Mechanical properties of semipermeable microcapsules

1968 ◽  
Vol 46 (5) ◽  
pp. 731-737 ◽  
Author(s):  
A. W. L. Jay ◽  
M. A. Edwards
Keyword(s):  
Mechanical Properties ◽  
Internal Pressure ◽  
Elastic Properties ◽  
High Resistance ◽  
Irreversible Change ◽  
Membrane Tension ◽  
Nylon Membrane ◽  
Laplace’S Law ◽  
A Cell ◽  
Very High

A study has been made of the mechanical properties of the membrane of semipermeable nylon microcapsules containing erythrocyte hemolysate. The use of a "cell elastimeter" and the application of Laplace's Law have shown that the nylon membrane has very high resistance to stretching, but only negligible resistance to bending. The membrane tension in undeformed microcapsules has been determined to be 1840 dynes/cm and observed to increase with deformation, indicating elastic properties in the membrane. At a tension of 2520 dynes/cm, resistance to stretching is sharply reduced. The results indicate that the internal pressure varies directly as the reciprocal of microcapsule radius, and an extrapolation of these results, assuming that the relation holds for very small capsules, yields an internal pressure of 4.3 × 106 dynes/cm2 for a microcapsule of erythrocyte diameter. Any stretch in the nylon membrane has been shown to be almost irreversible. The diameter of the smallest pipette through which a spherical microcapsule can pass without suffering irreversible change has been found to be no smaller than 90% of the microcapsule diameter, and the pressure required is of the order of 105 dynes/cm2.

scholarly journals Possible use of vacuum controlled pulsators for sheep milking machines

2012 ◽  
Vol 50 (No. 1) ◽  
pp. 23-27
Author(s):  
J. Fryč ◽  
R. Kukla ◽  
J. Los
Keyword(s):  
Mechanical Properties ◽  
High Resistance ◽  
Maximum Value ◽  
Pulsation Rate ◽  
The Moment ◽  
Comparison Measurements ◽  
Very High

Comparison measurements and evaluation of the suitability of three pulsators for sheep milking machines were carried out, i.e. a prototype made by the manufacturer of the milking parlour of the pulsator ratio 50% (50:50) and two hydraulic pulsators of the Danish manufacturer S.A. Christensen (SAC), models Unipuls-2 of the pulsator ratios 50% (50:50) and 60% (60:40). The specified pulsation rate was 2.5/s(150/min). It was found that the pulsator prototype made by the milking parlour manufacturer slowly passed air, whereby the vacuum in pulsation chambers did not attain the maximum value. Fig. 2 illustrates the operation of this pulsator. Both SAC pulsators had better parameters and their pulsograms are plotted in Figs. 3 and 4. Also the measurements of a liner deformation in dependence on the vacuum in the teatcup pulsation chamber were made based on which the moment of a real liner opening, i.e. at the vacuum of 35 kPa was determined. The results obtained by the experiments carried out can be summed up as follows: As the change in pulsation rate does not affect the time of transition phases “a” and “c”, the intervals “b” and “d” are shorter if the pulsation rate is increased. Interval “b”, i.e. a full liner opening, shortens with the rising rate and extends with the increased value of the pulsator ratio. For this reason higher pulsator ratios should be used at very high pulsation rates. The teatcup operation depends on the physical-mechanical properties of the liner used. On the milking unit measured considerable differences in time take place between the interval “b” and the liner full opening due to a relatively high resistance power of the liner to deformation. The pulsator prototype designed by the milking parlour producer revealed as fully unsuitable based on its pulsogram. As far as the time of the liner opening is concerned, its parameters were worse than on both SAC pulsators, however, we cannot indicate it as unsuitable.

The Mechanical Properties of the cell Surface

1954 ◽  
Vol 31 (3) ◽  
pp. 461-472
Author(s):  
J. M. MITCHISON ◽  
M. M. SWANN
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Internal Pressure ◽  
Sea Urchin ◽  
Tennis Ball ◽  
Pressure Measurements ◽  
Membrane Tension ◽  
Inflated Balloon ◽  
Sea Urchin Egg ◽  
Elastic Wall

1. Measurements were made with the cell elastimeter on the stiffness of the cell membrane in the unfertilized eggs of five species of sea urchin. Young's modulus varies in the different species between the values of 0.91 x 104 and 2.08 x 104 dynes/cm2. 2. Experiments on the change of stiffness in hypo- and hypertonic media indicated that there is probably no internal pressure and no membrane tension in the normal egg. If, however, there is an internal pressure, measurements of the minimum shrinkage of the membrane necessary to produce wrinkling showed that this pressure cannot exceed 95 dynes/cm2. 3. A drop in temperature of 18.5° C. produced an increase of stiffness by a factor of 2.1. 4. These experiments, together with other evidence, suggest that for mechanical purposes the unfertilized sea-urchin egg can be compared to a hollow sphere filled with fluid and surrounded by a solid elastic wall (the membrane or cortex) about 1.5 µ thick and with an elastic modulus about 1-2 x 104 dynes/cm2. This degree of rigidity is sufficient to ensure the maintenance of shape of the egg without the presence of an internal pressure or a tension in the membrane. In everyday terms, the egg therefore resembles a tennis ball or a child's rubber ball, rather than an inflated balloon or an oil drop in water.

KAISER ALUMINUM ALLOY 7149

Alloy Digest ◽  
2000 ◽  
Vol 49 (2) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Aluminum Alloy ◽  
High Resistance ◽  
Heat Treating ◽  
Kaiser Aluminum ◽  
Resistance To Stress ◽  
Structural Parts ◽  
Very High

Abstract Kaiser Aluminum alloy 7149 has very high mechanical properties and good machinability. The alloy offers a high resistance to stress-corrosion cracking (SCC) and is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: AL-367. Producer or source: Tennalum, A Division of Kaiser Aluminum.

UNS A97075

Alloy Digest ◽  
1986 ◽  
Vol 35 (7) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Temperature Performance ◽  
Structural Applications ◽  
Structural Parts ◽  
Very High

Abstract UNS No. A97075 is a wrought precipitation-hardenable aluminum alloy. It has excellent mechanical properties, workability and response to heat treatment and refrigeration. Its typical uses comprise aircraft structural parts and other highly stressed structural applications where very high strength and good resistance to corrosion are required. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on low temperature performance as well as forming, heat treating, and machining. Filing Code: Al-269. Producer or source: Various aluminum companies.

KAISER ALUMINUM ALLOY 7050

Alloy Digest ◽  
2000 ◽  
Vol 49 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Heat Treating ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Kaiser Aluminum ◽  
Structural Parts ◽  
Very High

Abstract Kaiser Aluminum Alloy 7050 has very high mechanical properties including tensile strength, high fracture toughness, and a high resistance to exfoliation and stress-corrosion cracking. The alloy is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: AL-366. Producer or source: Tennalum, A Division of Kaiser Aluminum.

AVESTA SHEFFIELD SAF 2507

Alloy Digest ◽  
1996 ◽  
Vol 45 (9) ◽  
Keyword(s):  
High Resistance ◽  
Stainless Steels ◽  
Coefficient Of Thermal Expansion ◽  
Austenitic Stainless Steels ◽  
High Strength ◽  
Heat Treating ◽  
General Corrosion ◽  
Temperature Performance ◽  
Chloride Stress Corrosion Cracking ◽  
Very High

Abstract Avesta Sheffield SAF 2507 is an austenitic/ferritic duplex stainless steel with very high strength. The alloy has a lower coefficient of thermal expansion and a higher thermal conductivity than austenitic stainless steels. The alloy has a high resistance to pitting, crevice, and general corrosion; it has a very high resistance to chloride stress-corrosion cracking. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-652. Producer or source: Avesta Sheffield Inc.

TIMKEN 16-15-6

Alloy Digest ◽  
1963 ◽  
Vol 12 (12) ◽  
Keyword(s):  
Mechanical Properties ◽  
Creep Resistance ◽  
Elevated Temperatures ◽  
Roller Bearing ◽  
Heat Treating ◽  
Resistant Steel ◽  
Heat Resistant Steel ◽  
Corrosion And Oxidation ◽  
Very High ◽  
High Creep Resistance

Abstract Timken 16-15-6 is a non-magnetic, austenitic, corrosion and heat resistant steel having high creep resistance at elevated temperatures and good corrosion and oxidation resistance. It age-hardens at elevated temperatures after solution quenching, and possesses very high mechanical properties. This datasheet provides information on composition, microstructure, hardness, and tensile properties as well as creep. It also includes information on forming, heat treating, machining, and joining. Filing Code: SS-150. Producer or source: Timken Roller Bearing Company.

scholarly journals Elevated Incidences of Antimicrobial Resistance and Multidrug Resistance in the Maumee River (Ohio, USA), a Major Tributary of Lake Erie

2021 ◽  
Vol 9 (5) ◽  
pp. 911
Author(s):  
Maitreyee Mukherjee ◽  
Leah Marie ◽  
Cheyenne Liles ◽  
Nadia Mustafa ◽  
George Bullerjahn ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
High Resistance ◽  
Lake Erie ◽  
Control Measures ◽  
Industrial Water ◽  
Western Basin ◽  
E Coli ◽  
Major Tributary ◽  
Very High

Maumee River, the major tributary in the western basin of Lake Erie, serves as one of major sources of freshwater in the area, supplying potable, recreational, and industrial water. In this study we collected water samples from four sites in the Maumee River Bay between 2016–2017 and E. coli was isolated, enumerated, and analyzed for antimicrobial resistance (AMR) and multidrug resistance (MDR). Strikingly, 95% of the total isolates were found to be resistant to at least one antibiotic. A very high resistance to the drugs cephalothin (95.3%), ampicillin (38.3%), tetracycline (8.8%), gentamicin (8.2%), ciprofloxacin (4.2%), cefoperazone (4%), and sulfamethoxazole (1.5%) was observed within isolates from all four sampling sites. Percentages of AMR and MDR was consistently very high in the summer and fall months, whereas it was observed to be lowest in the winter. A remarkably high number of the isolates were detected to be MDR—95% resistant to ≥1 antibiotic, 43% resistant to ≥2 antibiotics, 15% resistant to ≥3 antibiotics, 4.9% resistant to ≥4 antibiotic and 1.2% resistant to ≥5 antibiotics. This data will serve in better understanding the environmental occurrence and dissemination of AMR/MDR in the area and assist in improving and establishing control measures.

Processing of Nanoporous Gold by Dealloying and its Morphological Control

2007 ◽  
Vol 561-565 ◽  
pp. 1657-1660 ◽  
Author(s):  
Masataka Hakamada ◽  
Mamoru Mabuchi
Keyword(s):  
Mechanical Properties ◽  
Thermal Treatment ◽  
Acid Treatment ◽  
Nanoporous Gold ◽  
Anisotropic Structure ◽  
Ideal Strength ◽  
Pore Characteristics ◽  
Very High ◽  
Ligament Size ◽  
The Ideal

Nanoporous gold was fabricated by dealloying and their pore characteristics were further modified by thermal or acid treatment. The fabricated nanoporous gold had a ligament size of approximately 5 nm. Thermal treatment on the nanoporous gold increased the ligament size to approximately 500 nm. During the thermal treatment, ligaments are bonded across the cracks which had been generated during the dealloying. Acid treatment also increased the ligament size to approximately 500 nm; however, the acid treatment had a different effect on the pore characteristics from the thermal treatment. As a result, nanoporous gold prism microassembly with anisotropic structure was spontaneously fabricated by the acid treatment. The mechanical properties of nanoporous gold were also examined. It is estimated that the yield strength of nanosized ligaments in nanoporous gold is very high and close to the ideal strength of gold.

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