Miscellaneous Experiments Research Articles

PACTEL and PWR PACTEL Test Facilities for Versatile LWR Applications

This paper describes construction and experimental research activities with two test facilities, PACTEL and PWR PACTEL. The PACTEL facility, comprising of reactor pressure vessel parts, three loops with horizontal steam generators, a pressurizer, and emergency core cooling systems, was designed to model the thermal-hydraulic behaviour of VVER-440-type reactors. The facility has been utilized in miscellaneous applications and experiments, for example, in the OECD International Standard Problem ISP-33. PACTEL has been upgraded and modified on a case-by-case basis. The latest facility configuration, the PWR PACTEL facility, was constructed for research activities associated with the EPR-type reactor. A significant design basis is to utilize certain parts of PACTEL, and at the same time, to focus on a proper construction of two new loops and vertical steam generators with an extensive instrumentation. The PWR PACTEL benchmark exercise was launched in 2010 with a small break loss-of-coolant accident test as the chosen transient. Both facilities, PACTEL and PWR PACTEL, are maintained fully operational side by side.

Thermodynamic characterization of high-temperature superconductors in the yttrium-barium-copper-oxygen system. The Y123 solid solution (Technical Report)

Abstract The aim of this report is to inform the chemical community about a self-consistent thermodynamic data set for the YBa2 Cu3 O6+z (1 ≥ z ≥ 0) solid solution, that is well known as the Y123 phase and possesses superconducting properties at z~1 and low temperatures. About 3300 experimental points obtained in 240 miscellaneous experiments published in 78 papers have been processed simultaneously in order to obtain the most reliable Gibbs energy function of the Y123 phase in the temperature range from 250 to 1300 K and pressures up to 100 kbar. A function is recommended for approximation of the Gibbs energy, which has 16 adjustable parameters. All other thermodynamic properties of the Y123 solution, including the conditions for its internal stability, can be derived from the assessed Gibbs energy. Brief descriptions of the thermodynamic model, experimental and data assessment methods as well as examples of self-consistent thermodynamic data applications are given.

Simultaneous Assessment of the YBa2Cu3O6+z Thermodynamics Under the Linear Error Model

About 3000 experimental points obtained in 220 miscellaneous experiments published in 57 papers have been processed simultaneously in order to obtain the most reliable Gibbs energy of the YBa2Cu3O6+z solid solution in the temperature range from 250 to 1300 K. A part of this solution is well-known as the “Hi-Tc Y123” phase. All other thermodynamic properties of the solution including the conditions for the tetragonal-orthorhombic phase transition and the miscibility gap at lower temperatures, are derived from the assessed Gibbs energy. The linear error model introduced recently by one of the authors has been employed for the simultaneous assessment. The results obtained are compared with those of the conventional weighted least squares method and the benefit of the new approach is discussed. Another problem in simultaneous assessment that is also considered is visualizing the quality of the fit. New types of graphs (partly based on the linear error model) that facilitate visualizing the quality of the fit are presented. (A critical review with 72 references.)

T-Butyl bromide–dimethyl sulphoxide reactions. Pummerer-like reaction with carboxylic acids and N-protected amino-acids

t-Butyl bromide-activated dimethyl sulphoxide reacted with carboxylic acids and differently N-protected aminoacids in the presence of a base (NaHCO3 or Et3N). High to quantitative yields of methylthiomethyl (MTM) esters were obtained in all cases without interference by other functional groups or racemization. The mechanism of the reaction is discussed on the basis of the products formed, of spectral data, and of other miscellaneous experiments.

Review paper: Heat transfer between liquid helium and solids below 100 mK

The many experimental determinations of heat transfer between liquid helium and solids are reviewed and compared with the existing theories. Generally heat transfer is a complex process at low temperatures, involving parallel heat paths with several resistances in series in each path. The standard theories for the individual resistances are reviewed and as far as possible a definite value of the expected resistance obtained. The experiments have been considered in five groups: cerium magnesium nitrate in liquid3He, cerium magnesium nitrate in dilute3He in liquid4He, metals in liquid3He, metals in dilute3He in liquid4He, and miscellaneous experiments. Where appropriate, the experimental results have been reevaluated in terms of standard models for heat transfer and presented as resistance versus temperature on diagrams showing the theoretical predictions. Between 20 and 100 mK many measurements show good agreement with acoustic mismatch theory for thermal boundary resistance. Below 20 mK most experiments have been made with finely divided solids (sintered metals or powdered paramagnetic salts); invariably the resistance has been anomalously low, with the metal/3He systems showingR ∫ T −1 and the metal/dilute3He in4He systems showingR ∫ T −3. The cerium magnesium nitrate/helium experiments have shown a temperature—independent resistance and sometimes anR ∫ T ~1 dependence. These resistances have been attributed to the spin-lattice resistance in cerium magnesium nitrate. Evidence for heat transfer by magnetic coupling has been reviewed and it is concluded that the positive evidence has other explanations, while the lack of dependence upon helium pressure,3He phase, and large magnetic fields is strong negative evidence. If the disagreement of experimental results with standard theory is not to be attributed to magnetic coupling, then several theoretical questions remain to be answered; these questions are posed. Basically, at low temperatures the excitations in solids and liquid helium have wavelengths and mean free paths much larger than the size of the finely divided particles or pores between the particles. Thus theories for bulk solids and bulk liquid helium are not appropriate for describing excitations and their interactions at these low temperatures.

The energy dependence of secondary emission based on the range-energy retardation power formula

Based on the energy retardation power formula concerning the penetration and the energy loss of an electron probe into solid targets, the secondary electron emission yield delta due both to primary and back-scattered electrons is derived as functions of three parameters such as atomic number Z, first ionisation energy I and back-scattering coefficient r, which are found to be in good accordance with the results obtained experimentally. Notable in such theoretical procedures are the maximum yield delta m and the primary energy Em, giving delta m=0.12Z1/15I4/5(1+1.26r) for Em=57.9Z115/I4/5(1+5r2)4/5 (eV) which substantially agree with the miscellaneous experiments of many authors. The energy dependence of the yield-energy distributions, the yield of thin films and the lateral distribution of secondary yield at the distance from the centre of the beam are given as functions of the back-scattering coefficient and the primary energy.

カエル類の交雑実験

カエル類の交雑実験

Three-phase interactions in shear and electrical fields

When two immiscible liquid drops, designated as phase-1 and -3, suspended in a third immiscible liquid, phase-2, are brought into contact, the resulting equilibrium configuration is readily predicted from the interfacial tensions σ ij and spreading coefficients S i = σ jk − (σ ij + σ ik ). In terms of the convention σ 12 > σ 23 ( S 1 < 0), phase-1 is completely engulfed by phase-3 when S 3 > 0; no engulfing occurs when S 2 > 0; and S 1 , S 2 , S 3 < 0 leads to partial engulfing and formation of 2-phase drops with three interfaces the shapes of which can be calculated. The theory has been confirmed for a number of systems in which pairs of drops were made to interact in shear and electrical fields and also in three-phase emulsions. The behavior of the two types of two-phase drops in shear and electrical fields was examined and compared with that of one-phase drops. The mechanism of engulfing was established with the aid of high-speed cinematography and shown to involve two competitive processes: penetration and spreading. Finally, a number of miscellaneous experiments were performed to illustrate further the applicability of the principles to a variety of colloidal systems.

SOME MODEL EXPERIMENTS RELATING TO ELECTROMAGNETIC PROSPECTING WITH SPECIAL REFERENCE TO AIRBORNE WORK*

AbstractAfter a discussion of the underlying principles, some electromagnetic model experiments made primarily in connection with the development of the ABEM airborne method are described. The experiments were made on thin vertical and horizontal conductors of “infinite” extent with coil arrangements involving one transmitter and one receiver unit. The in‐phase and out‐of‐phase components of the field picked up by the receiver were measured in percent of the amplitude of the normal field at the receiver. In this case 1° phase‐shift corresponds to 1.75 % of the normal field amplitude. The experiments were made on a scale 600–2000 times smaller than the natural scale. The ores and overburdens normally encountered in the field were simulated by sheets of Cu, Al, Zn and Pb of varying thicknesses. The frequencies used were 500, 880 and 1500 c/s. The variation of the secondary fields with the thickness, resistivity and depths of the conductors causing them is discussed in some detail. The bearing of the laboratory work on ground and especially airborne electromagnetic methods is indicated. A few miscellaneous experiments are also described. The results of an airborne survey over a known ore body and those of the corresponding model experiments are given. The ABEM airborne electromagnetic method and the so‐called “Canadian” method are briefly compared in the light of the model experiments described.

Delineamentos e análises de experimentos com cafeeiros

Os autores apresentam, de forma sucinta, os principais delineamentos e processos de análise estatística utilizados na experimentação com o cafeeiro no Instituto Agronômico. Consideram quatro grupos de experimentos: experimentos de adubação, ensaios de variedades, ensaios de progênies e outros ensaios. No primeiro grupo discutem, além dós experimentos mais antigos com delineamentos sistemáticos, outros mais recentes, já com delineamentos casualizados. Consideram um experimento fatorial, o qual forneceu resultados conclusivos em poucos anos, indicando a conveniência de serem mudados alguns tratamentos. No segundo, discutem uma experiência sistemática de variedades analisada por W. L. Stevens (3). No terceiro, discutem a evolução dos delineamentos usados para a comparação de progênies e, finalmente, no quarto grupo, consideram os delineamentos para experimentos de espaçamento e outros, assim como os estudos sôbre a eficiência de parcelas com tamanhos diferentes.

Miscellaneous experiments

Miscellaneous experiments

The anodic oxidation of coal. Part V. Miscellaneous experiments

AbstractA number of miscellaneous experiments has been undertaken using the apparatus described in previous papers. An anthracite has been oxidized at the copper cathode and, as is to be expected, much smaller yields were obtained than from a similar treatment of a vitrain. The amount of water‐soluble acids was much less than that of the ulmic acids. An attempt to oxidize two durains, in order to isolate the plant remains, proved unsuccessful, for it was found that unless the coal was ground to pass a 240 B.S. sieve; little oxidation took place. The durains could not be. ground to this fineness since the original structure of the plant entities would be destroyed.Fractions obtained from coal by treatment with pyridine followed with chloroform, i.e., the β‐fraction and the γ‐fraction have been oxidized at the copper cathode and yield ulmic acids. The molecular weights were similar to those of ulmic acids obtained from the direct oxidation of coal. This accords with the work of Biggs who similarly examined the fractions obtained by pressure‐benzene extraction, followed by nitric acid oxidation, and supports his theory that the difference between the various fractions is one of molecular size rather than of chemical type.Reduction of the vitrain at a copper cathode appeared to effect little change. However, reduction of the ulmic acid appears to increase its adsorptive power for electrolytes. It was not found possible to free the reduced ulmic acids from electrolyte by prolonged washing and they were no longer soluble in furfural and other solvents. It was thus not found possible to obtain a pure sample of the reduced ulmic acids.A general summary of the work is given and suggestions made for further work.

Miscellaneous experiments.

Miscellaneous experiments.

Electrode Potentials of Carbon in Acid Electrolytes

When carbon is exposed to oxygen in the presence of acid, it develops oxidizing characteristics measurable as potential or as capacity to oxidize reducing agents such as ferrous iron. Sorption of both acid and oxygen is essential to the development of oxidizing properties. Quantitative correlations of active oxygen and potential with acid sorption are given for several carbons, and the results of miscellaneous experiments indicating a possible chemical mechanism for the formation of active surface complexes on carbon are presented.

DENSITY DISCONTINUITIES AT THE CRITICAL TEMPERATURE

A technique for measuring densities in various parts of a one- or two-component system, raised above its critical temperature, is described. Considerable improvements over a method for this purpose recently described by one of the writers consist in greater flexibility of manipulation and in making possible a variation in the volume of space confining the medium during the experiment. Propylene and methyl-ether were the two media examined. From the results the following generalizations regarding aberrations from the continuity of state were found to hold for both.When either liquid was heated above the temperature at which the visible meniscus disappeared, the density below this point of disappearance was found to be greater than that above. The density was uniform throughout each portion, undergoing a relatively sharp change in the small region where the meniscus was last seen. After one hour of temperature equilibrium, the difference in density between top and bottom became constant and remained unaltered for six hours. Constant stirring or temperature fluctuations of the order of 0.02 °C. do not alter this density difference. A decrease in the volume available for the medium increases the density difference between the top and bottom, a continuous relation existing between available space and density difference. With decrease in available space, the densities of both upper and lower portions of the medium increase, the density of the lower more rapidly than that of the upper. These results were reproducible quantitatively in the experiments carried out to date. The density difference for a fixed available space decreases with rise in temperature and is measurable up to at least 10 °C. above the critical temperature. A number of miscellaneous experiments are described which form the basis of work now being carried out. The theoretical significance of aberrations from the continuity of state is discussed to the extent warranted by the present stage of the experimental investigations, and tentative conclusions are drawn.

Osmotic And Ionic Regulation in the Shore Crab, Carcinus Maenas, with Notes on the Blood Concentrations of Gammarus Locusta and Ligia Oceanica

ABSTRACT The influence of some foreign ions and non-electrolytes on the relation between the chloride concentration and vapour pressure of the blood of Carcinus and the external solution has been studied. The added substances showed interesting specific effects, which are discussed in the text, but no general conclusion can be drawn. It is very probable, however, that the gill membrane is almost impermeable to water, so that osmotic forces, as such, play no part in producing the observed relationships between blood and the external medium. There is no evidence for active water regulation in Carcinus. The latter conclusion is supported by experiments on the effects of cyanide and hypertonic solutions. In the latter case, in spite of “osmotic” regulation being abolished, no significant water transfer occurs. Miscellaneous experiments on the result of varying pH and temperature are described ; in each case the effects are surprisingly small. In a single experiment, the isolated gill tissue of Carcinus showed no secretory activity. The method used, based on Hill’s “bound water” technique, is described in detail. An analysis of the dilution-time curves for Carcinus in dilute solutions suggests that the process is accompanied by considerable changes in the properties of the gill membrane, before the beginning of the real regulatory mechanism. The same data permit the calculation of the work done in maintaining the steady state, but the result is improbably high. A direct study has been made of the vapour pressure of the body fluid of Ligia oceánica living under various conditions. For short periods of immersion in dilute solutions the animals show a high degree of osmotic independence, but their resistance breaks down on prolonged immersion. A method was tested for the study of internal concentration changes in animals too small for direct measurement. The results of an experiment on Gammarus locusta are discussed.

Some Observations on Experimental Ascariasis in Pigs

During the latter half of 1930 and the beginning of the present year some miscellaneous experiments on Ascaris in pigs were carried out at the Institute of Agricultural Parasitology by Professor Leiper and myself. Although these experiments were of a preliminary nature it was thought that some of the observations made during their course might be of interest to other workers in this field and they are, therefore, placed on record.

Miscellaneous Experiments with Anthelminthics, Chiefly Alkyl-Chlorides, in the Treatment of Nematode Infestations of Sheep

Miscellaneous Experiments with Anthelminthics, Chiefly Alkyl-Chlorides, in the Treatment of Nematode Infestations of Sheep

Description of Some Experiments Made on the Providence, R. I., Water-Works, to Ascertain the Force of Water Ram in Pipes

The experiments were conducted by the writer, on the Providence, R. I., Water Works, a number of years since, at the request of Mr. S. M. Gray, City Engineer. At the time they were commenced, it was merely the intention to ascertain the force of water ram that could be generated above the static pressure, in a wrought-iron pipe of 1½ inches in diameter, under different conditions. But the character of the results obtained from this pipe led to miscellaneous experiments being made, with a line of cast and wrought-iron pipes of other sizes. To these pipes was connected a small air chamber, that could be used or thrown out of service at pleasure.

Physics without Apparatus 1

VIII. IN the preceding articles of this series we have shown how in every department of physics a large number of instructive experiments may be performed without the aid of any more formal apparatus than the usual domestic appliances of an ordinary household. There remain to be described a few miscellaneous experiments before concluding the subject.