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Difference between revisions of "Universal Harness clip-on Design Lit Review"

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*Personal monitor
 
*Personal monitor
  
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===Mechanical properties of components fabricated with open-source 3-D printers under realistic environmental conditions===
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B.M. Tymrak a, M. Kreiger b, J.M. Pearce, "Mechanical properties of components fabricated with open-source 3-D printers under realistic environmental conditions", Vol(58), 242-246, 2014.
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[https://doi.org/10.1016/j.matdes.2014.02.038]
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Abstract
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The recent development of the RepRap, an open-source self-replicating rapid prototyper, has made 3-D polymer-based printers readily available to the public at low costs ( < $500). The resultant uptake of 3-D printing technology enables for the first time mass-scale distributed digital manufacturing. RepRap variants currently fabricate objects primarily from acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA), which have melting temperatures low enough to use in melt extrusion outside of a dedicated facility, while high enough for prints to retain their shape at average use temperatures. In order for RepRap printed parts to be useful for engineering applications the mechanical properties of printed parts must be known. This study quantifies the basic tensile strength and elastic modulus of printed components using realistic environmental conditions for standard users of a selection of open-source 3-D printers. The results find average tensile strengths of 28.5 MPa for ABS and 56.6 MPa for PLA with average elastic moduli of 1807 MPa for ABS and 3368 MPa for PLA. It is clear from these results that parts printed from tuned, low-cost, open-source RepRap 3-D printers can be considered as mechanically functional in tensile applications as those from commercial vendors.
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Own Comments:
 +
* Mechanical properties of OS RepRap 3D printers
 +
**AVG. UTS ABS: 28.5 MPa (Improvised ASTM: D638 with realistic environmental conditions of distrb. Manuf.)
 +
* AVG. Modulus ABS: 1807 MPa (Improvised ASTM: D638 with realistic environmental conditions distrb. Manuf.)
 +
**AVG. UTS PLA: 56.6 MPa (Improvised ASTM: D638 with realistic environmental conditions distrb. Manuf.)
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* AVG. Modulus PLA: 3368 MPa (Improvised ASTM: D638 with realistic environmental conditions distrb. Manuf.)
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* ABS Orientation x-y plane 0/90: highest E
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* ABS Orientationx-y plane +45/-45: strongest TS
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* ABS Layer thickness of 0.2mm: greatest TS
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* ABS Layer thickness of 0.4mm: greatest E
  
 
== Patents ==
 
== Patents ==

Revision as of 10:25, 30 April 2018


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Contents

Google scholar Searches

  • Sterilization of ABS
  • Cleaning of ABS
  • testing of FDM materials
  • Cleaning of 3D printed parts
  • Harness design
  • Universal clip on
  • Universal harness attachment
  • Clip on attachment
  • Harness clip
  • Harness attachment
  • Harness holder
  • Harness attachment holder
  • Clip holder
  • Hose holder
  • Harness accessories
  • Workers breathing zone
  • Personal Sampling pump
  • Active sampling
  • Personal sampler cyclone

Books

Aerosol Tecnology

Hinds, W.C., 1999. Aerosol Tecnology, Properties, Beahavior and measurements of airborne particles, Second. ed. John wiley & Sons Inc.

Own Comments:

  • Basic information about airborne particles

Chemistry, Emission Control, Radioactive Pollution and Indoor Air Quality

Chemistry, Emission Control, Radioactive Pollution and Indoor Air Quality, Edited By Nicola Mazzeo 2011.

[1]

Own Comments:

  • Basic book about Air quality


Additive manufacturing technologies

Gibson, I., Rosen, D.W., Stucker, B., 2015. Additive manufacturing technologies, Rapid Prototyping to Direct Digital Manufacturing, Second. ed. Springer, New York. [DOI 10.1007/978-1-4939-2113-3]

Own Comments:

  • Basic information about 3D printing

The 3D Printing Handbook

Redwood, B., Schöffer, F., Garret, B., 2017. The 3D Printing Handbook. 3D Hubs.

Own Comments:

  • Basic information about Designing for 3D printing

Articles

Advances in passive sampling in environmental studies

Agata Kot-Wasik, Bożena Zabiegała, Magdalena Urbanowicz, Ewa Dominiak, Andrzej Wasik, Jacek Namieśnik

[2]

Abstract

Passive sampling is based on the phenomenon of mass transport due to the difference between chemical potentials of analytes in a given environmental compartment and the collection medium inside a dosimeter. The subsequent laboratory procedure (i.e. extraction, identification and determination of analytes) is the same as in the case of classic sampling techniques.

Passive sampling techniques are characterized by simplicity with regard to the dosimeter's construction as well as its maintenance. Therefore, they find ever increasing application in the field of environmental research and analytics. When choosing a passive sampling method, one should not forget that some passive samplers require the time-consuming calibration step before being used in the field.

Novel solutions and modifications of existing sampler designs have been presented. Practical application of passive dosimetry in environmental analytics, including sampling of water, soil, air and other atypical media are discussed. Some aspects of calibration methods in passive dosimetry are also described. The latest trends in the application of passive sampling are highlighted.

Own Comments:

  • state of the art of passive sampling
  • Passive sampling don't need pump, usually attached to the clothing

Bioaerosol sampling: sampling mechanisms, bioefficiency and field studies

C.W.Haig W.G.Mackay J.T.Walker C.Williamsa https://doi.org/10.1016/j.jhin.2016.03.017

[3]

Summary

Investigations into the suspected airborne transmission of pathogens in healthcare environments have posed a challenge to researchers for more than a century. With each pathogen demonstrating a unique response to environmental conditions and the mechanical stresses it experiences, the choice of sampling device is not obvious. Our aim was to review bioaerosol sampling, sampling equipment, and methodology. A comprehensive literature search was performed, using electronic databases to retrieve English language papers on bioaerosol sampling. The review describes the mechanisms of popular bioaerosol sampling devices such as impingers, cyclones, impactors, and filters, explaining both their strengths and weaknesses, and the consequences for microbial bioefficiency. Numerous successful studies are described that point to best practice in bioaerosol sampling, from the use of small personal samplers to monitor workers' pathogen exposure through to large static samplers collecting airborne microbes in various healthcare settings. Of primary importance is the requirement that studies should commence by determining the bioefficiency of the chosen sampler and the pathogen under investigation within laboratory conditions. From such foundations, sampling for bioaerosol material in the complexity of the field holds greater certainty of successful capture of low-concentration airborne pathogens. From the laboratory to use in the field, this review enables the investigator to make informed decisions about the choice of bioaerosol sampler and its application.


Evaluation of the SKC Personal Respirable Dust Sampling Cyclone

Göran Lidén (2011) Evaluation of the SKC Personal Respirable Dust Sampling Cyclone, Applied Occupational and Environmental Hygiene, 8:3, 178-190, DOI: 10.1080/1047322X.1993.10389189 

Abstract

Three generations of the SKC cyclone have been evaluated. The cyclone was intended to emulate the British Safety in Mines Personal Equipment for Dust Sampling (SIMPEDS). The size-selection efficiency of the first cyclone generation was evaluated by measuring its penetration curve with a TSI APS 3300, and was found to have a pronounced tail for large particle sizes. For smaller particle sizes the size-selection efficiency was very similar to that of the SIMPEDS. The cyclone's size-selection caused it to considerably oversample large particles, relative to both the SIMPEDS and the British Medical Research Council definition of respirable dust, but for smaller particles it compared favorably with the SIMPEDS. The second cyclone generation sampled somewhat more than the first. The third generation samples more closely to the SIMPEDS cyclone. The coefficient of variation for the third cyclone generation was estimated to be 0.038 for a foundry aerosol. Possible merits of the first two SKC cyclone generations are discussed in light of the new respirable sampling convention about to be adopted by the Comité Européen de Normalisation, the International Standards Organisation, and the American Conference of Governmental Industrial Hygienists.

Own Comments:

  • We redesigned one of skc cyclone
  • Asked for the the whole article
  • 1993

Exposure to airborne allergens: a review of sampling methods†

Anne Renström

Received 18th March 2002 , Accepted 14th June 2002 First published on 7th August 2002 [4]

Abstract

A number of methods are used to assess exposure to high-molecular weight allergens. In the occupational setting, airborne dust is often collected on filters using pumps, the filters are eluted and allergen content in the eluate analysed using immunoassays. Collecting inhalable dust using person-carried pumps may be considered the gold standard. Other allergen sampling methods are available. Recently, a method that collects nasally inhaled dust on adhesive surfaces within nasal samplers has been developed. Allergen content can be analysed in eluates using sensitive enzyme immunoassays, or allergen-bearing particles can be immunostained using antibodies, and studied under the microscope. Settling airborne dust can be collected in petri dishes, a cheap and simple method that has been utilised in large-scale exposure studies. Collection of reservoir dust from surfaces using vacuum cleaners with a dust collector is commonly used to measure pet or mite allergens in homes. The sampling methods differ in properties and relevance to personal allergen exposure. Since methods for all steps from sampling to analysis differ between laboratories, determining occupational exposure limits for protein allergens is today unfeasible. A general standardisation of methods is needed.

Own Comments:

  • "A summary of some positive and negative features regarding sampling of aeroallergens using person-carried pumps is shown in Table 1."

Field Evaluation of a Personal, Bioaerosol Cyclone Sampler

Janet Macher, Bean Chen & Carol Rao (2008) Field Evaluation of a Personal, Bioaerosol Cyclone Sampler, Journal of Occupational and Environmental Hygiene, 5:11, 724-734, DOI: 10.1080/15459620802400159 

[5]

Abstract

A personal cyclone sampler (cyclone) was operated continuously alongside a 25-mm filter sampler (filter), a slit impactor (Burkard slide), and a high-volume cyclone sampler (Burkard cyclone) at an outdoor location with abundant naturally occurring fungi (N = 30; sampling time: 12.5 ± 2.3 hr). Air concentrations (spore m-3) of 28 fungal groups were determined for all samplers by microscopy. Cyclone performance was judged using various indices to determine if it agreed with the other samplers in determination of the frequencies with which the fungal groups were observed, as well as their proportions of the total air concentration. Fungal diversity estimates were similar for all samplers and in the range of what has been reported nationally, i.e., observation of 9–11 equal groups per sample, but spore concentration dominated by 2–3 groups. Plots of paired cyclone:comparison sampler ratios against average concentrations identified biases. For example, ratios were correlated with concentration and there was greater uncertainty at lower concentrations. Mean ratios for cyclone:filter comparisons were not significantly different from one for ascospores, Aspergillus-Penicillium spp., basidiospores, Cladosporium spp., or total spore m-3. However, agreement was less consistent with the Burkard slide (0.74, 1.12, 0.91, 1.09, and 0.92, respectively) and the Burkard cyclone (2.31, 1.62, 1.43, 1.91, and 1.33, respectively). Concentrations of cell equivalent m-3 also were determined for the filter and two cyclone samples by polymerase chain reaction. Cell equivalents for Aspergillus fumigatus and Penicillium brevicompactum were compared with Aspergillus-Penicillium spp. spores, and Cladosporium cladosporioides and Cladosporium herbarum cell equivalents were compared with Cladosporium spp. spores. Cell equivalent:spore ratios below one for A. fumigatus and P. brevicompactum indicated that these species comprised smaller factions of total spores or were collected less efficiently than the larger C. cladosporioides and C. herbarum spores. The personal cyclone was shown to be suitable for collection of ambient airborne fungal spores and for analysis by microscopy and polymerase chain reaction. Keywords: cyclone sampler, fungal biodiversity, method comparison, outdoor air, sampler performance

Own Comments:

  • Personal sampling of fungi

Indoor aerosols: from personal exposure to risk assessment

Morawska, L. , Afshari, A. , Bae, G. N., Buonanno, G. , Chao, C. Y., Hänninen, O. , Hofmann, W. , Isaxon, C. , Jayaratne, E. R., Pasanen, P. , Salthammer, T. , Waring, M. and Wierzbicka, A. (2013), Indoor aerosols: from personal exposure to risk assessment. Indoor Air, 23: 462-487. doi:10.1111/ina.12044

Abstract

Motivated by growing considerations of the scale, severity, and risks associated with human exposure to indoor particulate matter, this work reviewed existing literature to: (i) identify state‐of‐the‐art experimental techniques used for personal exposure assessment; (ii) compare exposure levels reported for domestic/school settings in different countries (excluding exposure to environmental tobacco smoke and particulate matter from biomass cooking in developing countries); (iii) assess the contribution of outdoor background vs indoor sources to personal exposure; and (iv) examine scientific understanding of the risks posed by personal exposure to indoor aerosols. Limited studies assessing integrated daily residential exposure to just one particle size fraction, ultrafine particles, show that the contribution of indoor sources ranged from 19% to 76%. This indicates a strong dependence on resident activities, source events and site specificity, and highlights the importance of indoor sources for total personal exposure. Further, it was assessed that 10–30% of the total burden of disease from particulate matter exposure was due to indoor‐generated particles, signifying that indoor environments are likely to be a dominant environmental factor affecting human health. However, due to challenges associated with conducting epidemiological assessments, the role of indoor‐generated particles has not been fully acknowledged, and improved exposure/risk assessment methods are still needed, together with a serious focus on exposure control.

Own Comments:

  • State of the art indoor aerosols personal exposure

The Location of Personal Sampler Filter Heads

B. B. Chatterjee M.B, M. K. Williams D.M, Joan Walford A.I.S & E. King B.Sc (2007) The Location of Personal Sampler Filter Heads, American Industrial Hygiene Association Journal, 30:6, 643-645, DOI: 10.1080/00028896909343188 

[6]

Abstract

Fifteen pasters in an electric accumulator factory each wore two personal samplers simultaneously for two consecutive shifts. The filter heads were attached to the upper left chest, one about 5 inches below the other. During the second shift the locations of the two heads were interchanged. The mean concentration obtained with the filter heads in the upper position was 0.181 mg/m3, while that obtained in the lower position was 0.225 mg/m3. The difference was 22% of the overall mean, and statistically highly significant (p < 0.01). Differences between the six samplers used were not significant. It was concluded that the location of the filter head should be defined more precisely than has been suggested for other jobs, and that the findings will be of particular importance when deriving threshold limit values.

Own Comments:

  • Trying to find the whole article
  • 1968!


MEASUREMENT OF PERSONAL EXPOSURE TO 1,1,1-TRICHLOROETHANE AND TRICHLOROETHYLENE USING AN INEXPENSIVE SAMPLING DEVICE AND BATTERY-OPERATED PUMP

J. H. SIMMONS and INEZ M. MOSS Industrial Hygiene Laboratory, H.M. Factory Inspectorate, London

[7] [8]

Abstract

The vapours of trichloroethylene and/or 1,1,1-trichloroethane are trapped on silica gel contained in a robust sampling tube made from a galvanized iron pipe connector and Simplifix couplings. Air from the worker's breathing zone is sucked through the tube by a battery operated personal sampling pump, sampler and pump being held on a harness fitted to the worker. Adsorbed solvent is eluted with methanol and estimated by gas chromatography using Chromosorb 101 as stationary phase. Mean exposure over a shift can be determined and related to parallel physiological measurements.

Own Comments:

  • 1973
  • Personal sampling tube was devised and tested with exposure to Tris

Monitoring Real-time Aerosol Distribution in the Breathing Zone

CORINNE A. MARTINELLI, NAOMI H. HARLEY, MORTON LIPPMANN & BEVERLY S. COHEN (2010) Monitoring Real-time Aerosol Distribution in the Breathing Zone, American Industrial Hygiene Association Journal, 44:4, 280-285, DOI: 10.1080/15298668391404806 

Abstract

A prototype air sampling, data recording, and data retrieval system was developed for monitoring aerosol concentrations in a worker's breathing zone. Three continuous-reading, light-scattering aerosol monitors and a tape recorder were incorporated into a specially designed and fabricated backpack for detailed field monitoring of both temporal and spatial variability in aerosol concentrations within the breathing zone. The backpack was worn by workers in a beryllium refinery. The aerosol which passed through each monitor was collected on a back-up filter for later chemical analysis for Be and Cu. The aerosol concentrations were recorded on magnetic tape as a function of time. The recorded signals were subsequently transcribed onto a strip chart recorder, then evaluated using a microcomputer with graphics capability. Field measurements made of the aerosol concentration at the forehead, nose, and lapel of operators during the melting and casting of beryllium-copper alloy demonstrated that there is considerable variability in concentration at different locations within the breathing zone. They also showed that operations resulting in worker exposure can be identified, and the precise time and duration of exposure can be determined.

Own Comments:

  • Trying to find the whole article, The packback design could be really interesting!
  • 1983

Novel Active Personal Nanoparticle Sampler for the Exposure Assessment of Nanoparticles in Workplaces

Chuen-Jinn Tsai*†, Chun-Nan Liu†, Shao-Ming Hung†, Sheng-Chieh Chen†, Shi-Nian Uang‡, Yung-Sung Cheng§, and Yue Zhou§

Environ. Sci. Technol., 2012, 46 (8), pp 4546–4552DOI: 10.1021/es204580f Publication Date (Web): March 21, 2012

[9]

Abstract

A novel active personal nanoparticle sampler (PENS), which enables the collection of both respirable particulate mass (RPM) and nanoparticles (NPs) simultaneously, was developed to meet the critical demand for personal sampling of engineered nanomaterials (ENMs) in workplaces. The PENS consists of a respirable cyclone and a micro-orifice impactor with the cutoff aerodynamic diameter (dpa50) of 4 μm and 100 nm, respectively. The micro-orifice impactor has a fixed micro-orifice plate (137 nozzles of 55 μm in the inner diameter) and a rotating, silicone oil-coated Teflon filter substrate at 1 rpm to achieve a uniform particle deposition and avoid solid particle bounce. A final filter is used after the impactor to collect the NPs. Calibration results show that the dpa50 of the respirable cyclone and the micro-orifice impactor are 3.92 ± 0.22 μm and 101.4 ± 0.1 nm, respectively. The dpa50 at the loaded micro-Al2O3 mass of 0.36–3.18 mg is shifted to 102.9–101.2 nm, respectively, while it is shifted to 98.9–97.8 nm at the loaded nano-TiO2 mass of 0.92–1.78 mg, respectively. That is, the shift of dpa50 due to solid particle loading is small if the PENS is not overloaded.

Both NPs and RPM concentrations were found to agree well with those of the IOSH respirable cyclone and MOUDI. By using the present PENS, the collected samples can be further analyzed for chemical species concentrations besides gravimetric analysis to determine the actual exposure concentrations of ENMs in both RPM and NPs fractions in workplaces, which are often influenced by the background or incident pollution sources.

Own Comments:

  • This could be the new kind of personal sampler which could need clip-on

Personal exposure monitoring of PM2.5 in indoor and outdoor microenvironments

Susanne Steinle, Stefan Reis, Clive E.Sabel, Sean Semple, Marsailidh M.Twigg, Christine F.Braban, Sarah R.Leeson, Mathew R.Heal, David Harrison, Chun Lin, Hao Wua https://doi.org/10.1016/j.scitotenv.2014.12.003

[10]

Abstract

Adverse health effects from exposure to air pollution are a global challenge and of widespread concern. Recent high ambient concentration episodes of air pollutants in European cities highlighted the dynamic nature of human exposure and the gaps in data and knowledge about exposure patterns. In order to support health impact assessment it is essential to develop a better understanding of individual exposure pathways in people's everyday lives by taking account of all environments in which people spend time. Here we describe the development, validation and results of an exposure method applied in a study conducted in Scotland.

A low-cost particle counter based on light-scattering technology — the Dylos 1700 was used. Its performance was validated in comparison with equivalent instruments (TEOM-FDMS) at two national monitoring network sites (R2 = 0.9 at a rural background site, R2 = 0.7 at an urban background site). This validation also provided two functions to convert measured PNCs into calculated particle mass concentrations for direct comparison of concentrations with equivalent monitoring instruments and air quality limit values.

This study also used contextual and time-based activity data to define six microenvironments (MEs) to assess everyday exposure of individuals to short-term PM2.5 concentrations. The Dylos was combined with a GPS receiver to track movement and exposure of individuals across the MEs. Seventeen volunteers collected 35 profiles. Profiles may have a different overall duration and structure with respect to times spent in different MEs and activities undertaken. Results indicate that due to the substantial variability across and between MEs, it is essential to measure near-complete exposure pathways to allow for a comprehensive assessment of the exposure risk a person encounters on a daily basis. Taking into account the information gained through personal exposure measurements, this work demonstrates the added value of data generated by the application of low-cost monitors.

Own Comments:

  • Instruments attached to worker in a backpack


Personal Exposure to Ultrafine Particles in the Workplace: Exploring Sampling Techniques and Strategies

DERK H. BROUWER JOSÉ H. J. GIJSBERS MARC W. M. LURVINK The Annals of Occupational Hygiene, Volume 48, Issue 5, 1 July 2004, Pages 439–453, [11]

Abstract

Recently, toxicological and epidemiological studies on health effects related to particle exposure suggest that ‘ultrafine particles’ (particles with an aerodynamic diameter of <100 nm) may cause severe health effects after inhalation. Although the toxicological mechanisms for these effects have not yet been explained, it is apparent that measuring exposures against mass alone is not sufficient. It is also necessary to consider exposures against surface area and number concentration. From earlier research it was hypothesized that results on number concentration and particle distributions may vary with distance to the source, limiting the reliability of estimates of personal exposure from results which were obtained using static measurement equipment. Therefore, a workplace study was conducted to explore the performance of measurement methods in a multi-source emission scenario as part of a sampling strategy to estimate personal exposure. In addition, a laboratory study was conducted to determine possible influences of both distance to source and time course on particle number concentration and particle size distribution. In both studies different measurement equipment and techniques were used to characterize (total) particle number concentration. These included a condensation particle counter (CPC), a scanning mobility particle sizer (SMPS) and an electrical low pressure impactor (ELPI). For the present studies CPC devices seemed to perform well for the identification of particle emission sources. The range of ultrafine particle number concentration can be detected by both SMPS and ELPI. An important advantage of the ELPI is that aerosols with ultrafine sizes can be collected for further analysis. Specific surface area of the aerosols can be estimated using gas adsorption analysis; however, with this technique ultrafine particles cannot be distinguished from particles with non-ultrafine sizes. Consequently, estimates based on samples collected from the breathing zone and scanning electron microscopic analysis may give a more reliable estimate of the specific surface area of the ultrafine particles responsible for personal exposure. The results of both the experimental and the workplace study suggest both spatial and temporal variation in total number concentration and aerosol size distribution. Therefore, the results obtained from static measurements and grab sampling should be interpreted with care as estimates of personal exposure. For evaluation of workplace exposure to ultrafine particles it is recommended that all relevant characteristics of such exposure are measured as part of a well-designed sampling strategy.

Own Comments:

  • "It is important that the sampling of aerosols should be either (ultrafine) size-selective, e.g. ELPI samples, or from the breathing zone, e.g. personal air samples."


Review of measurement techniques and methods for assessing personal exposure to airborne nanomaterials in workplace

Christof Asbach, Carla Alexander, Simon Clavaguera, Dir kDahmann, Hélène Dozol, Bertrand Faure, Martin Fierz, Luca Fontana, Ivo Iavicoli, Heinz Kaminski, Laura MacCalman, Asmus Meyer-Plath, Barbara Simonow, Martievan Tongeren, Ana Maria Todea https://doi.org/10.1016/j.scitotenv.2017.03.049

[12]

Highlights

  • Personal samplers and monitors are robust and ready for field-use.
  • Typical accuracy of personal samplers and monitors around ± 30%
  • Combination of personal sampler and monitor may be the optimal choice.
  • Clear measurement strategy needed for assessing personal exposure

Abstract

Exposure to airborne agents needs to be assessed in the personal breathing zone by the use of personal measurement equipment. Specific measurement devices for assessing personal exposure to airborne nanomaterials have only become available in the recent years. They can be differentiated into direct-reading personal monitors and personal samplers that collect the airborne nanomaterials for subsequent analyses. This article presents a review of the available personal monitors and samplers and summarizes the available literature regarding their accuracy, comparability and field applicability. Due to the novelty of the instruments, the number of published studies is still relatively low. Where applicable, literature data is therefore complemented with published and unpublished results from the recently finished nanoIndEx project. The presented data show that the samplers and monitors are robust and ready for field use with sufficient accuracy and comparability. However, several limitations apply, e.g. regarding the particle size range of the personal monitors and their in general lower accuracy and comparability compared with their stationary counterparts.

The decision whether a personal monitor or a personal sampler shall be preferred depends strongly on the question to tackle. In many cases, a combination of a personal monitor and a personal sampler may be the best choice to obtain conclusive results.

STERILIZATION OF FDM-MANUFACTURED PARTS

Mireya Pereza, Michael Block, David Espalina, Rob Winker, Terry Hoppe,Francisco Medina, Ryan Wicker

The University of Texas at El Paso, Stratasys Inc.

[13]

Abstract

Fused Deposition Modeling (FDM) can be used to produce an array of medical devices; however, for such devices to be practical, they must be manufactured using sterilizable materials. Nine FDM materials were tested using four methods of sterilization: autoclave, ethylene oxide, hydrogen peroxide, and gamma radiation. Sterility testing was performed by incubating the samples in Tryptic Soy Broth for 14 days. The majority of the materials were sterilizable by all four methods while deformations were caused by autoclaving. Results from this research will allow medical staff to sterilize an FDM-manufactured device using a suitable method.

Own Comments:

  • ABSi, ABS-M30, ABS-M30i, ABS-ESD7, PCABS, PC, PC-ISO, PPSF, and Ultem 9085
  • Five test samples and one control were used for each method of sterilization
  • All but one control samples showed contamination-> unclean manufacturing process
  • Sterilization works, but not all samples could handle it without deforming (Don't but ABS to the autoclave)

The TEAM Study: Personal Exposures to Toxic Substances in Air, Drinking Water, and Breath of 400 Residents of New Jersey, North Carolina, and North Dakota

LANCE A. WALLACE AND EDO D. PELLIZZARI, TYLER O. HARTWELL, CHARLES SPARACINO, ROY WHITMORE, LINDA SHELDON, HARVEY ZELON, AND REBECCA PERRITT

[14]

Received July 25, 1986 Abstract EPA's TEAM Study has measured exposures to 20 volatile organic compounds in personal air, outdoor air, drinking water, and breath of -400 residents of New Jersey, North Carolina, and North Dakota. All residents were selected by a probability sampling scheme to represent 128,000 inhabitants of Elizabeth and Bayonne, New Jersey, 131,000 residents of Greensboro, North Carolina, and 7000 residents of Devils Lake, North Dakota. Participants carried a personal monitor to collect two 12-hr air samples and gave a breath sample at the end of the day. Two consecutive 12-hr outdoor air samples were also collected on identical Tenax cartridges in the backyards of some of the participants. About 5000 samples were collected, of which 1500 were quality control samples. Ten compounds were often present in personal air and breath samples at all locations. Personal exposures were consistently higher than outdoor concentrations for these chemicals and were sometimes 10 times the outdoor concentrations. Indoor sources appeared to be responsible for much of the difference. Breath concentrations also often exceeded outdoor concentrations and correlated more strongly with personal exposures than with outdoor concentrations. Some activities (smoking, visiting dry cleaners or service stations) and occupations (chemical, paint, and plastics plants) were associated with significantly elevated exposures and breath levels for certain toxic chemicals. Homes with smokers had significantly increased benzene and styrene levels in indoor air. Residence near major point sources did not affect exposure. © 1987 Academic Press, Inc.

Own Comments:

  • 1979-1985 goal develop methods for individual total exposure
  • one part of studies
  • Personal monitor

Mechanical properties of components fabricated with open-source 3-D printers under realistic environmental conditions

B.M. Tymrak a, M. Kreiger b, J.M. Pearce, "Mechanical properties of components fabricated with open-source 3-D printers under realistic environmental conditions", Vol(58), 242-246, 2014. [15]


Abstract The recent development of the RepRap, an open-source self-replicating rapid prototyper, has made 3-D polymer-based printers readily available to the public at low costs ( < $500). The resultant uptake of 3-D printing technology enables for the first time mass-scale distributed digital manufacturing. RepRap variants currently fabricate objects primarily from acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA), which have melting temperatures low enough to use in melt extrusion outside of a dedicated facility, while high enough for prints to retain their shape at average use temperatures. In order for RepRap printed parts to be useful for engineering applications the mechanical properties of printed parts must be known. This study quantifies the basic tensile strength and elastic modulus of printed components using realistic environmental conditions for standard users of a selection of open-source 3-D printers. The results find average tensile strengths of 28.5 MPa for ABS and 56.6 MPa for PLA with average elastic moduli of 1807 MPa for ABS and 3368 MPa for PLA. It is clear from these results that parts printed from tuned, low-cost, open-source RepRap 3-D printers can be considered as mechanically functional in tensile applications as those from commercial vendors.

Own Comments:

  • Mechanical properties of OS RepRap 3D printers
    • AVG. UTS ABS: 28.5 MPa (Improvised ASTM: D638 with realistic environmental conditions of distrb. Manuf.)
  • AVG. Modulus ABS: 1807 MPa (Improvised ASTM: D638 with realistic environmental conditions distrb. Manuf.)
    • AVG. UTS PLA: 56.6 MPa (Improvised ASTM: D638 with realistic environmental conditions distrb. Manuf.)
  • AVG. Modulus PLA: 3368 MPa (Improvised ASTM: D638 with realistic environmental conditions distrb. Manuf.)
  • ABS Orientation x-y plane 0/90: highest E
  • ABS Orientationx-y plane +45/-45: strongest TS
  • ABS Layer thickness of 0.2mm: greatest TS
  • ABS Layer thickness of 0.4mm: greatest E

Patents

personal dust sampler holder

[16]

Spring action retainers hold a particle separation cyclone and an air filter in operative position for filtering air samples drawn through an inlet aperture in the cyclone. The retainers include a fuse-type spring clip and a flat apertured retaining plate joined to the clip by coil springs. The filter and cyclone are supported by the clip at the neck of the cyclone adjacent the inlet aperture. The retaining plate, positioned over the filter, biases the cyclone and filter combination against a flange on the lower portion of the clip. A tubular connector, secured through the aperture in the retaining plate, connects with the filter on one side, and with a vacuum hose on the other side for connecting the filter outlet to the inlet of an air metering pump. The clip and several hose guides are scoured to a supporting plate which includes a pin-type fastener for attaching the sampler holder to the garment of a person in his breathing zone when collecting respirable dust samples

Expired (1969)

Own comments:

  • Sampler attached to the clothing with safety pin

Disposable air sampling filter cassette

[17]

Expired (1970)

A composite filter unit and cassette to serve as an air sampler for personal use in connection with a metering pump and a cyclone unit. The filter unit is formed of two opposed shells with interfitting flanges to provide a support for the circumferential edges of a filter disc and to form chambers on each side of the disc, one to serve as an inlet and one to serve as an outlet. The chambers are provided with tangential openings so that inlet air is directed parallel to the disc in a toroidal path where it can flow uniformly through the filter disc to the opposed chamber and outlet. The composite filter unit is encapsulated in a cassette during use to protect it against outside contamination, the encapsulator having a special configuration for cooperation with a garment support bracket.

Own comments:

  • Old design, where you can see how it was attached before

Personal sampling pump

[18]

Expired (1980)

"Personal sampling pumps are small battery operated vacuum pumps intended to be worn on the person to monitor the exposure of the wearer to hazardous atmospheric conditions."


Cyclone personal sampler for aerosols

[19]

Expired (1989)

"The present invention relates to a personal sampler, that is one which is of sufficiently small size so that it can be worn by a user to determine the quality of air being respirated, which utilizes a two-stage cyclone evaluator that includes a conventional elongated personal cyclone separator that has a lower cut-off size of in the range of 10 microns."

Universal backpack harness

[20]

Expired (1996)

Own comments:

  • Harness design

Personal particle monitor

[21]

Active (2001)

Provided is a personal sampler for PM that allows separation of airborne particles in several size ranges and operates at a high flow rate (9 L/min) by personal sampling standards that makes chemical analysis of the size-fractionated particles possible within a period of 24 hours or less

Own comments:

  • This could totally use univeral clip-on design

Harness for firearm accessories

[22]

Active (2006)

Own comments:

  • Harness design
  • also includes gun attached to the harness with a clip-on

Compact aerosol sampler

[23]

Active (2009)

Provided is an aerosol collector of reduced size having an aerosol inlet, an impactor plate containing several particle size-selecting nozzles therethrough, a replaceable collection layer and a fan having a power supply such as a battery pack, all of which fits a small container, attachable to, e.g., the lapel of the user, means to rotate the fan and move the aerosol through the sampler, so as to draw airborne particles through the inlet and through one or more nozzles, to impact the particles on the layer for analysis of same.

Own comments:

  • Attachment to the clothing


Personal nanoparticle respiratory depositions sampler and methods of using the same

[24]

Active (2012)

A personally portable nanoparticle respiratory deposition (NRD) sampler configured to collect nanoparticles based upon a sampling criterion. In an aspect, the NRD sampler has an impactor stage, and a diffusion stage. In another aspect, the NRD sampler includes a particle size separator in addition to an impactor stage and a diffusion stage.

Guidelines and Data Sheets

ISO/ASTM 52900:2015

Additive manufacturing -- General principles -- Terminology

ISO/ASTM 52900:2015 establishes and defines terms used in additive manufacturing (AM) technology, which applies the additive shaping principle and thereby builds physical 3D geometries by successive addition of material.

The terms have been classified into specific fields of application.

Fused Deposition Modeling (FDM) Design Guidelines

Stratasys Direct, Inc., "Fused Deposition Modeling (FDM) Design Guidelines", 2015.

[25]

Accessed 30.04.2018

Part Design For FDM

These guidelines are to be used as a starting point in understanding the basic aspects of part design and preparation for FDM components. When designing a part to be built using FDM technology, build process must be considered. FDM is accomplished by extruding thin layers of molten thermoplastic layer by layer until a part is produced. Because FDM produces parts with specific characteristics and capabilities different from those of other prototyping processes, the systems have become increasingly used as a tool for producing manufactured products.

Own Comments:

  • FDM Design considerations according to uPrint SE Pro

ABSplus-P430: Production-Grade Thermoplastic for 3D Printers

Stratasys Direct, Inc., "ABSplus-P430: Production-Grade Thermoplastic for 3D Printers", 2017.

[26]

Accessed 30.04.2018

Own Comments:

  • Mechanical properties of ABS plus
    • UTS:33MPa (ASTM D638)
    • YTS: 31MPa (ASTM D638)
    • Tensile Modulus: 2200 MPa (ASTM D638)
    • Toughness: 106 J/m (ASTM D638)
    • Hardness: 109.5 (ASTM D785)
  • Thermal Properties of ABS plus (ASTM D648)
  • Electrical Properties of ABS plus (ASTM D257, D150-98 and D149-09)

Personal Sampling for Air Contaminants

[27]

OSHA GUIDELINES

Safety Data Sheet

Stratasys Direct, Inc., "Safety Data Sheet", 2015.

[28]

Accessed 30.04.2018

Safety Data Sheet for ABS-M30/P430 ABS/P430XL ABS/ABSplus Model Material

Own Comments:

  • Not dangerous according to (REGULATION (EC) No 1272/2008)
  • Eye contact: rinse
  • Extinguishing Media: water, dry powder, foam, CO2
  • Keep tightly closed in a dry and cool place.
  • Does not contain any hazardous materials with occupational exposure limits established by the region specific regulatory bodies.
  • Contains no substances known to be hazardous to the environment or that are not degradable in waste water treatment plants.
  • Handle in accordance with good industrial hygiene and safety practice.
  • No protective equipment is needed under normal use conditions.