A STATISTICAL ANALYSIS OF GRAIN COUNTING IN PHOTOGRAPHIC EMULSIONS

1952 ◽  
Vol 30 (6) ◽  
pp. 699-714 ◽  
Author(s):  
W. W. Happ ◽  
T. E. Hull ◽  
A. H. Morrish

Fluctuations in the grain density of tracks of charged particles passing through photographic emulsions are examined in terms of the physical properties of grains and the type of counting convention used. A mathematical model, for one counting convention which takes into account both the frequency distribution of the grains and the frequency distribution of their lengths, yields numerical results in good agreement with experimental data. Other statistical problems of interest in grain counting are discussed.

2002 ◽  
Vol 4 (1) ◽  
pp. 21-38 ◽  
Author(s):  
C. E. Kelly ◽  
R. D. Leek ◽  
H. M. Byrne ◽  
S. M. Cox ◽  
A. L. Harris ◽  
...  

In this paper a mathematical model that describes macrophage infiltration into avascular tumours is presented. The qualitative accuracy of the model is assessed by comparing numerical results with independent experimental data that describe the infiltration of macrophages into two types of spheroids: chemoattractant-producing (hepa-1) and chemoattractant-deficient (or C4) spheroids. A combination of analytical and numerical techniques are used to show how the infiltration pattern depends on the motility mechanisms involved (i.e. random motion and chemotaxis) and to explain the observed differences in macrophage infiltration into the hepa-1 and C4 spheroids. Model predictions are generated to show how the spheroid's size and spatial structure and the ability of its constituent cells influence macrophage infiltration. For example, chemoattractant-producing spheroids are shown to recruit larger numbers of macrophages than chemoattractant-deficient spheroids of the same size and spatial structure. The biological implications of these results are also discussed briefly.


Author(s):  
R. Caracciolo ◽  
A. Gasparetto ◽  
A. Trevisani

Abstract This paper presents an experimental validation of a finite element approach for the dynamic analysis of flexible multi-body planar mechanisms. The mathematical model employed accounts for mechanism geometric and inertial non-linearities and considers coupling effects among rigid-body and elastic motion. A flexible five-bar linkage actuated by two electric motors is employed as a test case. Experimentally determined link absolute deformations are compared with the numerical results obtained simulating the system dynamic behavior through the mathematical model. The experimental and numerical results are in good agreement especially after the very first transient period.


Author(s):  
Yuelei Yang ◽  
Dan Zhang

This paper introduces a mathematical model which can be used to simulate the capillary pumping process of a micro heat engine. The micro heat engine has micron sized channels where the capillary pumping occurs. The classic Volume of Fluids (VOF) method is applied to obtain the velocity profiles of the fluids and to track the motions of the liquid-gas interfaces. The numerical results based this model have been compared with the experimental data and the initial retard of the pumping has been found and this phenomenon can be explained by the initial capillary pressure build-ups across the liquid-gas interfaces.


2019 ◽  
Vol 34 (16) ◽  
pp. 1950120 ◽  
Author(s):  
Q. Ali ◽  
Y. Ali ◽  
M. Haseeb ◽  
M. Ajaz

Transverse momentum distributions and nuclear modification factor of integrated charged particles yield produced in p[Formula: see text]+[Formula: see text]Pb collisions at [Formula: see text] = 5.02 TeV are investigated in mid-rapidity regions of [Formula: see text] at one event multiplicity class 0–5% in the transverse momentum range of [Formula: see text]20 GeV/c. Simulations with EPOS-1.99, EPOS-LHC and QGSJETII-04 are compared with the ALICE data. All three models are in good agreement with each other up to [Formula: see text]3 GeV/c for transverse momentum distributions but after that QGSJETII-04 overpredicts the experimental data. EPOS-LHC seems to describe the experimental data quite well as compared to the other two models. The ratios of the kaons to pions and protons to pions are also presented where again EPOS-LHC provides good agreement with the ALICE data. In case of the nuclear modification factor, for (anti) pions and (anti) kaons, the model distribution is around 1, whereas it is greater than 1 in case of (anti) protons which shows Cronin enhancement.


1982 ◽  
Vol 24 (2) ◽  
pp. 103-111 ◽  
Author(s):  
S. L. Grassie ◽  
R. W. Gregory ◽  
K. L. Johnson

The dynamical response in the frequency range 50–1500 Hz is investigated of a railway wheelset resting on the track and excited vertically, laterally and longitudinally at a point of contact. A mathematical model of a railway wheelset is developed which comprises a few simple components to which analytical methods can be applied. Good agreement is obtained between experimental data and calculations made using this model. For a given sinusoidal displacement imposed between wheel and rail, the contact force is in general greatest longitudinally and least laterally.


2011 ◽  
Vol 172-174 ◽  
pp. 973-978 ◽  
Author(s):  
Pavel A. Korzhavyi ◽  
Inna Soroka ◽  
Mats Boman ◽  
Börje Johansson

We apply density functional perturbation theory together with experimental studies in order to investigate the structure and physical properties of possible stable and metastable copper(I) compounds with oxygen and hydrogen. Copper(I) hydride, CuH, is found to be a metastable phase which decomposes at ambient conditions and exhibiting a semiconducting gap in the electronic spectrum. The calculated structure and phonon spectra are found to be in good agreement with experimental data. The phonon spectra of a novel metastable phase, copper(I) hydroxide, are also determined.


1987 ◽  
Vol 109 (3) ◽  
pp. 197-202 ◽  
Author(s):  
M. Acar ◽  
R. K. Turton ◽  
G. R. Wray

The air-jet texturing process, a purely mechanical means of texturing continuous filament yarns, is described. Industrial texturing nozzles are reviewed and categorized in two groups, either as converging-diverging or cylindrical type nozzles. A mathematical model is developed for the complex airflow in cylindrical type texturing nozzles, and experimental data obtained from various nozzles verify the flow predicted by this model. The mathematical model is also shown to be in good agreement with the data obtained from a modified experimental nozzle, which has a trumpet shaped diverging exit. Further experimental work with a scaled-up model of a typical industrial texturing nozzle is also reported.


2014 ◽  
Vol 971-973 ◽  
pp. 811-815 ◽  
Author(s):  
Tian Fei Ma ◽  
Qian Chen

The pneumatic ABS pressure regulator of commercial vehicle is submitted to study in this paper. Its structure and operating principle are introduced, and a simulation model based on the AMESim is established on the basis of its mathematical model. Then the static characteristics and dynamic characteristics are researched by simulation model and the characteristic curves are compared with experimental data for the verification. The results show that simulation curves and experiment curves are in good agreement, which can be tolerated in the engineering.


2019 ◽  
Vol 81 (4) ◽  
pp. 488-499
Author(s):  
Wang Cheng ◽  
Yang Tonghui ◽  
Li Wan ◽  
Tao Li ◽  
M.H. Abuziarov ◽  
...  

The spatial problem of internal explosive loading of an elastoplastic cylindrical container filled with water in Eulerian - Lagrangian variables using multigrid algorithms is considered. A defining system of three-dimensional equations of the dynamics of gas, fluid, and elastoplastic medium is presented. For numerical modeling, a modification of S.K. Godunov scheme of the increased accuracy for both detonation products and liquids, and elastoplastic container is used. At the moving contact boundaries “detonation products - liquid”, “liquid - deformable body”, the exact solution of the Riemann's problem is used. A time dependent model is used to describe the propagation of steady-state detonation wave through an explosive from an initiation region. In both cases, the initiation of detonation occurs at the center of the charge. Two problems have been solved: the first task for the aisymmetric position of the charge, the second for the charge shifted relative to the axis of symmetry. In the first task, the processes are two-dimensional axisymmetric in nature, in the second task, the processes are essentially three-dimensional. A comparison is made of the results of calculations of the first problem using a three-dimensional method with a solution using a previously developed two-dimensional axisymmetric method and experimental data. Good agreement is observed between the numerical results for the maximum velocities and circumferential strains obtained by various methods and experimental data. There is good agreement between the numerical results obtained by various methods and the known experimental data. Comparison of the results of solving the first and second problems shows a significant effect of the position of the charge on the wave processes in the liquid, the processes of loading the container and its elastoplastic deformation. The dynamic behavior of a gas bubble with detonation products is analyzed. A significant deviation of the bubble shape from the spherical one, caused by the action of shock waves reflected from the structure, is shown. Comparison of the results of solving the first and second problems showed a significant effect of the charge position on wave processes in a liquid, the processes of loading a container and its elastoplastic deformation. In particular, in the second problem, shock waves of higher amplitude are observed in the liquid when reflected from the walls of the container.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1064 ◽  
Author(s):  
Christoph Mankel ◽  
Antonio Caggiano ◽  
Andreas König ◽  
Diego Said Schicchi ◽  
Mona Nazari Sam ◽  
...  

This paper reports a numerical approach for modelling the thermal behavior and heat accumulation/liberation of sustainable cementitious composites made with Recycled Brick Aggregates (RBAs) employed as carriers for Phase-Change Materials (PCMs). In the framework of the further development of the fixed grid modelling method, classically employed for solving the well-known Stefan problem, an enthalpy-based approach and an apparent calorific capacity method have been proposed and validated. More specifically, the results of an experimental program, following an advanced incorporation and immobilization technique, developed at the Institut für Werkstoffe im Bauwesen for investigating the thermal responses of various combinations of PCM-RBAs, have been considered as the benchmark to calibrate/validate the numerical results. Promising numerical results have been obtained, and temperature simulations showed good agreement with the experimental data of the analyzed mixtures.


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