The Separation of Light Gaseous Isotopes by Mass Diffusion Columns II

1964 ◽  
Vol 19 (6) ◽  
pp. 747-755
Author(s):  
W. J. De Wet ◽  
J. Los
Keyword(s):  
Theoretical Analysis ◽  
Mass Diffusion ◽  
Experimental Results ◽  
The Other ◽  
Countercurrent Flow ◽  
Gas Solubility ◽  
Flow Rates ◽  
Mixing Effects ◽  
Other Hand ◽  
Good Agreement

The design of mass diffusion columns operated with partition membranes, for the separation of light gaseous isotopes, is discussed. A theoretical analysis of experimental results obtained indicates that a good agreement between experimental results and theory is only obtained at low column pressures and moderate countercurrent flow rates. At fairly low countercurrent flow rates mixing effects due to viscous dragging and gas solubility by the condensate appear to be considerable whereas excessively high countercurrent flow rates, on the other hand, also seem undesirable. Some suggestions are proposed to obviate impairing effects at least to some extent.

Kinetics of Aqueous Alteration of P0798 Simulated Waste Glass in the Presence of Bentonite

2006 ◽  
Vol 932 ◽  
Author(s):  
K. Yamaguchi ◽  
Y. Inagaki ◽  
T. Saruwatari ◽  
K. Idemitsu ◽  
T. Arima ◽  
...  
Keyword(s):  
Secondary Phase ◽  
Model Analysis ◽  
Water Diffusion ◽  
Experimental Results ◽  
The Other ◽  
Protective Effects ◽  
Aqueous Alteration ◽  
Other Hand ◽  
Initial Stage ◽  
Good Agreement

ABSTRACTStatic aqueous alteration tests were performed with a Japanese simulated HLW glass, P0798, in the presence of bentonite in order to understand the effects of bentonite on the glass alteration kinetics and on the associated Cs release. Analogous alteration tests were performed in 0.001M NaOH solution without bentonite for comparison. The results indicated that; 1) at the initial stage of alteration up to 50 days, no remarkable difference was observed in the alteration rate between both cases “with” and “without” bentonite, 2) at the later stage beyond 50 days, however, the rate in the case “with” bentonite was larger than that in the case “without” bentonite. These results on the alteration rate were analyzed by use of a water-diffusion model. In the case “without” bentonite, a good agreement was observed between the model analysis and the experimental results at the initial stage of alteration up to 50 days, however, the model analysis deviated from the experimental results at the later stage beyond 50 days. In the case “with” bentonite, on the other hand, a good agreement was observed even at the later stage to give the value of the apparent diffusion coefficient, Di of 3.5×10−21m2/s. The comparison between both cases suggests that the alteration rate is controlled by the water diffusion in both cases “with” and “without” bentonite, however, the rate is depressed in the case “without” bentonite probably by the protective effects of the alteration layer developing at the glass surface. In the case “with” bentonite, on the other hand, the alteration layer is expected to be less protective. Cesium desorption tests performed for the altered glass and bentonite indicated that most of the cesium dissolved from the glass is retained in the secondary phase of smectite developing in the precipitated layer by sorption with ion-exchange in the case “without” bentonite. In the case “with” bentonite, however, it is likely to be sorbed at bentonite surface.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

Natural Vulcanization Accelerators in Hevea Latex

1948 ◽  
Vol 21 (4) ◽  
pp. 853-859
Author(s):  
R. F. A. Altman
Keyword(s):  
Amino Acids ◽  
Experimental Results ◽  
The Other ◽  
Active Nitrogen ◽  
Nitrogen Bases ◽  
Other Hand ◽  
Decomposition Processes ◽  
Volatile Products ◽  
Nitrogenous Substances ◽  
The One

Abstract As numerous investigators have shown, some of the nonrubber components of Hevea latex have a decided accelerating action on the process of vulcanization. A survey of the literature on this subject points to the validity of certain general facts. 1. Among the nonrubber components of latex which have been investigated, certain nitrogenous bases appear to be most important for accelerating the rate of vulcanization. 2. These nitrogen bases apparently occur partly naturally in fresh latex, and partly as the result of putrefaction, heating, and other decomposition processes. 3. The nitrogen bases naturally present in fresh latex at later stages have been identified by Altman to be trigonelline, stachhydrine, betonicine, choline, methylamine, trimethylamine, and ammonia. These bases are markedly active in vulcanization, as will be seen in the section on experimental results. 4. The nitrogenous substances formed by the decomposition processes have only partly been identified, on the one hand as tetra- and pentamethylene diamine and some amino acids, on the other hand as alkaloids, proline, diamino acids, etc. 5. It has been generally accepted that these nitrogenous substances are derived from the proteins of the latex. 6. Decomposition appears to be connected with the formation of a considerable amount of acids. 7. The production of volatile nitrogen bases as a rule accompanies the decomposition processes. These volatile products have not been identified. 8. The active nitrogen bases, either already formed or derived from complex nitrogenous substances, seem to be soluble in water but only slightly soluble in acetone.

Preliminary Investigation on the Effect of the Modification of the Sweep Angle at the Blade Tip of Forward Swept Axial Fans

2017 ◽  
Author(s):  
Massimo Masi ◽  
Andrea Lazzaretto
Keyword(s):  
Preliminary Investigation ◽  
Suction Side ◽  
The Other ◽  
Axial Fan ◽  
Sweep Angle ◽  
End Effects ◽  
Flow Rates ◽  
Stall Margin ◽  
Other Hand ◽  
Blade Tip

The flow path close to the suction side of fan rotor blades mostly affects the overall drag of the blading. The blade lift is affected as well because of the separation of the low energy boundary layer that drives the blade into stall at low fan flow rates. Forward sweep allows to position the airfoil sections of blades featuring a positive circulation gradient along the span so that they “accompany” the near-wall flow trajectories at the blade suction side. So, rotor efficiency and stall margin of the fan can be improved. On the other hand, blade end effects play a relevant role in high hub-to-tip and low aspect ratio rotors and may compromise the effectiveness of forward sweep. Nevertheless, some authors in the literature stated the beneficial contribution of changing the sweep angle at the ends of the blade both at design and off-design conditions. The paper studies the end effects on constant-swirl design rotors by means of CFD simulations focusing on the distribution of blade sweep in the near-tip region. In particular, the performance and efficiency calculated for a forward swept tube-axial fan featuring a hub-to-tip ratio equal to 0.4 are compared with those estimated for the corresponding unswept fan at equal duty point. Several modifications of the sweep distribution in the blade tip region are considered in the swept fan to quantify their effect on performance, efficiency and stall margin. Results show that the addition of up to 6 degrees of local forward sweep at the blade tip to the unswept blading does not affect fan pressure at design operation. On the other hand, this local increase of the sweep angle allows for a very notable increase of the peak pressure and efficiency at flow rates close to stall inception.

scholarly journals Comparison of the Fungicidal Properties of Different Humectants in a Tobacco Blend / Vergleich der fungistatischen Wirkung verschiedener Feuchthaltemittel bei einer ungesoßten Tabakmischung

1966 ◽  
Vol 3 (7) ◽  
Author(s):  
H. van Nooy
Keyword(s):  
Experimental Results ◽  
The Other ◽  
Other Hand ◽  
Tobacco Treatment

AbstractThe experimental results indicated in the present paper reveal that among all humectants admitted 1,3-butyleneglycol alone has marked fungicidal properties satisfying the requirements of practical tobacco treatment, and that, on the other hand, diethyleneglycol and glycerine practically do not have such qualities

scholarly journals Elastic Properties of Magnetorheological Elastomers in a Heterogeneous Uniaxial Magnetic Field

2018 ◽  
Vol 19 (10) ◽  
pp. 3045 ◽  
Author(s):  
Takehito Kikuchi ◽  
Yusuke Kobayashi ◽  
Mika Kawai ◽  
Tetsu Mitsumata
Keyword(s):  
Magnetic Field ◽  
Elastic Properties ◽  
Uniform Magnetic Field ◽  
Large Strain ◽  
Small Strain ◽  
Experimental Results ◽  
The Other ◽  
Magnetorheological Elastomers ◽  
Other Hand ◽  
Strain Model

Magnetorheological elastomers (MREs) are stimulus-responsive soft materials that consist of polymeric matrices and magnetic particles. In this study, large-strain response of MREs with 5 vol % of carbonyl iron (CI) particles is experimentally characterized for two different conditions: (1) shear deformation in a uniform magnetic field; and (2), compression in a heterogeneous uniaxial magnetic field. For condition (1), dynamic viscoelastic measurements were performed using a rheometer with a rotor disc and an electric magnet that generated a uniform magnetic field on disc-like material samples. For condition (2), on the other hand, three permanent magnets with different surface flux densities were used to generate a heterogeneous uniaxial magnetic field under cylindrical material samples. The experimental results were mathematically modeled, and the relationship between them was investigated. We also used finite-element method (FEM) software to estimate the uniaxial distributions of the magnetic field in the analyzed MREs for condition (2), and developed mathematical models to describe these phenomena. By using these practicable techniques, we established a simple macroscale model of the elastic properties of MREs under simple compression. We estimated the elastic properties of MREs in the small-strain regime (neo–Hookean model) and in the large-strain regime (Mooney–Rivlin model). The small-strain model explains the experimental results for strains under 5%. On the other hand, the large-strain model explains the experimental results for strains above 10%.

Unconditional and conditional as categories of the dialectic of law

2021 ◽  
pp. 58
Author(s):  
Grigory N. Utkin
Keyword(s):  
Theoretical Analysis ◽  
Social Life ◽  
The Other ◽  
Other Hand ◽  
Dialectical Relationship ◽  
Three Stages ◽  
The One ◽  
Dialectical Analysis ◽  
Conceptual Meaning

The article reveals the conceptual, meaning-forming role of the categories of the unconditional and conditional in law. At the same time, their dialectical relationship with each other and with other categories is put in the center of attention. The dialectic of the unconditional and conditional is revealed by achieving the unity of the three stages of theoretical analysis, which allows us to present the unconditional and conditional, on the one hand, as the content of all concepts, through which the idea of law is generally expressed in various aspects and elements; on the other hand, the entire set of categories subject to dialectical analysis appears as elements of the content of the unconditional and conditional as semantic units that Express the universal characteristics of law in its features, isolation from other forms of social life.

Effect of Manganese Addition on Strength and Fracture Toughness in Mg-6Al-1Zn Alloy

2006 ◽  
Vol 306-308 ◽  
pp. 857-862 ◽  
Author(s):  
Taisuke Sasaki ◽  
Tokuteru Uesugi ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Fracture Toughness ◽  
Magnesium Alloy ◽  
Yield Strength ◽  
Ductile Fracture ◽  
Manganese Content ◽  
Experimental Results ◽  
The Other ◽  
Excessive Amount ◽  
Void Coalescence ◽  
Other Hand

The effect of manganese on strength and fracture toughness was investigated using five kinds of Mg-6Al-1Zn alloys. From the experimental results, the yield strength increased with increasing in manganese content until manganese content reached 0.14 wt. %. On the other hand, further increase in yield strength was not observed in case larger than 0.14 % of manganese was added. In addition, fracture toughness decreases with increasing manganese content. Fracture of magnesium alloy was ductile fracture by void coalescence. Adding excessive amount of manganese caused the increase in the presence of inclusions. This kind of particle easily became the nucleus of microvoid. As a conclusion, manganese should be added so that coarse manganese-bearing particle is not formed. Thus, 0.14 wt. % of manganese should be added to Mg-6Al-1Zn alloy in order to develop the alloy with well-balanced relationship between strength and fracture toughness.

Effects of Mandarin Cultivar on Quality of Mandarin Juice

2008 ◽  
Vol 14 (4) ◽  
pp. 307-313 ◽  
Author(s):  
F. Beltrán ◽  
A.J. Perez-López ◽  
J.M. López-Nicolás ◽  
A.A. Carbonell-Barrachina
Keyword(s):  
Vitamin C ◽  
Volatile Compounds ◽  
Experimental Results ◽  
The Other ◽  
Total Volatile ◽  
Color Coordinates ◽  
Juice Processing ◽  
Other Hand ◽  
Cielab Color

Eight mandarin cultivars have been analyzed for their content of vitamin C, minerals (Ca, Mg, K, Na, Fe, Cu, Mn, and Zn), CIELab color coordinates (L*, a*, b*, C*, and h ab), total volatile compounds content and sensory aroma intensity of juice. Experimental results proved that no important enough differences were found in the minerals contents to decide which mandarin cultivar was of higher quality. Clemenules provided the darkest juice with the highest vitamin C content and with the most intense mandarin aroma. On the other hand, Nova and Hernandina mandarin could be considered as the worst cultivars for juice production. Finally if Clemenules mandarins were not available for juice processing, Orogrande, Clemenpons, Ellendale, and Marisol could also be good options.

scholarly journals A bistable structural element

2008 ◽  
Vol 222 (11) ◽  
pp. 2045-2051 ◽  
Author(s):  
T Schioler ◽  
S Pellegrino
Keyword(s):  
Theoretical Analysis ◽  
Analytical Model ◽  
Mechanical Behaviour ◽  
The Other ◽  
Experimental Measurements ◽  
Structural Element ◽  
High Stiffness ◽  
Revolute Joints ◽  
Prototype Structure ◽  
Good Agreement

This article presents a novel bistable structural element that has high stiffness in stable configurations, but requires only a small amount of energy to be switched from one configuration to the other. The element is based on a planar linkage of four bars connected by revolute joints, braced by tape-spring diagonals. A description of the concept is presented, along with a detailed theoretical analysis of its mechanical behaviour. Experimental measurements obtained from a prototype structure are found to be in very good agreement with the predictions from this analytical model.

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