scholarly journals Diffusion and chemical reaction velocity as joint factors in determining the rate of uptake of oxygen and carbon monoxide by the red blood corpuscle

1932 ◽  
Vol 111 (769) ◽  
pp. 1-36 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Cross Sections ◽  
The Other ◽  
Blood Corpuscle ◽  
Reaction Velocity ◽  
Two Fluids ◽  
Mixing Chamber ◽  
Haemoglobin Solution ◽  
Moving Fluid

In a paper on this subject published four years age, Hartridge and Roughton (1927) described some preliminary experiments upon the rate of uptake of oxygen and carbon monoxide by the red blood corpuscle, the observations being made by means of their reaction velocity technique (Hartridge and Roughton, 1922–1927). The general principles of the method were as follows. Through one lead of the apparatus a suspension of reduced corpuscles in saline was forces into the mixing chamber, whilst through the other lead was forced a solution of oxygen (or carbon monoxide) in saline. The two fluids mixed in the mixing chamber within 0·001 second or less and then travelled down the observation tube. Determination of the percentage of oxyhæmoglobin (or carboxyhæmoglobin) in the moving fluid at various cross sections of the observation tube was made by means of the reversion spectroscope, these measurements, together with a knowledge of the rate of flow of the fluid down the observation tube, giving the necessary data for plotting the rate of uptake of O 2 or CO by the corpuscles against time. The most interesting feature of the results was the much slower uptake of O 2 by hæmoglobin in the intact corpuscle as compared with the of O 2 by hæmoglobin in laked solution as previously recorded by Hartridge and Roughton (1925). In the corpuscle experiments the time scale had to be expressed in hundredths of a second instead of in thousandths of a second as in the hæmoglobin solution experiments ( vide fig. 2 of Hartridge and Roghton, 1927). Confirmatory results by somewhat different technique have been obtained lately by Dirken and Mook (1931). These will be referred to again later.

The determination of cross-sections for the quenching of resonance radiation of metal atoms. IV. Results for lithium

1968 ◽  
Vol 306 (1486) ◽  
pp. 413-421 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Cross Section ◽  
Cross Sections ◽  
Hollow Cathode ◽  
Alkali Metals ◽  
Resonance Radiation ◽  
The Other ◽  
Fluorescence Technique ◽  
Metal Atoms

The flame fluorescence technique has been used to study the fluorescence of lithium in sets of isothermal hydrogen-oxygen flames diluted with each of the gases argon, nitrogen and carbon dioxide. The measurements have given the following values (Å 2 ) for the quenching cross-sections, σ 2 , of lithium in the 2 p 2 P state: σ 2 H 2 = 5⋅2, σ 2 H 2 O ═ 1⋅9, σ 2 N 2 ═ 6⋅75, σ 2 CO ═ 12⋅6, σ 2 CO 2 ═ 9⋅2, σ 2 Ar ≼ 0⋅3. The cross-section is defined as the square of the distance between centres of colliding species. These values are compared with those previously reported (Jenkins 1966, 1968) for the other alkali metals and their interpretation discussed. Details of the high intensity hollow cathode lamp used as a source of lithium resonance radiation are also given.

De Haas – van Alphen effect and Fermi surface of the intermetallic compound PtSn

1970 ◽  
Vol 48 (10) ◽  
pp. 1151-1160 ◽  
Author(s):  
W. N. Cathey ◽  
P. T. Coleridge ◽  
J.-P. Jan
Keyword(s):  
Intermetallic Compound ◽  
Fermi Surface ◽  
Cross Sections ◽  
Experimental Results ◽  
The Other ◽  
Platinum Atom ◽  
Spin Splitting ◽  
Approximate Determination ◽  
Formula Unit

Extremal cross sections of the Fermi surface of the intermetallic compound PtSn (NiAs structure) have been determined by means of the de Haas – van Alphen effect. The Fermi surface proposed here is similar to that found in isostructural AuSn by Edwards et al. Several of the frequencies have been inverted to yield the profile of the corresponding sheets of the Fermi surface. An approximate determination of the dimensions of the other sheets shows that the observed Fermi surface encloses 4.60 ± 0.27 electrons per formula unit; this suggests that one or several sheets of the Fermi surface containing 0.6 d-band holes per platinum atom have remained undetected. Some cyclotron masses have been measured and to explain all the features of the experimental results, it is necessary to invoke spin splitting with a g factor different from 2, and to postulate magnetic breakdown.

Application of methods for analysing combinations of wheelset sizes and switch elements to determine the size of gutters of check-rail assemblies

2021 ◽  
pp. 3-9
Author(s):  
B. E. Glyuzberg ◽  
◽  
A. A. Loktev ◽  
V. V. Korolev ◽  
V. S. Kuskov ◽  
...  
Keyword(s):  
Cross Sections ◽  
Accurate Method ◽  
The Other ◽  
Conditional Probabilities ◽  
Rail Wear ◽  
Method Of Determination ◽  
Train Operation ◽  
Motion Paths ◽  
The One

The paper considers methods for analysis of size combinations of wheelsets and elements of switches that are used at determination of dimensions of gutters for check-rail assemblies. The method of limit combinations, from the one side, doesn’t guarantee a reliable train operation on crossing assemblies in real operation, but, from the other side, it makes unreasonably strict demands to the design of the assembly. In order to eliminate the contradictions the paper proposes to use a method of probable compositions that allows not only solving an issue of limited safe dimensions of gauge and gutters, but also determining repeatability of impacts on check-rails in the most loaded cross sections and repeatability of motion paths of wheels on crossing. However, while using this method the authors have revealed a number of contradictions between calculated results and real operation. They show that it is possible to avoid the contradictions by the use of conditional probabilities method that allows calculating probabilities of phenomena for specific size combinations of gauge and gutters. As a result, the authors have concluded that it is the most accurate method of determination of permissible dimensions for gauge and gutters on switches. With the use of the method the authors have determined the maximal values of check-rail wear for straight track made of SP special profiles in conditions of nonexceedance of «impact effect» in bent part of the check-rail for switches with various angles.

scholarly journals Determination of an Injection Sprayer's Technological Parameters

2018 ◽  
Vol 12 (5) ◽  
pp. 31-38
Author(s):  
L. A. Marchenko ◽  
M. A. Safonov
Keyword(s):  
Cross Sections ◽  
Pressure Difference ◽  
Design Parameters ◽  
Flow Section ◽  
Relative Pressure ◽  
Technological Parameters ◽  
Mixing Chamber ◽  
Injection Coefficient ◽  
Injection Ratio

Agricultural boom sprayers are equipped with injection sprayers of mainly foreign origin. The main parameters of the injection sprayers shown in the catalogs display the consumption characteristics in cer­tain ranges without taking into account the design parameters.(Research purpose)Determination of the design and technological parameters of an injection sprayer for the introduction of pesticides.(Materials and methods)The injection sprayer belongs to the class of two­phase liquid­gas isothermal jet devices with the formation of an air­gas mixture at the outlet. It has been established that the design model of the working process of an injection sprayer is based both on the laws of the conservation of mass, energy, momentum, as well as theoretical relation­ships in the form of equations describing two­phase jet devices, and empirical relationships characterizing flow parameters, geometric transverse and longitudinal dimensions of the spray channels.(Results and discussion)The following analytical relationships have been obtained: the relative pressure difference generated by an injec­tion sprayer and the volume injection coefficient for different surface area ratios of the working nozzle to the flow section of the sprayer; the ratio between the cross­sectional area of the mixing chamber to the area of the working nozzle outlet and the injection ratio; relative pressure difference and the injection ratio; the ratio be­tween the cross­sectional area of the mixing chamber and the working nozzle and the relative pressure difference. The authors have determined a set of dimensionless pressure characteristics of the injection sprayer for different ratios between the cross­sectional areas of the working nozzle and the mixing chamber. It has been established that the ratio between the cross sections of the mixing chamber area and the working nozzle area increases as the injection ratio increases. It has been shown that for each injection coefficient, there is an achievable relative pressure difference in the injection sprayer.(Conclusions)The authors have proposed the design equations that determine the characteristics of an injection sprayer and its main design parameters – the diameters of nozzle and mixing chambers. They have calculated the main dimensions of the sprayer for aerial top­dressing by introducing working solutions of pesticides.

The determination of cross-sections for the quenching of resonance radiation of metal atoms. V. Results for lead

1969 ◽  
Vol 313 (1515) ◽  
pp. 551-564 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Cross Sections ◽  
Intensity Distribution ◽  
Equilibrium Distribution ◽  
Metal Atoms ◽  
The Cross ◽  
Equilibrium Effect ◽  
Non Equilibrium

The flame fluorescence method has been used to determine the cross-sections for the collisional de-excitation of lead atoms from the first resonance level (6p7s 3 P 0 1 ) by hydrogen, oxygen, water, nitrogen, carbon dioxide, carbon monoxide, argon and helium. The values obtained for the cross-sections—the square of the collision diameter—are (in 10 -16 cm 2 units) σ 2 H 2 = 0.4 ± 0.1, σ 2 O 2 , = 15 ± 3, σ 2 N 2 = 5.7 ± 0.5, σ 2 H 2 O = 8 ± 2, σ 2 CO = 13 ± 3, σ 2 CO 2 = 29 ± 5, σ 2 Ar ≈ 0 ( < 1.6), σ 2 He ≈ 0 (< 0.6). The interpretation of these overall quenching cross-sections in terms of the various possible quenching processes is discussed. For some flames the fluorescence has been resolved into the component wavelengths— 405.8, 368.3, and 364.0 nm—and found to have a non-equilibrium distribution of intensities. An additional non-equilibrium effect on the intensity distribution which is attributable to chemi-excitation of lead atoms in the flames is described and discussed. The apparatus previously used is modified; the high intensity hollow cathode lead lamp used is described.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

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