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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Measuring manufacturing assembly worker task duration with radio frequency identification technology

Kersten, Joshua Todd 01 May 2017 (has links)
Musculoskeletal disorders (MSDs) are common among working populations, especially manufacturing workers, with exposure to non-neutral postures frequently cited as a risk factor. However, the magnitudes and precision of risk estimates vary between field-based studies, as it is difficult to continually follow and sample large study samples with time-varying exposures to non-neutral postures. Development of a low cost location-tracking system may help overcome this methodological limitation. The purpose of this thesis was to explore the utility of radio frequency identification (RFID) technology for extracting task-specific exposure data from full-shift measurements of upper arm posture as machine-paced assembly workers rotated job tasks. Full-shift upper arm posture and movement velocities were recorded using inertial measurement units (IMUs) across up to 15 consecutive working days from among a sample of 8 participants. Workers scanned RFID tags with RFID readers at job task workstation as they started and finished performing a task, effectively measuring task duration. At the end of each shift, workers self-reported task duration estimates in a diary. Self-report and RFID-based measurement bias and agreement range were estimated using Bland-Altman analyses. Fully nested, random-effects analysis of variance (ANOVA) models were used to estimate the relative contribution of components of exposure variance to overall posture and movement exposure variance. The study observed a slight measurement bias for self-reported task duration estimates when comparing both incomplete (i.e., single measurement from either self-report or RFID methodology) and complete task observation data (i.e., measurements from both methodologies), while the RFID system displayed a similar bias when comparing only complete task observation data. However, regardless of the data set, a large measurement agreement range was observed. The between-subjects and between-tasks-within-day (and within-subject) variance components generally contributed the most to total exposure variance, with the between-day-within-subject component contributing little if nothing at all. Depending on velocity level summary measure, between 65.7% and 84.5% of the total exposure variance was associated with the between-tasks-within-day (and within-subject) component. The RFID system did prove useful in extracting task-specific exposure data from full-day IMU measurements. However, there were unexpected instances in which workers failed to follow RFID system user protocol and generate irregular timestamp sequences. Future research and development is encouraged to refine the pairing of RFID technology with IMUs for ergonomic exposure assessment. Specifically, an active RFID system with adjustable read range could potentially overcome the limitation of requiring that a worker place the RFID tag within inches of the low frequency RFID reader to perform a scan.
52

Effect of deposited polydispersed particles on respirable cyclone penetration

Leach, William Andrew 01 May 2013 (has links)
Workplace aerosol sampling has been used to assess exposure to airborne materials that are known to cause adverse health effects in the respiratory system. Respirable cyclones are a common instrument used to monitor occupational exposures to respirable particles and are designed to have a penetration similar to the definition for the respirable fraction. However, deposited particles inside the walls of the cyclone may influence the penetration of cyclones. The aim of this study was to determine if there is a difference in collection efficiencies of a clean SKC 37-mm aluminum cyclone compared to a SKC 37-mm aluminum cyclone deposited with polydispersed dust. Glass beads (Count Median Diameter CMD 3.3 µm, Geometric Standard Deviation GSD 1.7) were used to test a clean cyclone. The cyclone was then loaded by sampling with one of three dust types individually for three hours at concentrations of at least 3 mg/m3: Arizona Road Dust (CMD 1.04 µm, GSD 1.57), organic dust (CMD 2.90 µm, GSD 1.77), and titanium oxide (CMD 0.85 µm, GSD 1.28). After the cyclone was deposited with dust without cleaning, glass beads were used to retest the penetration. Particle penetration was measured using the Aerosol Particle Sizer (APS, TSI 3321). Particles depositing on the walls of the cyclone caused a shift in the penetration compared to clean samplers. When the cyclone was loaded with Arizona Road Dust, the penetration of particles increased as much as 5% at 3.5 µm. Depositing with Organic Dust increased particle penetration as much as 4% at 3.5 µm. Depositing did not occur with Titanium Oxide and did not significantly particle penetration. Sampling with cyclones deposited with polydispersed particles can cause sampling errors by oversampling, and therefore overestimate the respirable concentration relative to a clean sampler. To counteract sampling errors from deposited particles would require the cyclone to be thoroughly dried and clean before sampling.
53

Assessment of microscopy methods for distinguishing engineered nanoparticles from incidental nanoparticles

Ellickson, Daniel Emick 01 May 2011 (has links)
The objective of this study was to assess the utility of electron microscopy for the purpose of distinguishing engineered nanoparticles from "incidental" nanoparticles. Methods included the use of transmission electron microscopy (TEM) with energy dispersive spectroscopy (EDS) to analyze samples of known ratios of titanium dioxide (TiO2) to Arizona road dust (ARD) or incense particles. TEM collection methods were analyzed for two different samplers: a Marple impactor and an electro-static precipitator (ESP). TEM grids were placed on the four lowest stages of the impactor. Results for impactor stages of a 10:1 ratio of TiO2/ARD mixture displayed the following percentages TiO2: 44%, 44%, 83%, and 90%. TiO2/incense samples had very high (79%-90%) TiO2 proportions, which was not expected since the ratio was 1:1. These combustion particles did not collect with the same efficiency as TiO2 or ARD. In conclusion, incense particles were entirely carbon based and were not identifiable using TEM/EDS. The TiO2/ARD mixture demonstrated that the impactor would remove most of the larger particles so that grids on the filter stage could be used to analyze and image TiO2 mostly alone. Sampling criteria for desired particle loading had to be established in order to obtain usable TEM grids. TiO2 was distinguishable from all other particles, but accurate particle identity and proportion in samples was not obtainable for combustion particles using these methods.
54

Field portable X-Ray fluorescence for rapid analysis Of titanium dioxide on air filters

Hill, Barry Keith 01 July 2012 (has links)
Field portable x-ray fluorescence (FPXRF) was evaluated as a method for screening titanium dioxide (TiO2) on air filters. Mixed cellulose ester (MCE) and polycarbonate (PC) filter types were compared to gravimetric filters to determine if there was a benefit of using one over the other during FPXRF analysis. No significant difference (p-value = 0.92) was found between MCE and PC filters for FPXRF. MCE filters had a higher coefficient of determination (R2 = 0.97) with the FPXRF analyzer than the PC filters (R2 = 0.70) when compared to gravimetric filter results. The limit of detection (LOD) and limit of quantitation (LOQ) of the FPXRF analyzer were determined through the analysis of blank filters and filters with low levels of TiO2 analyte. The LOD for TiO2 using filter blanks was 7.3 μg/filter, and 25 μg/filter with low levels of TiO2 analyte. The LOQ was 12.8 μg/filter determined with filter blanks, and from the low level analyte samples was 0.82 μg/filter. Filter samples were collected at varying TiO2 concentrations and submitted to FPXRF and inductively couple plasma - mass spectrometry (ICP-MS) analysis. Linear regression was used to determine the relationship between the two methods for TiO2 assessment. A high coefficient of determination (R2 = 0.90) was found between FPXRF and ICP-MS at lower TiO2 concentrations while a low coefficient of determination (R2 = 0.24) was shown for the high TiO2 concentrations. Statistical analysis was used to determine the overall accuracy of the FPXRF method. The FPXRF method did not meet the NIOSH accuracy requirements to be considered an acceptable method; however there were unexplained anomalies within the ICP-MS data.
55

Analysis of the administration of the health examination in the public schools of Oregon

Bech, Jack Karl 23 October 1954 (has links)
The school-age period is one in which the health status of the pupil must be constantly observed and appraised if optimal growth and development are to be realized. Therefore, Oregon laws provide that the State Board of Health shall have direct supervision of all matters pretaining to the preservation of the life and health of the people of the state. To achieve this purpose, the Superintendant of Public Instruction is given the duty to prescribe for, with the advice of the State Board of Health, the program of health examinations for pupils. The county and city school superintendants are made responsible for carrying out this program. These health examinations render a type of health service to children that develop understanding and action by parents and result in an improved health status of the child. In this study the questionnaire method was used and brought a fifty per cent return which was considered sufficient to make the study factual. Information for this study was collected from all areas of the state and included completed questionnaires from elementary, junior high and high schools. The total enrollment of the 125 schools returning the questionnaire came to a figure of 40,101 students. Of this total number only 36,455 were reported by the administrators as being in one of the nine categories available for health examination on the questionnaire. Of the 36,455 students recorded, only 23,378 were provided with health examinations, or 64 plus per cent. This figure is rather disappointing as it was hoped the percentage would be at least in the nineties. As was expected, the students participating in athletics are receiving a higher per cent of examinations than any other group of school-age children. Of the 8,894 athletes listed, 8,610 were given health examinations, or 97 per cent. The principals indicated that of the 4,765 pupils entering school for the first time, 4,101 received health examinations, or 87 per cent of the total. This group ranked second in the percentages, a full ten per cent behind the athletic participant group. There were 2,011 pupils referred for examination by the teacher or by the teacher-nurse screening. Of this number, 1,679 pupils were examined which indicates that 83 per cent of those referred were examined. This particular group ranked third in the over-all picture. Of the pupils entering the ninth grade and new to the school, 73 per cent are being examined according to the questionnaire. There were 6,647 pupils in this group and 4,848 received examinations. Of the 2,260 seventh grade pupils, 1,181 were given a health examination which gives a percentage figure of 52 plus per cent. Very little examining is done in the tenth or other grades according to the information gathered. Of the 961 students listed in this group, only 328 received examinations, or 34 per cent. Of the 10,917 students participating in the intramural and recreation program, only 1,631 were given a health examination, or 15 per cent. / Graduation date: 1955
56

The perceived need for a master's of science in dental hygiene degree program in Ohio : opinions of licensed dental hygienists' and baccalaureate degree dental hygiene program directors /

Dawson, Stephanie Anne. January 2006 (has links)
Thesis (M.S.)--Ohio State University, 2006. / Includes vita. Includes bibliographical references (leaves 87-89). Available online via OhioLINK's ETD Center
57

A road to new beginnings creating a healthy workplace for case management /

Wilson, Julia A. January 1900 (has links)
Thesis (M.A.)--Royal Roads University (Canada), 2007. / Includes bibliographical references.
58

An evaluation of Germ City finding a suitable design /

Lusher, Suzanne Cherie. January 2002 (has links)
Thesis (M.A.)--Marshall University, 2002. / Title from document title page. Document formatted into pages; contains viii, 80 p. Includes vitae. Includes bibliographical references (p. 54-56).
59

Evaluation of Pulmonary Risks Associated with Selected Occupations

Harbison, Stephen Casey 01 January 2013 (has links)
Occupational health surveillance programs are designed to evaluate and reduce injury, illness, and deaths related to workplace hazards. In the state of Florida, there are numerous industries where workers are potentially exposed to airborne hazards from gases, vapors and dusts. Airborne occupational exposures to irritants, vesicants, and fibrogens have the potential to cause pulmonary function impairment if exposures are not properly controlled for high-level acute exposure as well as chronic exposure. For occupations that demand workers be exposed to substances known to be associated with pulmonary function impairment, respirators may be a principal method for exposure control. OSHA requires pulmonary function testing for specific substances and it is a best practice that is utilized in a majority of occupational settings and is typically included in an organizations respiratory protection program. A literature review identified that boat manufacturing, utilities, and first responders in the State of Florida have the potential for increased pulmonary impairment amongst workers. This research demonstrated the feasibility of using pulmonary function data collected for the purposes of compliance and/or best practices for workers who use respiratory protection because they are potentially exposed to pulmonary toxicants in the workplace. This research did not identify any pulmonary function deficits in the target occupational populations and it demonstrated that in most cases, the study populations had modestly superior pulmonary function compared to a baseline population.
60

Age related changes in height and weight of residents of long term care facility

Ehrlich, Rachelle Cindy, 1953- January 1977 (has links)
No description available.

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