Characterization and Validation of the Second-generation wPUM Topography Monitors

Author(s):  
Risa J Robinson ◽  
Shehan Jayasekera ◽  
Gary DiFrancesco ◽  
Edward C Hensel

Abstract Introduction Little is known about the natural use behavior of new and emerging tobacco products due to the limited availability of reliable puff topography monitors suitable for ambulatory deployment. An understanding of use behavior is needed to assess the health impact of emerging tobacco products and inform realistic standardized topography profiles for emissions studies. The purpose of this study is to validate four monitors: the wPUM cigalike, vapepen, hookah, and cigarette monitors. Aims and Methods Each wPUM monitor was characterized and validated for range, accuracy, and resolution for puff flow rate, duration, volume, and interpuff gap in a controlled laboratory environment. Monitor repeatability was assessed for each wPUM monitor using four separate week-long natural environment monitoring studies including cigalike, vapepen, hookah, and cigarette users. Results The valid flow rate range was 10 to 100 mL/s for cigalike and cigarette monitors, 10 to 95 mL/s for vapepen monitors, and 50 to 400 mL/s hookah monitors. Flow rate accuracy was within ±2 mL/s for cigalike, vapepen, and cigarette monitors and ±6 mL/s for the hookah monitor. Durations and interpuff gaps as small as 0.2 s were measured to within ±0.07 s. Monitor calibrations changed by 4.7% (vapepen), 1.5% (cigarette), 0.5% (cigalike), and 0.1% (hookah) after 1 week of natural environment use. Conclusions The wPUM topography monitors were demonstrated to be reliable when deployed in the natural environment for a range of emerging tobacco products. Implications The current study addresses the lack of available techniques to reliably monitor topography in the natural environment, across multiple emerging tobacco products. Natural environment topography data will inform standardized puffing protocols for premarket tobacco product applications. The ability to quantify topography over extended periods of time will lead to a better understanding of use behavior and better-informed regulations to protect public health.

2018 ◽  
Vol 27 (Suppl 1) ◽  
pp. s82-s86 ◽  
Author(s):  
Wendy B Max ◽  
Hai-Yen Sung ◽  
James Lightwood ◽  
Yingning Wang ◽  
Tingting Yao

ObjectivesWe review the Population Health Impact Model (PHIM) developed by Philip Morris International and used in its application to the US Food and Drug Administration (FDA) to market its heated tobacco product (HTP), IQOS, as a modified-risk tobacco product (MRTP). We assess the model against FDA guidelines for MRTP applications and consider more general criteria for evaluating reduced-risk tobacco products.MethodsIn assessing the PHIM against FDA guidelines, we consider two key components of the model: the assumptions implicit in the model (outcomes included, relative harm of the new product vs cigarettes, tobacco-related diseases considered, whether dual or polyuse of the new product is modelled, and what other tobacco products are included) and data used to estimate and validate model parameters (transition rates between non-smoking, cigarette-only smoking, dual use of cigarettes and MRTP, and MRTP-only use; and starting tobacco use prevalence).ResultsThe PHIM is a dynamic state transition model which models the impact of cigarette and MRTP use on mortality from four tobacco-attributable diseases. The PHIM excludes morbidity, underestimates mortality, excludes tobacco products other than cigarettes, does not include FDA-recommended impacts on non-users and underestimates the impact on other population groups.ConclusionThe PHIM underestimates the health impact of HTP products and cannot be used to justify an MRTP claim. An assessment of the impact of a potential MRTP on population health should include a comprehensive measure of health impacts, consideration of all groups impacted, and documented and justifiable assumptions regarding model parameters.


2021 ◽  
pp. 1-9
Author(s):  
Hao-tian Fan ◽  
Hong Li ◽  
Wei Mao ◽  
Yong-Jie Ding ◽  
Li-Qiu Wei ◽  
...  

Author(s):  
Shunya Takao ◽  
Kentarou Hayashi ◽  
Masahiro Miyabe

Abstract In order to improve suction performance, centrifugal pumps with an inducer are used for rocket pumps, liquid gas transport such as LNG, and general-purpose pumps. Since a higher suction performance than conventional pump is required, a splitter blade that consists of a long blade and a short blade is sometimes adopted. However, the design becomes more difficult due to the increased number of parameters. The stable operation over a wide flow rate range are required in the general-purpose pumps. Therefore it is necessary to design them so that unstable flow phenomena such as surges do not occur. However, the design method to avoid them is not well understood yet. In this study, we focused on the splitter blade impeller in a general-purpose low-speed centrifugal pump with an inducer. Six parameters such as leading edge position and trailing edge position of the short blade for both hub-side and tip-side were set as design ones. A multi-objective optimization method using a commercial software was applied to improve suction performance while maintaining high efficiency. Then obtained optimal shape were analyzed by CFD calculation and extracted the feature. Furthermore, optimized impellers were manufactured and confirmed the performance over a wide flow rate range by experiments. In addition, a optimizing design method that improves pump performance at lower cost was studied.


2012 ◽  
Vol 220-223 ◽  
pp. 875-879
Author(s):  
Ying Xu ◽  
Cun Yin ◽  
Zheng Hai Long

In order to better simulate the flowing condition of wet gas, Tianjin University has designed and built up a wet gas flow experimental facility with adjustable and intermediate pressure in the flow laboratory. The designed pressure of the facility which used standard meter method and dual closed-loop design is 4MPa. The experiment medium is air and water, and the highest operation pressure is 1.6MPa. The gas flow rate range is 3~1000m3/h, and the liquid flow rate range is 0.05~8 m3/h. This article includes the structure introduction of the facility and the calculation of pressure loss of the system, etc. By the uncertainty assessment for the discussed facility, the conclusion is stated that the facility’s gas measurement uncertainty is 1% and the facility’s liquid measurement uncertainty is 0.35%.


Author(s):  
Toru Shigemitsu ◽  
Akinori Furukawa ◽  
Satoshi Watanabe ◽  
Kusuo Okuma

An application of contra-rotating rotors, consisting of front and rear rotors rotating in the opposite direction from each other, has been proposed against a demand for developing a higher specific speed axial flow pump with a more compact structure, higher efficiency and higher cavitation performance. As axial flow pumps are used for standby operations of air-lock and air/water mixing discharge to prevent floods, air/water two-phase flow performance of the contra-rotating pump has to be also investigated. In the present paper, therefore, experimental results on air/water two-phase flow performance of a test pump with contra-rotating rotors are shown and compared with those of a conventional axial flow pump, consisting of a front rotor and a rear stator. Even under two-phase flow conditions head characteristic curve of the contra-rotating type has a more strongly negative slope than that of the conventional type. The contra-rotating type maintains higher head and higher efficiency even in the low flow rate range and vice versa in the high flow rate range. This result will be discussed by considering the change of outlet flow from front rotor due to two-phase flow with the help of observed air behavior in the rotors. Then effects of changes of rear rotor rotational speed different from front rotor speed, which is an advantage of the contra-rotating axial flow pump, on two-phase flow performance are examined. Under the condition of constant ratio of air to water flow rates, the head rise of the rear rotor linearly increases with rear rotor rotational speed. Air/water two-phase flow performance of the contra-rotating axial flow pump can be improved by this control procedure for the rear rotor rotational speed.


Author(s):  
Tetsuya Yamashita ◽  
Satoshi Watanabe ◽  
Yoshinori Hara ◽  
Hiroyoshi Watanabe ◽  
Kazuyoshi Miyagawa

In this study, radial and axial thrust forces working on the whole rotor in a three-stages centrifugal pump are measured in a wide range of flow rate. The forces are measured at two floating journal bearings and one floating ball bearing, which are supported by the individual load cells. The effects of the offset of rotor position in the axial direction on the thrust forces are investigated. It is found that the effect of the axial offset is significant for the axial thrust force in the low flow rate range, whereas it has little influence on the head and efficiency performances in the whole flow rate range.


Author(s):  
Hugo Bissig ◽  
Harm Tido Petter ◽  
Peter Lucas ◽  
Elsa Batista ◽  
Eduarda Filipe ◽  
...  

AbstractMicroflow and nanoflow rate calibrations are important in several applications such as liquid chromatography, (scaled-down) process technology, and special health-care applications. However, traceability in the microflow and nanoflow range does not go below 16 μl/min in Europe. Furthermore, the European metrology organization EURAMET did not yet validate this traceability by means of an intercomparison between different National Metrology Institutes (NMIs). The NMIs METAS, Centre Technique des Industries Aérauliques et Thermiques, IPQ, Danish Technological Institute, and VSL have therefore developed and validated primary standards to cover the flow rate range from 0.1 μl/min to at least 1 ml/min. In this article, we describe the different designs and methods of the primary standards of the gravimetric principle and the results obtained at the intercomparison for the upper flow rate range for the various NMIs and Bronkhorst High-Tech, the manufacturer of the transfer standards used.


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