Distribution of Non-Rubber Substances in Preserved Latex Part II. Acids

1943 ◽  
Vol 16 (2) ◽  
pp. 365-380
Author(s):  
H. C. Baker
Keyword(s):  
Particle Size ◽  
Present Author ◽  
Acetone Extract ◽  
Alkaline Ph ◽  
Protein Distribution ◽  
Active Materials ◽  
Different Types ◽  
Surface Active ◽  
Rubber Phase ◽  
General Method

Abstract In a previous paper by the present author, a general method for determining the distribution of the nonrubber substances between the rubber-and-water phases in latex was described and results were given of its application to the study of the distribution of nitrogen and materials extractable with acetone. It was shown that the nitrogen associated with the rubber phase is of two different types, a small amount (about 0.02 per cent) being independent of particle size and consequently distributed throughout the mass of the rubber, whereas the remainder is a function of particle size, replaceable by surface-active materials, such as soaps, and is, consequently, situated at the surface of the particles. The surface nitrogen in ammoniated latex was variable, decreased with age of latex, could be partially desorbed at an alkaline pH by washing the latex, for instance, by dilution or repeated creaming, and is considered to represent the protective protein covering of the latex globules. The total variation experienced in unconcentrated ammoniated latices of varying ages was from 0.11 to 0.18 per cent, but in latex of good quality about six months old, surface nitrogen was 0.15 per cent, corresponding to about 1 per cent protein. Distribution experiments on the acetone extract showed that there is from 2 to 3 per cent of acetone-soluble substances associated with the rubber, of which less than one-half represents ammonium soaps at the surface of the particles. The surface of the rubber particles is, therefore, composed largely of protein and fat acids, and it was thought probable that the ratio between them might change, both during the life of a single latex and from one latex to another.

Effect of grain size on the vapour phase hydration of monoclinic and triclinic modifications of tricalcium silicate; role of high temperature activation

1991 ◽  
Vol 56 (10) ◽  
pp. 1993-2008
Author(s):  
S. Hanafi ◽  
G. M. S. El-Shafei ◽  
B. Abd El-Hamid
Keyword(s):  
Particle Size ◽  
Vapour Phase ◽  
Tricalcium Silicate ◽  
Active Centers ◽  
Thermally Activated ◽  
Grain Sizes ◽  
Intermediate Size ◽  
Surface Active ◽  
Temperature Activation

The hydration of tricalcium silicate (C3S) with three grain sizes of monoclinic (M) and triclinic (T) modifications and on their thermally activated samples were investigated by exposure to water vapour at 80°C for 60 days. The products were investigated by XRD, TG and N2 adsorption. The smaller the particle size the greater was the hydration for both dried and activated samples from (M). In the activated samples a hydrate with 2θ values of 38.4°, 44.6° and 48.6° could be identified. Hydration increased with particle size for the unactivated (T) samples but after activation the intermediate size exhibited enhanced hydration. Thermal treatment at 950°C of (T) samples increased the surface active centers on the expense of those in the bulk. Changes produced in surface texture upon activation and/or hydration are discussed.

scholarly journals Visualizing Spatial Economic Supply Chains to Enhance Sustainability and Resilience

2021 ◽  
Vol 13 (3) ◽  
pp. 1512
Author(s):  
Yicheol Han ◽  
Stephan J. Goetz ◽  
Claudia Schmidt
Keyword(s):  
Supply Chains ◽  
Preferential Attachment ◽  
Material Balance ◽  
Service Industries ◽  
Firm Location ◽  
Commodity Flows ◽  
Geographic Space ◽  
Different Types ◽  
Gravity Equations ◽  
General Method

This article presents a spatial supply network model for estimating and visualizing spatial commodity flows that used data on firm location and employment, an input–output table of inter-industry transactions, and material balance-type equations. Building on earlier work, we proposed a general method for visualizing detailed supply chains across geographic space, applying the preferential attachment rule to gravity equations in the network context; we then provided illustrations for U.S. extractive, manufacturing, and service industries, also highlighting differences in rural–urban interdependencies across these sectors. The resulting visualizations may be helpful for better understanding supply chain geographies, as well as business interconnections and interdependencies, and to anticipate and potentially address vulnerabilities to different types of shocks.

scholarly journals CHEMICAL INVESTIGATIONS ON THE ACTIVE PRINCIPLES OF THE PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES

1938 ◽  
Vol 67 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Gregory Shwartzman ◽  
S. A. Morell
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Ammonium Sulfate ◽  
Culture Filtrate ◽  
Active Materials ◽  
Local Skin ◽  
Skin Reactivity ◽  
Average Porosity ◽  
Active Substances ◽  
Capillary Analysis

Several physicochemical properties of the active principles of the phenomenon of local skin reactivity to bacterial filtrates have been investigated. Ultrafiltration through Zsigmondy filters of graded porosities has shown that the active substances are retained by membranes finer than 100 to 120 seconds, whereas coarser ones readily permit their passage. The average porosity of this filtration end-point represents a particle size of about 50 to 100 mµ. When fractionally precipitated with ammonium sulfate, most of the activity of a culture filtrate was concentrated in the two-thirds saturated portion. Isoelectric properties were studied by means of capillary analysis and cataphoresis. At pH 3.0 and below, the substances suspended in the culture filtrates migrated to the cathode; activity in this chamber, however, could not be demonstrated. At pH 4.0 and above, reversal to the anode occurred, as the active materials became negatively charged and readily migrated to this chamber. The isoelectric point, therefore, was considered to be between pH 3.0 and 4.0. Preliminary experiments on adsorption, extraction, and pH stability have been described.

Study of the turbulent flow of solutions of surface-active materials by means of a laser anemometer

1975 ◽  
Vol 29 (5) ◽  
pp. 1408-1410 ◽  
Author(s):  
I. L. Povkh ◽  
A. B. Stupin ◽  
S. N. Maksyutenko ◽  
P. V. Aslanov ◽  
E. A. Roshchin ◽  
...  
Keyword(s):  
Turbulent Flow ◽  
Active Materials ◽  
Laser Anemometer ◽  
Surface Active

The Chorionic Plastron and its Role in the Eggs of the Muscinae (Diptera)

1960 ◽  
Vol s3-101 (55) ◽  
pp. 313-332
Author(s):  
H. E. HINTON
Keyword(s):  
Surface Tension ◽  
High Pressures ◽  
Middle Layer ◽  
Clean Water ◽  
Active Materials ◽  
Great Resistance ◽  
Plane Normal ◽  
Air Interface ◽  
Surface Active ◽  
Egg Shell

In flies of the subfamily Muscinae the egg-shell has both an outer and an inner meshwork layer, each of which holds a continuous film of air. Between these two meshwork layers there is a more or less thick middle layer to which the shell chiefly owes its mechanical strength. Holes or aeropyles through the middle layer effect the continuity of the outer and inner films of air. Both meshwork layers consist of struts that arise perpendicularly from the middle layer. In both layers the struts are branched at their apices in a plane normal to their long axes. These horizontal branches form a fine and open hydrofuge network that provides a large water-air interface when the egg is immersed. When it rains or when the egg is otherwise immersed in water, the film of air held in the outer meshwork layer of the shell funtions as a plastron. To be an efficient respiratory structure a plastron must resist wetting by both the hydrostatic pressures and the surface active materials to which it is normally exposed. The plastrons of all the Muscinae tested resist wetting in clean water by pressures far in excess of any they are likely to encounter in nature. The resistance of a plastron to hydrostatic pressures varies directly as the surface tension of the water, and the surface tension of water in contact with the decomposing materials in which the Muscinae lay their eggs is much lowered by surface active materials. These considerations seem to provide an explanation for the great resistance of the plastron of the Muscinae to wetting by excess pressures and for the paradox that the plastrons of these terrestrial eggs are more resistant to high pressures than are the plastrons of some aquatic insects that live in clean water.

Proteins Induced Formation of Hydrothermal Nitrogen Doped Carbons

2009 ◽  
Vol 1219 ◽  
Author(s):  
Niki Baccile ◽  
Maria-Magdalena Titirici
Keyword(s):  
Particle Size ◽  
Carbon Source ◽  
Nitrogen Sources ◽  
Model Compounds ◽  
Nitrogen Doped ◽  
Carbon Particles ◽  
Structural Order ◽  
Different Types

AbstractThis contribution illustrates the synthesis of nitrogen-containing hydrothermal carbon particles from a mixture of glucose, as carbon source, and different types of proteins, as nitrogen sources. Casein, ovalbumin, hemoglobin and gelatin were chosen here as model compounds. The particle size and the level of structural order could be tuned according to the protein type and the amount utilized.

Differential inactivation of three bacteriophages by acid and alkaline pH used in the membrane adsorption–elution method of virus recovery

1980 ◽  
Vol 26 (12) ◽  
pp. 1403-1407 ◽  
Author(s):  
Carolyn M. Sabatino ◽  
Siegfried Maier
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Differential Susceptibility ◽  
Alkaline Ph ◽  
Alkaline Elution ◽  
Adsorption Method ◽  
Acid Ph ◽  
Elution Method ◽  
Virus Recovery ◽  
General Method

The study was prompted by our inability to concentrate phages by a membrane adsorption method effective for polioviruses. Consequently two coliphages, WPK and T4, and F116 of Pseudomonas aeruginosa were tested for their resistance to acid (pH 5.2–3.2) and alkaline (pH 10–11.5) exposures. Only T4 proved acid resistant, allowing for acid adsorption, and only WPK was sufficiently alkaline resistant to allow for alkaline elution. Thus, the differential susceptibility of various phages precludes the use of the acid membrane adsorption–alkaline elution method as a general method for the concentration of phages from large volumes of water.

Titanium dioxide nanoparticles as multifunctional surface-active materials for smart/active nanocomposite packaging films

2021 ◽  
pp. 102593
Author(s):  
Mahmood Alizadeh Sani ◽  
Mohammad Maleki ◽  
Hadi Eghbaljoo-Gharehgheshlaghi ◽  
Arezou Khezerlou ◽  
Esmaeil Mohammadian ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Titanium Dioxide Nanoparticles ◽  
Active Materials ◽  
Packaging Films ◽  
Surface Active

scholarly journals Ice-nucleating ability of aerosol particles and possible sources at three coastal marine sites

2018 ◽  
Vol 18 (21) ◽  
pp. 15669-15685 ◽  
Author(s):  
Meng Si ◽  
Victoria E. Irish ◽  
Ryan H. Mason ◽  
Jesús Vergara-Temprado ◽  
Sarah J. Hanna ◽  
...  
Keyword(s):  
Particle Size ◽  
Aerosol Particles ◽  
Freezing Temperature ◽  
The Arctic ◽  
Labrador Sea ◽  
Sea Spray ◽  
Site Density ◽  
Coastal Marine ◽  
Surface Active ◽  
Surface Area Basis

Abstract. Despite the importance of ice-nucleating particles (INPs) for climate and precipitation, our understanding of these particles is far from complete. Here, we investigated INPs at three coastal marine sites in Canada, two at mid-latitude (Amphitrite Point and Labrador Sea) and one in the Arctic (Lancaster Sound). For Amphitrite Point, 23 sets of samples were analyzed, and for Labrador Sea and Lancaster Sound, one set of samples was analyzed for each location. At all three sites, the ice-nucleating ability on a per number basis (expressed as the fraction of aerosol particles acting as an INP) was strongly dependent on the particle size. For example, at diameters of around 0.2 µm, approximately 1 in 106 particles acted as an INP at −25 ∘C, while at diameters of around 8 µm, approximately 1 in 10 particles acted as an INP at −25 ∘C. The ice-nucleating ability on a per surface-area basis (expressed as the surface active site density, ns) was also dependent on the particle size, with larger particles being more efficient at nucleating ice. The ns values of supermicron particles at Amphitrite Point and Labrador Sea were larger than previously measured ns values of sea spray aerosols, suggesting that sea spray aerosols were not a major contributor to the supermicron INP population at these two sites. Consistent with this observation, a global model of INP concentrations under-predicted the INP concentrations when assuming only marine organics as INPs. On the other hand, assuming only K-feldspar as INPs, the same model was able to reproduce the measurements at a freezing temperature of −25 ∘C, but under-predicted INP concentrations at −15 ∘C, suggesting that the model is missing a source of INPs active at a freezing temperature of −15 ∘C.

Sign in / Sign up

Export Citation Format

Share Document