISO, and other styles
9

Shpilka, N. N. "IMPROVING THE STABILITY TWO-LEVEL CAR HAULER." ACADEMIC JOURNAL Series: Industrial Machine Building, Civil Engineering 1, no. 48 (March 27, 2017): 8–18. http://dx.doi.org/10.26906/znp.2017.48.209.

Full text
Abstract:
To improve the lateral stability of car hauler way you value optimal cargo location parameters, elastically mounted on a platform, developed a mathematical model of its motion. At the same time take into account fluctuations in cargo and car hauler. According to the simulation results revealed that the system for car «hauler – cargo» accounting for elastic properties leads to a significant decrease in the frequency and amplitude of the system vertical oscillations. Therefore, the presence of the cargo can be regarded as a dynamic passive damping (in the case of a correct choice and design of layout parameters). There is proposed to reduce the distance between the cargo and the upper platform by determination of maximum values of the cargo oscillations amplitudes. In turn, the reduction of the height of the platform reduces the height of the center of gravity of the system, improves the stability of car hauler. Keywords: car hauler, dynamic processes, fluctuations, platform, stability.
APA, Harvard, Vancouver, ISO, and other styles
10

Chang, Shyang-Jye, and Jing Chen. "Design and Fabrication of the Large Thrust Force Piezoelectric Actuator." Advances in Materials Science and Engineering 2013 (2013): 1–5. http://dx.doi.org/10.1155/2013/912587.

Full text
Abstract:
This paper presents a novel piezoelectric actuator containing double pushers. By using finite element analysis software, this study simulated the vibration mode and amplitude of piezoelectric actuators. The Taguchi method was used to design the parameters of piezoelectric actuators including length, width, height, and electrodes setting. This paper also presents a discussion regarding the influence that the design parameters had on the actuator amplitudes. Based on optimal design parameters, a novel piezoelectric actuator containing double pushers is produced and some thrust tests are also carried out. From the experiment results, the piezoelectric actuator containing double pushers can provide a greater thrust force than that of traditional actuators containing a single pusher as the preload is greater. Comparing with the traditional actuators, the thrust force of new actuator can be increased by 48% with the double preload.
APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic "Amplitude and height parameters"

1

Fuciman, Lukáš. "Rozbor a zhodnocení vlivů textury povrchu zkušebních vzorků." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2020. http://www.nusl.cz/ntk/nusl-417440.

Full text
Abstract:
The thesis deals with an evaluation of the surface texture of various materials, created by machining technologies (turning, milling and grinding). As for the theoretical part of the thesis, it contains a theoretical analysis of the effect of surface texture on friction, wear, coating and lubricating properties. The main emphasis is put on the analysis of the most frequently evaluated profile and surface parameters as well as their possible influence on the functional areas of machined parts. The experimental part includes evaluated and compared measured data based on the monitored parameters with benefits for machinery industry.
APA, Harvard, Vancouver, ISO, and other styles
2

Škeřík, Filip. "Hodnocení vlivu technologií obrábění na analýzu textury povrchu technických plastů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-443214.

Full text
Abstract:
The diploma thesis deals with the influence of machining technologies (turning, milling, grinding and polishing) on the surface texture of functional surfaces of selected materials from technical plastics. In the first part of the thesis there is a theoretical analysis of the possibilities of machining plastic materials. Furthermore, an analysis of the most commonly used parameters for evaluating the roughness of the machined surface and their effect on functionality is performed. The experimental part of the thesis describes samples preparation, analysis of measured data and subsequent evaluation with benefits for machinery industry.
APA, Harvard, Vancouver, ISO, and other styles
3

Richardson, Stephen Jon. "Acoustical parameters for the classical guitar." Thesis, Cardiff University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390804.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Vural, Aydin. "Precise Height Estimation By Differential Amplitude Measurement For An Airborne Cw Doppler Proximity Sensor." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614956/index.pdf.

Full text
Abstract:
Airborne CW doppler proximity sensors are very sensitive, but leaks precise height measurement. It may be possible to estimate the heigth at the terminal phase (the case where the sensor is at a heigth close to ground) precisely by using the doppler shift and amplitude information. The thesis includes this novel concept with theoritical analysis and simulation results.
APA, Harvard, Vancouver, ISO, and other styles
5

Elia, Letizia. "PCA study of the interannual variability of the GPS height and environmental parameters." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/20438/.

Full text
Abstract:
The objective of this study is to investigate a large network of GPS stations to identify and analyze spatially coherent signals present in the Up coordinate time series of the stations and, at the same locations, to identify and analyze common patterns in the series of environmental parameters and climate indices. The study is confined to Europe and the Mediterranean area, where 107 GPS sites were selected from the archive of the Nevada Geodetic Laboratory (NGL) on the basis of the completeness and length of the data series. The parameters of interest the Up coordinate of the GPS stations, the surface pressure (SP), the terrestrial water storage (TWS) and various climate indices: NAO (North Atlantic Oscillation), EA (East Atlantic), AO (Artic Oscillation), SCAND (Scandinavia), TNA (Tropical North Atlantic) and MEI v2 (Multivariate ENSO Index version 2). The Principal Component Analysis (PCA) is the methodology adopted to extract the main patterns of the space/time variability of these parameters. The work also focused on the coupled modes of space/time interannual variability between pairs of variables using the Singular Value Decomposition (SVD) methodology. The coupled variability between all the aforementioned parameters is investigated. This study has identified, over Europe and the Mediterranean, main modes of variability in the time series of the GPS Up coordinate, SP and TWS. The SVD analysis of coupled parameters, namely GPS Up-SP and GPS Up-TWS, showed that most of the common variability is explained by the first 3 modes. Moreover, the correlation between the GPS Up coordinate and the climate indices was estimated to investigate the possible influence of climate variability on the GPS Up behaviour. More than 30 stations, over the total of 107, show significant correlations with the AO, TNA and SCAND indices. The correlation coefficients with MEI v2 turn out to be significant and up to 0.5 for about half of the stations.
APA, Harvard, Vancouver, ISO, and other styles
6

Call, Robert Welch. "The Effect of Growth Parameters on the Height and Density of Carbon Nanotube Forests." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1261.

Full text
Abstract:
Carbon nanotube forests (CNTFs) are grown using an injection chemical vapor deposition method. Images of CNTFs are taken using a scanning electron microscope and are used to measure their height and density. Growth parameters are systematically varied to determine their effect on the height and density of CNTFs. Investigations of CNTF density as a function of distance from the growth substrate reveal that diffusion can be a limiting factor on CNTF growth. Our findings indicate that height and density are related and that each growth parameter has multi-dimensional effects.
APA, Harvard, Vancouver, ISO, and other styles
7

Walter, Fredrik. "Extraction of forest stand parameters from CARABAS VHF SAR images /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1999. http://epsilon.slu.se/avh/1999/91-576-5649-5.pdf.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Popescu, Sorin Cristian. "Estimating Plot-Level Forest Biophysical Parameters Using Small-Footprint Airborne Lidar Measurements." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/27109.

Full text
Abstract:
The main study objective was to develop robust processing and analysis techniques to facilitate the use of small-footprint lidar data for estimating forest biophysical parameters measuring individual trees identifiable on the three-dimensional lidar surface. This study derived the digital terrain model from lidar data using an iterative slope-based algorithm and developed processing methods for directly measuring tree height, crown diameter, and stand density. The lidar system used for this study recorded up to four returns per pulse, with an average footprint of 0.65 m and an average distance between laser shots of 0.7 m. The lidar data set was acquired over deciduous, coniferous, and mixed stands of varying age classes and settings typical of the southeastern United States (37° 25' N, 78° 41' W). Lidar processing techniques for identifying and measuring individual trees included data fusion with multispectral optical data and local filtering with both square and circular windows of variable size. The window size was based on canopy height and forest type. The crown diameter was calculated as the average of two values measured along two perpendicular directions from the location of each tree top, by fitting a four-degree polynomial on both profiles. The ground-truth plot design followed the U.S. National Forest Inventory and Analysis (FIA) field data layout. The lidar-derived tree measurements were used with regression models and cross-validation to estimate plot level field inventory data, including volume, basal area, and biomass. FIA subplots of 0.017 ha each were pooled together in two categories, deciduous trees and pines. For the pine plots, lidar measurements explained 97% of the variance associated with the mean height of dominant trees. For deciduous plots, regression models explained 79% of the mean height variance for dominant trees. Results for estimating crown diameter were similar for both pines and deciduous trees, with R2 values of 0.62-0.63 for the dominant trees. R2 values for estimating biomass were 0.82 for pines (RMSE 29 Mg/ha) and 0.32 for deciduous (RMSE 44 Mg/ha). Overall, plot level tree height and crown diameter calculated from individual tree lidar measurements were particularly important in contributing to model fit and prediction of forest volume and biomass.
Ph. D.
APA, Harvard, Vancouver, ISO, and other styles
9

Briggs, John Charles. "Force identification using extracted modal parameters, with applications to glide height testing of computer hard disks." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/33250.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Srivastava, Siddharth. "Assessment of critical parameters that affect the seismic performance of bridge steel pedestals." [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3142.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Books on the topic "Amplitude and height parameters"

1

Henriksen, Niels Engholm, and Flemming Yssing Hansen. Microscopic Interpretation of Arrhenius Parameters. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198805014.003.0008.

Full text
Abstract:
This chapter reviews the microscopic interpretation of the pre-exponential factor and the activation energy in rate constant expressions of the Arrhenius form. The pre-exponential factor of apparent unimolecular reactions is, roughly, expected to be of the order of a vibrational frequency, whereas the pre-exponential factor of bimolecular reactions, roughly, is related to the number of collisions per unit time and per unit volume. The activation energy of an elementary reaction can be interpreted as the average energy of the molecules that react minus the average energy of the reactants. Specializing to conventional transition-state theory, the activation energy is related to the classical barrier height of the potential energy surface plus the difference in zero-point energies and average internal energies between the activated complex and the reactants. When quantum tunnelling is included in transition-state theory, the activation energy is reduced, compared to the interpretation given in conventional transition-state theory.
APA, Harvard, Vancouver, ISO, and other styles
2

Pitt, Matthew. Motor unit anatomy and physiology. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780198754596.003.0006.

Full text
Abstract:
This chapter focuses on the signals recorded with needle electromyography (EMG) and the measurement of their specific parameters. These parameters include duration, amplitude, number of phases, and stability. The concept of the electrophysiologic biopsy and the explanation of unusual findings seen on EMG are introduced. In relation to the interference pattern, discussions of the firing rate, recruitment order, and interference pattern are given. Moving from the theoretical explanation of the findings, the problems of the accurate quantitative analysis of the motor unit potential are discussed and measures to improve quantification, particularly in children, are highlighted. The importance of filter settings, the storage of signals, and the different ways of collecting and analysing the potentials are all covered. This section finishes with discussion of the normative range for motor unit duration, and concludes with the automatic analysis of the interference pattern, including turns/amplitude analysis, number of short segments measurement, and envelope analysis.
APA, Harvard, Vancouver, ISO, and other styles
3

Puntis, John. Nutritional assessment. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198759928.003.0003.

Full text
Abstract:
Routine assessment of nutritional status should be part of normal practice when seeing any patient. The purpose is to document objective nutritional parameters (e.g. anthropometry), identify nutritional deficiencies, and establish nutritional needs. Protein–energy malnutrition has many adverse consequences including growth failure (identified by reference to standard growth charts). Worldwide, malnutrition contributes to a third of deaths in children under 5 years of age, and one in nine people don’t have enough food to lead an active and healthy life. In developed countries, malnutrition complicates both acute and chronic illness with negative effects on outcomes. In clinical practice, a useful approach to nutritional assessment is to consider three elements: ‘what you are’ (i.e. body habitus—underweight for height; short for age; etc.), ‘what you can do’ (functional activity), and ‘what you eat’ (current nutritional intake).
APA, Harvard, Vancouver, ISO, and other styles
4

Claussen, Martin, Anne Dallmeyer, and Jürgen Bader. Theory and Modeling of the African Humid Period and the Green Sahara. Oxford University Press, 2017. http://dx.doi.org/10.1093/acrefore/9780190228620.013.532.

Full text
Abstract:
There is ample evidence from palaeobotanic and palaeoclimatic reconstructions that during early and mid-Holocene between some 11,700 years (in some regions, a few thousand years earlier) and some 4200 years ago, subtropical North Africa was much more humid and greener than today. This African Humid Period (AHP) was triggered by changes in the orbital forcing, with the climatic precession as the dominant pacemaker. Climate system modeling in the 1990s revealed that orbital forcing alone cannot explain the large changes in the North African summer monsoon and subsequent ecosystem changes in the Sahara. Feedbacks between atmosphere, land surface, and ocean were shown to strongly amplify monsoon and vegetation changes. Forcing and feedbacks have caused changes far larger in amplitude and extent than experienced today in the Sahara and Sahel. Most, if not all, climate system models, however, tend to underestimate the amplitude of past African monsoon changes and the extent of the land-surface changes in the Sahara. Hence, it seems plausible that some feedback processes are not properly described, or are even missing, in the climate system models.Perhaps even more challenging than explaining the existence of the AHP and the Green Sahara is the interpretation of data that reveal an abrupt termination of the last AHP. Based on climate system modeling and theoretical considerations in the late 1990s, it was proposed that the AHP could have ended, and the Sahara could have expanded, within just a few centuries—that is, much faster than orbital forcing. In 2000, paleo records of terrestrial dust deposition off Mauritania seemingly corroborated the prediction of an abrupt termination. However, with the uncovering of more paleo data, considerable controversy has arisen over the geological evidence of abrupt climate and ecosystem changes. Some records clearly show abrupt changes in some climate and terrestrial parameters, while others do not. Also, climate system modeling provides an ambiguous picture.The prediction of abrupt climate and ecosystem changes at the end of the AHP is hampered by limitations implicit in the climate system. Because of the ubiquitous climate variability, it is extremely unlikely that individual paleo records and model simulations completely match. They could do so in a statistical sense, that is, if the statistics of a large ensemble of paleo data and of model simulations converge. Likewise, the interpretation regarding the strength of terrestrial feedback from individual records is elusive. Plant diversity, rarely captured in climate system models, can obliterate any abrupt shift between green and desert state. Hence, the strength of climate—vegetation feedback is probably not a universal property of a certain region but depends on the vegetation composition, which can change with time. Because of spatial heterogeneity of the African landscape and the African monsoon circulation, abrupt changes can occur in several, but not all, regions at different times during the transition from the humid mid-Holocene climate to the present-day more arid climate. Abrupt changes in one region can be induced by abrupt changes in other regions, a process sometimes referred to as “induced tipping.” The African monsoon system seems to be prone to fast and potentially abrupt changes, which to understand and to predict remains one of the grand challenges in African climate science.
APA, Harvard, Vancouver, ISO, and other styles
5

Wang, Bin. Intraseasonal Modulation of the Indian Summer Monsoon. Oxford University Press, 2018. http://dx.doi.org/10.1093/acrefore/9780190228620.013.616.

Full text
Abstract:
The strongest Indian summer monsoon (ISM) on the planet features prolonged clustered spells of wet and dry conditions often lasting for two to three weeks, known as active and break monsoons. The active and break monsoons are attributed to a quasi-periodic intraseasonal oscillation (ISO), which is an extremely important form of the ISM variability bridging weather and climate variation. The ISO over India is part of the ISO in global tropics. The latter is one of the most important meteorological phenomena discovered during the 20th century (Madden & Julian, 1971, 1972). The extreme dry and wet events are regulated by the boreal summer ISO (BSISO). The BSISO over Indian monsoon region consists of northward propagating 30–60 day and westward propagating 10–20 day modes. The “clustering” of synoptic activity was separately modulated by both the 30–60 day and 10–20 day BSISO modes in approximately equal amounts. The clustering is particularly strong when the enhancement effect from both modes acts in concert. The northward propagation of BSISO is primarily originated from the easterly vertical shear (increasing easterly winds with height) of the monsoon flows, which by interacting with the BSISO convective system can generate boundary layer convergence to the north of the convective system that promotes its northward movement. The BSISO-ocean interaction through wind-evaporation feedback and cloud-radiation feedback can also contribute to the northward propagation of BSISO from the equator. The 10–20 day oscillation is primarily produced by convectively coupled Rossby waves modified by the monsoon mean flows. Using coupled general circulation models (GCMs) for ISO prediction is an important advance in subseasonal forecasts. The major modes of ISO over Indian monsoon region are potentially predictable up to 40–45 days as estimated by multiple GCM ensemble hindcast experiments. The current dynamical models’ prediction skills for the large initial amplitude cases are approximately 20–25 days, but the prediction of developing BSISO disturbance is much more difficult than the prediction of the mature BSISO disturbances. This article provides a synthesis of our current knowledge on the observed spatial and temporal structure of the ISO over India and the important physical processes through which the BSISO regulates the ISM active-break cycles and severe weather events. Our present capability and shortcomings in simulating and predicting the monsoon ISO and outstanding issues are also discussed.
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Amplitude and height parameters"

1

Huang, Pei Te, and M. K. Alice. "Prediction of Optimal Pillow Height by Anthropometric Parameters." In 3rd Kuala Lumpur International Conference on Biomedical Engineering 2006, 222–23. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-68017-8_58.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Ershov, Dmitry, and Irina Lukyanenko. "Vibration Amplitude and Frequency Parameters of Technological Equipment Drives." In Proceedings of 15th International Conference on Electromechanics and Robotics "Zavalishin's Readings", 537–48. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-5580-0_44.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Singh, P., S. Srivastava, and N. S. Thakur. "Design of Land Leveller Height Measuring Physiological and Psychophysical Parameters." In Design Science and Innovation, 189–98. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-15-9054-2_21.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Ma, Jun. "Estimation of Amplitude-Dependent Dynamic Parameters from Ambient Vibration Data." In Lecture Notes in Civil Engineering, 679–89. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-2349-6_43.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Kozior, Tomasz, and Stanisław Adamczak. "Amplitude Surface Texture Parameters of Models Manufactured by FDM Technology." In Proceedings of the International Symposium for Production Research 2018, 208–17. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-92267-6_17.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Kiryushin, A. V. "On Estimation of Source Parameters from Amplitude Spectra of Surface Waves." In Selected Papers From Volumes 22 and 23 of Vychislitel'naya Seysmologiya, 80–86. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/cs001p0080.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Kohl, O. "Identification of Parameters of Stiffness and Damping Based on the Amplitude Frequency Characteristics." In The Latest Methods of Construction Design, 421–25. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-22762-7_63.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Manokruang, Supasit, Frederic Vignat, Matthieu Museau, and Maxime Limousin. "Process Parameters Effect on Weld Beads Geometry Deposited by Wire and Arc Additive Manufacturing (WAAM)." In Lecture Notes in Mechanical Engineering, 9–14. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-70566-4_3.

Full text
Abstract:
AbstractAmong Additive Manufacturing technologies, Wire and Arc Additive Manufacturing process is strongly dependent of deposition conditions such as welding parameters, substrate temperature, trajectory. In this research, geometry and temperature evolutions of single beads have been investigated according to process parameters modifications. For our experiment, a heating device have been used in order to control the substrate temperature from room temperature up to 400 °C. Considering the Cold Metal Transfer technology, welding parameters, Wire Feed Speed (WFS) and Travel Speed (TS), have been modified while keeping a constant ratio λ (WFS/TS). Results indicate that weld bead geometry, height (h) and width (w), is influenced by substrate temperature and welding parameters. It has been shown that substrate temperature, itself influenced by process parameters, tends to produce thicker and lower weld beads while it increases.
APA, Harvard, Vancouver, ISO, and other styles
9

Patel, Sumit, Shalin Marathe, Keyur Desai, and Harit Raval. "Effect of Friction Stir Welding Process Parameters on Tensile Strength and Forming Height of Tailor Welded Blanks." In Lecture Notes in Mechanical Engineering, 123–34. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-9117-4_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Jadhav, Aniket, and Shailendra Kumar. "Laser Machining of AISI 304: An Experimental Study of Influence of Process Parameters on Dross Height Formation." In Lecture Notes in Mechanical Engineering, 537–45. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-6619-6_59.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Amplitude and height parameters"

1

Kozlova, Elena S., Victor V. Kotlyar, Anton G. Nalimov, Sergey S. Stafeev, Maria V. Kotlyar, and Liam O'Faolain. "Dependence of the focal spot parameters on the relief height of the amplitude zone plate." In 2017 19th International Conference on Transparent Optical Networks (ICTON). IEEE, 2017. http://dx.doi.org/10.1109/icton.2017.8025096.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Sagrilo, Lui´s Volnei Sudati, Edison Castro Prates de Lima, and Arnaldo Papaleo. "A Joint Probability Model for Environmental Parameters." In ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/omae2008-57890.

Full text
Abstract:
The joint probabilistic models (JPM) of the environmental parameters of wave, wind and current are nowadays extremely needed in order to perform reliability analyses of offshore structures. These JPM are also essential steps for the design of offshore structures based on long-term statistics and to perform dynamic response analysis of floating units that are strongly dependent on the directionality of the environmental actions, such as turret-moored FPSOs. Recently, some JPM have been proposed in the literature to represent the joint statistics of a reduced number of environmental parameters. However, it is difficult to find a practical and fully operational model taking into account the complete statistical dependence among all the environmental parameters intensities and their correspondent directions. In this paper, it is presented a straightforward methodology, based on the Nataf transformation, to create a JPM of the environmental parameters taking into account the dependence between the intensity and direction of all variables. The proposed model considers the statistical dependence of ten short-term variables: the significant wave height, peak period and direction of the sea waves, the significant wave height, peak period and direction of the swell waves, the amplitude and direction of the 1-h wind velocity and, finally, the amplitude and direction of the surface current velocity. The statistical dependence between them is evaluated using concepts of linear-linear, linear-circular and circular-circular variables correlation. Some results of the proposed JPM methodology are presented based on simultaneous environmental data gathered in a location offshore Brazil.
APA, Harvard, Vancouver, ISO, and other styles
3

Daqaq, Mohammed F., Yawen Xu, and Walter Lacarbonara. "Nonlinearity of Finite-Amplitude Waves in Rectangular Containers." In ASME 2016 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/detc2016-59908.

Full text
Abstract:
This paper investigates the two-dimensional nonlinear finite-amplitude sloshing dynamics of an irrotational, incompressible fluid in a rectangular container. In specific, the paper addresses the influence of surface tension represented by a coefficient, β, and the ratio between the fluid height and the container’s width, represented by h/L, on the nonlinear normal sloshing modes. To achieve this objective, we first study the influence of, β, and, h/L, on the modal frequencies and generate a map in the (h/L, β) parameters’ space to highlight regions of possible nonlinear internal resonances up to the fifth mode. The map is used to characterize the regions where a single uncoupled nonlinear mode is sufficient to capture the response of surface waves. For these regions, we study the influence of surface tension on the effective nonlinearity of the first four modes and illustrate its considerable influence on the softening/hardening behavior of the uncoupled nonlinear modes. Subsequently, we investigate the response of the sloshing waves near internal resonance of the two-to-one type. We show that, in the vicinity of these internal resonances, the steady-state sloshing response can either contain a contribution from the two interacting modes (coupled-mode response) or only the higher frequency mode (un-coupled high-frequency mode response). We show that the regions where the coupled-mode uniquely exists has a clear dependence on the surface tension.
APA, Harvard, Vancouver, ISO, and other styles
4

Riegel, Kimberly A., and Victor W. Sparrow. "Sonic Boom Propagation in Urban Canyons." In ASME 2012 Noise Control and Acoustics Division Conference at InterNoise 2012. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ncad2012-0656.

Full text
Abstract:
In order to make civilian supersonic flight over land possible, the resulting sonic boom must be acceptable to the people exposed. In order to determine the impact on people, determining the behavior of a sonic boom in a large city is critical. A combined ray tracing radiosity method was developed to propagate sonic booms into urban canyons. A variety of environmental parameters were changed to determine their effect on the resulting sound field. The arrival angles of the boom, the height of the canyons, the width of the canyons, and the amount of diffusion were all varied. It was shown that the resulting sound levels from most of these parameters was highly dependent on the combination of the parameters rather than a single parameter. Diffusion was the only parameter that showed a consistent trend in the amplitude of the sound field. [Work funded by NASA and the FAA’s PARTNER Center of Excellence.]
APA, Harvard, Vancouver, ISO, and other styles
5

Waikar, R. A., and Y. B. Guo. "The Synergistic Effect of Tool Geometry and Hard Turning vs. Grinding Processes on 3D Surface Micro Topography." In ASME 2007 International Manufacturing Science and Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/msec2007-31086.

Full text
Abstract:
Surface topography induced by precision machining is critical for component performance. This paper is to study the synergistic effects of work materials, machining processes, and tool geometry on the geometrical surface quality. Four representative surface topographies of turned and ground surfaces were prepared at “extreme” machining conditions (gentle and abusive) and compared in terms of 3-dimensional (3D) surface features of amplitude, area and volume, spatial, and hybrid parameters. The 3D surface topography maps revealed the anisotropic and repeatable nature of a turned surface which was in sharp contrast with the random and isotropic nature of a ground surface. In general, a gentle turned surface has higher values of amplitude parameters (arithmetic mean, root mean square, maximum height of summits, maximum depth of valleys, and ten-point height) than an abusively turned surface, whereas the opposite was true for the ground counterparts. Only the gentle ground surface has a negative skewness which means that the topography distribution is more biased towards the valley side. The larger kurtosis value of the abusively ground surface implies a more peaked surface topography. The gentle ground and abusively turned surfaces have a much larger bearing area ratio and therefore better bearing capacity than the gentle turned and abusively ground ones. The abusively ground surface has higher fluid retainability than other surfaces in terms of mean void volume.
APA, Harvard, Vancouver, ISO, and other styles
6

Barve, Vinayak V., Ofodike A. Ezekoye, and Noel T. Clemens. "Effects of Flame Lift-Off Height on Soot Processes in Strongly Forced Methane-Air Laminar Diffusion Flames." In ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference collocated with the ASME 2007 InterPACK Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ht2007-32816.

Full text
Abstract:
Previous work has shown that for sufficiently high periodic forcing amplitudes, laminar diffusion flames can burn in an effectively partially premixed mode. Experimental observations show that the luminosity and sooting properties of the forced flames are significantly modified by the presence of strong forcing. In this work, simulations are performed to study the effects of strong forcing on flow field development in strongly forced laminar isothermal jets and methane air diffusion flames. Unforced and strongly forced cold-flow jets are simulated using a higher order finite volume CFD code. The jet was forced by varying the jet exit velocity over a range of forcing amplitudes and frequencies and it was found that the jet Strouhal number (St) was the important parameter in characterizing flowfield development. Further, the forced jets showed increased entrainment and increased entrainment rates as compared to the non-forced jets. The computations are performed for laminar methane–air diffusion flames. The combustion reactions were modeled using detailed gas-phase chemistry and complex thermo-physical properties. The radiation heat transfer was modeled using the S-6 Discrete Ordinates Method. A 2 equation soot chemistry model for soot nucleation, surface growth and oxidation was used. First an unforced flickering methane–air diffusion flame was modeled and then the flame was forced by varying the amplitude and frequency of the fuel velocity in the nozzle. Cases where the peak velocity in the fuel stream reached 6 times the mean velocity are examined. The internal nozzle flow was also simulated since the near-nozzle region was of particular interest due to the strong mixing processes occurring there and the subsequent effect on the flame properties. Lifted forced flames were also examined, and it was found that the partial premixing in the near nozzle region and increased oxygen entrainment in the forced flames can explain the reduction in soot production for the strongly forced flames.
APA, Harvard, Vancouver, ISO, and other styles
7

Liu, Liqin, Xiaorui Zhang, Ying Guo, and Yu Qiu. "Study on the Hydrodynamic Characteristic of a Spar Type Floating Foundation Which Used to Support a Vertical Axis Wind Turbine." In ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/omae2016-54337.

Full text
Abstract:
The vertical axis wind turbine has more advantages in the development of the large-scale offshore wind power, on account of that its drive system is placed on the bottom of the turbine and has little influence on the tower. This paper presents a preliminary design of a Spar foundation, which can support a Darrieus vertical axis wind turbine with a generated power of 5 MW. The influences of structure’s parameters of the floating foundation, such as the radius of flotation tank, the radius and height of upper ballast tank, the height of bottom ballast tank and other factors on the motions of the floating wind turbine system are analyzed. The initial structure parameters of the floating foundation are determined, and the hydrodynamic parameters are calculated as well. It is found that the radius of floatation tank and bottom ballast tank have more impact on the Response Amplitude Operators (RAOs) and natural period of heave of the floating foundation. The interval of center of gravity and center of buoyancy and the height of upper ballast tank influence obviously on the RAOs and natural period of pitch of the floating foundation. Heave and pitch motions of the floating foundation designed here are relatively small. The natural periods of heave and pitch of the floating foundation are away from the main wave energy periods.
APA, Harvard, Vancouver, ISO, and other styles
8

Arena, Felice, and Francesco Fedele. "Non-Linear Space-Time Evolution of Wave Groups With a High Crest." In ASME 2003 22nd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2003. http://dx.doi.org/10.1115/omae2003-37161.

Full text
Abstract:
The theory of quasi-determinism, for the mechanics of linear three-dimensional waves, was obtained by Boccotti in the eighties. The first formulation of the theory deals with the largest crest amplitude; the second formulation deals with the largest wave height. The theory was verified in the nineties with some small-scale field experiments. In this paper the first formulation of Boccotti’s theory, valid for the space-time domain, is extended to the second order. The analytical expressions of the non-linear free surface displacement and velocity potential are obtained. Therefore the space-time evolution of a wave group, to the second-order in a Stokes expansion, when a very large crest occurs at a fixed time and location, is investigated. Finally the second-order probability of exceedance of the crest amplitude is obtained, as a function of two deterministic parameters.
APA, Harvard, Vancouver, ISO, and other styles
9

Yu, Hongyi, Tatiana Gambaryan-Roisman, and Peter Stephan. "Numerical Simulations of Hydrodynamics and Heat Transfer in Wavy Falling Liquid Films on Vertical and Inclined Walls." In ASME 2012 10th International Conference on Nanochannels, Microchannels, and Minichannels collocated with the ASME 2012 Heat Transfer Summer Conference and the ASME 2012 Fluids Engineering Division Summer Meeting. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/icnmm2012-73269.

Full text
Abstract:
The flow of thin falling liquid films is unstable to long-wave disturbances. The flow instability leads to development of waves at the liquid-gas interface. The wave patterns depend on the properties of the liquid, the Reynolds number, the plate inclination angle, and the distance from the film inlet. The effect of the waves on heat and mass transfer in falling liquid films is a subject of ongoing scientific discussion. In this work numerical investigation of the wave dynamics has been performed using a modified Volume of Fluid (VOF) method for tracking the free surface. The surface tension is described using the Continuum Surface Force (CSF) model. At low disturbance frequency solitary waves of large amplitude are developed, which are preceded by low-amplitude capillary waves. At high disturbance frequency low amplitude sinusoidal waves are developed. The wave parameters (peak height, length, propagation speed) are computed from the simulation results and compared with available experimental correlations in a wide range of parameters. The effects of the disturbance frequency and the plane inclination angle on the wave dynamics have been studied. The interaction of waves initiated by simultaneous disturbances of two different frequencies has been investigated. The heat transfer in the wavy film has been simulated for constant wall temperature boundary condition. The effect of the Prandtl number and the disturbance frequency on the local and global heat transfer parameters has been investigated. It has been shown that the influence of waves on heat transfer is significant for large Prandtl numbers in a specific range of disturbance frequencies.
APA, Harvard, Vancouver, ISO, and other styles
10

Clauss, Gu¨nther F., Marco Klein, and Matthias Dudek. "Influence of the Bow Shape on Loads in High and Steep Waves." In ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/omae2010-20142.

Full text
Abstract:
To ensure survival of floating structures in rough seas, a precise knowledge of global and local loads is an inevitable integral part for safe design. One of the key parameters is the vertical bending moment. Not only vertical forces but — as previous investigations revealed — also longitudinal forces significantly contribute to the vertical wave bending moment. Three segmented ships, equipped with force transducers, are investigated systematically in high and steep regular waves and in harsh wave environments at several cruising speeds to identify the structural loads. The model tests are carried out in the seakeeping basin of the Technical University Berlin at a scale of 1:70. To cover possible influences of the bow geometry, three different types of vessels are chosen, a bulk carrier with a full bow, a Ro/Ro vessel and a container vessel with a V-shaped frame design. For identifying the influence of the wave height and steepness on the vertical bending moment, model tests in regular waves with different crest/trough asymmetries are performed with the Ro/Ro vessel and the bulk carrier. The program can be subdivided into three parts, each characterized by the same wave lengths with varying wave steepness. The first test series includes regular waves with small amplitudes, thus linear wave theory can be applied. In the second part the same (regular) wave lengths have been generated with increased wave heights, i.e. increasing crest/trough asymmetries and wave profiles within Stokes II domain. During the last part of the experimental program the wave heights are further increased to reach wave profiles within Stokes III domain. For the evaluation of the test results in regular waves — in particular in high steep waves — the results are compared to the respective Response Amplitude Operator determined by the transient wave package technique. Here the focus lies on the asymmetry of the hogging and sagging loads with respect to the wave steepness and the bow geometry of the investigated ship models. Furthermore, the influence of the freeboard height on the vertical bending moment is analysed. For this purpose a container vessel is investigated with two different freeboard configurations in a harsh wave environment.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Amplitude and height parameters"

1

Rahman, Shahedur, Rodrigo Salgado, Monica Prezzi, and Peter J. Becker. Improvement of Stiffness and Strength of Backfill Soils Through Optimization of Compaction Procedures and Specifications. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317134.

Full text
Abstract:
Vibration compaction is the most effective way of compacting coarse-grained materials. The effects of vibration frequency and amplitude on the compaction density of different backfill materials commonly used by INDOT (No. 4 natural sand, No. 24 stone sand, and No. 5, No. 8, No. 43 aggregates) were studied in this research. The test materials were characterized based on the particle sizes and morphology parameters using digital image analysis technique. Small-scale laboratory compaction tests were carried out with variable frequency and amplitude of vibrations using vibratory hammer and vibratory table. The results show an increase in density with the increase in amplitude and frequency of vibration. However, the increase in density with the increase in amplitude of vibration is more pronounced for the coarse aggregates than for the sands. A comparison of the maximum dry densities of different test materials shows that the dry densities obtained after compaction using the vibratory hammer are greater than those obtained after compaction using the vibratory table when both tools were used at the highest amplitude and frequency of vibration available. Large-scale vibratory roller compaction tests were performed in the field for No. 30 backfill soil to observe the effect of vibration frequency and number of passes on the compaction density. Accelerometer sensors were attached to the roller drum (Caterpillar, model CS56B) to measure the frequency of vibration for the two different vibration settings available to the roller. For this roller and soil tested, the results show that the higher vibration setting is more effective. Direct shear tests and direct interface shear tests were performed to study the impact of particle characteristics of the coarse-grained backfill materials on interface shear resistance. The more angular the particles, the greater the shear resistance measured in the direct shear tests. A unique relationship was found between the normalized surface roughness and the ratio of critical-state interface friction angle between sand-gravel mixture with steel to the internal critical-state friction angle of the sand-gravel mixture.
APA, Harvard, Vancouver, ISO, and other styles
2

Singhvi, Punit, Javier García Mainieri, Hasan Ozer, and Brajendra Sharma. Rheology-Chemical Based Procedure to Evaluate Additives/Modifiers Used in Asphalt Binders for Performance Enhancements: Phase 2. Illinois Center for Transportation, June 2021. http://dx.doi.org/10.36501/0197-9191/21-020.

Full text
Abstract:
The increased use of softer binders in Illinois over the past decade is primarily attributed to the increased use of recycled materials in asphalt pavement construction. The shift in demand of using PG 58-28 over PG 64-22 has resulted in potential alternative methods to produce softer binders more economically using proprietary products. However, there are challenges in using these proprietary products for asphalt modification because of uncertainty in their long-term performance and significant variability in binder chemistry. The current SuperPave performance grading specification for asphalt binders is insufficient in differentiating binders produced from these modifiers. Therefore, the objective of this study is to evaluate the performance of various softener-type asphalt binder modifiers using a wide array of rheological and chemistry tests for their integration into the Illinois Department of Transportation’s material specifications. The small-strain rheological tests and their parameters allowed for consistent grouping of modified binders and can be used as surrogates to identify performing and nonperforming asphalt binders. A new parameter, Δ|G*|peak τ, was developed from the linear amplitude sweep test and showed potential to discriminate binders based on their large-strain behavior. Chemistry-based parameters were shown to track aging and formulation changes. The modifier sources were identified using fingerprint testing and were manifested in the modified binder chemical and compositional characteristics. The two sources of base binders blended with the modifiers governed the aging rate of the modified binders. Mixture performance testing using the Illinois Flexibility Index Test and the Hamburg Wheel-Track Test were consistent with the rheological and chemical findings, except for the glycol amine-based modified binder, which showed the worst cracking performance with the lowest flexibility index among the studied modifiers. This was contrary to its superior rheological performance, which may be attributed to lower thermal stability, resulting in high mass loss during mixing. According to the characterization of field-aged binders, laboratory aging of two pressurized aging vessel cycles or more may represent realistic field aging of 10 to 15 years at the pavement surface and is able to distinguish modified binders. Therefore, an extended aging method of two pressurized aging vessel cycles was recommended for modified binders. Two different testing suites were recommended for product approval protocol with preliminary thresholds for acceptable performance validated with field-aged data.
APA, Harvard, Vancouver, ISO, and other styles
3

Phonomyography and electromyography: correlations and differences from amplitude and frequency parameters. Hanno Felder, Laura Steffny, Daniel Friemert, December 2018. http://dx.doi.org/10.14526/2070-4798-2018-13-4-144-149.

Full text
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography