Measures of vibration exposure for a high-speed craft crew

2011 ◽  
Vol 225 (4) ◽  
pp. 338-349 ◽  
Author(s):  
K Garme ◽  
L Burström ◽  
J Kuttenkeuler
Keyword(s):  
High Speed ◽  
Whole Body ◽  
Vibration Exposure ◽  
Short Term ◽  
Transient Vibration ◽  
Static Compression ◽  
Acceleration Signal ◽  
Exposure Data ◽  
Iso 2631

The paper compares measurement-based measures for human vibration exposure. Data were collected during sea trials on a 10 m, 50 kn coastguard craft equipped with a three-axial accelerometer at the coxswain seat and with vertically mounted gauges measuring the acceleration of the cockpit floor. The ISO 2631-1:1997 measures of vibration (namely the root-mean-square (r.m.s.) value of the whole-body vibration (determined from the frequency-weighted acceleration signal), the maximum transient vibration value (MTVV), and the vibration dose value), the ISO 2631-5:2004 measure (namely the daily equivalent static compression dose Sed), and also statistically based measures to evaluate the acceleration magnitude are compared and discussed with respect to their ability to identify the mitigating effect of the suspension seat and how the different measures rank the severity of the high-speed craft (HSC) ride. The paper concludes that the r.m.s. value and the MTVV are unsuitable for evaluation of the conditions aboard while the other investigated measures show potential in this respect. Further the approach of ISO 2631-5:2004 taking both the short-term and the long-term perspectives on the human exposure to vibration is concluded to be the most mature method well suited to evaluation of HSC conditions.

scholarly journals Whole Body Vibration Analysis of Baby Hammock

2018 ◽  
Vol 217 ◽  
pp. 01005
Author(s):  
Ying Hao Ko ◽  
Chia Sin Geh
Keyword(s):  
High Speed ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Asian Countries ◽  
Body Vibration ◽  
Limit Value ◽  
Exposure Limit ◽  
Rocking Motion ◽  
Action Value ◽  
Iso 2631

Studies have been carried on the effect of rocking on a baby and concluded that baby sleeps easier while being rocked. In Malaysia, as in many Southeast Asian Countries, it is common to put babies to sleep in a baby hammock. the vertical rocking motion generated by baby hammock has exposed babies to whole-body vibration (WBV). It has been shown by ISO2631 (1997) that WBV may lead the discomfort and adverse effect on health. Standards have been set by ISO 2631 (1997) concerning the WBV for people in a recumbent position and consider weighted vibrations of more than 2 m/s2 to be extremely uncomfortable. However, standards concerning the allowable amount vibrations a baby in a baby hammock can safety endure are currently lacking. WBV analysis of the baby hammock with the weight ranged from 3kg to 14kg is conducted. For each measurement, four conditions are considered: manual rocking, auto rocking with low, medium and high speed. In this study, average root-mean-square values for the acceleration were found to be at a maximum of 2.46 m/s2, and to be above the extremely uncomfortable level. This study develops a baseline exposure time for the baby hammock before it reaches the safety values of exposure action value (EAV) and exposure limit value (ELV) set by ISO 2631(1997).

A dynamic and robust image processing based method for measuring the yarn diameter and its variation

2014 ◽  
Vol 84 (18) ◽  
pp. 1948-1960 ◽  
Author(s):  
Mohamed Eldessouki ◽  
Sayed Ibrahim ◽  
Jiři Militky
Keyword(s):  
High Speed ◽  
Dynamic Change ◽  
Effective Property ◽  
Periodic Variation ◽  
Short Term ◽  
Reasonable Time ◽  
Yarn Diameter ◽  
Fabric Structure ◽  
Robust Image

The yarn diameter is an effective property in determining fabric structure and processing settings. There are different systems of measuring the yarn diameter; among them is the image analysis of the yarn’s microscopic images. This method is considered to be more precise than other methods, but it is “static” in nature as it measures the property at scattered intervals and does not reflect the continuous variation of the yarn diameter. The goal of the current work is to measure the yarn diameter and its variation over a long length of yarn at fixed intervals to consider the “dynamic” change in the property. To achieve this goal, a high-speed camera (HSC) with a proper magnification was used to capture the images of the yarn and a new robust algorithm was developed to analyze the massive amount of yarn pictures in a reasonable time. The collected data for the yarn diameter were analyzed and compared to the results of the commercial Uster Evenness Tester IV. The results of the HSC were very comparable to the results of Uster and they were able to detect the short-term, the long-term, and the periodic variation of the yarn diameter.

scholarly journals The effect of short-term and long-term application of fisetin on experimentally induced airway hyperreactivity

2017 ◽  
Vol 64 (1) ◽  
pp. 7-9
Author(s):  
I. Kazimierová ◽  
L. Pappová ◽  
M. Šútovská ◽  
S. Fraňová
Keyword(s):  
Airway Inflammation ◽  
Airway Resistance ◽  
Chronic Administration ◽  
Airway Hyperreactivity ◽  
Whole Body ◽  
Short Term ◽  
Specific Airway Resistance ◽  
Term Administration

AbstractBackground:Fisetin, a derivate from the flavonol group may possess a variety of pharmacological effects. The aim of the presented study was to evaluate the bronchodilatory effect of fisetin after the acute or the chronic administration to guinea pigs with allergic airway inflammation.Methods:Experimental animals were sensitized and challenged by ovalbumin. Fisetin was administered in dose 5mg/kg/p.o., either once after the end of 21-days sensitization or daily during the 21-days sensitization. By using the whole-body plethysmograph, we monitored the specific airway resistance, a parameter of airway hyperreactivityin vivo. The changes of the specific airway resistance were evaluated after the short-term inhalation of the bronchoconstriction mediator-histamine (10−6mol.1−1).Results:Our results showed that the short-term as well as the long-term administration of fisetin caused decrease of the specific airway resistance values. The bronchodilatory effect of fisetin was comparable to the long-acting beta2sympathomimetic – salmeterol after the long-term administration. The measurements of the bronchodilatory activity after single administration have revealed more prolonged effect of fisetin comparing to the short-acting beta2sympathomimetic – salbutamol, as this remained even after the 5 hours, when salbutamol was already ineffective.Conclusion:In conclusion, flavonol – fisetin has shown bronchodilatory potential. In the light of this fact, fisetin may represent potential substance that can be effective in both prevention as well as control of airway inflammation symptoms.

Whole-body vibration exposure experienced by motorcycle riders – An evaluation according to ISO 2631-1 and ISO 2631-5 standards

2009 ◽  
Vol 39 (5) ◽  
pp. 708-718 ◽  
Author(s):  
Hsieh-Ching Chen ◽  
Wei-Chyuan Chen ◽  
Yung-Ping Liu ◽  
Chih-Yong Chen ◽  
Yi-Tsong Pan
Keyword(s):  
Whole Body Vibration ◽  
Whole Body ◽  
Vibration Exposure ◽  
Body Vibration ◽  
Iso 2631

scholarly journals Whole Body Vibration Exposure during Rotary Soil Tillage Operation:

2018 ◽  
Vol 15 (4) ◽  
pp. 5927-5940 ◽  
Author(s):  
Amandeep Singh ◽  
Naser Nawayseh ◽  
Lakhwinder Pal Singh ◽  
Sarbjit Singh ◽  
Harwinder Singh
Keyword(s):  
Average Velocity ◽  
Soil Tillage ◽  
Whole Body ◽  
Average Error ◽  
Vibration Exposure ◽  
Desirability Approach ◽  
Tillage Operation ◽  
Actual Field ◽  
Iso 2631 ◽  
Fft Analysis

The present investigation attempted to study the overall daily vibration exposure A(8) in actual field rotary tillage operation at various ride conditions (i.e. average velocity, draft and average soil tillage depth). Three different levels of each ride condition were chosen to formulate an organised design of experiments by using Taguchi’s approach. The concurrent root mean square (RMS) acceleration values were measured at the tractor platform, seat pan and seat backrest along the three translation axes to determine the A(8). Signal-to-noise ratios (SNRs) were computed and analysed concerning the conducted experiments. Further, the dominant frequencies at each set of experiment were determined by fast fourier transform (FFT) analysis. A linear regression model was developed to predict the output response and further, the ride conditions were optimised by using desirability approach. The overall daily vibration exposure was found between fairly uncomfortable to uncomfortable category (i.e. 0.64 and 0.84 m/s2) as per ISO 2631-1 (1997). Moreover, the exposure levels are beyond the exposure action limit recommended by Directive2002/44/EU. The average velocity and draft effects on the A(8) response were found significant (p≤0.05) with a contribution of 78.38% and 18.54%, respectively. The FFT analysis depicted a range of dominant peaks in the frequency range of 0.8 to 3.7 Hz. However, the exact frequency of the peaks was found to depend on the experimental condition. The prediction model indicates a good correlation between predicted and actual experimental response with an average error of 1.02%. Desirability and Taguchi’s approaches gave identical optimised ride conditions (i.e. 0.6 m/s, 6 kN, and 0.14 m) with the aim of reducing the A(8) value.

A Unified Laboratory and Field Testing Approach of Marine Shock Mitigating Seats

2014 ◽  
Author(s):  
Mark D. Lougheed ◽  
James Canova
Keyword(s):  
High Speed ◽  
Injury Risk ◽  
Mechanical Vibration ◽  
Whole Body Vibration ◽  
Field Testing ◽  
Whole Body ◽  
Planing Craft ◽  
Shock Testing ◽  
Severity Of Injury ◽  
Iso 2631

Marine shock mitigating seats have been shown to reduce fatigue and decrease the likelihood and severity of injury of seated persons –particularly when installed aboard high speed commercial or combatant planing craft. Not so clear is how the performance of such seating systems are characterized so informed decisions can be made as to which seats perform best in specific conditions. Standards do exist to help quantify the injury risks associated with exposure to repeated shock and whole body vibration. However, such methods are field test based and the results somewhat difficult to understand. Work by the authors is presented from their experiences in characterizing seat performance to different standards includingSed8(ISO 2631-5,1997), UK Ministry of Defense Protocol 1 (UK MoD, 2014) as well as members sitting on the new ISO TC108/SC4/WG18 subcommittee on Human Exposure to Mechanical Vibration and Shock, Testing of Shock Mitigating Marine Seats. A new method is presented that allows for results obtained by both field and laboratory seat testing to be related to injury risk and compared equally in meaningful, understandable and objective ways.

scholarly journals The Effect of a Short-Term and Long-Term Whole-Body Vibration in Healthy Men upon the Postural Stability

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e88295 ◽  
Author(s):  
Magdalena Piecha ◽  
Grzegorz Juras ◽  
Piotr Król ◽  
Grzegorz Sobota ◽  
Anna Polak ◽  
...  
Keyword(s):  
Postural Stability ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Short Term ◽  
Healthy Men ◽  
Body Vibration

scholarly journals Whole-Body 12C Irradiation Transiently Decreases Mouse Hippocampal Dentate Gyrus Proliferation and Immature Neuron Number, but Does Not Change New Neuron Survival Rate

2018 ◽  
Vol 19 (10) ◽  
pp. 3078 ◽  
Author(s):  
Giulia Zanni ◽  
Hannah Deutsch ◽  
Phillip Rivera ◽  
Hung-Ying Shih ◽  
Junie LeBlanc ◽  
...  
Keyword(s):  
Survival Rate ◽  
Dentate Gyrus ◽  
Cell Survival ◽  
Time Course ◽  
Whole Body ◽  
Short Term ◽  
Hze Particles ◽  
Immature Neurons ◽  
Time Point

High-charge and -energy (HZE) particles comprise space radiation and they pose a challenge to astronauts on deep space missions. While exposure to most HZE particles decreases neurogenesis in the hippocampus—a brain structure important in memory—prior work suggests that 12C does not. However, much about 12C’s influence on neurogenesis remains unknown, including the time course of its impact on neurogenesis. To address this knowledge gap, male mice (9–11 weeks of age) were exposed to whole-body 12C irradiation 100 cGy (IRR; 1000 MeV/n; 8 kEV/µm) or Sham treatment. To birthdate dividing cells, mice received BrdU i.p. 22 h post-irradiation and brains were harvested 2 h (Short-Term) or three months (Long-Term) later for stereological analysis indices of dentate gyrus neurogenesis. For the Short-Term time point, IRR mice had fewer Ki67, BrdU, and doublecortin (DCX) immunoreactive (+) cells versus Sham mice, indicating decreased proliferation (Ki67, BrdU) and immature neurons (DCX). For the Long-Term time point, IRR and Sham mice had similar Ki67+ and DCX+ cell numbers, suggesting restoration of proliferation and immature neurons 3 months post-12C irradiation. IRR mice had fewer surviving BrdU+ cells versus Sham mice, suggesting decreased cell survival, but there was no difference in BrdU+ cell survival rate when compared within treatment and across time point. These data underscore the ability of neurogenesis in the mouse brain to recover from the detrimental effect of 12C exposure.

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