scholarly journals Preliminary rolling noise measurements toward the design of a standard rolling noise device

2021 ◽  
pp. 1351010X2110192
Author(s):  
Matthew Edwards ◽  
Raimundo Gonzalez Diaz ◽  
Nadia Dallaji ◽  
Luc Jaouen ◽  
Fabien Chevillotte ◽  
...  

The tapping machine has long existed as the primary standard method for measuring the performance of floors in buildings in response to structure-borne noise. However, other sources of structure-borne noise exist. One of these is rolling noise: such as a trolley rolling across the floor in an indoor building environment. Because the sound profile of indoor rolling noise is substantially different than that of impact noise, the techniques developed to reduce the latter may not necessarily be effective at reducing the former. To this end, a means of repeatably measuring indoor rolling noise is needed. Here the results of a study on indoor rolling noise are presented, identifying the various characteristics of this type of excitation which until now have been left unexplored. The proposal for a standard rolling device is also put forth: a machine which may be capable of characterizing a floor’s performance with regards to indoor rolling noise. A series of indoor rolling noise tests were conducted in order to characterize the range of sound profiles that various indoor rolling items are capable of producing, as well as identify how the different characteristics govern the shape of the sound profile produced. Just as the standard tapping machine assesses a floor’s performance in response to impact noise, a standard rolling machine may assess a floor’s performance in response to rolling noise.

1963 ◽  
Vol 35 (11) ◽  
pp. 1888-1888
Author(s):  
Michael J. Kodaras ◽  
Robert A. Hansen

Author(s):  
A Bracciali ◽  
L Ciuffi ◽  
R Ciuffi

An on-board device for bolting to the axlebox of a railway vehicle or locomotive to measure rolling noise close to the wheel surface has been developed by the authors (1, 2). Even though laboratory calibration and test runs have shown that the measured noise data are consistent, there was no way to prove that they were in accordance with the on-ground measured ones. Italian State Railways (FS) have performed tests with different wheelsets to evaluate the efficiency of several noise-reduction solutions; during these tests it was possible to repeat noise measurements on-board, therefore obtaining a sufficient amount of data to calibrate the device and to analyse in detail the behaviour of such wheelsets. Calculated calibration constants prove that on-board measured data can be used with confidence to estimate noise levels at several distances from the track, thereby reducing the necessity of long and expensive on-ground tests to measure environmental noise pollution.


Author(s):  
Vladimir Rodrigues de Lima ◽  
Mohamed Agazar ◽  
Isabelle Blanc ◽  
Pierre Jean Janin ◽  
Patricia Cals de Oliveira Vitorio ◽  
...  

2010 ◽  
Vol 128 (4) ◽  
pp. 1747-1754 ◽  
Author(s):  
Joel Preto Paulo ◽  
J. L. Bento Coelho ◽  
Mário A. T. Figueiredo

1996 ◽  
Vol 76 (06) ◽  
pp. 0893-0896 ◽  
Author(s):  
P Kälebo ◽  
S Ekman ◽  
S Lindbratt ◽  
B I Eriksson ◽  
U Pauli ◽  
...  

SummaryThis study examines inadequacy rates for phlebography in two multicenter trials for the prevention of post-operative DVT and determines inter- and intra-observer variability in evaluating phlebograms. A total of 991 (I) and 385 (II) patients underwent bilateral phlebography in two studies of thromboprophylaxis. Phlebography was performed using a standard method designed to visualize and assess all deep veins. Each vein was scored as normal, DVT or inadequate by both local and central assessment. The study showed low inadequacy rates for phlebograms of 12.2% (121/991) and 6.5% (25/385). Inter-observer agreement (local vs. central assessment) was moderate in both studies (1:74.8%, Kappa-value 0.41; II: 82.6%, Kappa-value 0.51). Good intraobserver agreement (within the central assessment group) was observed (I: 88.8%, Kappa-value 0.75). This study demonstrates low inadequacy rates for phlebograms using a standardized methodology and superior intra-observer agreement compared to inter-observer agreement and supports the importance of central assessment of phlebograms in thromboprophylactic multicenter trials to reduce observer variability.


1975 ◽  
Vol 34 (01) ◽  
pp. 115-126 ◽  
Author(s):  
Kiyoake Watanabe ◽  
Francis C Chao ◽  
James L Tullis

SummaryAntithrombin activity has been identified in intact washed human platelets. An apparent activity was demonstrated at platelet concentrations above 0.31 × 109/ml, when platelet suspensions were incubated with 2.0 NIH units/ml of thrombin. Neither red cells nor white cells revealed antithrombin activity. No significant loss of the platelet antithrombin activity was observed after ten successive washings or after treatment of platelets with antibodies to antithrombin III or α2-macroglobulin. Almost the same amount of antithrombin activity as normal platelets was demonstrated in the platelets from an afibrinogenemic patient. Pre-treatment of platelets with trypsin, papain, and neuroaminidase reduced the activity significantly, whereas lipase was without effect. The platelet antithrombin reacted with thrombin in less than 3 seconds, and this rapid reaction of platelet antithrombin was different from that of plasma antithrombin III or fibrinogen. The thrombin-like clotting activity of ancrod was inhibited by fibrinogen but not platelets. Also, unlike plasma antithrombin III or fibrinogen, brief exposure to heat (56° C or 60° C) reduced considerable amounts of platelet antithrombin activity. These results suggest that platelets possess a specific antithrombin with different characteristics from other known antithrombins.


1968 ◽  
Vol 19 (03/04) ◽  
pp. 423-429 ◽  
Author(s):  
G. M Thelin ◽  

SummaryA stable, lyophilized AHF reference plasma has been prepared from pooled plasma from at least 50 normal healthy donors and standardized against a primary standard of fresh plasma from 20 healthy male donors aged 20 to 40. Average AHF potency of a typical lot is 98.8%, and moisture content is less than 0.5%. Under storage at -25° C, this AHF reference plasma is stable for at least 18 months. It has been used in several major coagulation laboratories, and has given consistently satisfactory and reproducible results in AHF assays.


1961 ◽  
Vol 06 (03) ◽  
pp. 492-497 ◽  
Author(s):  
Janet C. Macpherson ◽  
R. M Hardisty

SummaryA modification of the thromboplastin screening test of Hicks and Pitney is described, in which the effect of surface contact on the test plasma is controlled by the addition of a suspension of kaolin to the incubation mixture before recalcification.Comparative studies show the modified test to give more reproducible results than the standard method.


2020 ◽  
pp. 8-12
Author(s):  
Alexandr V. Oborin ◽  
Anna Y. Villevalde ◽  
Sergey G. Trofimchuk

The results of development of the national primary standard of air kerma, air kerma rate, exposure, exposure rate and energy flux for X-rays and gamma radiation GET 8-2011 in 2019 are presented according to the recommendations of the ICRU Report No. 90 “Key Data for Ionizing-Radiation Dosimetry: Measurement Standards and Applications”. The following changes are made to the equations for the units determination with the standard: in the field of X-rays, new correction coefficients of the free-air ionization chambers are introduced and the relative standard uncertainty of the average energy to create an ion pair in air is changed; in the field of gamma radiation, the product of the average energy to create an ion pair in air and the electron stopping-power graphite to air ratio for the cavity ionization chambers is changed. More accurate values of the units reproduced by GET 8-2019 are obtained and new metrological characteristics of the standard are stated.


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