Field investigation on the lateral resistance of ballasted tracks with strengthened steel sleepers using the multi sleeper push test

2019 ◽  
Vol 234 (9) ◽  
pp. 969-975 ◽  
Author(s):  
Jabbar Ali Zakeri ◽  
Roshan Talebi ◽  
Fatemeh Rahmani
Keyword(s):  
Laboratory Tests ◽  
Field Investigation ◽  
Test Methods ◽  
Radial Force ◽  
The Other ◽  
Railway Track ◽  
Lateral Forces ◽  
Lateral Resistance

Lack of lateral resistance is one of the emerging problems in continuously welded rails. Lateral resistance is a type of resistance in which the railway track mobilizes against the applied lateral forces. Thus, curved tracks, especially sharp curves (curves with small radiuses), are the most susceptible segments for the lack of lateral resistance. The reason is, on curved tracks, in addition to the lateral forces applied by the train, longitudinal forces are decomposed into two parts, with one part being tangential (tangent to the curve) and the other part being radial. This radial force causes some defects to the track such as track buckling, transversal shifting of the track, pulling out of fastening shoulders, etc. Therefore, according to the general track instructions, welding of rails is not possible on curved tracks with a radius less than 400 m. With the help of laboratory tests, the authors of this paper previously showed that using two stiffeners under the steel sleeper increased the lateral resistance of the track adequately (by 140%) compared to the track with normal steel sleepers. In this paper, the effect of using two plate stiffeners under the steel sleepers was examined by field investigation on a real track. Two test methods, including the Single Tie (sleeper) Push Test (STPT) and the Multiple Tie (sleeper) Push Test (MTPT), were used to investigate the lateral resistance of the track. The results obtained by the STPT and MTPT methods showed an increase in lateral resistance by 139.6% and 135.5%, respectively. The obtained results are in accordance with the results of the laboratory tests. Moreover, the results showed that using two stiffeners under steel sleepers increased the lateral resistance of the track adequately, thereby enabling rails to be welded on curved tracks.

scholarly journals Field Investigations on the Effects of Track Lateral Supports on the Ballasted Railway Lateral Resistance

2020 ◽  
Author(s):  
Jabbar Ali Zakeri ◽  
Milad Alizadeh Galdiani ◽  
Seyed Ali Mosayebi
Keyword(s):  
Numerical Modeling ◽  
Bilinear Form ◽  
Field Tests ◽  
New Method ◽  
Railway Track ◽  
Lateral Forces ◽  
Lateral Resistance ◽  
Field Investigations ◽  
Continuous Welded Rail ◽  
Lateral Displacements

Lateral movements of the ballasted railway track especially in the continuous welded rail (CWR) occur in sharp curves because of high lateral forces. Several strategies have been proposed to increase the track lateral resistance which most of them related to track curves with small radii. In this paper, track lateral supports as a new method have been utilized and a series of field tests have been conducted by using the Single Tie Push Tests (STPT) and Multi Tie Push Tests (MTPT) and their results are compared with the numerical modeling. The results of numerical modeling and field tests show that the track lateral resistance significantly increases in the railway with lateral supports, so that the lateral displacements of track are as a bilinear form.

The Reliability of Retrieval-Induced Forgetting

2012 ◽  
Vol 17 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Rosalind Potts ◽  
Robin Law ◽  
John F. Golding ◽  
David Groome
Keyword(s):  
Individual Differences ◽  
Recognition Test ◽  
Laboratory Tests ◽  
The Other ◽  
Clinical Factors ◽  
Test Items ◽  
T1 And T2 ◽  
Test Materials ◽  
Induced Forgetting

Retrieval-induced forgetting (RIF) refers to the finding that the retrieval of an item from memory impairs the retrieval of related items. The extent to which this impairment is found in laboratory tests varies between individuals, and recent studies have reported an association between individual differences in the strength of the RIF effect and other cognitive and clinical factors. The present study investigated the reliability of these individual differences in the RIF effect. A RIF task was administered to the same individuals on two occasions (sessions T1 and T2), one week apart. For Experiments 1 and 2 the final retrieval test at each session made use of a category-cue procedure, whereas Experiment 3 employed category-plus-letter cues, and Experiment 4 used a recognition test. In Experiment 2 the same test items that were studied, practiced, and tested at T1 were also studied, practiced, and tested at T2, but for the remaining three experiments two different item sets were used at T1 and T2. A significant RIF effect was found in all four experiments. A significant correlation was found between RIF scores at T1 and T2 in Experiment 2, but for the other three experiments the correlations between RIF scores at T1 and T2 failed to reach significance. This study therefore failed to find clear evidence for reliable individual differences in RIF performance, except where the same test materials were used for both test sessions. These findings have important implications for studies involving individual differences in RIF performance.

Platelet Suruival and Function in Rats with Enhanced Thrombotic Tendency

1985 ◽  
Vol 54 (04) ◽  
pp. 739-743 ◽  
Author(s):  
Federica Delaini ◽  
Elisabetta Dejana ◽  
Ine Reyers ◽  
Elisa Vicenzi ◽  
Germana De Bellis Vitti ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Nephrotic Syndrome ◽  
Platelet Function ◽  
Laboratory Tests ◽  
Thrombus Formation ◽  
The Other ◽  
Mean Survival Time ◽  
The Mean ◽  
And Function ◽  
Thrombotic Tendency

SummaryWe have investigated the relevance of some laboratory tests of platelet function in predicting conditions of thrombotic tendency. For this purpose, we studied platelet survival, platelet aggregation in response to different stimuli, TxB2 and 6-keto-PGFlα production in serum of rats bearing a nephrotic syndrome induced by adriamycin. These animals show a heavy predisposition to the development of both arterial and venous thrombosis. The mean survival time was normal in nephrotic rats in comparison to controls. As to aggregation tests, a lower aggregating response was found in ADR-treated rats using ADP or collagen as stimulating agents. With arachidonic acid (AA) we observed similar aggregating responses at lower A A concentrations, whereas at higher AA concentrations a significantly lower response was found in nephrotic rats, despite their higher TxB2 production. Also TxB2 and 6-keto-PGFlα levels in serum of nephrotic rats were significantly higher than in controls. No consistent differences were found in PGI2-activity generated by vessels of control or nephrotic rats.These data show that platelet function may appear normal or even impaired in rats with a markedly increased thrombotic tendency. On the other hand, the significance of high TxB2 levels in connection with mechanisms leading to thrombus formation remains a controversial issue.

Fidelity of J1269 and J24523

2007 ◽  
Vol 35 (2) ◽  
pp. 94-117 ◽  
Author(s):  
James A. Popio ◽  
John R. Luchini
Keyword(s):  
Steady State ◽  
Rolling Resistance ◽  
Test Methods ◽  
The Other ◽  
Reference Condition ◽  
Test Standards

Abstract This study compares data from the two Society of Automotive Engineers test methods for rolling resistance: J-2452 (Stepwise Coast-Down) and J-1269 (Equilibrium) steady state. The ability of the two methods to evaluate tires was examined by collecting data for 12 tires. The data were analyzed and the data showed that the two methods ranked the tires the same after the data were regressed and the rolling resistance magnitude was calculated at the Standard Reference Condition. In addition, analysis of the two methods using this matched set of testing provided an opportunity to evaluate each of these test standards against the other. It was observed that each test has merits absent from the other.

scholarly journals A Balloon Sounding Technique for Measuring SO2 Plumes

2010 ◽  
Vol 27 (8) ◽  
pp. 1318-1330 ◽  
Author(s):  
Gary A. Morris ◽  
Walter D. Komhyr ◽  
Jun Hirokawa ◽  
James Flynn ◽  
Barry Lefer ◽  
...  
Keyword(s):  
Detection Limit ◽  
Laboratory Tests ◽  
Field Experience ◽  
Electrochemical Cell ◽  
The Other ◽  
New Technique ◽  
A New Technique

Abstract This paper reports on the development of a new technique for inexpensive measurements of SO2 profiles using a modified dual-ozonesonde instrument payload. The presence of SO2 interferes with the standard electrochemical cell (ECC) ozonesonde measurement, resulting in −1 molecule of O3 reported for each molecule of SO2 present (provided [O3] > [SO2]). In laboratory tests, an SO2 filter made with CrO3 placed on the inlet side of the sonde removes nearly 100% of the SO2 present for concentrations up to 60 ppbv and remained effective after exposure to 2.8 × 1016 molecules of SO2 [equivalent to a column ∼150 DU (1 DU = 2.69 × 1020 molecules m−2)]. Flying two ECC instruments on the same payload with one filtered and the other unfiltered yields SO2 profiles, inferred by subtraction. Laboratory tests and field experience suggest an SO2 detection limit of ∼3 pbb with profiles valid from the surface to the ozonopause [i.e., ∼(8–10 km)]. Two example profiles demonstrate the success of this technique for both volcanic and industrial plumes.

scholarly journals Using CPTs to derive thermal properties of soil

2020 ◽  
Vol 205 ◽  
pp. 04005
Author(s):  
Philip J. Vardon ◽  
Joek Peuchen
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Laboratory Tests ◽  
Field Investigation ◽  
Volumetric Heat Capacity ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
Penetration Tests ◽  
Properties Of Soil

A method of utilizing cone penetration tests (CPTs) is presented which gives continuous profiles of both the in situ thermal conductivity and volumetric heat capacity, along with the in situ temperature, for the upper tens of meters of the ground. Correlations from standard CPT results (cone resistance, sleeve friction and pore pressure) are utilized for both thermal conductivity and volumetric heat capacity for saturated soil. These, in conjunction with point-wise thermal conductivity and in situ temperature results using a Thermal CPT (T-CPT), allow accurate continuous profiles to be derived. The CPT-based method is shown via a field investigation supported by laboratory tests to give accurate and robust results.

scholarly journals GEOTECHNICAL CHARACTERISTICS OF EMBANKMENT ALONG THE RAILWAY ROUTE OF ENTITY BORDER OF FEDERATION OF BIH – MAGLAJ, SECTION km 103+500 MAGLAJ

2017 ◽  
Vol 1 (16) ◽  
Author(s):  
Neđo Đurić
Keyword(s):  
European Union ◽  
Laboratory Tests ◽  
Soil Depth ◽  
The Other ◽  
Geotechnical Characteristics ◽  
Time Period ◽  
European Union Countries ◽  
Improvement Measures ◽  
Train Speed

Railway route from entity border to Maglaj is on corridor V of railways that connects Adriatic seawith European Union countries. More precisely, it is on the railway Samac – Sarajevo that was builtduring the fifties. From Doboj to Zenica exist two tracks, one built in 1947. and the other thirty yearslater. In time, the railway worn out, since it was not maintained properly during its exploitation, soallowed train speed is 40 km/h. Reconstruction of railway had previously started on sections with aimto achieve the level of train speed to 120 km/h.Terrain research in order to overview quality of material on which the railway is laid, and immediateenvironment that has effect on railway route, were conducted by sections, from which section km103+500 – Maglaj is one of the most important considering characteristics of the terrain on which theroute passes. Research along railway route were conducted by using research trial pits from both sidesand in between tracks, to depth of entry in basic soil. Depth of research works is different for old andnew track, considering the way of construction in time period of 30 years. Beyond narrow corridor ofrailway route research of characteristics of the terrain were not conducted, because of inability toaccess due to mining. Results of terrain and laboratory tests showed geotechnical characteristics ofmaterial, based on which were given quality improvement measures for deposited materials, and basefor reconstruction of railway.

Study on the interference of pier on the channel bed

2021 ◽  
pp. 278-284
Author(s):  
Atul Kumar Rahul ◽  
Akash Priyadarshee ◽  
Prabhat Kumar Singh ◽  
Shyam Bihari Dwivedi
Keyword(s):  
Laboratory Tests ◽  
The Other ◽  
Straight Channel ◽  
Sand Mining ◽  
Continuous Processes ◽  
River Bed ◽  
Natural Flow ◽  
Scouring Process ◽  
Study Laboratory ◽  
The Impact

Scoring and sedimentation are two continuous processes which take place in river bed. These two phenomena have significant impact over the overall behavior of river. Scoring and sedimentation process get affected due the construction of structures like Bridges. Piers of bridge alter the natural flow of rivers. Due to this scouring process increases near to the pier. The scouring process gets affected due to the other activities like sand mining or filling. Also any obstruction like some construction can also affect the scouring. In this study laboratory tests were conducted to understand the nature of scouring near to the pier. For this purpose, model test were conducted in a straight channel with a model concrete pier. The impact of the obstruction in flow, mining of sand and filling of the sand is investigated through this investigation. The finding of this study can be utilized in understanding and development of techniques of controlling scouring near the pier

scholarly journals Design and Experimental Validation of a 3-DOF Force Feedback System Featuring Spherical Manipulator and Magnetorheological Actuators

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 19 ◽  
Author(s):  
Bao Tri Diep ◽  
Ngoc Diep Nguyen ◽  
Thanh T. Tran ◽  
Quoc Hung Nguyen
Keyword(s):  
Control System ◽  
Shoulder Joint ◽  
Experimental Validation ◽  
Force Feedback ◽  
Feedback System ◽  
Radial Force ◽  
Experimental Results ◽  
The Other ◽  
Sliding Joint ◽  
End Effectors

This research focuses on the development of a new 3-DOF (Degree of Freedom) force feedback system featuring a spherical arm mechanism and three magnetorheological (MR) brakes, namely two rotary MR brakes and one linear MR brake. The first rotary MR brake is integrated in the waist joint to reflect the horizontal tangent force, the other rotary MR brake is integrated in the shoulder joint to reflect the elevation tangent force, while the linear MR brake is integrated in the sliding joint of the arm to reflect the radial force (approach force). The proposed configuration can reflect a desired force to the operator at the end-effectors of the arm independently in 3 DOFs by controlling the current applied to the coils of the MR brakes. After the introduction, the configuration of the proposed force feedback system is presented. Afterward, the design and conducted simulation of the MR brakes for the systems are provided. The prototype of the force feedback system, which was manufactured for the experiment, is then presented as well as some of the obtained experimental results. Finally, the proposed control system is presented and its implementation to provide a desired feedback force to the operator is provided.

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