Real-time performance of filtering facepiece respirators at the workplace/Echtzeit-Performance partikelfiltrierender Halbmasken am Arbeitsplatz

Gefahrstoffe ◽  
2019 ◽  
Vol 79 (10) ◽  
pp. 378-384
Author(s):  
C. Sun ◽  
C. Thelen ◽  
I. Sancho Sanz ◽  
A. Wittmann
Keyword(s):  
Field Measurements ◽  
Paper Mill ◽  
Measuring System ◽  
Pilot Test ◽  
Protection Factor ◽  
Workplace Performance ◽  
Geometric Means ◽  
Training Facility ◽  
Workplace Conditions

The efficacy of a respirator under real workplace conditions is presented by its workplace protection factor (WPF). The aim of this study was to assess a portable measuring system for the determination of WPF for particulate filtering facepiece respirators. WPFs of CE-marked FFP2 and FFP3 filtering facepiece respirators were measured as a pilot test conducted at two workplaces: an inter-company training facility and a paper mill, with a total of seven test subjects. Each subject was quantitatively fit tested prior to the field measurements. Two TSI PortaCount instruments measured the particle concentrations simultaneously and continuously inside and outside the respirator for 15 min, with three repetitions. The results of the fit test (overall fit factor) ranged from 22 to 199. Individual WPF results ranged from 16 to 568 for FFP2 respirators, and from 13 to 232 for FFP3 respirators. The geometric means (GM) of the WPF were 135 with a 5th percentile value of 37 (FFP2), and 47 with a 5th percentile value of 12 (FFP3). This pilot test provides a new method of evaluating the workplace performance of filtering facepiece respirators.

scholarly journals Raman Sensor for the Determination of Gas Solubility

Physchem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 176-188
Author(s):  
Gregor Lipinski ◽  
Markus Richter
Keyword(s):  
Carbon Dioxide ◽  
Gas Separation ◽  
Accurate Determination ◽  
Measurement Techniques ◽  
Screening Tools ◽  
Measuring System ◽  
Separation Processes ◽  
Use Of Resources ◽  
Gas Solubilities

Efficient and environmentally responsible use of resources requires the development and optimization of gas separation processes. A promising approach is the use of liquids that are designed for specific tasks, e.g., the capture of carbon dioxide or other greenhouse gases. This requires an accurate determination of gas solubilities for a broad range of temperatures and pressures. However, state of the art measurement techniques are often very time consuming or exhibit other pitfalls that prevent their use as efficient screening tools. Here, we show that the application of Raman spectroscopy through a compact measuring system can simplify data acquisition for the determination of gas solubilities in liquids. To demonstrate that this approach is expedient, we determined gas solubilities of carbon dioxide in water for three isotherms T = (288.15, 293.15, 298.15) K over a pressure range from p = (0.5–5) MPa and in three imidazolium-based ionic liquids for one isotherm T = 298.15 K at pressures from p = (0.1–5) MPa. When compared to data in the literature, all results are within the reported uncertainties of the measurement techniques involved. The developed analysis method eliminates the need for a lengthy volume or mass calibration of the sample prior to the measurements and, therefore, allows for fast screening of samples, which can help to advance gas separation processes in scientific and industrial applications.

scholarly journals Laboratory and In Situ Determination of Hydraulic Conductivity and Their Validity in Transient Seepage Analysis

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1131
Author(s):  
Soonkie Nam ◽  
Marte Gutierrez ◽  
Panayiotis Diplas ◽  
John Petrie
Keyword(s):  
Hydraulic Conductivity ◽  
Field Measurements ◽  
Natural Soil ◽  
In Situ Tests ◽  
Seepage Analysis ◽  
Soil Deposits ◽  
Seepage Modeling ◽  
Sample Disturbance

This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. Laboratory determination of hydraulic conductivity used the constant head permeability and oedometer tests on undisturbed Shelby tube and block soil samples. The auger hole method and Guelph permeameter tests were performed in the field. Groundwater table elevations in natural soil deposits with different hydraulic conductivity values were predicted using finite element seepage modeling and compared with field measurements to assess the various test results. Hydraulic conductivity values obtained by the auger hole method provide predictions that best match the groundwater table’s observed location at the field site. This observation indicates that hydraulic conductivity determined by the in situ test represents the actual conditions in the field better than that determined in a laboratory setting. The differences between the laboratory and in situ hydraulic conductivity values can be attributed to factors such as sample disturbance, soil anisotropy, fissures and cracks, and soil structure in addition to the conceptual and procedural differences in testing methods and effects of sample size.

Public Accountability or Fiscal Control? Benchmarks of Performance in Australian Schooling

1996 ◽  
Vol 40 (1) ◽  
pp. 104-123 ◽  
Author(s):  
Louise Watson
Keyword(s):  
Performance Indicators ◽  
Service Provision ◽  
School Effectiveness ◽  
Measuring System ◽  
Government Schools ◽  
Public Resources ◽  
Government Education ◽  
Efficiency And Effectiveness ◽  
Performance Benchmarks

The Industry Commission review of service provision in school education aims to define performance benchmarks for Australia's eight government education systems, by providing comparative measures of efficiency in education provision. Such benchmarks are likely to lead to a reduction in the level of public resources for government schools unless it is possible to demonstrate the link between expenditure on schooling and school effectiveness. If efficiency audits like the Industry Commission review are to deal with issues of school effectiveness adequately, they should avoid the tendency of previous public sector audits to focus on financial data on schools expenditure to the exclusion of data on student achievement. This paper suggests an approach to measuring system performance which would establish benchmarks that reflected both the efficiency and effectiveness of Australian school systems, and warns against the misuse of performance indicators as an instrument in the determination of funding levels for schools.

Micro Roughness Determination Of Periodic Microelectronics Structures Using Optical Far Field Measurements

2011 ◽  
Author(s):  
Alexandre Vauselle ◽  
Philippe Maillot ◽  
Gaëlle Georges ◽  
Carole Deumié ◽  
David G. Seiler ◽  
...  
Keyword(s):  
Field Measurements ◽  
Far Field

Corrosion Metal Loss Interaction From In-Line Inspection and How it Can Affect the Calculated Failure Pressure

2012 ◽  
Author(s):  
Lucinda Smart ◽  
Richard McNealy ◽  
Harvey Haines
Keyword(s):  
Field Measurements ◽  
Metal Loss ◽  
Data Correlation ◽  
Failure Pressure ◽  
Industry Standards ◽  
Direct Measurements ◽  
Non Destructive ◽  
Flux Leakage

In-Line Inspection (ILI) is used to prioritize metal loss conditions based on predicted failure pressure in accordance with methods prescribed in industry standards such as ASME B31G-2009. Corrosion may occur in multiple areas of metal loss that interact and may result in a lower failure pressure than if flaws were analyzed separately. The B31G standard recommends a flaw interaction criterion for ILI metal loss predictions within a longitudinal and circumferential spacing of 3 times wall thickness, but cautions that methods employed for clustering of ILI anomalies should be validated with results from direct measurements in the ditch. Recent advances in non-destructive examination (NDE) and data correlation software have enabled reliable comparisons of ILI burst pressure predictions with the results from in-ditch examination. Data correlation using pattern matching algorithms allows the consideration of detection and reporting thresholds for both ILI and field measurements, and determination of error in the calculated failure pressure prediction attributable to the flaw interaction criterion. This paper presents a case study of magnetic flux leakage ILI failure pressure predictions compared with field results obtained during excavations. The effect of interaction criterion on calculated failure pressure and the probability of an ILI measurement underestimating failure pressure have been studied. We concluded a reason failure pressure specifications do not exist for ILI measurements is because of the variety of possible interaction criteria and data thresholds that can be employed, and demonstrate herein a method for their validation.

scholarly journals A Study on Factors Influencing the Determination of Moisture Content of Fibrous Peat

2011 ◽  
Vol 2 (2) ◽  
pp. 39-47 ◽  
Author(s):  
Pui Tau Shien ◽  
Seneviratne H.N. ◽  
Dygku Salma Awg Ismail
Keyword(s):  
Moisture Content ◽  
Particle Density ◽  
Peat Soil ◽  
Test Procedure ◽  
Field Measurements ◽  
Standard Test ◽  
Moisture Loss ◽  
Fibrous Peat ◽  
Saturated Sample

Fibrous peat is an undrained peat that usually possesses very high moisture content. However, not all experimental procedures are applicable for determination of moisture content of fibrous peat. This research is aimed at examining the determination of insitu moisture content of fibrous peat using field measurements. The peat soil samples were collected at shallow depths from Asajaya at Kota Samarahan and Taman Kopodims at Matang , Kuching Sarawak by using peat auger. The laboratory tests such as determination of moisture content, fiber content, particle density and ash content were conducted on the collected samples in order to establish relationships between the parameters. Undisturbed peat samples from Matang were subjected to falling head permeability test to determine the saturated permeability. The saturated sample were then allowed to drain freely to simulate the moisture loss possible during sampling when samples were brought out of boreholes. The test results showed that moisture content varies according to the drying temperature and position of the soil sample (top, middle and bottom) during sampling. Comparing samples from both locations, peat soil from Kota Samarahan possessed higher moisture content. The saturated permeability of peat sample was in the range of 2.62 – 3.05 cm/s. The free draining trial showed that moisture loss during sampling significantly influence the moisture content measurement. The variation in value of moisture content for fibrous peat may occurs due to several factors such as existing ground water table, sampling method by boring, existing standard test procedure which is not suitable for peat soils requirement and also because of the physical properties which varied according to depth of soil.

scholarly journals Features of the Surface and Subsurface Waves Application for Ultrasonic Evaluation of Physicomechanical Properties of Solids. Part 1. Influence of the Geometrical Parameters

2018 ◽  
Vol 9 (4) ◽  
pp. 325-326
Author(s):  
A. R. Baev ◽  
A. L. Mayorov ◽  
M. V. Asadchaya ◽  
V. N. Levkovich ◽  
K. G. Zhavoronkov
Keyword(s):  
Protective Coating ◽  
Layer Structure ◽  
Base Material ◽  
Protective Layer ◽  
Body Waves ◽  
Measuring System ◽  
Geometrical Parameters ◽  
Small Aperture ◽  
Ultrasonic Evaluation

Application of surface and subsurface waves for control of objects with a double-layer structure allows to extend possibilities of diagnostics of their physico-mechanical properties. The purpose of work was to determine conditions and offer recommendations providing measuring of ultrasonic velocity and amplitude of the former modes in protective layers and in basis of object at one-sided access to its surface.The analysis of an acoustic path of a measuring system in relation to ultrasonic evaluation of the objects having the restricted sizes and the protective coating according to velocity data of the surface and subsurface waves propagation is made. On the basis of representations of beam acoustics the dependences connecting a wavelength of the excited surface and subsurface modes, thickness and width of a controlled object, acoustic base of a sounding are defined. There are to provide a condition leveling of the influence of an acoustical noise created by the reflected and accompanying waves on parameters of acoustic signal with the given quantity of oscillations in an impulse.The principle opportunity is shown and conditions for determination of velocity of subsurface body waves in the base material which is under a protective coating layer are established. For these purposes on the basis of use of the block of ultrasonic probes the optimum scheme of a sounding is offered and the analytical expression for calculation of required velocity considering varying of thickness of a covering is received.The method of acoustical measuring realized by a direct and reverse sounding of the objects with small aperture and angle probes was analysed and formulas for determination of speed of subsurface wave under protective layer of the wedge form have been got. An ultrasonic device is suggested for the excitationreception of subsurface waves with different speed in objects (on 20–35 %) using for the acoustic concordance of environments of metallic sound duct as a wedge. Possibility of leveling of interference in a protective layer to control efects in basis of material by a volume wave by creation of supporting echo-signal of longitudinal wave of the set frequency and entered normally to the surface of object was studied.

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