scholarly journals Development of an efficient viral aerosol collector for higher sampling flow rate

2017 ◽  
Vol 25 (4) ◽  
pp. 3884-3893 ◽  
Author(s):  
Xiao-Ting Lin ◽  
Nai-Yun Hsu ◽  
Jen-Ren Wang ◽  
Nai-Tzu Chen ◽  
Huey-Jen Su ◽  
...  
Keyword(s):  
Flow Rate ◽  
Viral Aerosol ◽  
Sampling Flow Rate ◽  
Sampling Flow

scholarly journals Ozone removal efficiency of the KI-denuder in the carbonyl sampling

2019 ◽  
Vol 2 (5) ◽  
pp. 153-160
Author(s):  
Huy Huu Duong ◽  
Vui Thi Kim Tran ◽  
Chuong Thanh Nguyen ◽  
Hien Thi To
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Carbonyl Compounds ◽  
Climatic Conditions ◽  
Ho Chi Minh City ◽  
High Humidity ◽  
Optimum Parameters ◽  
Sampling Flow Rate ◽  
High Humidity Condition ◽  
Sampling Flow

In the carbonyl sampling of 2, 4- dinitrophenylhydrazine (DNPH) impregnated cartridge, the ozone removal was necessary because ozone reacted with the DNPH derivatives. A commercial ozone scrubber was usually used to remove O3. However, high humidity leaded to carbonyl compounds being trapped on the ozone scrubber before passing through the DNPH cartridge. The purpose of this study was to assess the ozone removal by KI-denuder under the climatic conditions of Ho Chi Minh City. Several parameters including air sampling flow rate and denuder length were optimized to achieve the highest removal efficiency. The optimum parameters of the KI denuder were the sampling flow rate of less than 1 L/min, and the denuder length of 20 cm. The effect of the initial O3 concentration on the removal efficiency was also investigated. Finally, the ozone removal efficiency of KI-denuder was compared to that of ozone scrubber when two devices were applied for the carbonyl sampling during field measurement. The results show that KI-denuder could be used to replace the ozone scrubber with high removal efficiency, particularly in high humidity condition. In conclusion, KI-denuder was effective, simple, easy to use and cheap. Therefore, it was encouraged to use in carbonyl sampling.

Respiratory Gas Analysers

2011 ◽  
Author(s):  
Patrick Magee ◽  
Mark Tooley
Keyword(s):  
Flow Rate ◽  
Delay Time ◽  
Physical Principle ◽  
Breathing System ◽  
Sampling Tube ◽  
Gas Concentration ◽  
Square Wave ◽  
Gas Sampling ◽  
Sampling Flow Rate ◽  
Sampling Flow

The purpose of respiratory gas analysis during anaesthesia is to identify and measure the concentrations, on a breath by breath basis, of the individual gases and vapours in use. It may also be useful as a guide to cardiac function or to identify trace contaminant gases. Different techniques use different physicochemical properties of the gas or vapour. An understanding of the physical principle underlying each method is necessary in order to recognise the value and limitations of each. In terms of the device’s ability to respond on a breath by breath basis, there are two important components: the time taken for the gas to be sampled from the anaesthetic machine or breathing system, the delay time; then there is the time taken for the device to measure the gas concentration, the response time. This is depicted in Figure 16.1. Most of the delay occurs in the delay time or transit time and can be reduced either by analysing the gas sample close to the airway, or by using as short and thin a sampling tube and as high a sampling flow rate to the analyser as possible [Chan et al. 2003]; the sampling flow rate is usually of the order of 100 to 200 ml min−1. If minimal fresh gas flow rates are being used in a circle anaesthetic breathing system and the sampled gas is not returned to the breathing system, then a high gas sampling rate could represent a significant gas leak. Figure 16.1 shows a sigmoid curve of recorded gas concentration change in response to a square wave input change. The response of a gas analyser is often expressed as the time taken to produce a 90–95% response to a step or square wave input change. A square wave change in gas concentration can be produced by moving a gas sampling tube rapidly into and out of a gas stream, by bursting a small balloon within a sampling volume containing a gas sample, or by switching a shutter to a gas sample volume using a solenoid valve. An important part of the use of gas analysers is zeroing and calibration since they are all prone to drift in both zero and gain.

Mass change tracking approach as collection guidelines for aerosol and vapor samples released during e-cigarette smoking

2016 ◽  
Vol 8 (10) ◽  
pp. 2305-2311 ◽  
Author(s):  
Ki-Hyun Kim
Keyword(s):  
Cigarette Smoking ◽  
Flow Rate ◽  
Electronic Cigarettes ◽  
Mass Change ◽  
Solution Composition ◽  
Charge Condition ◽  
Battery Charge ◽  
Methodological Basis ◽  
Sampling Flow Rate ◽  
Sampling Flow

There are growing concerns about the lack of a methodological basis for the quantification of various pollutants from electronic cigarettes (ECs). In this study we use a mass change tracking (MCT) approach to explore the potent roles of key sampling variables in the quantitation of EC-produced aerosols/vapors: the sampling flow rate (or puff velocity), battery charge condition, and solution composition.

Individual and synergistic effects of sniffing frequency and flow rate on olfactory bulb activity

2011 ◽  
Vol 106 (6) ◽  
pp. 2813-2824 ◽  
Author(s):  
Emmanuelle Courtiol ◽  
Chloé Hegoburu ◽  
Philippe Litaudon ◽  
Samuel Garcia ◽  
Nicolas Fourcaud-Trocmé ◽  
...  
Keyword(s):  
Olfactory Bulb ◽  
Flow Rate ◽  
Animal Behavior ◽  
Synergistic Effects ◽  
Field Potential ◽  
Sampling Frequency ◽  
Experimental Approaches ◽  
Sampling Flow Rate ◽  
Additional Support ◽  
Local Field Potential Lfp

Is faster or stronger sniffing important for the olfactory system? Odorant molecules are captured by sniffing. The features of sniffing constrain both the temporality and intensity of the input to the olfactory structures. In this context, it is clear that variations in both the sniff frequency and flow rate have a major impact on the activation of olfactory structures. However, the question of how frequency and flow rate individually or synergistically impact bulbar output has not been answered. We have addressed this question using multiple experimental approaches. In double-tracheotomized, anesthetized rats, we recorded both the bulbar local field potential (LFP) and mitral/tufted cells' activities when the sampling flow rate and frequency were controlled independently. We found that a tradeoff between the sampling frequency and the flow rate could maintain olfactory bulb sampling-related rhythmicity and that only an increase in flow rate could induce a faster, odor-evoked response. LFP and sniffing were recorded in awake rats. We found that sampling-related rhythmicity was maintained during high-frequency sniffing. Furthermore, we observed that the covariation between the frequency and flow rate, which was necessary for the tradeoff seen in the anesthetized preparations, also occurred in awake animals. Our study shows that the sampling frequency and flow rate can act either independently or synergistically on bulbar output to shape the neuronal message. The system likely takes advantage of this flexibility to adapt sniffing strategies to animal behavior. Our study provides additional support for the idea that sniffing and olfaction function in an integrated manner.

Comparison of Radon Daughter Measurement Techniques Used in European Animal Exposure Facilities

1994 ◽  
Vol 56 (1-4) ◽  
pp. 259-262 ◽  
Author(s):  
J.C. Strong ◽  
J.P. Morlier ◽  
J.S. Groen ◽  
R.W. Bartstra ◽  
S.T. Baker
Keyword(s):  
The Netherlands ◽  
Flow Rate ◽  
Measurement Techniques ◽  
Measurement Methods ◽  
Individual Exposure ◽  
Radon Daughter ◽  
Sampling Flow Rate ◽  
The Individual ◽  
Animal Exposure ◽  
Future Work

Abstract The effects of radon daughter inhalation by animals is being studied by three organisations in Europe. The individual exposure facilities used are described. For meaningful comparisons of the results from these studies, the radiological character of the exposure atmospheres must be compared, therefore a series of comparison exercises has been initiated. It is planned to make measurements of radon daughter concentrations and 'unattached' fractions by the three groups side by side at each facility. The exposure atmospheres at two facilities have been studied to date; CEA/COGEMA, Razes, France and TNO, Rijswijk, The Netherlands. Sampling flow rate and reference standards were also intercompared by the groups. The paper discusses the measurement methods employed, and the reasons for discrepancies in results between the groups, thus ensuring that future work by all three groups will be directly comparable.

scholarly journals Characterization of Commercially Available Active-Type Radon–Thoron Monitors at Different Sampling Flow Rates

Atmosphere ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 971
Author(s):  
Yuki Tamakuma ◽  
Chutima Kranrod ◽  
Yuto Jin ◽  
Hiromu Kobayashi ◽  
Eka Djatnika Nugraha ◽  
...  
Keyword(s):  
Flow Rate ◽  
Reference Value ◽  
Measured Concentration ◽  
Grab Sampling ◽  
Flow Rates ◽  
Active Type ◽  
Measurement Monitoring ◽  
Multiple Sampling ◽  
The Difference ◽  
Sampling Flow

Recently, some commercially available active-type radon–thoron monitors were developed; however, their performance has not been characterized. This article presents the characteristics of three commercially available active-type radon–thoron monitors (RAD7, Radon Mapper, and AlphaGUARD) at different sampling flow rates. The thoron concentration measured by the monitors was compared with the reference value measured by a grab sampling method. As a result, the ratio of the measured concentration to the reference increased with flow rate for the RAD7 and the Radon Mapper although that of the AlphaGUARD decreased. The difference may be attributed to the coefficients used in the calculation and the measurement time scheme. The results indicate the importance of the sampling flow rate in thoron measurement. Monitoring of flow rate at the measurement and periodic calibration at multiple sampling flow rates should be conducted for quality assurance and quality control of the measurand.

scholarly journals An Equilibrator System to Measure Dissolved Oxygen and Its Isotopes

2013 ◽  
Vol 30 (2) ◽  
pp. 361-377 ◽  
Author(s):  
Lauren Elmegreen Rafelski ◽  
Bill Paplawsky ◽  
Ralph F. Keeling
Keyword(s):  
Flow Rate ◽  
Operating Conditions ◽  
Equilibration Time ◽  
Performance Tests ◽  
Gas Composition ◽  
Gas Sampling ◽  
Isotope Ratio Mass Spectrometer ◽  
Sampling Flow Rate ◽  
La Jolla ◽  
Further Development

Abstract An equilibrator is presented that is designed to have a sufficient equilibration time even for insoluble gases, and to minimize artifacts associated with not equilibrating to the total gas tension. A gas tension device was used to balance the pressure inside the equilibrator with the total gas tension. The equilibrator has an e-folding time of 7.36 ± 0.74 min for oxygen and oxygen isotopes, allowing changes on hourly time scales to be easily resolved. The equilibrator delivers “equilibrated” air at a flow rate of 3 mL min−1 to an isotope ratio mass spectrometer. The high gas sampling flow rate would allow the equilibrator to be interfaced with many potential devices, but further development may be required for use at sea. This system was tested at the Scripps Institution of Oceanography pier, in La Jolla, California. A mathematical model validated with performance tests was used to assess the sensitivity of the equilibrated air composition to headspace pressure and makeup gas composition. Parameters in this model can be quantified to establish corrections under different operating conditions. For typical observed values, under the operating conditions presented here, the uncertainty in the measurement due to the equilibrator system is 2.2 per mil for δ(O2/N2), 1.5 per mil for δ(O2/Ar), 0.059 per mil for δ18O, and 0.0030 per mil for Δ17O.

scholarly journals Polarographic measurement of ascorbate washout in isolated perfused rabbit hearts

1985 ◽  
Vol 249 (1) ◽  
pp. H150-H154
Author(s):  
T. Arts ◽  
J. T. Kuikka ◽  
R. S. Reneman ◽  
J. B. Bassingthwaighte
Keyword(s):  
Isolated Heart ◽  
Rabbit Heart ◽  
Isolated Hearts ◽  
On Line ◽  
Sampling Flow Rate ◽  
Time Courses ◽  
Arteriovenous Difference ◽  
Calibration Setup ◽  
Polarographic Measurement ◽  
Sampling Flow

To study the myocardial washout of ascorbate, the applicability of polarographic detection of ascorbate ions by a platinum electrode (sensitive area 0.03 mm2) was investigated, in both a calibration setup (sampling flow along the electrode: 100 microliter X s-1) and isolated, retrogradely perfused rabbit hearts. In the calibration setup at pH 7.4, the sensitivity of the electrode was 70 microA/mol. This sensitivity increased moderately with increasing pH (13%/unit pH) and increasing sampling flow rate (14% at an increase from 100 to 150 microliter X s-1). In the isolated hearts, ascorbate infused into the aorta was detected in a right ventricular drain by the electrode as well as by the use of 14C-labeled ascorbate. Both recorded time courses were similar except for a scaling factor dependent on flow velocity. During continuous infusion the arteriovenous difference of ascorbate was 2 +/- 2% (SD), indicating a relatively low consumption of ascorbate by the isolated heart. We conclude that polarographic measurement of ascorbate in the coronary effluent of an isolated rabbit heart can be performed on-line and relatively easily.

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