scholarly journals FOSSIL. I. The Spin Rate Limit of Jupiter Trojans

2021 ◽  
Vol 2 (5) ◽  
pp. 191
Author(s):  
Chan-Kao Chang ◽  
Ying-Tung Chen ◽  
Wesley C. Fraser ◽  
Fumi Yoshida ◽  
Matthew J. Lehner ◽  
...  
Keyword(s):  
Rate Limit

scholarly journals Effect of Mechanical Ventilation on Accidental Hydrogen Releases—Large-Scale Experiments

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3008
Author(s):  
Agnieszka W. Lach ◽  
André V. Gaathaug
Keyword(s):  
Mechanical Ventilation ◽  
Mass Flow ◽  
Large Scale ◽  
Ventilation System ◽  
Hydrogen Gas ◽  
Forced Ventilation ◽  
British Standard ◽  
Confined Spaces ◽  
Series Of Experiments ◽  
Rate Limit

This paper presents a series of experiments on the effectiveness of existing mechanical ventilation systems during accidental hydrogen releases in confined spaces, such as underground garages. The purpose was to find the mass flow rate limit, hence the TPRD diameter limit, that will not require a change in the ventilation system. The experiments were performed in a 40 ft ISO container in Norway, and hydrogen gas was used in all experiments. The forced ventilation system was installed with a standard 315 mm diameter outlet. The ventilation parameters during the investigation were British Standard with 10 ACH and British Standard with 6 ACH. The hydrogen releases were obtained through 0.5 mm and 1 mm nozzles from different hydrogen reservoir pressures. Both types of mass flow, constant and blowdown, were included in the experimental matrix. The analysis of the hydrogen concentration of the created hydrogen cloud in the container shows the influence of the forced ventilation on hydrogen releases, together with TPRD diameter and reservoir pressure. The generated experimental data will be used to validate a CFD model in the next step.

How to use body tilt for the simulation of linear self motion

2004 ◽  
Vol 14 (5) ◽  
pp. 375-385 ◽  
Author(s):  
E.L. Groen ◽  
W. Bles
Keyword(s):  
Visual Motion ◽  
Detection Threshold ◽  
Stimulus Frequency ◽  
Flight Simulation ◽  
Body Tilt ◽  
Whole Body ◽  
Motion Percept ◽  
Self Motion ◽  
Rate Limit ◽  
Pitch Tilt

We examined to what extent body tilt may augment the perception of visually simulated linear self acceleration. Fourteen subjects judged visual motion profiles of fore-aft motion at four different frequencies between 0.04âĂŞ0.33 Hz, and at three different acceleration amplitudes (0.44, 0.88 and 1.76 m / s 2 ). Simultaneously, subjects were tilted backward and forward about their pitch axis. The amplitude of pitch tilt was systematically varied. Using a two-alternative-forced-choice paradigm, psychometric curves were calculated in order to determine: 1) the minimum tilt amplitude required to generate a linear self-motion percept in more than 50% of the cases, and 2) the maximum tilt amplitude at which rotation remains sub-threshold in more than 50% of the cases. The results showed that the simulation of linear self motion became more realistic with the application of whole body tilt, as long as the tilt rate remained under the detection threshold of about 3 deg/s. This value is in close agreement with the empirical rate limit commonly used in flight simulation. The minimum required motion cue was inversely proportional to stimulus frequency, and increased with the amplitude of the visual displacement (rather than acceleration). As a consequence, the range of useful tilt stimuli became more critical with increasing stimulus frequency. We conclude that this psychophysical approach reveals valid parameters for motion driving algorithms used in motion base simulators.

Drying-Rate Limit in Condenser Drying of Thin Film Coatings

2006 ◽  
Vol 39 (8) ◽  
pp. 814-817 ◽  
Author(s):  
Masato Yamamura ◽  
Takayuki Inoue ◽  
Yoshihide Mawatari ◽  
Hiroyuki Kage
Keyword(s):  
Thin Film ◽  
Drying Rate ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Rate Limit

scholarly journals Distinct Mg2+-dependent Steps Rate Limit Opening and Closing of a Single CFTR Cl− Channel

2002 ◽  
Vol 119 (6) ◽  
pp. 545-559 ◽  
Author(s):  
Athanasios G. Dousmanis ◽  
Angus C. Nairn ◽  
David C. Gadsby
Keyword(s):  
Open Channel ◽  
Tight Binding ◽  
Single Channels ◽  
Channel Opening ◽  
Subsequent Exposure ◽  
Cl Channels ◽  
Excised Patches ◽  
Atp Binding And Hydrolysis ◽  
Opening And Closing ◽  
Rate Limit

The roles played by ATP binding and hydrolysis in the complex mechanisms that open and close cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channels remain controversial. In this work, the contributions made by ATP and Mg2+ ions to the gating of phosphorylated cardiac CFTR channels were evaluated separately by measuring the rates of opening and closing of single channels in excised patches exposed to solutions in which [ATP] and [Mg2+] were varied independently. Channel opening was found to be rate-limited not by the binding of ATP alone, but by a Mg2+-dependent step that followed binding of both ATP and Mg2+. Once a channel had opened, sudden withdrawal of all Mg2+ and ATP could prevent it from closing for tens of seconds. But subsequent exposure of such an open channel to Mg2+ ions alone could close it, and the closing rate increased with [Mg2+] over the micromolar range (half maximal at ∼50 μM [Mg2+]). A simple interpretation is that channel closing is stoichiometrically coupled to hydrolysis of an ATP molecule that remains tightly associated with the open CFTR channel despite continuous washing. If correct, that ATP molecule appears able to reside for over a minute in the catalytic site that controls channel closing, implying that the site must entrap, or have an intrinsically high apparent affinity for, ATP, even without a Mg2+ ion. Such stabilization of the open-channel conformation of CFTR by tight binding, or occlusion, of an ATP molecule echoes the stabilization of the active conformation of a G protein by GTP.

scholarly journals Endothelial cells act as gatekeepers for LTβR-dependent thymocyte emigration

2018 ◽  
Vol 215 (12) ◽  
pp. 2984-2993 ◽  
Author(s):  
Kieran D. James ◽  
Emilie J. Cosway ◽  
Beth Lucas ◽  
Andrea J. White ◽  
Sonia M. Parnell ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Gene Targeting ◽  
Developmental Stages ◽  
Perivascular Space ◽  
Specific Gene ◽  
Thymic Epithelium ◽  
Cell Compartments ◽  
Rate Limit ◽  
Test Current ◽  
Limit Access

The emigration of mature thymocytes from the thymus is critical for establishing peripheral T cell compartments. However, the pathways controlling this process and the timing of egress in relation to postselection developmental stages are poorly defined. Here, we reexamine thymocyte egress and test current and opposing models in relation to the requirement for LTβR, a regulator of thymic microenvironments and thymocyte emigration. Using cell-specific gene targeting, we show that the requirement for LTβR in thymocyte egress is distinct from its control of thymic epithelium and instead maps to expression by endothelial cells. By separating emigration into sequential phases of perivascular space (PVS) entry and transendothelial migration, we reveal a developmentally ordered program of egress where LTβR operates to rate limit access to the PVS. Collectively, we show the process of thymic emigration ensures only the most mature thymocytes leave the thymus and demonstrate a role for LTβR in the initiation of thymus emigration that segregates from its control of medulla organization.

scholarly journals Determination of Mercury, Methylmercury and Selenium Concentrations in Elasmobranch Meat: Fish Consumption Safety

2022 ◽  
Vol 19 (2) ◽  
pp. 788
Author(s):  
Arianna Storelli ◽  
Grazia Barone ◽  
Rita Garofalo ◽  
Antonio Busco ◽  
Maria Maddalena Storelli
Keyword(s):  
Total Mercury ◽  
Health Benefit ◽  
Absorption Spectrometry ◽  
Human Consumption ◽  
Apex Predators ◽  
Safety Level ◽  
Italian Market ◽  
Elasmobranch Fish ◽  
Rate Limit

This study measures total mercury (THg), methylmercury (MeHg) and selenium (Se) concentrations in elasmobranch fish from an Italian market with the aim of evaluating the risk-benefit associated with their consumption, using estimated weekly intake (EWI), permissible safety level (MeHgPSL), selenium health benefit value (HBVSe) and monthly consumption rate limit (CRmm) for each species. THg and Se were analysed by atomic absorption spectrometry, while MeHg was determined by HrGc/Ms. THg and MeHg concentrations ranged from 0.61 to 1.25 μg g−1 w.w. and from 0.57 to 0.97 μg g−1 w.w., respectively, whereas Se levels were 0.49–0.65 μg g−1 w.w. In most samples European Community limits for THg were surpassed, while for MeHg none of the fish had levels above the limit adopted by FAO/WHO. EWIs for THg and MeHg in many cases were above the provisional tolerable weekly intakes (PTWIs). MeHgPSL estimate showed that fish should contain approximately 50% of the concentration measured to avoid exceeding the PTWI. Nevertheless, the HBVSe index indicated that solely skates were safe for human consumption (HBVSe = 3.57–6.22). Our results highlight the importance of a constant monitoring of THg and MeHg level in fish, especially in apex predators, to avoid the risk of overexposure for consumers.

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