scholarly journals Applicability of a 3D Laser Scanner for Characterizing the Spray Distribution Pattern of an Air-Assisted Sprayer

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
F. Javier García-Ramos ◽  
Alfredo Serreta ◽  
Antonio Boné ◽  
Mariano Vidal
Keyword(s):  
Air Flow ◽  
Sonic Anemometer ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Static Mode ◽  
Static Test ◽  
Axial Fans ◽  
Spray Distribution ◽  
The One ◽  
The Right

Three-dimensional (3D) laser technology has been tested for assessing the performance of air-assisted spraying. A static test using an air-assisted sprayer equipped with two axial fans (front and back) with opposing directions of rotation was developed. The sprayer was adjusted to spread water in a static mode, at a pressure of 10 bars, with four air volumetric flow rates. Measurements were performed using a Leica HDS6000 3D laser scanner. In addition, the flow and velocity of air generated by the air-assisted sprayer were measured using a hot-wire anemometer and a 3D sonic anemometer with the objective of estimating the influence of air flow on the spatial distribution of spray droplets. To carry out the analysis, all of the droplets detected by the laser were considered to be of the same size. The distribution of products was asymmetric when the machine only worked with the back fan, with 41% of the product distributed on the left side versus 59% on the right side, as referenced to the direction of the machine’s advance. This asymmetry was corrected when the machine functioned with the two fans activated. These spray data were concordant with the measured air flow generated by the machine in the different working conditions. For the different regulation settings of the machine, taking the vertical of the machine as 0°, the angular region comprised between 40° and 60° was the one that received the highest quantity of product. The increase of the air flow produced a greater distance of the product. For the highest air flow configuration, 99% of the product detected by the laser was detected within a distance of 16 m from the axis of the machine.

scholarly journals Design of Two-Wheeled Motorcycle Tire Crown Contour Bioinspired by Cat Paw Pads

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Congzhen Liu ◽  
Guolin Wang ◽  
Haichao Zhou ◽  
Ye Mei ◽  
Yongqiang Li ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Contact Area ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Operating Conditions ◽  
Tire Model ◽  
Static Test ◽  
Pressure Sensitive ◽  
Comparative Results

The grip force of tires is crucial for vehicle security and drivability under different driving conditions. A small contact area and stress concentration in the contact patch of two-wheeled motorcycle (TWM) tires result in a reduction in grip performance and wear resistance. Even worse, improving the grip and wear resistance together is difficult to achieve. The purpose of the current study is to analyze the dynamic grounding characteristics and geometry of a cat paw pad and then apply its structure to the TWM tire to improve the contact area and wear resistance under different operating conditions. A nonlinear finite element tire model that could accurately reconstruct the tire structure and realistically reflect the mechanical response to different loads was employed. Then, the accuracy of the tire model was validated by a static test with a control tire. For cats, the dynamic grounding characteristics and topology of paw pads were determined using a pressure-sensitive walkway and a three-dimensional (3D) laser scanner. The results indicated that the cat forepaw third pad (CFTP) exhibited excellent grip capacity. According to similarity transformation, a bionic tire crown was designed according to the lateral fitting curve of the CFTP. Comparative results showed the enlargement of the contact area and decreases in peak pressure and frictional energy rate for the bionic tire under different conditions. With these improvements, the grip performance was improved, and the service life was extended synchronously. These research results can be applied for the design of TWM tires, especially cross-country motorcycle tires.

scholarly journals Three-Dimensional Visualization System with Spatial Information for Navigation of Tele-Operated Robots

Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 746 ◽  
Author(s):  
Seung-Hun Kim ◽  
Chansung Jung ◽  
Jaeheung Park
Keyword(s):  
Real Time ◽  
Spatial Information ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Effective Control ◽  
Visualization System ◽  
Level Information ◽  
Surrounding Space ◽  
The Right ◽  
High Level

This study describes a three-dimensional visualization system with spatial information for the effective control of a tele-operated robot. The environmental visualization system for operating the robot is very important. The tele-operated robot performs tasks in a disaster area that is not accessible to humans. The visualization system should perform in real-time to cope with rapidly changing situations. The visualization system should also provide accurate and high-level information so that the tele-operator can make the right decisions. The proposed system consists of four fisheye cameras and a 360° laser scanner. When the robot moves to the unknown space, a spatial model is created using the spatial information data of the laser scanner, and a single-stitched image is created using four images from cameras and mapped in real-time. The visualized image contains the surrounding spatial information; hence, the tele-operator can not only grasp the surrounding space easily, but also knows the relative position of the robot in space. In addition, it provides various angles of view without moving the robot or sensor, thereby coping with various situations. The experimental results show that the proposed method has a more natural appearance than the conventional methods.

scholarly journals On the Merits of Using a 3D-FGAT Assimilation Scheme with an Outer Loop for Atmospheric Situations Governed by Transport

2010 ◽  
Vol 138 (12) ◽  
pp. 4509-4522 ◽  
Author(s):  
Sébastien Massart ◽  
Benjamin Pajot ◽  
Andrea Piacentini ◽  
Olivier Pannekoucke
Keyword(s):  
Transport Model ◽  
Computing Time ◽  
Three Dimensional ◽  
Observation Time ◽  
Chemical Transport Model ◽  
Outer Loop ◽  
Pros And Cons ◽  
The One ◽  
The Right ◽  
Assimilation Scheme

Abstract Three-dimensional variational data assimilation (3D-Var) with the first guess at appropriate time (FGAT) appears to be an attractive compromise between accuracy and overall computing time. It is computationally cheaper than four-dimensional (4D)-Var as the increment is not propagated back and forth in time by a model, yet the comparison between the model and the observations is still computed at the right observation time. An interesting feature of the 4D-Var is the iterative process known as the outer loop. This outer-loop approach can also be used in conjunction with 3D-FGAT. But it requires the application of the 3D-FGAT analysis increment at the beginning of the assimilation window. The pros and cons of using this unusual 3D-FGAT variant are illustrated in this paper on two applications focused on the transport, one of the main phenomena governing the atmospheric evolution. The first one is the one-dimensional advection of a passive tracer. By three representative situations, it shows the benefits of the outer loop, except for practical situations driven by very rapid dynamics such as a zonal wind of 50 m s−1 on the earth’s great circle, when the assimilation window has a size of 3 h. The second application is the 3D-FGAT assimilation of true ozone measurements into a chemical–transport model. It confirms the previous results, showing that the 3D-FGAT analysis with the outer loop produces an overestimation of the ozone increment in regions where the wind speed is high compared to the time length of the assimilation window.

scholarly journals LASER-SCANNER SURVEY OF STRUCTURAL DISORDERS: AN INSTRUMENT TO INSPECT THE HISTORY OF PARMA CATHEDRAL’S CENTRAL NAVE

2017 ◽  
Vol XLII-5/W1 ◽  
pp. 167-174 ◽  
Author(s):  
N. Bruno ◽  
E. Coïsson ◽  
M. Cotti
Keyword(s):  
Structural Analysis ◽  
Distinct Element ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
First Case ◽  
Transverse Arch ◽  
Structural Disorders ◽  
The One

This paper presents the use of laser scanner derived data for the study of the structural disorders in the central nave of the Parma Cathedral. An accurate three-dimensional model of the entire nave was realized to investigate deformations, in order to reconstruct the original conformation and the subsequent evolutions, also in comparison with previous surveys. Specifically, for the analysis presented in the paper, seven scans were performed, one for each bay: the results allowed to compare the deformations on the seven vaults, on the transverse and diagonal arches, giving first hints on the possible differences in the behaviour between the different elements. The measures on the levels of floor and pillars bases were analysed in a historical monitoring approach, in order to retrace the evolution of the differential settlements in time, since the construction of the building. Moreover, a structural analysis has been carried out on one transverse arch with distinct element analysis, with two different approaches. In one case, the structure was inserted exactly as surveyed, and then subjected to the actions. In the second case, the original geometry, before the deformation, was retraced through a parametric approach and the structural analysis basically started at the beginning of the building’s life, thus trying to model not only the present structural situation, but also the path which led to the current deformation. The results were particularly meaningful as they showed that in the first case, disregarding the footsteps of history, the stress pattern inside the masonry was very different from the one obtained in the second case, which is more likely to represent the present conditions.

scholarly journals Cognitive abilities of horses in terms of visual and olfactory perception

2017 ◽  
Vol 73 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Tomasz Próchniak ◽  
Iwona Rozempolska-Rucińska ◽  
Monika Petrykowska ◽  
Grzegorz Zięba ◽  
Brygida Ślaska ◽  
...  
Keyword(s):  
Visual Stimulus ◽  
Cognitive Abilities ◽  
Three Dimensional ◽  
Negative Reaction ◽  
Olfactory Perception ◽  
Two Dimensional ◽  
Object A ◽  
The One ◽  
Dimensional Object ◽  
The Right

The aim of the study was to assess the cognitive abilities of horses in recognizing humans by sight and smell. Two experiments were performed. In the first experiment, the behaviour of horses exposed to a visual stimulus (photographs of familiar and unfamiliar people) was observed. The second experiment examined their behaviour evoked by an olfactory stimulus. The following variables was assessed: the duration of approach to the object in seconds (s), interest in the object, a negative reaction, the duration of the observation of the object (s), the duration of looking with the left eye and the right eye (s), and other signs of interest, e.g. licking, grasping with lips, and touching the object. It was found that the horses were able to identify the human by transferring the identification of a three-dimensional object (a person that positively conditioned the horse) to a two-dimensional object (a photograph of that person’s face). It was also shown that the horses used the sense of smell in associating clothes with the person wearing them (the one who positively conditioned the horse). It was found that positively conditioned horses reacted more strongly to the smell of human clothes than to a photograph of the human.

scholarly journals Documentación 3D y visualización multimedia de la Cova del Parpalló (Gandia)

2010 ◽  
Vol 1 (2) ◽  
pp. 123 ◽  
Author(s):  
José Luis Lerma García ◽  
Miriam Cabrelles López ◽  
Santiago Navarro Tarín ◽  
Sergio Galcerá Ustero
Keyword(s):  
Cultural Heritage ◽  
Laser Scanning ◽  
Three Dimensional ◽  
3D Models ◽  
The Other ◽  
Its Analysis ◽  
3D Documentation ◽  
The One ◽  
The Right ◽  
Cultural Heritage Objects

<p>The three-dimensional (3D) documentation by means of laser scanning and photogrammetry eases exhaustive recording, the right lecture of cultural heritage objects and its analysis in order to, on the one hand, adopt appropriate decisions and interventions, on the other hand, move forward the generation of virtual animated replicas of great value and smooth multimedia dissemination. The present paper tackles the different stages of graphic documentation and visualization undertaken in the Parpalló Cave (Cova del Parpalló), Gandia, Valencia. Besides traditional surveying documentation that is based on planimetric and altimetric maps, this paper presents the plotting and animated visualization of the Palaeolithic set not only making use of lights and shadows but also from photorealistic textured 3D models.</p>

scholarly journals Analysis of the Air Flow Generated by an Air-Assisted Sprayer Equipped with Two Axial Fans Using a 3D Sonic Anemometer

Sensors ◽  
2012 ◽  
Vol 12 (6) ◽  
pp. 7598-7613 ◽  
Author(s):  
F. Javier García-Ramos ◽  
Mariano Vidal ◽  
Antonio Boné ◽  
Hugo Malón ◽  
Javier Aguirre
Keyword(s):  
Air Flow ◽  
Sonic Anemometer ◽  
Axial Fans

Diffraction contrast of dislocations in icosahedral quasicrystals

1990 ◽  
Vol 48 (4) ◽  
pp. 454-455
Author(s):  
K. Urban ◽  
Z. Zhang ◽  
M. Wollgarten ◽  
D. Gratias
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Complete Characterization ◽  
Extinction Condition ◽  
Burgers Vector ◽  
Diffraction Contrast ◽  
Lattice Geometry ◽  
Reference Space ◽  
Icosahedral Quasicrystals ◽  
The One

Recently dislocations have been observed by electron microscopy in the icosahedral quasicrystalline (IQ) phase of Al65Cu20Fe15. These dislocations exhibit diffraction contrast similar to that known for dislocations in conventional crystals. The contrast becomes extinct for certain diffraction vectors g. In the following the basis of electron diffraction contrast of dislocations in the IQ phase is described. Taking account of the six-dimensional nature of the Burgers vector a “strong” and a “weak” extinction condition are found.Dislocations in quasicrystals canot be described on the basis of simple shear or insertion of a lattice plane only. In order to achieve a complete characterization of these dislocations it is advantageous to make use of the one to one correspondence of the lattice geometry in our three-dimensional space (R3) and that in the six-dimensional reference space (R6) where full periodicity is recovered . Therefore the contrast extinction condition has to be written as gpbp + gobo = 0 (1). The diffraction vector g and the Burgers vector b decompose into two vectors gp, bp and go, bo in, respectively, the physical and the orthogonal three-dimensional sub-spaces of R6.

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

Mechanisms of Resource Curse and Economic Policy

2007 ◽  
pp. 4-27 ◽  
Author(s):  
V. Polterovich ◽  
V. Popov ◽  
A. Tonis
Keyword(s):  
Real Exchange Rates ◽  
Resource Curse ◽  
Budget Deficits ◽  
Resource Abundance ◽  
Fuel Prices ◽  
Use Of Resources ◽  
Resource Wealth ◽  
The One ◽  
The Right ◽  
Rich Countries

This paper compares various mechanisms of resource curse leading to a potentially inefficient use of resources; it is demonstrated that each of these mechanisms is associated with market imperfections and can be "corrected" with appropriate government policies. Empirical evidence seems to suggest that resource abundant countries have on average lower budget deficits and inflation, and higher foreign exchange reserves. Besides, lower domestic fuel prices that are typical for resource rich countries have a positive effect on long-term growth even though they are associated with losses resulting from higher energy consumption. On top of that resource abundance allows to reduce income inequalities. So, on the one hand, resource wealth turns out to be conducive to growth, especially in countries with strong institutions. However, on the other hand, resource abundance leads to corruption of institutions and to overvalued real exchange rates. On balance, there is no solid evidence that resource abundant countries grow more slowly than the others, but there is evidence that they grow more slowly than could have grown with the right policies and institutions.

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