scholarly journals Experimental data on the mechanism of direct lesion of the medulla oblongata in acute diffuse peritonitis

1929 ◽  
Vol 25 (7-8) ◽  
pp. 776-786
Author(s):  
P. V. Manenkov
Keyword(s):  
Experimental Data ◽  
Medulla Oblongata ◽  
Diffuse Peritonitis ◽  
Long Time ◽  
Respiratory Centers

The question of the cause of the extremely severe course and death in acute diffuse peritonitis remained unresolved for a long time. The work of Heineke establishes that this reason lies in the paralysis of the vasomotor and respiratory centers of the medulla oblongata. However, this could not exhaust this issue.

scholarly journals Experimental data on the mechanism of direct lesion of the medulla oblongata in diffuse peritonitis

1929 ◽  
Vol 25 (1) ◽  
pp. 49-57
Author(s):  
P. V. Manenkov
Keyword(s):  
Experimental Data ◽  
Central Nervous System ◽  
Nervous System ◽  
Medulla Oblongata ◽  
Nerve Cells ◽  
Diffuse Peritonitis ◽  
Main Role ◽  
The Central Nervous System ◽  
Harmful Substances ◽  
Lymphatic Pathways

Research A.D.Speransky and his collaborators established that in the origin of some of the so-called. "Local" processes the main role is played by the direct nested damage to the nerve cells of the central nervous system by those harmful substances that are delivered here from the periphery through the neuro-lymphatic pathways.

Interaction of Point Defects in Ice

1978 ◽  
Vol 21 (85) ◽  
pp. 115-122
Author(s):  
J. H. Bilgram ◽  
H. Gränicher
Keyword(s):  
Experimental Data ◽  
Dielectric Properties ◽  
Temperature Dependence ◽  
Point Defects ◽  
Low Frequency ◽  
Defect Concentration ◽  
Dielectric Measurements ◽  
Long Time ◽  
Nmr Techniques ◽  
Bjerrum Defect

AbstractThe interaction of point detects in ice has been neglected for a long time. Experimental data obtained from dielectric measurements on HF-doped crystals stimulated a new evaluation of the possibility of an interaction between Bjerrum defects and ions. In a previous paper it has been shown that this leads us to assume the existence of aggregates of Bjerrum defects and ions. In this paper these aggregates and Bjerrum defects are used to explain the dielectric properties of ice, especially the temperature dependence of the product of the high and low frequency conductivity σ0σ∞.The interaction of Bjerrum defects and impurity molecules leads to a dependence of the concentration of frenkel pairs on Bjerrum-defect concentration. At HF concentrations above the native Bjerrum-defect concentration the formation of a Frenkel pair is enhanced. This leads to the fast out-diffusion which has been studied in highly doped crystals by means of NMR techniques.

scholarly journals Ut vis sic tensio

2018 ◽  
Vol 45 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Giuseppe Saccomandi
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Elastic Strain ◽  
Strain Energy ◽  
Nonlinear Response ◽  
Solid Mechanics ◽  
Functional Form ◽  
Elastic Strain Energy ◽  
Strongly Nonlinear ◽  
Long Time

The mechanical properties of rubber-like materials have been offering an outstanding challenge to the solid mechanics community for a long time. The behaviour of such materials is quite difficult to predict because rubber self-organizes into mesoscopic physical structures that play a prominent role in determining their complex, history-dependent and strongly nonlinear response. In this framework one of the main problems is to find a functional form of the elastic strain-energy that best describes the experimental data in a mathematical feasible way. The aim of this paper is to give a survey of recent advances aimed at solving such a problem.

Parallel Multi-Cycle LES of an Optical Pent-Roof DISI Engine Under Motored Operating Conditions

2017 ◽  
Author(s):  
Noah Van Dam ◽  
Wei Zeng ◽  
Magnus Sjöberg ◽  
Sibendu Som
Keyword(s):  
Experimental Data ◽  
Direct Injection ◽  
Operating Conditions ◽  
New Strategy ◽  
Long Time ◽  
Order Of Magnitude ◽  
Structure Index ◽  
Number Of Cycles ◽  
The Many ◽  
Direct Injection Spark Ignition

The use of Large-eddy Simulations (LES) has increased due to their ability to resolve the turbulent fluctuations of engine flows and capture the resulting cycle-to-cycle variability. One drawback of LES, however, is the requirement to run multiple engine cycles to obtain the necessary cycle statistics for full validation. The standard method to obtain the cycles by running a single simulation through many engine cycles sequentially can take a long time to complete. Recently, a new strategy has been proposed by our research group to reduce the amount of time necessary to simulate the many engine cycles by running individual engine cycle simulations in parallel. With modern large computing systems this has the potential to reduce the amount of time necessary for a full set of simulated engine cycles to finish by up to an order of magnitude. In this paper, the Parallel Perturbation Methodology (PPM) is used to simulate up to 35 engine cycles of an optically accessible, pent-roof Direct-injection Spark-ignition (DISI) engine at two different motored engine operating conditions, one throttled and one un-throttled. Comparisons are made against corresponding sequential-cycle simulations to verify the similarity of results using either methodology. Mean results from the PPM approach are very similar to sequential-cycle results with less than 0.5% difference in pressure and a magnitude structure index (MSI) of 0.95. Differences in cycle-to-cycle variability (CCV) predictions are larger, but close to the statistical uncertainty in the measurement for the number of cycles simulated. PPM LES results were also compared against experimental data. Mean quantities such as pressure or mean velocities were typically matched to within 5–10%. Pressure CCVs were under-predicted, mostly due to the lack of any perturbations in the pressure boundary conditions between cycles. Velocity CCVs for the simulations had the same average magnitude as experiments, but the experimental data showed greater spatial variation in the root-mean-square (RMS). Conversely, circular standard deviation results showed greater repeatability of the flow directionality and swirl vortex positioning than the simulations.

Commutation Loss in Hydrostatic Pumps and Motors

2021 ◽  
Author(s):  
Robin Mommers ◽  
Peter Achten ◽  
Jasper Achten ◽  
Jeroen Potma
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Simulation Model ◽  
Operating Conditions ◽  
Chamber Pressure ◽  
Working Mechanism ◽  
Working Chamber ◽  
Lumped Parameter ◽  
Long Time ◽  
Pressure Changes

Abstract In mobile hydraulic applications, more efficient machinery generally translates to smaller batteries or less diesel consumption, and smaller cooling solutions. A key part of such systems are hydrostatic pumps and motors. While these devices have been around for a long time, some of the causes of energy loss in pump and motors are still not properly defined. This paper focuses on one of the causes of energy loss in pumps and motors, by identifying the energy loss as a result of the process of commutation. By nature, all hydrostatic pumps and motors have some form of commutation: the transition from the supply port to the discharge port of the machine (and vice versa). During commutation, the connection between the working chamber and the ports is temporarily closed. The chamber pressure changes by compression or decompression that is the result of the rotation of the working mechanism. Ideally, the connection to one of the ports is opened once the chamber pressure equals the port pressure. When the connection is opened too early or too late, energy is lost. This paper describes a method to predict the commutation loss using a lumped parameter simulation model. To verify these predictions, experimental data of a floating cup pump was compared to the calculated values, which show a decent match. Furthermore, the results show that, depending on the operating conditions, up to 50% of all losses in this pump are caused by improper commutation.

scholarly journals Using An Exponential Equation to Describe Adsorption/Desorption Processes of Water on Composite Soil at Constant Pressure

2003 ◽  
Vol 21 (4) ◽  
pp. 383-388
Author(s):  
Lianxi Ma ◽  
James C. Holste ◽  
Kenneth R. Hall
Keyword(s):  
Experimental Data ◽  
Water Vapour ◽  
Constant Pressure ◽  
Exponential Equation ◽  
Desorption Process ◽  
Experimental Time ◽  
Long Time ◽  
Experimental Values ◽  
Adsorption Desorption

Using the assumption that adsorption as a function of time may be expressed by an exponential equation, viz. ΔM = g + he−t/τ, it is possible to obtain the amount of water vapour adsorbed by a composite soil without waiting for equilibrium, which usually takes a long time. Given the experimental data for the amounts adsorbed versus time, one can determine g, h and τ, together with the amounts adsorbed at equilibrium by extrapolating the above equation to t → ∞. It is also possible to calculate the error trends in these parameters as a function of time by comparing the values at time t with those obtained for the longest experimental time. The error trends of the equation with time arise from the comparison of the experimental values with those predicted by the exponential equation. We have discovered that although different lengths of time are necessary for different pressures, generally a time between 1.5τ and 2τ is sufficient to obtain reliable results with errors less than 5%. We have also found that this equation describes the desorption process as well.

scholarly journals Delayed luminescence of seeds: are shining seeds viable?

2020 ◽  
Vol 48 (2) ◽  
pp. 167-177
Author(s):  
Kehinde Adeboye ◽  
Andreas Börner
Keyword(s):  
Experimental Data ◽  
Developmental Biology ◽  
Biological Materials ◽  
Physiological Status ◽  
Delayed Luminescence ◽  
Seed Testing ◽  
Analytical Studies ◽  
Genebank Management ◽  
Long Time ◽  
History Of

Delayed luminescence (DL) has been widely studied for its applications in developmental biology and describes a phenomenon whereby biological materials radiate for a relatively long time (seconds and more) after illumination. Researchers have postulated that DL is potentially useful for determining the physiological status of biological materials, including crop seeds. Until recently this claim only remained within academia and there have been no known reports for the advancement of its use in seed testing and genebank management. This article examines the gaps in knowledge for adopting DL for seed testing by reviewing the history of DL applications in analytical studies of crop seeds and the incompletely understood mechanisms within seeds for displaying DL. We identified a need for more experimental data to validate the DL mechanisms in seeds before the procedure can be used for seed testing.

scholarly journals Numerical prediction of steady state temperature based on transient measurements

2018 ◽  
Vol 240 ◽  
pp. 05024
Author(s):  
Ewa Pelińska-Olko ◽  
Marek Lewkowicz
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Heat Exchange ◽  
Time Range ◽  
Radiative Heat Exchange ◽  
Steady State Temperature ◽  
Long Time ◽  
Experimental Values ◽  
Short Time ◽  
Transient Measurements

We show how to use numerical analysis of short-time range experimental data for predicting the limit steady-state value of the investigated parameter. In this article the approach has been applied to a specific, although typical, thermal problem: determining the average steady-state temperature of a heater in the convective and radiative heat exchange with the environment. First, we describe a heat exchange experiment aimed at obtaining temperature experimental data in both short and long time range. Then we present a methodology for applying two methods, i.e., neural networks and least squares approximations, for obtaining predictions about the steady-state temperature values based on short time experimental data. The aim of the study is to compare the predictions to each other and to the long time experimental values, with the aim of determining the applicability range of the two methods.

Thermal Conductivity Equations Based on Brownian Motion in Suspensions of Nanoparticles (Nanofluids)

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Bao Yang
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Brownian Motion ◽  
Relaxation Time ◽  
Kinetic Theory ◽  
Significant Role ◽  
Particle Velocity ◽  
Long Time ◽  
Theoretical Results ◽  
Enhanced Thermal Conductivity

Thermal conductivity equations for the suspension of nanoparticles (nanofluids) have been derived from the kinetic theory of particles under relaxation time approximations. These equations, which take into account the microconvection caused by the particle Brownian motion, can be used to evaluate the contribution of particle Brownian motion to thermal transport in nanofluids. The relaxation time of the particle Brownian motion is found to be significantly affected by the long-time tail in Brownian motion, which indicates a surprising persistence of particle velocity. The long-time tail in Brownian motion could play a significant role in the enhanced thermal conductivity in nanofluids, as suggested by the comparison between the theoretical results and the experimental data for the Al2O3-in-water nanofluids.

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