Search results for "pressure [gas]"
showing 10 items of 99 documents
Stylolite interfaces and surrounding matrix material: Nature and role of heterogeneities in roughness and microstructural development
2010
Rough pressure solution interfaces, like stylolites, are one of the most evident features of localized slow deformation in rocks of the upper crust. There is a general consensus that the development of these rough structures is a result of localized, stress enhanced, dissolution of material along a fluid filled interface, but little is known on the initiation of this roughness. The aim of this article is to reveal the role of heterogeneities initially present in the host-rock on roughness initiation. This should give insights on whether stylolite roughness is generated by a stress-induced instability or by the presence of disorder in the material (i.e. quenched noise). We use a microstructu…
Enfisema subcutáneo durante tratamiento restaurador: caso clínico
2006
El enfisema subcutáneo es una complicación poco frecuente en la práctica odontológica, que ha ido en aumento debido al uso de instrumentos con aire a presión. Muchos de los casos no son reconocidos o presentan un diagnóstico errado. La mayor parte de los pacientes con esta complicación presentan resolución espontánea, sin embargo algunos pueden evolucionar con complicaciones que ponen en peligro la vida. Aquí presentamos un caso de enfisema subcutáneo ocurrido durante un procedimiento restaurador de rutina. El diagnóstico diferencial y el manejo de esta condición son discutidos. Subcutaneous emphysema is a relatively rare complication of dental treatment, although increasingly due to the us…
Thermobarometric constraints on pressure variations across the Plattengneiss shear zone of the Eastern Alps: implications for exhumation models durin…
2014
Forward and inverse mineral equilibria modelling of metapelitic rocks in the hangingwall and footwall of the Plattengneiss, a major shear zone in the Eastern Alps, is used to constrain their tectonometamorphic evolution and assess models for their exhumation. Forward (pseudosection) modelling of two metapelitic rocks suggests a steep clockwise P–T path with a near-isothermal decompression segment from a pressure peak at ~18–19 kbar and 670 °C to the metamorphic peak at 680–720 °C and 11–13 kbar. A subsequent decrease to 600–645 °C and 8–9 kbar is inferred from the late growth of staurolite in some samples. Conventional thermobarometric calculations (inverse modelling) on 18 samples with the…
PVA Hydrogel Electrolyte and Porous Polyisoprene Carbon Nanostructure Composite Based Pressure Sensitive Supercapacitor
2019
Special gratitude is in order to Raimonds Orlovs for temperature dependent resistance measurements. Financial support of project 1.1.1.1/16/A/013, “Hybrid energy harvesting systems” is greatly appreciated.
Assessment of particle suspension conditions in stirred vessels by means of pressure gauge technique
2002
In this work the quantitative assessment of the mass of suspended solid particles in stirred vessels is performed using the Pressure Gauge Technique. This is based on the measurements of the pressure increase on the tank bottom due to the presence of suspended solid particles at any agitation speed. The method has the advantages of not utilising visual observations and of easy and inexpensive application to both laboratory and industrial equipment. Very few data are available in literature and the experimental results collected using the present PGT technique and the correlations here proposed are of considerable academic and industrial interest.
Position paper - progress towards standards in integrated (aerobic) MBR modelling.
2020
Membrane bioreactor (MBR) models are useful tools for both design and management. The system complexity is high due to the involved number of processes which can be clustered in biological and physical ones. Literature studies are present and need to be harmonized in order to gain insights from the different studies and allow system optimization by applying a control. This position paper aims at defining the current state of the art of the main integrated MBR models reported in the literature. On the basis of a modelling review, a standardized terminology is proposed to facilitate the further development and comparison of integrated membrane fouling models for aerobic MBRs. ispartof: WATER …
A device to trigger automatically electrical stimulation at different states of in- or expiration on the background of variable lung inflation in the…
1975
A device is described which permits to obtain a signal at the beginning of in- or expiration respectively. This signal may be used to trigger an electrical stimulator. To permit studies at different states of lung inflation the tracheal cannula is connected to a spirometer circuit. To produce constant positive or negative air pressure this bellows-type spirometer is loaded with exchangeable metal weights. The tracheal pressure is recorded by means of a pressure transducer, the output of which is taken as signal. The device allows accurate compensation of the DC-component of the transducer output resulting from spirometer operation at a maintained positive or negative pressure.
Problems in Precise Measurement of Tidal Volumes
1998
Respiratory gas flows and volumes can conveniently be measured by pneumo-tachography.3 However, the pneumotachographic signal depends on gas temperature, humidity, and composition, and therefore the achievable precision of measurement is limited to about 5–10%2,8 — which is not sufficient for determining the human ventilation distribution with satisfactory accuracy.6,7,5 As a — potentially more accurate — alternative, a plethysmographic method may be used in which the tested subject breathes out of and into bags that are suspended in a large tank of constant volume (Figure 1). Volume V and pressure P in the system (consisting of tank, tubings, valves, and the subject) are related via Boyle-…
Fine adaptive control of precision grip without maximum pinch strength changes after median nerve mobilization
2020
ABSTRACTFine dexterity critically depends on information conveyed by the median nerve. While the effects of its compression and vibration are well characterized, little is known about longitudinal tension and excursion. Using a force-sensitive manipulandum, a numeric dynamometer and Semmes-Weinstein monofilaments, we examined the adaptations of precision grip control, maximum pinch strength and fingertips pressure sensation threshold before and immediately after the application of longitudinal tension and excursion mobilizations applied on the median nerve. Grip (GF) and load (LF) forces applied by the thumb, index and major fingers were collected in 40 healthy young participants during thr…
Measurements of pressure and frictional tractions along walls of a large-scale conical shallow hopper and comparison with Eurocode 1991-4:2006
2014
Abstract A silo׳s hopper supports the majority loads induced by the stored particulate solids. Such loads vary from filling to discharging provided the hopper is steep enough to secure a mass flow; when the hopper is too shallow to promote a mass flow, funnel flow usually prevails – where how loads develop along walls of a shallow hopper remains to be addressed. In the paper, normal pressure and frictional traction were measured with pressure transducers as imposed by testing material sand along the walls of a full-scale conical shallow hopper. The transducers were carefully mounted in the designated positions of hopper walls along a generator. To make the measurement results representative…