A THERMISTOR HYPSOMETER

1959 ◽  
Vol 37 (12) ◽  
pp. 1331-1338
Author(s):  
W. R. Blackmore
Keyword(s):  
Pressure Measurement ◽  
Pressure Fluctuations ◽  
Gas Pressure ◽  
Measuring Device ◽  
Boiling Liquid ◽  
Short Period ◽  
Pressure Measuring Device

A thermistor hypsometer used as a sensitive, recording, gas-pressure measuring device is described. It is shown that the limitation on this device is the noise introduced by the pressure fluctuations over the surface of the boiling liquid. These fluctuations are about ±(5–10) μ(microns) Hg peak-to-peak. When a pressure measurement is averaged over a moderately short period of time it may be estimated to ± 1 μHg.

scholarly journals Nano silica diaphragm in-fiber cavity for gas pressure measurement

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Shen Liu ◽  
Yiping Wang ◽  
Changrui Liao ◽  
Ying Wang ◽  
Jun He ◽  
...  
Keyword(s):  
Pressure Measurement ◽  
Gas Pressure ◽  
Nano Silica

Low Cost Foot Pressure Measuring Device

2021 ◽  
Author(s):  
Titus E. Crisan ◽  
Madalin I. Ardelean ◽  
Bogdan Tebrean ◽  
Tudor Oltean
Keyword(s):  
Low Cost ◽  
Foot Pressure ◽  
Measuring Device ◽  
Pressure Measuring Device

Toward Controllable Infill Completions Using Frac-Driven Interactions FDI Data

2021 ◽  
Author(s):  
Yuzhe Cai ◽  
Arash Dahi Taleghani
Keyword(s):  
Pressure Fluctuations ◽  
Pressure Response ◽  
Sudden Increase ◽  
Short Period ◽  
Coupled Geomechanics ◽  
Multi Phase ◽  
Shale Oil Reservoirs ◽  
Pressure Changes ◽  
Observation Wells ◽  
Bottomhole Pressure

Abstract Infill completions have been explored by many operators in the last few years as a strategy to increase ultimate recovery from unconventional shale oil reservoirs. The stimulation of infill wells often causes pressure increases, known as fracture-driven interactions (FDIs), in nearby wells. Studies have generally focused on the propagation of fractures from infill wells and pressure changes in treatment wells rather than observation wells. Meanwhile, studies regarding the pressure response in the observation (parent) wells are mainly limited to field observations and conjecture. In this study, we provide a partialcorrective to this gap in the research.We model the pressure fluctuations in parent wells induced by fracking infill wells and provide insight into how field operators can use the pressure data from nearby wells to identify different forms of FDI, including fracture hit (frac-hit) and fracture shadowing. First,we model the trajectory of a fracture propagating from an infill well using the extended finite element methods (XFEM). This method allows us to incorporatethe possible intersection of fractures independent of the mesh gridding. Subsequently, we calculate the pressure response from the frac-hit and stress shadowing using a coupled geomechanics and multi-phase fluid flow model. Through numerical examples, we assess different scenarios that might arise because of the interactions between new fractures and old depleted fractures based on the corresponding pressure behavior in the parent wells. Typically, a large increase in bottomhole pressure over a short period is interpreted as a potential indication of a fracture hit. However, we show that a slower increase in bottomhole pressure may also imply a fracture hit, especially if gas repressurization was performed before the infill well was fracked. Ultimately, we find that well storage may buffer the sudden increase in pressure due to the frac-hit. We conclude by summarizing the different FDIs through their pressure footprints.

scholarly journals Dynamic Mechanical Fatigue Behavior of Polymer Electrolyte Membranes for Fuel Cell Electric Vehicles Using a Gas Pressure-Loaded Blister

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4177
Author(s):  
Jun Hyun Lim ◽  
Jian Hou ◽  
Chang Hyun Lee
Keyword(s):  
Proton Conductivity ◽  
Hydrogen Gas ◽  
Gas Pressure ◽  
Operating Conditions ◽  
Mechanical Resistance ◽  
Dynamic Mechanical ◽  
Mechanical Fatigue ◽  
Aging Test ◽  
Short Period ◽  
Mechanical Aging

This study reports on an innovative press-loaded blister hybrid system equipped with gas-chromatography (PBS-GC) that is designed to evaluate the mechanical fatigue of two representative types of commercial Nafion membranes under relevant PEMFC operating conditions (e.g., simultaneously controlling temperature and humidity). The influences of various applied pressures (50 kPa, 100 kPa, etc.) and blistering gas types (hydrogen, oxygen, etc.) on the mechanical resistance loss are systematically investigated. The results evidently indicate that hydrogen gas is a more effective blistering gas for inducing dynamic mechanical losses of PEM. The changes in proton conductivity are also measured before and after hydrogen gas pressure-loaded blistering. After performing the mechanical aging test, a decrease in proton conductivity was confirmed, which was also interpreted using small angle X-ray scattering (SAXS) analysis. Finally, an accelerated dynamic mechanical aging test is performed using the homemade PBS-GC system, where the hydrogen permeability rate increases significantly when the membrane is pressure-loaded blistering for 10 min, suggesting notable mechanical fatigue of the PEM. In summary, this PBS-GC system developed in-house clearly demonstrates its capability of screening and characterizing various membrane candidates in a relatively short period of time (<1.5 h at 50 kPa versus 200 h).

Gas-pressure measurement for preparing ICF cryotargets

2012 ◽  
Vol 24 (10) ◽  
pp. 2343-2346
Author(s):  
林伟 Lin Wei ◽  
王凯 Wang Kai ◽  
毕鹏 Bi Peng ◽  
黎军 Li Jun ◽  
马坤全 Ma Kunquan ◽  
...  
Keyword(s):  
Pressure Measurement ◽  
Gas Pressure

Variable Lower Limb Alignment of Clinical Measures With Digital Photographs and the Footscan Pressure System

2020 ◽  
pp. 1-8
Author(s):  
Figen Govsa ◽  
Gkionoul Nteli Chatzioglou ◽  
Simin Hepguler ◽  
Yelda Pinar ◽  
Ozden Bedre
Keyword(s):  
Lower Limb ◽  
Plantar Pressure ◽  
Subtalar Joint ◽  
Positive Contribution ◽  
Digital Photogrammetry ◽  
Limb Alignment ◽  
Lower Limb Alignment ◽  
Measuring Device ◽  
Joint Flexibility ◽  
Pressure Measuring Device

Objective: This study examines the effect of the lower limb misalignment and its possible compensatory effect on plantar pressure in a normal population. The aim of this paper is to present a structured method for the analysis of posture and its changes using a standardized digital photography technique and plantar pressure measuring device. Design: Cohort. Setting: Laboratory. Participants: A total of 200 adult volunteers between 18 and 22 years of age who had no current symptoms of pain and foot or ankle pathology participated in the study. Main Outcome Measures: The gold standard measure of lower limb alignment with weight-bearing status is the mechanical axis and their angles using Image J software. Structural and functional measurements of the same foot were taken using a plantar pressure measuring device. In this study, 5 alignment (thigh, knee, leg, ankle, and foot) characteristics were measured on the lower limb using the 2 techniques, and, additionally, the foot contact area, peak pressure, foot axis, rearfoot angle, and subtalar joint flexibility score were analyzed in 10 different regions of the foot. Results: This study has shown a reasonable correlation between digitalized measurements and plantar pressures values. Quadriceps angle affected midfoot impulse, foot axis angle, subtalar joint minimum angle, and rearfoot angle positively. Subtalar joint flexibility scores were analyzed in 10 different regions of the foot. There was a positive correlation between rearfoot angle and quadriceps angle (P = .009, r = .261). Results of both methods show that they endorse each other. Conclusions: The posture of the standing feet may have influence on lower limb alignment. Currently, there are no studies carried out by using digital photogrammetry and foot scan. The authors claim that patient-friendly digital photogrammetry would have a positive contribution to the monitoring of patients, even including new ones in the treatment programs, reducing any possible loss in the personal and national economy.

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