scholarly journals Effect of the Shoe Sole on the Vibration Transmitted from the Supporting Surface to the Feet

Vibration ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 743-758
Author(s):  
Marco Tarabini ◽  
Tammy Eger ◽  
Katie Goggins ◽  
Alex P. Moorhead ◽  
Filippo Goi
Keyword(s):  
Blood Circulation ◽  
Subjective Evaluation ◽  
Future Research ◽  
Poor Correlation ◽  
Vibration Exposure ◽  
Supporting Surface ◽  
Vibration Transmissibility

Vibration transmitted through the foot can lead to vibration white feet, resulting in blanching of the toes and the disruption of blood circulation. Controlled studies identifying industrial boot characteristics effective at attenuating vibration exposure are lacking. This work focused on the evaluation of vibration transmissibility of boot midsole materials and insoles across the range 10–200 Hz at different foot locations. Questionnaires were used to evaluate the comfort of each material. The materials were less effective at attenuating vibration transmitted to the toe region of the foot than the heel. Between 10 and 20 Hz, all midsole materials reduced the average vibration transmitted to the foot. The average transmissibility at the toes above 100 Hz was larger than 1, evidencing that none of the tested material protects the worker from vibration-related risks. There was a poor correlation between the vibration transmissibility and the subjective evaluation of comfort. Future research is needed to identify materials effective for protecting both the toe and the heel regions of the foot. Specific standards for shoe testing are required as well.

scholarly journals Cybersickness in current-generation virtual reality head-mounted displays: systematic review and outlook

2021 ◽  
Author(s):  
Polona Caserman ◽  
Augusto Garcia-Agundez ◽  
Alvar Gámez Zerban ◽  
Stefan Göbel
Keyword(s):  
Systematic Review ◽  
Virtual Reality ◽  
Meta Analysis ◽  
Subjective Evaluation ◽  
Future Research ◽  
Current Generation ◽  
Research Areas ◽  
Head Mounted Displays ◽  
Skin Response ◽  
Golden Standard

AbstractCybersickness (CS) is a term used to refer to symptoms, such as nausea, headache, and dizziness that users experience during or after virtual reality immersion. Initially discovered in flight simulators, commercial virtual reality (VR) head-mounted displays (HMD) of the current generation also seem to cause CS, albeit in a different manner and severity. The goal of this work is to summarize recent literature on CS with modern HMDs, to determine the specificities and profile of immersive VR-caused CS, and to provide an outlook for future research areas. A systematic review was performed on the databases IEEE Xplore, PubMed, ACM, and Scopus from 2013 to 2019 and 49 publications were selected. A summarized text states how different VR HMDs impact CS, how the nature of movement in VR HMDs contributes to CS, and how we can use biosensors to detect CS. The results of the meta-analysis show that although current-generation VR HMDs cause significantly less CS ($$p<0.001$$ p < 0.001 ), some symptoms remain as intense. Further results show that the nature of movement and, in particular, sensory mismatch as well as perceived motion have been the leading cause of CS. We suggest an outlook on future research, including the use of galvanic skin response to evaluate CS in combination with the golden standard (Simulator Sickness Questionnaire, SSQ) as well as an update on the subjective evaluation scores of the SSQ.

scholarly journals Vibration Exposure and Transmissibility on Dentist’s Anatomy: A Study of Micro Motors and Air-Turbines

2021 ◽  
Vol 18 (8) ◽  
pp. 4084
Author(s):  
Harish Kumar Banga ◽  
Pankaj Goel ◽  
Raman Kumar ◽  
Vikas Kumar ◽  
Parveen Kalra ◽  
...  
Keyword(s):  
Research Work ◽  
High Amplitude ◽  
Vibration Exposure ◽  
Body Parts ◽  
Descriptive Research ◽  
Air Turbine ◽  
Test Of Homogeneity ◽  
Hand Piece ◽  
Vibration Transmissibility ◽  
Levene Test

The use of dental hand pieces endanger dentists to vibration exposure as they are subjected to very high amplitude and vibration frequency. This paper has envisaged a comparative analysis of vibration amplitudes and transmissibility during idling and drilling with micro motor (MM) and air-turbine (AT) hand pieces. The study aims to identify the mean difference in vibration amplitudes during idling, explore different grasp forces while drilling with irrigant injection by the dentist, and various vibration transmission of these hand pieces. The study utilized 22 separate frequency resonances on two new and eight used MMs and two new and eight used ATs of different brands by observing the investigator at 16 different dentist clinics. The study adopted a descriptive research design with non–probability sampling techniques for selecting dentists and hand pieces. Statistical methods like Levene Test of Homogeneity, Welch ANOVA, independent t-test, and Games–Howell test were utilized with SPSS version 22 and MS-Excel. The results reveal that vibration amplitudes and vibration transmissibility when measured at position 2 are higher than in another position 1. Vibrations during idling for used MMs are more than AT hand pieces, and the used MM (MUD) and used AT (AUA) hand pieces differ due to their obsolescence and over-usage. Vibration amplitudes increase every time with the tightening of grasping of the hand piece. Vibration amplitudes for each grasping style of MM hand piece differ from all other grasping styles of AT hand pieces. Routine exposure to consistent vibrations has ill physical, mental, and psychological effects on dentists. The used hand pieces more hazardous as compared to newer ones. The study suggests that these hand pieces must be replaced periodically, sufficient to break between two operations, especially after every hand piece usage. Hence, the present research work can be further extended by creating some control groups among dentists and then studying the vibration amplitude exposure of various dental hand pieces and subsequent transmissibility to their body parts.

scholarly journals DOES THE ASSOCIATION BETWEEN AGE AND MAJOR ILLNESS VARY BY NATIONAL HEALTHCARE QUALITY?

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S140-S140
Author(s):  
Matthew A Andersson ◽  
Lindsay R Wilkinson ◽  
Markus H Schafer
Keyword(s):  
Healthy Aging ◽  
Subjective Evaluation ◽  
Healthcare Quality ◽  
Attributable Mortality ◽  
Future Research ◽  
Older Individuals ◽  
Social Survey ◽  
National Healthcare ◽  
Age Related ◽  
Major Illness

Abstract Though the risk of chronic disease and disability accelerates once adults are in their 60s, 70s, and 80s, researchers have long suspected that economic, social, and institutional variation — even among high-income Western nations — may powerfully influence the likelihood that people remain healthy at advanced ages. This study builds on comparative research into global aging, by offering a multiple-indicator test of whether national healthcare quality modifies the association between age and major illness. Recent individual-level data on morbidity among respondents aged 50 or older (16 countries; 2014 European Social Survey) are merged with nation-level healthcare indicators. Healthcare quality is assessed using a subjective, evaluation-based approach (based on the 2011 International Social Survey Programme) and an objective, attributable-mortality approach (2010 Healthcare Access and Quality, based on the Global Burden of Disease Study). Lagged nation-level economic and health indicators are controlled to help isolate healthcare effects. Multilevel logistic and linear regression models of any major health condition and morbidity reveal that while older individuals showed approximately a 10% reduction in probability of major illness when residing in countries with higher healthcare quality, associations between age and morbidity indices combining number and severity of illness showed greater modification by healthcare quality, with reductions around 18%. Results across subjective and objective approaches to healthcare quality are strikingly consistent. Taken together, results are suggestive of healthcare’s protective role in reducing age-related illness and disability. Future research should illuminate pathways by which healthcare quality may lead to differences in healthy aging among advanced nations.

scholarly journals A comprehensive biogeochemical record and annual flux estimates for the Sabaki River (Kenya)

2017 ◽  
Author(s):  
Trent R. Marwick ◽  
Fredrick Tamooh ◽  
Bernard Ogwoka ◽  
Alberto V. Borges ◽  
François Darchambeau ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
River Basin ◽  
Sediment Yield ◽  
Future Research ◽  
Poor Correlation ◽  
Inland Waters ◽  
Base Line ◽  
Nutrient Export ◽  
Anthropogenic Pressures ◽  
Organic C

Abstract. Inland waters impart considerable influence on nutrient cycling and budget estimates across local, regional and global scales, whilst anthropogenic pressures, such as rising populations and the appropriation of land and water resources, are undoubtedly modulating the flux of carbon (C), nitrogen (N), and phosphorus (P) between terrestrial biomes to inland waters, and the subsequent flux of these nutrients to the marine and atmospheric domains. Here, we present a two year biogeochemical record (October 2011–December 2013) at bi-weekly sampling resolution for the lower Sabaki River, Kenya, and provide estimates for suspended sediment and nutrient export fluxes from the Athi-Galana-Sabaki (A-G-S) river basin under pre-dam conditions, and in light of the approved construction of the Thwake Multi-purpose Dam on the Athi River. Erratic seasonal variation was typical for most parameters, with generally poor correlation between discharge and material concentrations and stable isotopic signatures of C (δ13C) and N (δ15N). Although high total suspended matter (TSM) concentrations are reported here (up to ~ 3.8 g L−1), peak concentrations of TSM rarely coincided with peak discharge. The contribution of particulate organic C (POC) to the TSM pool indicates a wide bi-annual variation in suspended sediment load from OC-poor (0.3 %) to OC-rich (14.9 %), with the highest %POC occurring when discharge is  80 % of the total load for TSM (~ 86 %), POC (~ 89 %), DOC (~ 81 %), PN (~ 89 %) and TPP (~ 82 %), with > 50 % of each fraction exported during the long wet season (March–May). Our estimated sediment yield of 85 Mg km−2 yr−1 is relatively low on the global scale and is considerably less than the recently reported average sediment yield of ~ 630 Mg km−2 yr−1 for African river basins. Regardless, sediment and OC yields were all at least equivalent or greater than reported yields for the neighbouring and flow-regulated Tana River. Rapid pulses of heavily 13C-enriched POC coincided with peak concentrations of PN, ammonium, CH4 and low dissolved oxygen saturation, lead to the suggestion that large mammalian herbivores (e.g. hippopotami) may mediate the delivery of C4 organic matter to the river during the dry season. Given recent projections for increasing dissolved nutrient export from African rivers, as well as planned flow regulation on the Athi River, these first estimates of material fluxes from the Sabaki River provide base-line data for future research initiatives assessing anthropogenic perturbation of the A-G-S river basin.

scholarly journals Mapping the conceptual structure of environmental management: a co-word analysis

2019 ◽  
Vol 20 ◽  
pp. 69-80 ◽  
Author(s):  
Juan-José Nájera-Sánchez ◽  
Eva-María Mora-Valentín ◽  
Marta Ortiz-de-Urbina-Criado ◽  
Pablo Moura-Díez
Keyword(s):  
Environmental Management ◽  
Corporate Social Responsibility ◽  
Quality Management ◽  
Social Responsibility ◽  
Subjective Evaluation ◽  
Future Research ◽  
Word Analysis ◽  
Literature Reviews ◽  
Corporate Social ◽  
View Management

This paper contributes to a better understanding of the research on environmental management using bibliometric methods to supplement the subjective evaluation of literature reviews. Focusing on the Management and Business fields, our main objective is to analyse the knowledge structure of environmental management literature and the evolution of related topics. We apply the co-word analysis method to identify different topics treated by the field across the studied periods, and to create networks and sub-networks. The results show the main topics and their evolution. We identify and explain six topics: green/environmental, resource-based-view, management, performance, corporate social responsibility and quality management. Development in this line of research shows progress in this discipline that commences with the green or environmental dimension and its effects on results and continues with issues that are more focused on quality management and corporate social responsibility. This study can be used as a reference for future research and help to increase company awareness of the importance of environmental issues in the design and implementation of strategies.

scholarly journals Autonomously Propelled Colloids for Penetration and Payload Delivery in Complex Extracellular Matrices

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1216
Author(s):  
Shrishti Singh ◽  
Jeffrey Moran
Keyword(s):  
Drug Delivery ◽  
Blood Circulation ◽  
Therapeutic Agents ◽  
Extracellular Matrices ◽  
Future Research ◽  
Use Of Self ◽  
Dense Network ◽  
Different Types ◽  
Delivery Efficiency

For effective treatment of diseases such as cancer or fibrosis, it is essential to deliver therapeutic agents such as drugs to the diseased tissue, but these diseased sites are surrounded by a dense network of fibers, cells, and proteins known as the extracellular matrix (ECM). The ECM forms a barrier between the diseased cells and blood circulation, the main route of administration of most drug delivery nanoparticles. Hence, a stiff ECM impedes drug delivery by limiting the transport of drugs to the diseased tissue. The use of self-propelled particles (SPPs) that can move in a directional manner with the application of physical or chemical forces can help in increasing the drug delivery efficiency. Here, we provide a comprehensive look at the current ECM models in use to mimic the in vivo diseased states, the different types of SPPs that have been experimentally tested in these models, and suggest directions for future research toward clinical translation of SPPs in diverse biomedical settings.

Sex Bias in Evaluating Motor Activity: General or Task-specific Performance Expectancy?

1980 ◽  
Vol 2 (4) ◽  
pp. 279-287 ◽  
Author(s):  
L. R. Brawley ◽  
R. C. Powers ◽  
K. A. Phillips
Keyword(s):  
Estimation Error ◽  
Subjective Evaluation ◽  
Sex Bias ◽  
Future Research ◽  
Muscular Endurance ◽  
Performance Expectancy ◽  
Error Magnitude ◽  
Specific Performance ◽  
Motor Accuracy ◽  
Male Superiority

This experiment examined if a general expectancy for male superiority biased subjective evaluation of motor performance. Alternatively, sex bias could be specific to tasks involving muscular work. If the former, rather than the latter explanation is viable, a bias favoring males would be generalized to a task not obviously sex typed: motor accuracy. Observers, 22 of each sex, watched the softball pitching accuracy of performers of both sexes. Performer accuracy was trained and tested to ensure equality. Observers estimated preperformance accuracy, then observed three throws, estimating postperformance after each. Unlike the muscular endurance experiments, neither preperformance nor postperformance analysis revealed a sex bias. Thus a task-specific expectancy rather than general expectancy for male superiority was suggested to explain evaluation sex bias of previous muscular endurance experiments. Surprisingly, mean error magnitude of postperformance estimates was significantly greater for performers observed second than those viewed first, although actual performer accuracy was not different. This finding appears analogous to psychophysical judgment results in which successive stimulus judgments were conditions sufficient to cause estimation error. Suggestions are made for future research.

scholarly journals Vibration transmissibility and apparent mass changes from vertical whole-body vibration exposure during stationary and propelled walking

2021 ◽  
Vol 90 ◽  
pp. 103283
Author(s):  
Delphine Chadefaux ◽  
Alex P. Moorhead ◽  
Pietro Marzaroli ◽  
Stefano Marelli ◽  
Enrico Marchetti ◽  
...  
Keyword(s):  
Whole Body Vibration ◽  
Whole Body ◽  
Vibration Exposure ◽  
Apparent Mass ◽  
Body Vibration ◽  
Vibration Transmissibility

A comparison of the dynamic properties of transducer adapters for measurement of hand-transmitted vibration

2009 ◽  
Vol 223 (2) ◽  
pp. 345-351 ◽  
Author(s):  
C M Song ◽  
H-K Jang ◽  
J Chai
Keyword(s):  
Dynamic Characteristics ◽  
Grip Force ◽  
Dynamic Properties ◽  
Vibration Exposure ◽  
Frequency Range ◽  
Second Best ◽  
Best Estimate ◽  
Feed Force ◽  
Vibration Transmissibility ◽  
Exposure Levels

The dynamic characteristics of five types of widely used transducer adapters were compared in terms of vibration transmissibility between an accelerometer on the surface of the gripping area and another within each of the transducer adapters over a frequency range of 25–1250 Hz. Performance was also assessed from the ratio between two human vibration exposure levels, ahv, 1 and ahv, 2, measured using the two accelerometers over nine combinations of grip force and feed force. In this study, vibration transmissibility and ahv ratio of unity are considered. The vibration transmissibility and ahv ratio indicated that the flexible palm adapter provided the best estimate of vibration transmission to the hand. This transducer adapter exhibited the smallest deviation from unity for vibration transmissibility, which was <1.8 per cent over the frequency range, and ahv ratio, which was <4 per cent over nine combinations of grip and feed forces. From the investigation, the flexible palm adapter showed negligible distortion over the frequency range and high applicability, regardless of the gripping condition. The handle-type adapter provided the second-best estimate.

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