Effect of Brake Chamber Pressure Area on Dynamic and Static Braking Performance of Articulated Train

2017 ◽  
pp. 182-191
Author(s):  
Jin-song Dong ◽  
Hong-wei Zhang ◽  
Hai-yan Ji ◽  
Cheng-qiang Zong ◽  
Jia-qi Yang
Keyword(s):  
Chamber Pressure ◽  
Braking Performance ◽  
Pressure Area

scholarly journals Design of a pressure modulator using fast-acting bistable valves

2020 ◽  
pp. 095440622094420
Author(s):  
L Henderson ◽  
D Cebon
Keyword(s):  
Design Method ◽  
Detection Algorithm ◽  
Chamber Pressure ◽  
Low Friction ◽  
Vehicle Performance ◽  
Braking Performance ◽  
Straight Line ◽  
Pneumatic Valves ◽  
Pressure Observer ◽  
Fast Acting

Fast-acting pneumatic valves, combined with a slip-control braking algorithm, have recently been used to improve the straight-line braking performance of an experimental heavy goods vehicle, on low friction roads, by 16%. This paper describes how the fast-acting valves, which were central to the aforementioned research, were designed for use on a commercial vehicle. Design equations, as well as a generalized design method, are first presented for the fast-acting bistable pneumatic valve. A pressure observer is developed to predict the brake chamber pressure in cases where a pressure transducer is mounted upstream. A simple fault detection algorithm is then introduced, which utilizes some of the calculations made in the pressure observer, and is shown to correctly identify faults on a real vehicle. Performance comparisons are made between the new modulator and a conventional heavy goods vehicle electro-pneumatic brake system. Closed-loop frequency response tests show that the control bandwidth of brake chamber pressure on a heavy goods vehicle can be increased from 1.5 Hz to 10 Hz using the new hardware.

Residual Gas Reaction in the Electron Microscope: II The Design of a Gas-Control Chamber for Quantitative Observations

1969 ◽  
Vol 27 ◽  
pp. 82-83
Author(s):  
Chester J. Calbick ◽  
Richard E. Hartman
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Local Environment ◽  
Chamber Pressure ◽  
Objective Lens ◽  
Ion Pump ◽  
Quantitative Studies ◽  
Precise Knowledge ◽  
Differential Pumping ◽  
And Control

Quantitative studies of the phenomenon associated with reactions induced by the electron beam between specimens and gases present in the electron microscope require precise knowledge and control of the local environment experienced by the portion of the specimen in the electron beam. Because of outgassing phenomena, the environment at the irradiated portion of the specimen is very different from that in any place where gas pressures and compositions can be measured. We have found that differential pumping of the specimen chamber by a 4" Orb-Ion pump, following roughing by a zeolite sorption pump, can produce a specimen-chamber pressure 100- to 1000-fold less than that in the region below the objective lens.

Studies of the scanning ion beam sputter-cleaned MgO crystal surface by scanning reflection electron microscopy

1987 ◽  
Vol 45 ◽  
pp. 144-145
Author(s):  
H.-J. Ou ◽  
J. M. Cowley ◽  
A. A. Higgs
Keyword(s):  
Crystal Surface ◽  
Ion Beam ◽  
Carbon Film ◽  
Surface Region ◽  
Bulk Sample ◽  
Chamber Pressure ◽  
Specimen Preparation ◽  
Detailed Surface ◽  
Gate Control ◽  
Reflection Electron Microscopy

A scanning ion gun system has been installed on the specimen preparation chamber (pressure ∼5xl0-8 torr) of the VG-HB5 STEM microscope. By using the specimen current imaging technique, it is possible to use an ion beam to sputter-clean the preferred surface region on a bulk sample. As shown in figure 1, the X-Y raster-gate control of the scanning unit for the Krato Mini-Beam I is used to minimize the beam raster area down to a 800μm x800μm square region. With beam energy of 2.5KeV, the MgO cleavage surface has been ion sputter-cleaned for less than 1 minute. The carbon film or other contaminant, introduced during the cleavage process in air, is mostly removed from the MgO crystal surfaces.The immediate SREM inspection of this as-cleaned MgO surface, within the adjacent STEM microscope, has revealed the detailed surface structures of atomic steps, which were difficult to observe on the as-cleaved MgO surfaces in the previous studies.

Electron behavior in the gaseous environment of the ESEM chamber

1996 ◽  
Vol 54 ◽  
pp. 838-839 ◽  
Author(s):  
S.A. Wight
Keyword(s):  
Secondary Electron ◽  
High Vacuum ◽  
Beam Current ◽  
Chamber Pressure ◽  
Environmental Scanning ◽  
Carbon Block ◽  
Faraday Cup ◽  
X Ray ◽  
Gaseous Environment ◽  
Working Distance

Measurements of electrons striking the sample in the Environmental Scanning Electron Microscope (ESEM) are needed to begin to understand the effect of the presence of the gas on analytical measurements. Accurate beam current is important to x-ray microanalysis and it is typically measured with a faraday cup. A faraday cup (Figure 1) was constructed from a carbon block embedded in non-conductive epoxy with a 45 micrometer bore platinum aperture over the hole. Currents were measured with an electrometer and recorded as instrument parameters were varied.Instrument parameters investigated included working distance, chamber pressure, condenser percentage, and accelerating voltage. The conditions studied were low vacuum with gaseous secondary electron detector (GSED) voltage on; low vacuum with GSED voltage off; and high vacuum (GSED off). The base conditions were 30 kV, 667 Pa (5 Torr) water vapor, 100,000x magnification with the beam centered inside aperture, GSED voltage at 370 VDC, condenser at 50%, and working distance at 19.5 mm. All modifications of instrument parameters were made from these conditions.

Nanocrystalline silicon ( nc-Si ) from single ion beam sputtering

2003 ◽  
Vol 762 ◽  
Author(s):  
Z.B. Zhou ◽  
G.M. Hadi ◽  
R.Q. Cui ◽  
Z.M. Ding ◽  
G. Li
Keyword(s):  
Solar Cell ◽  
Ion Beam ◽  
Nanocrystalline Silicon ◽  
Silicon Films ◽  
Chamber Pressure ◽  
Ion Beam Sputtering ◽  
High Hydrogen ◽  
Beam Sputtering ◽  
Si Films ◽  
Nanocrystalline Silicon Films

AbstractBased on a small set of selected publications on the using of nanocrystalline silicon films (nc-Si) for solar cell from 1997 to 2001, this paper reviews the application of nc-Si films as intrinsic layers in p-i-n solar cells. The new structure of nc-Si films deposited at high chamber pressure and high hydrogen dilution have characters of nanocrystalline grains with dimension about several tens of nanometer embedded in matrix of amorphous tissue and a high volume fraction of crystallinity (60~80%). The new nc-Si material have optical gap of 1.89 eV. The efficiency of this single junction solar cell reaches 8.7%. This nc-Si layer can be used not only as an intrinsic layer and as a p-type layer. Also nanocrystalline layer may be used as a seed layer for the growth of polycrystalline Si films at a low temperature.We used single ion beam sputtering methods to synthesize nanocrystalline silicon films successfully. The films were characterized with the technique of X-ray diffraction, Atomic Force Micrographs. We found that the films had a character of nc-amorphous double phase structure. Conductivity test at different temperatures presented the transportation of electrons dominated by different mechanism within different temperature ranges. Photoconductivity gains of the material were obtained in our recent investigation.

Evaluation of Combustion Chamber Pressure of 1N-Class Green Monopropellant Thruster with Discharge Plasma System

2017 ◽  
Vol 65 (3) ◽  
pp. 117-122
Author(s):  
Asato WADA ◽  
Hiroshi MAEDA ◽  
Takahiro SHINDO ◽  
Hiroki WATANABE ◽  
Haruki TAKEGAHARA
Keyword(s):  
Combustion Chamber ◽  
Discharge Plasma ◽  
Chamber Pressure ◽  
Plasma System

A Study on the Contour of the Radial Tire: Rolling Contour Optimization Theory — RCOT

1987 ◽  
Vol 15 (1) ◽  
pp. 3-29 ◽  
Author(s):  
K. Yamagishi ◽  
M. Togashi ◽  
S. Furuya ◽  
K. Tsukahara ◽  
N. Yoshimura
Keyword(s):  
Fuel Efficiency ◽  
Optimization Theory ◽  
Radial Tire ◽  
Braking Performance ◽  
Equilibrium Profiles ◽  
Natural Equilibrium

Abstract The Rolling Contour Optimization Theory (RCOT) can lead to improved steering, fuel efficiency, riding comfort, and braking performance of tires relative to those of conventional shape. The conventional shape has been guided by natural equilibrium profiles, while the RCOT technology shape is guided by that of the tire in motion. This reduces useless distortions caused by running the tire under load. The RCOT design focuses on the distribution of belt and sidewall tension in the tire. Controlling tension in the belt and carcass area while the tire is in motion was the key to creating this new tire shape.

Recent Studies of Tire Braking Performance

1973 ◽  
Vol 1 (2) ◽  
pp. 121-137 ◽  
Author(s):  
J. L. McCarty ◽  
T. J. W. Leland
Keyword(s):  
Steady State ◽  
Rapid Cycling ◽  
Single Cycle ◽  
Steering Angle ◽  
Slip Ratio ◽  
Factors Affecting ◽  
Braking Performance ◽  
Constant Rate

Abstract The results from recent studies of some factors affecting tire braking and cornering performance are presented together with a discussion of the possible application of these results to the design of aircraft braking systems. The first part of the paper is concerned with steady-state braking, that is, results from tests conducted at a constant slip ratio or steering angle or both. The second part deals with cyclic braking tests, both single cycle, where brakes are applied at a constant rate until wheel lockup is achieved, and rapid cycling of the brakes under control of a currently operational antiskid system.

Applanation Tonometry for Assessment of Left Ventricular Systolic Load

2019 ◽  
Vol 12 (2) ◽  
pp. 94-99
Author(s):  
Rene D. Mileva-Popova ◽  
Nina Y. Belova
Keyword(s):  
Arterial Stiffness ◽  
Augmentation Index ◽  
Age Groups ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Applanation Tonometry ◽  
Non Invasive ◽  
Pressure Area ◽  
Older Subjects ◽  
And Gender

Summary Vascular-ventricular coupling is a major determinant of left ventricular load. The aim of our study was to assess non- invasively left ventricular load and its dependency on central hemodynamics. Sixty-five healthy and gender-matched individuals were divided in two groups according to their age: 20y/o and 50y/o. Applanation tonometry was performed using the Sphygmocor device. Central pressures and pulse wave analysis indices were computed. Central systolic (120±3 vs. 98±2 mm Hg) and pulse pressures (43±3 vs. 29±1 mm Hg) as well as the augmentation index (AIx75) (23±3 vs. 6±2%) were significantly higher in the 50y/o group (p<0.01). These parameters are relevant markers of arterial stiffness and evidenced the development of central arterial morphological and functional alterations in the older subjects. The time-tension index (TTI) computed from the systolic pressure area was significantly higher in the 50y/o subjects as compared to the 20y/o group (2378±66 vs. 1954±73 mmHg×s, p<0.01). Moreover, we have shown the presence of significant correlation between TTI and AIx75 (p<0.01) in both age groups. This finding confirmed the contribution of arterial stiffness for the impaired vascular-ventricular coupling. In conclusion, applanation tonometry might be utilized for non-invasive evaluation of the left ventricular load, which is an important parameter of cardiovascular risk.

The Comparison of Ostecyte in the Pressure area and Tension area on Tooth Movement Because of Hyperbaric Oxygen Therapy

DENTA ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 34
Author(s):  
Arya Barahmanta ◽  
Muhammad Faizal Winaris ◽  
Pambudi Raharjo
Keyword(s):  
Hyperbaric Oxygen ◽  
Oxygen Therapy ◽  
Tooth Movement ◽  
Bone Remodelling ◽  
Orthodontic Tooth Movement ◽  
Negative Control Group ◽  
Positive Control ◽  
Negative Control ◽  
Control Group ◽  
Pressure Area

<p><strong><em>Background:</em></strong><em> Orthodontic tooth movement is a </em><em>interaction prosess</em><em> of resorption and deposition of bone remodeling. Orthodontic tooth movement by mechanical strength causes changes in alveolar bone. Osteocyte is an essential cell to respond bone remodelling. Hyperbaric Oxygen Therapy affects production of osteocyte because it can release Reactive Oxygen Species (ROS) and Nitrid Oxide (NO).  <strong>Purpose: </strong>To determine the difference number  of osteocyte in pressure and tension area during tooth movement by adjuvant of Hyperbaric Oxygen 2,4 ATA during 7 days starting on day 8 to day 14. <strong>Materials and Methods</strong>: This research used Completery Randomized Control Group Post Test Only Design. 36 cavia cobaya (male)  were divided into 3 groups randomly : the negative control groups, positive control group, and treatment group. Preparat staining used Hematoxylin Eosin (HE) and calculated on microscop 1000x with 20 field of view. Data analyses used one way ANOVA and LSD test then compared each area by using paired T test. <strong>Result:</strong> The data showed that the treatment group (P=10,67) tension area has the highest number of osteocyte than  negative control group (K-=3,67), positive control (K+=7,42). In the pressure area showed that negative control group (K-=5,00) has the highest  than positive control group (K+=3,83) and treatment (P=3,25). <strong>Conclusion: </strong>Therapy HBO 2,4 ATA 7 days starting on day 8 to day 14 is could increase osteocyte in the tissue to stimulate process of bone remodelling.</em></p><pre><strong> </strong></pre><p><strong><em>Keywords:</em></strong><em> Hyperbaric Oxygen, Tooth movement, Bone remodeling, </em><em>Osteocyte</em><em></em></p><p><em> </em></p><p><strong><em>Correspondence:</em></strong><em> </em><em>Arya Brahmanta</em><em>, Department of Orthodonty, Faculty of Dentistry, Hang Tuah University, Arif Rahman Hakim 150, Surabaya, Phone 031-5945864, Email:</em><em> </em><a href="mailto:[email protected]"><em>arya.brahmanta</em><em>@</em><em>hangtuah.ac.id</em></a></p>

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