scholarly journals Evaluation of Health Risk Level of Hand-Arm and Whole-Body Vibrations on the Technical Operators and Equipment in a Tobacco-Producing Company in Nigeria

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Oluseyi Adewale Orelaja ◽  
Xingsong Wang ◽  
Dauda Sh. Ibrahim ◽  
Umer Sharif
Keyword(s):  
Whole Body ◽  
Risk Level ◽  
Time Frequency ◽  
Daily Exposure ◽  
Limit Value ◽  
Exposure Limit ◽  
High Acceleration ◽  
External Forces ◽  
Secondary Manufacturing ◽  
Iso 2631

Vibration is experienced when a body is subjected to either internal or external forces which cause oscillation, with most operators of industrial equipment often exposed to high dosage, higher than the stipulated values. In this research, Digital Real-Time Frequency Analyzer (RSA 5106A) was used, while the results obtained were evaluated and compared with the health guidelines of the ISO 2631-1 : 1997 and ISO 2631-5 : 2004 standards, as described in the Health Guidance Caution Zone for a daily exposure action value (EAV) of 0.47 m/s2 and a daily exposure limit value (ELV) of 0.93 m/s. High acceleration was mostly seen on the z-axis in all the results obtained, whereas many were not within the HGCZ (Arms <0.47, and >0.93 m/s2). Comparing (VDV <8.5 m/s1.75 and >17 m/s1.75) with the ISO standard, the accelerations on all x- and y-axes were slightly within the HGCZ, with just a little below 0.47 m/s2 limit. The results obtained clearly showed that urgent action is needed virtually on all the equipment in both the Secondary Manufacturing Department (SMD) and Primary Manufacturing Department (PMD) to minimize vibration exposure on the technical operators.

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).

Whole Body Vibration Measurements and Calculations of the Daily 8-hour Values in Finnish Working Environments

2005 ◽  
Vol 24 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Ykä Marjanen
Keyword(s):  
Whole Body ◽  
The European Union ◽  
Exposure Limits ◽  
Simple Task ◽  
Limit Values ◽  
Daily Exposure ◽  
Limit Value ◽  
Working Environments ◽  
Exposure Limit ◽  
Action Value

The European Union Physical Agents Directive (vibration) sets vibration exposure limits for an employer. The measured values from different work phases should be time weighted and summed together to represent a daily 8-hour exposure value. The directive has two limit values, the daily exposure action value and the daily exposure limit value. For the employer the greatest concern is to comply with the exposure limit value, but also exceeding the action value will cause implications. To calculate the daily 8-hour value is not a simple task, because there are normally several different work phases that the worker does in a normal day. Also the assessment of measurements of the vibration levels have to be made in real working environments. The work phases need to be calculated correctly to get the representative daily value. Also breaks and other non-work operations need to be included. This will make the complete assessment very difficult without proper knowledge. In this study a large number of measurements from different mobile work machines were made to establish whether the daily values would exceed the limit values. Analyses were made using three examples to show how the employer can use the standard and directive to assess the daily exposure values or times. The results were largely dependent on the work pattern and the dominant levels.

A Methodology for the Test Design and Evaluation of Human Whole-Body Vibration in Ground Vehicle Systems

1989 ◽  
Vol 33 (18) ◽  
pp. 1192-1196
Author(s):  
Ellen C. Haas
Keyword(s):  
Whole Body Vibration ◽  
International Standards ◽  
Whole Body ◽  
Test Design ◽  
Exposure Limits ◽  
Ground Vehicle ◽  
Body Vibration ◽  
Exposure Limit ◽  
Vehicle Systems ◽  
Iso 2631

To date, testing and evaluation of whole-body vibration in ground vehicle systems have not always fully utilized appropriate experimental design methodology, applicable statistical tests, or relevant criteria. A test design and evaluation methodology was developed to eliminate these oversights. This methodology uses inferential statistics, questionnaires, and a comparison of vibration data with representative mission scenarios. The methodology was employed in the evaluation of two alternative tracked ground vehicle designs. The independent variables were track type, terrain, vehicle speed, and crew position. The dependent variables were International Standards Organization (ISO) 2631 whole-body vibration exposure limit times at the lateral, transverse, and vertical axes. Two different multivariate analyses of variance (MANOVAs) performed on the exposure limit data indicated that all main effects, as well as several interactions, were significant (p < .01). A comparison of exposure limits to a representative mission scenario indicated that both track types would exceed ISO 2631 exposure, comfort, and fatigue limits during expected travel over cross-country terrain. Crew questionnaires also indicated crew discomfort when exposed to this type of terrain. The experiment demonstrated that the procedure was useful in helping to determine the extent that vehicle vibration permits the performance of the vehicle mission, within limits dictated by safety, efficiency, and comfort.

scholarly journals Occupational Exposure on Board Fishing Vessels: Risk Assessments of Biomechanical Overload, Noise and Vibrations among Worker on Fishing Vessels in Southern Italy

Environments ◽  
2019 ◽  
Vol 6 (12) ◽  
pp. 127 ◽  
Author(s):  
Francesca Mansi ◽  
Enza Sabrina Silvana Cannone ◽  
Antonio Caputi ◽  
Luigi De Maria ◽  
Leonardo Lella ◽  
...  
Keyword(s):  
Noise Exposure ◽  
Southern Italy ◽  
Whole Body ◽  
Work Related ◽  
Limit Value ◽  
Fishing Vessels ◽  
Exposure Limit ◽  
High Prevalence ◽  
Measurement Tools ◽  
Whole Body Vibrations

Sea fishing is one of the sectors with the highest risk of illness and work-related accidents. The purpose of the study is to evaluate the exposure of fishing workers to three major risks: biomechanical overload, noise, and whole-body vibrations. We used common methods and measurement tools in the field: observational video analysis, questionnaires, and direct measurement. Noise and vibrations levels were measured aboard five boats belonging to the main fishing communities of Southern Italy. The random sample consisted of 310 workers, of whom 108 agreed to complete a questionnaire to collect data on the perception of occupational risk and self-perception of health conditions. We found that fishermen had a high prevalence of osteoarticular pathologies (42%) and that the biomechanical overload risk is mainly related to handling manual loads. Furthermore, the results indicate that the levels of weekly noise exposure exceed the exposure limit value of 87 decibel A (dBA) for fishing workers, and that the most noisiest area is the engine room. Exposure levels to whole-body vibrations were below <0.5 m/s2. Knowledge on occupational hazards and health effects in the fisheries sector should be used to develop ship technology, raise awareness of the correct use of personal protective equipment, and improve health surveillance of these workers.

Numerical Advances in Gross-Motion Simulations of Head/Neck Dynamics

1987 ◽  
Vol 109 (2) ◽  
pp. 163-168 ◽  
Author(s):  
C. S. Tien ◽  
R. L. Huston
Keyword(s):  
Experimental Data ◽  
Efficient Method ◽  
Whole Body ◽  
Motion Simulation ◽  
Finite Segment ◽  
Body Model ◽  
High Acceleration ◽  
Head Neck

An efficient method for gross-motion simulation of head/neck dynamics in accidents and high acceleration environments is presented. The method uses finite-segment modelling to develop a 3-body model of the head/neck system. The model is shown to compare favorably with an analogous 9-body model and with experimental data. The model is expected to be useful for: (1) efficient analysis of gross-motion head/neck dynamics during accidents; (2) for developing increased intuitive understanding of head/neck behavior; and (3) for use with gross-motion, whole-body, crash-victim simulators.

Gefahrstoffe am Arbeitsplatz – Arbeitsplatzgrenzwert, Immissionsgrenzwert oder Innenraumrichtwert?/Hazardous substances at workplace – Occupational exposure limit, immission limit value or indoor air guide value?

Gefahrstoffe ◽  
2019 ◽  
Vol 79 (07-08) ◽  
pp. 255-259
Author(s):  
R. Hebisch ◽  
T. Kuhlbusch ◽  
K. Bux ◽  
D. Breuer ◽  
T. Lahrz
Keyword(s):  
Occupational Exposure ◽  
Indoor Air ◽  
Hazardous Substances ◽  
Occupational Exposure Limit ◽  
Guide Value ◽  
Limit Value ◽  
Exposure Limit

Die Beurteilung der Konzentrationen von Gefahrstoffen in der Luft kann anhand verschiedener Beurteilungsmaßstäbe erfolgen. Einerseits ist dafür ausschlaggebend, ob Tätigkeiten mit Gefahrstoffen oder ohne Gefahrstoffe ausgeführt werden. Andererseits ist auch immer zu berücksichtigen, ob die Tätigkeiten im Freien, in teilweise geschlossenen oder geschlossenen Arbeitsbereichen erfolgen. Es werden einzelne Szenarien näher betrachtet und die Expositionsbeurteilung wird anhand von Arbeitsplatzgrenzwerten, Immissionsgrenzwerten und Innenraumrichtwerten dargestellt. Dabei wird insbesondere auf solche Situationen eingegangen, die sich nicht eindeutig voneinander abgrenzen lassen.

scholarly journals Assessment of whole-body vibration exposure of mining truck drivers

2020 ◽  
Vol 120 (9) ◽  
Author(s):  
B. Erdem ◽  
T. Dogan ◽  
Z. Duran
Keyword(s):  
Health Effect ◽  
Whole Body Vibration ◽  
Correlation Coefficients ◽  
Dominant Frequency ◽  
Truck Drivers ◽  
Whole Body ◽  
Vibration Acceleration ◽  
Body Vibration ◽  
Dump Trucks ◽  
Iso 2631

SYNOPSIS Whole-body vibration (WBV) exposure measurements taken from 105 truck drivers employed in 19 mines and other workplaces were evaluated with the criteria prescribed in EU 2002/44/EC directive, BS 6841 (1987), ISO 2631-1 (1997). and ISO 2631-5 (2004) standards. The highest vibration acceleration was measured on the vertical Z-axis. The highest WBV exposure occurred in the RETURN, HAUL, and SPOT phases while the lowest exposure took place in the LOAD and WAIT phases. Crest factors on all axes were generally greater than nine, yet strong correlation coefficients were achieved in VDV-eVDV analyses. Driver seats generally dampened the vibration along the Z-axis but exacerbated it along X and Y axes. The dominant frequency for the X and Y-axes rose up to 40 Hz while it ranged between 1 Hz and 2.5 Hz along the Z-axis. While the probability of an adverse health effect was higher with BS 6841 (1987) and ISO 2631-1 (1997) standards, it was low according to EU 2002/44/EC and ISO 2631-5 (2004). The 91 t, 100 t, and 170 t capacity trucks produced lower vibration magnitudes. Drivers were exposed to approximately equivalent levels of WBV acceleration and dose in contractor-type trucks and mining trucks. Rear-dump trucks exposed their drivers to a slightly higher level of vibration than bottom-dump trucks. Underground trucks exposed their drivers to a significantly higher level of vibration than mining trucks. Both driver age and driver experience were inversely proportional to vibration acceleration and dose. Conversely, there was a positive relationship between the truck service years and the WBV acceleration and dose to which drivers were exposed to. Loads of blocky material exposed drivers to higher vibration acceleration and dose levels than non-blocky material. Keywords: whole-body vibration, mining truck, A(8), BS 6841, EU 2002/EC/44, ISO 2631-1, ISO 2631-5, VDV(8).

scholarly journals Emergence of Heartbeat Frailty in Advanced Age: Perspectives from Life-Long EKG Recordings in Mice

2022 ◽  
Author(s):  
Jack M Moen ◽  
Christopher H Morrell ◽  
Ismayil Ahmet ◽  
Michael G Matt ◽  
Moran Davoodi ◽  
...  
Keyword(s):  
Sinus Bradycardia ◽  
Progressive Increase ◽  
Advanced Age ◽  
Whole Body ◽  
Energetic Efficiency ◽  
Cross Sectional ◽  
Time Frequency ◽  
Cell Dysfunction ◽  
Rr Interval ◽  
The Mean

SAN failure, aka sick-sinus syndrome, which features sinus bradycardia, SAN impulse pauses, and irregularity of RR interval rhythms are manifestations of SAN cell dysfunction that increases exponentially with advanced age, i.e., SAN frailty. Abnormalities in intrinsic RR interval variability may be the earliest signatures of SAN cell dysfunction leading to SAN frailty in late life. We measured RR interval variability within EKG time-series prior to and during double autonomic blockade in long-lived C57/BL6 mice at 3 month intervals from 6 months of age until the end of life. Long-lived mice (those that achieved the median cohort lifespan of 24 months and beyond) displayed relatively minor changes in intrinsic RR interval variability prior to 21 months of age. Between 21 and 30 months of age, marked changes in intrinsic RR interval variability signatures in time, frequency, non-linear, and fragmentation domains result in a marked increase in the mean intrinsic RR interval. The effects of autonomic input partially compensated for the prolongation of the mean RR interval by impacting the age-associated deterioration in the RR interval variability signatures toward a youthful pattern. Cross-sectional analyses of other subsets of mice at ages at or beyond the median life span of our longitudinal cohort demonstrated increased non-cardiac, constitutional, whole body frailty, a decrease in energetic efficiency, and an increase in respiratory exchange ratio. In this context, we interpret the progressive increase in intrinsic RR interval variability beyond 21 months of age to be an indication of heartbeat frailty.

scholarly journals Online Gain Adaptation of Whole-Body Control for Legged Robots with Unknown Disturbances

2022 ◽  
Vol 8 ◽  
Author(s):  
Jaemin Lee ◽  
Junhyeok Ahn ◽  
Donghyun Kim ◽  
Seung Hyeon Bang ◽  
Luis Sentis
Keyword(s):  
Legged Robots ◽  
Whole Body ◽  
Tracking Errors ◽  
Loop Control ◽  
Gain Adaptation ◽  
Closed Loop Control System ◽  
Unknown Disturbances ◽  
Loop Control System ◽  
External Forces ◽  
Task Goals

This paper proposes an online gain adaptation approach to enhance the robustness of whole-body control (WBC) framework for legged robots under unknown external force disturbances. Without properly accounting for external forces, the closed-loop control system incorporating WBC may become unstable, and therefore the desired task goals may not be achievable. To study the effects of external disturbances, we analyze the behavior of our current WBC framework via the use of both full-body and centroidal dynamics. In turn, we propose a way to adapt feedback gains for stabilizing the controlled system automatically. Based on model approximations and stability theory, we propose three conditions to ensure that the adjusted gains are suitable for stabilizing a robot under WBC. The proposed approach has four contributions. We make it possible to estimate the unknown disturbances without force/torque sensors. We then compute adaptive gains based on theoretic stability analysis incorporating the unknown forces at the joint actuation level. We demonstrate that the proposed method reduces task tracking errors under the effect of external forces on the robot. In addition, the proposed method is easy-to-use without further modifications of the controllers and task specifications. The resulting gain adaptation process is able to run in real-time. Finally, we verify the effectiveness of our method both in simulations and experiments using the bipedal robot Draco2 and the humanoid robot Valkyrie.

scholarly journals DETERMINATION OF DEFORMABILITY PARAMETERS OF CONCRETE SAMPLES BY THE FORMULAS OF FRACTURE MECHANICS

2020 ◽  
Vol 11 (2) ◽  
pp. 88-98
Author(s):  
B. A Bondarev ◽  
N. N Chernousov ◽  
V. A Sturova
Keyword(s):  
Fracture Mechanics ◽  
Lower Surface ◽  
Local Deformation ◽  
Concrete Sample ◽  
Test Scheme ◽  
Limit Value ◽  
Bending Load ◽  
Internal Forces ◽  
The Moment ◽  
External Forces

To determine the deformability parameters of concrete samples by the formulas of fracture mechanics, equilibrium tests were carried out at the stage of local deformation of the sample, which showed the correspondence of the change in external forces to the internal forces of the material resistance with the corresponding static development of the main crack. For the same purpose, the samples are tested for bending with an initial notch and the “load-deflection” diagram is recorded. In this work, we presented a test scheme for a specimen with a notch (crack) and constructed a diagram of the deformation of a specimen under bending “load-deflection”. Based on it, it is possible to predict the destruction of the material, that is, to determine the value of the load at which the limit value of deflection or the displacement of the outer edges of the notch (opening the throat of the crack on the lower surface of the specimen) can be taken as the moment of loss of the resource of the material. Also, we examined the deformation of a concrete sample during three-point bending and presented a diagram of the deformation of a concrete sample within the plastic zone. Dependencies were derived for determining the ultimate relative strains under tension and bending. Based on the results obtained, the state diagrams of the stretched concrete and the deformation scheme of the normal section of the concrete sample were constructed. As a result, the conclusion and convergence of the results.

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