46 CFR 160.052-1 - Incorporation by reference.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam... Preservers, Unicellular Plastic Foam, Adult and Child. 164.015—Plastic Foam, Unicellular, Buoyant Sheet and... manufactured, form a part of this subpart: Dwg. No. 160.052-1: Sheet 1—Cutting Pattern and General Arrangement...

46 CFR 164.015-3 - Material and workmanship.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-3 Material and workmanship. (a) The unicellular plastic foam shall be all new material complying with the... values within the limits shown in Table 164.015-4(a). (b) The unicellular plastic foam shall be produced...

46 CFR 26.30-1 - Approved unicellular plastic foam work vests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Approved unicellular plastic foam work vests. 26.30-1 Section 26.30-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS OPERATIONS Work Vest § 26.30-1 Approved unicellular plastic foam work vests. (a) Buoyant work vests carried under the...

46 CFR 26.30-1 - Approved unicellular plastic foam work vests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Approved unicellular plastic foam work vests. 26.30-1 Section 26.30-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS OPERATIONS Work Vest § 26.30-1 Approved unicellular plastic foam work vests. (a) Buoyant work vests carried under the...

46 CFR 26.30-1 - Approved unicellular plastic foam work vests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Approved unicellular plastic foam work vests. 26.30-1 Section 26.30-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS OPERATIONS Work Vest § 26.30-1 Approved unicellular plastic foam work vests. (a) Buoyant work vests carried under the...

46 CFR 26.30-1 - Approved unicellular plastic foam work vests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Approved unicellular plastic foam work vests. 26.30-1 Section 26.30-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS OPERATIONS Work Vest § 26.30-1 Approved unicellular plastic foam work vests. (a) Buoyant work vests carried under the...

46 CFR 26.30-1 - Approved unicellular plastic foam work vests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Approved unicellular plastic foam work vests. 26.30-1 Section 26.30-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS OPERATIONS Work Vest § 26.30-1 Approved unicellular plastic foam work vests. (a) Buoyant work vests carried under the...

Distortion-free foamed-plastic parts

NASA Technical Reports Server (NTRS)

Hogenson, P. A.; Jackson, R. G.

1979-01-01

In process for molding foamed-plastic products, gases that are formed as byproducts of foaming reaction escape through perforated die. Thus, volatiles are not trapped in pockets that can deform and weaken the molded part.

In Situ Observation of Plastic Foaming under Static Condition, Extensional Flow and Shear Flow

NASA Astrophysics Data System (ADS)

Wong, Anson Sze Tat

Traditional blowing agents (e.g., hydrochlorofluorocarbons) in plastic foaming processes has been phasing out due to environmental regulations. Plastic foaming industry is forced to employ greener alternatives (e.g., carbon dioxide, nitrogen), but their foaming processes are technologically challenging. Moreover, to improve the competitiveness of the foaming industry, it is imperative to develop a new generation of value-added plastic foams with cell structures that can be tailored to different applications. In this context, the objective of this thesis is to achieve a thorough understanding on cell nucleation and growth phenomena that determine cell structures in plastic foaming processes. The core research strategy is to develop innovative visualization systems to capture and study these phenomena. A system with accurate heating and cooling control has been developed to observe and study crystallization-induced foaming behaviors of polymers under static conditions. The cell nucleation and initial growth behavior of polymers blown with different blowing agents (nitrogen, argon and helium, and carbon dioxide-nitrogen mixtures) have also been investigated in great detail. Furthermore, two innovative systems have been developed to simulate the dynamic conditions in industrial foaming processes: one system captures a foaming process under an easily adjustable and uniform extensional strain in a high temperature and pressure environment, while the other achieves the same target, but with shear strain. Using these systems, the extensional and shear effects on bubble nucleation and initial growth processes has been investigated independently in an isolated manner, which has never been achieved previously. The effectiveness of cell nucleating agents has also been evaluated under dynamic conditions, which have led to the identification of new foaming mechanisms based on polymer-chain alignment and generation of microvoids under stress. Knowledge generated from these researches and the wide range of future studies made possible by the visualization systems will be valuable to the development of innovative plastic foaming technologies and foams.

Compact assembly generates plastic foam, inflates flotation bag

NASA Technical Reports Server (NTRS)

1965-01-01

Device for generating plastic foam consists of an elastomeric bag and two containers with liquid resin and a liquid catalyst. When the walls of the containers are ruptured the liquids come into contact producing foam which inflates the elastomeric bag.

46 CFR 164.015-5 - Procedure for acceptance.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: SPECIFICATIONS AND APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-5 Procedure for acceptance. (a) Unicellular plastic foam is not subject to formal approval, but will be... manufacturing methods and to select from foam already manufactured sufficient sample material for testing for...

Physicomechanical Characteristics of Spray-On Rigid Polyurethane Foams at Normal and Low Temperatures

NASA Astrophysics Data System (ADS)

Yakushin, V. A.; Zhmud', N. P.; Stirna, U. K.

2002-05-01

The effect of processing factors on the inhomogeneity and physicomechanical characteristics of spray-on polyurethane foams is studied. The dependences of the basic characteristics of foam plastics on the apparent density and cell-shape factor are determined. A method is offered for evaluating the effect of the technological surface skin on the tensile characteristics of foam plastics under normal and low temperatures.

46 CFR 160.055-5 - Construction-standard life preservers.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic...) General. This specification covers life preservers which essentially consist of plastic foam buoyant... dip coated life preserver. This device is constructed from one piece of unicellular plastic foam with...

46 CFR 160.055-5 - Construction-standard life preservers.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic...) General. This specification covers life preservers which essentially consist of plastic foam buoyant... dip coated life preserver. This device is constructed from one piece of unicellular plastic foam with...

46 CFR 160.055-5 - Construction-standard life preservers.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic...) General. This specification covers life preservers which essentially consist of plastic foam buoyant... dip coated life preserver. This device is constructed from one piece of unicellular plastic foam with...

Heavy metals, metalloids and other hazardous elements in marine plastic litter.

PubMed

Turner, Andrew

2016-10-15

Plastics, foams and ropes collected from beaches in SW England have been analysed for As, Ba, Br, Cd, Cl, Cr, Cu, Hg, Ni, Pb, Sb, Se, Sn and Zn by field-portable-x-ray fluorescence spectrometry. High concentrations of Cl in foams that were not PVC-based were attributed to the presence of chlorinated flame retardants. Likewise, high concentrations of Br among both foams and plastics were attributed to the presence of brominated flame retardants. Regarding heavy metals and metalloids, Cd and Pb were of greatest concern from an environmental perspective. Lead was encountered in plastics, foams and ropes and up to concentrations of 17,500μgg(-1) due to its historical use in stabilisers, colourants and catalysts in the plastics industry. Detectable Cd was restricted to plastics, where its concentration often exceeded 1000μgg(-1); its occurrence is attributed to the use of both Cd-based stabilisers and colourants in a variety of products. Copyright © 2016 Elsevier Ltd. All rights reserved.

46 CFR 164.015-4 - Inspections and tests.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: SPECIFICATIONS AND APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-4 Inspections and tests. (a) General. Unicellular plastic foam to be used in a finished product subject to inspection by the Coast Guard also shall be subject to inspection at the plant where the foam is manufactured...

46 CFR 164.015-4 - Inspections and tests.

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-4 Inspections and tests. (a) General. Unicellular plastic foam to be used in a finished product subject to inspection by the Coast Guard also shall be subject to inspection at the plant where the foam is manufactured...

46 CFR 164.015-4 - Inspections and tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-4 Inspections and tests. (a) General. Unicellular plastic foam to be used in a finished product subject to inspection by the Coast Guard also shall be subject to inspection at the plant where the foam is manufactured...

46 CFR 164.015-4 - Inspections and tests.

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-4 Inspections and tests. (a) General. Unicellular plastic foam to be used in a finished product subject to inspection by the Coast Guard also shall be subject to inspection at the plant where the foam is manufactured...

46 CFR 160.049-4 - Construction and workmanship.

Code of Federal Regulations, 2011 CFR

2011-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam... box type filled with unicellular plastic foam buoyant material. Such cushions consist essentially of a...

46 CFR 160.049-4 - Construction and workmanship.

Code of Federal Regulations, 2014 CFR

2014-10-01

... MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam... box type filled with unicellular plastic foam buoyant material. Such cushions consist essentially of a...

Stochastic metallic-glass cellular structures exhibiting benchmark strength.

PubMed

Demetriou, Marios D; Veazey, Chris; Harmon, John S; Schramm, Joseph P; Johnson, William L

2008-10-03

By identifying the key characteristic "structural scales" that dictate the resistance of a porous metallic glass against buckling and fracture, stochastic highly porous metallic-glass structures are designed capable of yielding plastically and inheriting the high plastic yield strength of the amorphous metal. The strengths attainable by the present foams appear to equal or exceed those by highly engineered metal foams such as Ti-6Al-4V or ferrous-metal foams at comparable levels of porosity, placing the present metallic-glass foams among the strongest foams known to date.

46 CFR 160.049-7 - Procedure for approval.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-7... be granted separately to each manufacturer for each unicellular plastic foam buoyant cushion he...

46 CFR 160.053-2 - Type.

Code of Federal Regulations, 2010 CFR

2010-10-01

... APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-2 Type. (a) Unicellular plastic foam work vests specified by this subpart shall be of the type described in Military Specification...

46 CFR 160.053-2 - Type.

Code of Federal Regulations, 2011 CFR

2011-10-01

... APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-2 Type. (a) Unicellular plastic foam work vests specified by this subpart shall be of the type described in Military Specification...

46 CFR 160.049-7 - Procedure for approval.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-7... be granted separately to each manufacturer for each unicellular plastic foam buoyant cushion he...

46 CFR 160.053-2 - Type.

Code of Federal Regulations, 2013 CFR

2013-10-01

... APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-2 Type. (a) Unicellular plastic foam work vests specified by this subpart shall be of the type described in Military Specification...

46 CFR 160.053-2 - Type.

Code of Federal Regulations, 2012 CFR

2012-10-01

... APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-2 Type. (a) Unicellular plastic foam work vests specified by this subpart shall be of the type described in Military Specification...

46 CFR 160.053-2 - Type.

Code of Federal Regulations, 2014 CFR

2014-10-01

... APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-2 Type. (a) Unicellular plastic foam work vests specified by this subpart shall be of the type described in Military Specification...

46 CFR 160.049-7 - Procedure for approval.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-7... be granted separately to each manufacturer for each unicellular plastic foam buoyant cushion he...

46 CFR 160.010-1 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Specification, Plastic Material, Cellular Polyurethane, Foam-In-Place, Rigid (2 and 4 Pounds per Cubic Foot....mil/quicksearch/. (1) MIL-P-19644C, Military Specification, Plastic Molding Material (Polystyrene Foam...

46 CFR 160.010-1 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Specification, Plastic Material, Cellular Polyurethane, Foam-In-Place, Rigid (2 and 4 Pounds per Cubic Foot....mil/quicksearch/. (1) MIL-P-19644C, Military Specification, Plastic Molding Material (Polystyrene Foam...

46 CFR 160.053-1 - Applicable specifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-1 Applicable... plastic foam work vests are manufactured, form a part of this subpart: (1) Military specification: MIL-L-17653A—Life Preserver, Vest, Work Type, Unicellular Plastic. (2) [Reserved] (b) Copies on file. Copies of...

46 CFR 160.053-1 - Applicable specifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-1 Applicable... plastic foam work vests are manufactured, form a part of this subpart: (1) Military specification: MIL-L-17653A—Life Preserver, Vest, Work Type, Unicellular Plastic. (2) [Reserved] (b) Copies on file. Copies of...

46 CFR 160.053-1 - Applicable specifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-1 Applicable... plastic foam work vests are manufactured, form a part of this subpart: (1) Military specification: MIL-L-17653A—Life Preserver, Vest, Work Type, Unicellular Plastic. (2) [Reserved] (b) Copies on file. Copies of...

46 CFR 160.053-1 - Applicable specifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... plastic foam work vests are manufactured, form a part of this subpart: (1) Military specification: MIL-L-17653A—Life Preserver, Vest, Work Type, Unicellular Plastic. (2) [Reserved] (b) Copies on file. Copies of...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-1 Applicable...

46 CFR 160.053-1 - Applicable specifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-1 Applicable... plastic foam work vests are manufactured, form a part of this subpart: (1) Military specification: MIL-L...

46 CFR 164.015-2 - Types.

Code of Federal Regulations, 2010 CFR

2010-10-01

... APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-2 Types. (a..., polymer or copolymer plastic foam shall be of three types as follows: Type A—for life preservers, buoyant...

46 CFR 164.015-2 - Types.

Code of Federal Regulations, 2011 CFR

2011-10-01

... APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-2 Types. (a..., polymer or copolymer plastic foam shall be of three types as follows: Type A—for life preservers, buoyant...

46 CFR 164.015-2 - Types.

Code of Federal Regulations, 2014 CFR

2014-10-01

... APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-2 Types. (a..., polymer or copolymer plastic foam shall be of three types as follows: Type A—for life preservers, buoyant...

Fire Resistant Composite Closed Cell Foam and Nonwoven Textiles for Tents and Shelters

DTIC Science & Technology

2006-01-01

when heated. The heat causes the plasticizer to dissolve in the PVC to form a flexible, plasticized PVC film . The foam and/or fabric surfaces were...PVC/NBR AF-U9D foam formed a char and only the edge of the material was damaged. These data suggested that burn-through resistance , in addition to...AFRL-ML-TY-TR-2006-4571 FIRE RESISTANT COMPOSITE CLOSED CELL FOAM AND NONWOVEN TEXTILES FOR TENTS AND SHELTERS Stephen C. Davis

Evolution of shock through a void in foam

NASA Astrophysics Data System (ADS)

Kim, Y.; Smidt, J. M.; Murphy, T. J.; Douglass, M. R.; Devolder, B. G.; Fincke, J. R.; Schmidt, D. W.; Cardenas, T.; Newman, S. G.; Hamilton, C. E.; Sedillo, T. J.; Los Alamos, NM 87544 Team

2016-10-01

Marble implosion is an experimental campaign intended to study the effects of heterogeneous mix on fusion burn. A spherical capsule is composed of deuterated plastic foam of controlled pore (or void) size with tritium fill in pores. As capsule implosion evolves, the initially separated deuterium and tritium will mix, producing DT yields. Void evolution during implosion is of interest for the Marble campaign. A shock tube, driven by the laser at Omega, was designed to study the evolution of a shock through a foam-filled ``void'' and subsequent void evolution. Targets were comprised of a 100 mg/cc CH foam tube containing a 200-µm diameter, lower density doped foam sphere. High-quality, radiographic images were obtained from both 2% iodine-doped in plastic foam and 15% tin-doped in aerogel foam. These experiments will be used to inform simulations.

Plastic Materials for Insulating Applications.

ERIC Educational Resources Information Center

Wang, S. F.; Grossman, S. J.

1987-01-01

Discusses the production and use of polymer materials as thermal insulators. Lists several materials that provide varying degrees of insulation. Describes the production of polymer foam and focuses on the major applications of polystyrene foam, polyurethane foam, and polyisocyanurate foam. (TW)

Starch/fiber/poly(lactic acid) foam and compressed foam composites

USDA-ARS?s Scientific Manuscript database

Composites of starch, fiber, and poly(lactic acid) (PLA) were made using a foam substrate formed by dehydrating starch or starch/fiber gels. PLA was infiltrated into the dry foam to provide better moisture resistance. Foam composites were compressed into plastics using force ranging from 4-76MPa. Te...

Polystyrene Foam Products Equation of State as a Function of Porosity and Fill Gas

NASA Astrophysics Data System (ADS)

Mulford, R. N.; Swift, D. C.

2009-12-01

An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO2-blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O2-blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO2 decomposes at high temperatures.

46 CFR 164.015-1 - Applicable specifications and standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet... following specification and standard, of the issue in effect on the date the plastic foam material is...) ASTM D4986-98, Standard Test Method for Horizontal Burning Characteristics of Cellular Polymeric...

46 CFR 160.035-1 - Applicable specifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Laminates, Fibrous Glass Reinforced, Marine Structural. MIL-P-19644—Plastic Foam, Molded Polystyrene..., Polyester, Low Pressure Laminating, Fire Retardant. MIL-P-21929—Plastic Material, Cellular Polyurethane, Rigid, Foam-In-Place, Low Density. (3) Federal specifications: TT-P-59—Paint, Ready-Mixed, International...

46 CFR 160.035-1 - Applicable specifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Laminates, Fibrous Glass Reinforced, Marine Structural. MIL-P-19644—Plastic Foam, Molded Polystyrene..., Polyester, Low Pressure Laminating, Fire Retardant. MIL-P-21929—Plastic Material, Cellular Polyurethane, Rigid, Foam-In-Place, Low Density. (3) Federal specifications: TT-P-59—Paint, Ready-Mixed, International...

Numerical modeling of the effect of heat and mass transfer in porous low-temperature heat insulation in composite material structures on the magnitude of stresses which develop

NASA Astrophysics Data System (ADS)

Kuznetsov, G. V.; Rudzinskaya, N. V.

1997-05-01

The stressed state of multilayer low-temperature heat insulation for a cryogenic fuel tank is considered. Account is taken of heat and mass transfer in foam plastic (the main heat insulation material) occurring at cryogenic temperatures. A method is developed for solving a set of differential equations and boundary conditions. Numerical studies of the main features of these processes are performed. It is established that below 200 K the stresses which arise in foam plastic markedly exceed the ultimate strength for this material. Stresses develop as a result of both a reduction in temperature and a drop in pressure in the foam plastic pores connected with material cooling. On the basis of the results obtained it is established that the combination of thermophysical processes which occur in foam plastic during cooling to cryogenic temperatures leads to changes in the stress-strained state of structure, which should be considered in planning aerospace technology.

Foam rheology at large deformation

NASA Astrophysics Data System (ADS)

Géminard, J.-C.; Pastenes, J. C.; Melo, F.

2018-04-01

Large deformations are prone to cause irreversible changes in materials structure, generally leading to either material hardening or softening. Aqueous foam is a metastable disordered structure of densely packed gas bubbles. We report on the mechanical response of a foam layer subjected to quasistatic periodic shear at large amplitude. We observe that, upon increasing shear, the shear stress follows a universal curve that is nearly exponential and tends to an asymptotic stress value interpreted as the critical yield stress at which the foam structure is completely remodeled. Relevant trends of the foam mechanical response to cycling are mathematically reproduced through a simple law accounting for the amount of plastic deformation upon increasing stress. This view provides a natural interpretation to stress hardening in foams, demonstrating that plastic effects are present in this material even for minute deformation.

Experimental demonstration of laser imprint reduction using underdense foams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delorme, B.; Casner, A.; CELIA, University of Bordeaux-CNRS-CEA, F-33400 Talence

2016-04-15

Reducing the detrimental effect of the Rayleigh-Taylor (RT) instability on the target performance is a critical challenge. In this purpose, the use of targets coated with low density foams is a promising approach to reduce the laser imprint. This article presents results of ablative RT instability growth measurements, performed on the OMEGA laser facility in direct-drive for plastic foils coated with underdense foams. The laser beam smoothing is explained by the parametric instabilities developing in the foam and reducing the laser imprint on the plastic (CH) foil. The initial perturbation pre-imposed by the means of a specific phase plate wasmore » shown to be smoothed using different foam characteristics. Numerical simulations of the laser beam smoothing in the foam and of the RT growth are performed with a suite of paraxial electromagnetic and radiation hydrodynamic codes. They confirmed the foam smoothing effect in the experimental conditions.« less

46 CFR 164.015-5 - Procedure for acceptance.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: SPECIFICATIONS AND APPROVAL MATERIALS Plastic Foam, Unicellular, Buoyant, Sheet and Molded Shape § 164.015-5 Procedure for acceptance. (a) Unicellular plastic foam is not subject to formal approval, but will be... District will detail a marine inspector to the factory to observe the production facilities and...

46 CFR 160.010-5 - Buoyant apparatus with plastic foam buoyancy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Buoyant apparatus with plastic foam buoyancy. 160.010-5 Section 160.010-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Buoyant Apparatus for Merchant...

46 CFR 160.010-5 - Buoyant apparatus with plastic foam buoyancy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Buoyant apparatus with plastic foam buoyancy. 160.010-5 Section 160.010-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Buoyant Apparatus for Merchant...

46 CFR 160.052-5 - Construction-standard vests.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam... arranged and distributed so as to provide the flotation characteristics and buoyancy required to hold the...) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as shown on Dwg. 160...

Structure formation control of foam concrete

NASA Astrophysics Data System (ADS)

Steshenko, Aleksei; Kudyakov, Aleksander; Konusheva, Viktoriya; Syrkin, Oleg

2017-01-01

The process of predetermined foam concrete structure formation is considered to be a crucial issue from the point of process control and it is currently understudied thus defining the need for additional research. One of the effective ways of structure formation control in naturally hardening foam concrete is reinforcement with dispersed fibers or introduction of plasticizers. The paper aims at studying the patterns of influence of microreinforcing and plasticizing additives on the structure and performance properties of foam concrete. Preparation of foam concrete mix has been conducted using one-step technology. The structure of modified foam concrete has been studied by means of electron microscopy. The cellular structure of foam concrete samples with the additives is homogeneous; the pores are uniformly distributed over the total volume. It has been revealed that introduction of the Neolas 5.2 plasticizer and microreinforcing fibers in the foam concrete mixture in the amount of 0.4 - 0.1 % by weight of cement leads to reduction of the average pore diameter in the range of 45.3 to 30.2 microns and the standard deviation of the pore average diameter from 23.6 to 9.2 in comparison with the sample without additive. Introduction of modifying additives has stimulated formation of a large number of closed pores. Thus porosity of conditionally closed pores has increased from 16.06 % to 34.48 %, which has lead to increase of frost resistance brand of foam concrete from F15 to F50 and to reduction of its water absorption by weight by 20 %.

40 CFR 82.62 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... distributes that product in interstate commerce for export from the United States. Foam Insulation Product, when used to describe a product containing or consisting of plastic foam, means a product containing or consisting of the following types of foam: (1) Closed cell rigid polyurethane foam; (2) Closed cell rigid...

40 CFR 82.62 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... distributes that product in interstate commerce for export from the United States. Foam Insulation Product, when used to describe a product containing or consisting of plastic foam, means a product containing or consisting of the following types of foam: (1) Closed cell rigid polyurethane foam; (2) Closed cell rigid...

40 CFR 82.62 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... distributes that product in interstate commerce for export from the United States. Foam Insulation Product, when used to describe a product containing or consisting of plastic foam, means a product containing or consisting of the following types of foam: (1) Closed cell rigid polyurethane foam; (2) Closed cell rigid...

40 CFR 82.62 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... distributes that product in interstate commerce for export from the United States. Foam Insulation Product, when used to describe a product containing or consisting of plastic foam, means a product containing or consisting of the following types of foam: (1) Closed cell rigid polyurethane foam; (2) Closed cell rigid...

The effects of foaming conditions on plasticized polyvinyl chloride foam morphology by using liquid carbon dioxide

NASA Astrophysics Data System (ADS)

Chuaponpat, N.; Areerat, S.

2017-11-01

This research studies the effects of foaming conditions by using liquid carbon dioxide (CO2) as a physical blowing agent on plasticized polyvinyl chloride (PVC) foam morphology. Foaming conditions were soaking time of 6, 10, and 12 h, foaming temperature of 70, 80, 90 °C for 5 s, at constant soaking temperature of -20 °C and pressure of 50 bar. Instantaneously increasing temperature was employed in this process for making foam structure. PVC foam samples were calculated percentage of shrinkage (Sh) by using density at before and after aging process at 30 °C for 12 h. When PVC samples were activated to form foam by using liquid CO2 as a physical blowing agent, it reveal bimodal foam structure with a thick bubble wall (10-20 μm). Bubble diameter of PVC foam at longer soaking time is in the range of 40-60 μm and its at shorter soaking time reveal a large bubble that is in the range of 80-120 μm. Foaming condition slightly affected to bubble density that was in the narrow range of 106-108 bubbles/cm3. PVC foam reveal reduction of density up to 65% when compare with PVC and Sh is less than 10%.

Polystyrene foam products equation of state as a function of porosity and fill gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulford, Roberta N; Swift, Damian C

2009-01-01

An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO{sub 2}-blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O{submore » 2}-blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO{sub 2} decomposes at high temperatures.« less

46 CFR 160.052-5 - Construction-standard vests.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as shown on Dwg. 160...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam.... Two pieces of fabric shall be cut to the pattern shown on Dwg. No. 160.052-1, Sheet 1 for adult size...

46 CFR 160.052-5 - Construction-standard vests.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as shown on Dwg. 160...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam.... Two pieces of fabric shall be cut to the pattern shown on Dwg. No. 160.052-1, Sheet 1 for adult size...

46 CFR 160.052-5 - Construction-standard vests.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as shown on Dwg. 160...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam.... Two pieces of fabric shall be cut to the pattern shown on Dwg. No. 160.052-1, Sheet 1 for adult size...

46 CFR 160.052-5 - Construction-standard vests.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as shown on Dwg. 160...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam.... Two pieces of fabric shall be cut to the pattern shown on Dwg. No. 160.052-1, Sheet 1 for adult size...

Failure Maps for Rectangular 17-4PH Stainless Steel Sandwiched Foam Panels

NASA Technical Reports Server (NTRS)

Raj, S. V.; Ghosn, L. J.

2007-01-01

A new and innovative concept is proposed for designing lightweight fan blades for aircraft engines using commercially available 17-4PH precipitation hardened stainless steel. Rotating fan blades in aircraft engines experience a complex loading state consisting of combinations of centrifugal, distributed pressure and torsional loads. Theoretical failure plastic collapse maps, showing plots of the foam relative density versus face sheet thickness, t, normalized by the fan blade span length, L, have been generated for rectangular 17-4PH sandwiched foam panels under these three loading modes assuming three failure plastic collapse modes. These maps show that the 17-4PH sandwiched foam panels can fail by either the yielding of the face sheets, yielding of the foam core or wrinkling of the face sheets depending on foam relative density, the magnitude of t/L and the loading mode. The design envelop of a generic fan blade is superimposed on the maps to provide valuable insights on the probable failure modes in a sandwiched foam fan blade.

Results from the MARBLE Campaign on the National Ignition Facility: Implosion of Foam-Filled Capsules for Studying Thermonuclear Burn in the Presence of Heterogeneous Mix

NASA Astrophysics Data System (ADS)

Murphy, T. J.; Douglas, M. R.; Cardenas, T.; Devolder, B. G.; Fincke, J. R.; Gunderson, M. A.; Haines, B. M.; Hamilton, C. E.; Kim, Y. H.; Lee, M. N.; Oertel, J. A.; Olson, R. E.; Randolph, R. B.; Shah, R. C.; Smidt, J. M.

2016-10-01

The MARBLE campaign on NIF investigates the effect of heterogeneous mix on thermonuclear burn for comparison to a probability distribution function (PDF) burn model. MARBLE utilizes plastic capsules filled with deuterated plastic foam and tritium gas. The ratio of DT to DD neutron yield is indicative of the degree to which the foam and the gas atomically mix. Platform development experiments have been performed to understand the behavior of the foam and of the gas separately using two types of capsule. The first uses partially deuterated foam and hydrogen gas fill to understand the burn in the foam. The second uses undeuterated foam and deuterium gas fill to understand the dynamics of the gas. Experiments using deuterated foam and tritium gas are planned. Results of these experiments, and the implications for our understanding of thermonuclear burn in heterogeneously mixed separated reactant experiments will be discussed. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

Plastic Foam Withstands Greater Temperatures And Pressures

NASA Technical Reports Server (NTRS)

Cranston, John A.; Macarthur, Doug

1993-01-01

Improved plastic foam suitable for use in foam-core laminated composite parts and in tooling for making fiber/matrix-composite parts. Stronger at high temperatures, more thermally and dimensionally stable, machinable, resistant to chemical degradation, and less expensive. Compatible with variety of matrix resins. Made of polyisocyanurate blown with carbon dioxide and has density of 12 to 15 pounds per cubic feet. Does not contibute to depletion of ozone from atmosphere. Improved foam used in cores of composite panels in such diverse products as aircraft, automobiles, railroad cars, boats, and sporting equipment like surfboards, skis, and skateboards. Also used in thermally stable flotation devices in submersible vehicles. Machined into mandrels upon which filaments wound to make shells.

Foam Insulation for Cryogenic Flowlines

NASA Technical Reports Server (NTRS)

Sonju, T. R.; Carbone, R. L.; Oves, R. E.

1985-01-01

Welded stainless-steel vacuum jackets on cryogenic ducts replaced by plastic foam-insulation jackets that weigh 12 percent less. Foam insulation has 85 percent of insulating ability of stainless-steel jacketing enclosing vacuum of 10 microns of mercury. Foam insulation easier to install than vacuum jacket. Moreover, foam less sensitive to damage and requires minimal maintenance. Resists vibration and expected to have service life of at least 10 years.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neilsen, Michael K.; Lu, Wei-Yang; Scherzinger, William M.

Numerous experiments were performed to characterize the mechanical response of several different rigid polyurethane foams (FR3712, PMDI10, PMDI20, and TufFoam35) to large deformation. In these experiments, the effects of load path, loading rate, and temperature were investigated. Results from these experiments indicated that rigid polyurethane foams exhibit significant volumetric and deviatoric plasticity when they are compressed. Rigid polyurethane foams were also found to be very strain-rate and temperature dependent. These foams are also rather brittle and crack when loaded to small strains in tension or to larger strains in compression. Thus, a new Unified Creep Plasticity Damage (UCPD) model wasmore » developed and implemented into SIERRA with the name Foam Damage to describe the mechanical response of these foams to large deformation at a variety of temperatures and strain rates. This report includes a description of recent experiments and experimental findings. Next, development of a UCPD model for rigid, polyurethane foams is described. Selection of material parameters for a variety of rigid polyurethane foams is then discussed and finite element simulations with the new UCPD model are compared with experimental results to show behavior that can be captured with this model.« less

Biot theory and acoustical properties of high porosity fibrous materials and plastic foams

NASA Technical Reports Server (NTRS)

Allard, J.; Aknine, A.

1987-01-01

Experimental values of acoustic wave propagation constant and characteristic impedance in fibrous materials, and normal absorption for two plastic foams, were compared to theoretical predictions obtained with Biot's theory. The best agreement was observed for fibrous materials between Biot's theory and Delany and Bazley experiments for a nearly zero mass coupling parameter. For foams, the lambda/4 structure resonance effect on absorption was calculated by using four-pole modelling of the medium. A significant mass coupling parameter is then necessary for obtaining agreement between the behavior of the measured absorption coefficients and the theoretical predictions. It is shown how the formalism used for predicting foams absorption coefficients may be used for studying the acoustic behavior of multi-layered media.

Shooting in a foam.

PubMed

Le Goff, Anne; Quéré, David; Clanet, Christophe

2014-09-21

We study the motion of a solid sphere after its fast impact on a bath of liquid foam. We identify two regimes of deceleration. At short times, the velocity is still large and the foam behaves similar to a Newtonian fluid of constant viscosity. Then we measure a velocity threshold below which the sphere starts experiencing the foam's elasticity. We interpret this behavior using a visco-elasto-plastic model for foam rheology. Finally we discuss the possibility of stopping a projectile in the foam, and evaluate the capture efficiency.

Fabrication of superhydrophobic film by microcellular plastic foaming method

NASA Astrophysics Data System (ADS)

Zhang, Zhen Xiu; Li, Ya Nan; Xia, Lin; Ma, Zhen Guo; Xin, Zhen Xiang; Kim, Jin Kuk

2014-08-01

To solve the complicated manufacturing operation and the usage of toxic solvent problems, a simple and novel method to fabricate superhydrophobic film by surface foaming method was introduced in this paper. The superhydrophobic property of the foamed material was obtained at a contact angle >150° and a rolling angle about 8°. The foamed material can instantly generate its superhydrophobicity via peeling process. The effects of blowing agent content, foaming time and peeling rate on the foam structure and superhydrophobicity were studied.

Results from MARBLE DT Experiments on the National Ignition Facility: Implosion of Foam-Filled Capsules for Studying Thermonuclear Burn in the Presence of Heterogeneous Mix

NASA Astrophysics Data System (ADS)

Murphy, T. J.; Douglas, M. R.; Cardenas, T.; Cooley, J. H.; Gunderson, M. A.; Haines, B. M.; Hamilton, C. E.; Kim, Y.; Lee, M. N.; Oertel, J. A.; Olson, R. E.; Randolph, R. B.; Shah, R. C.; Smidt, J. M.

2017-10-01

The MARBLE campaign on NIF investigates the effect of heterogeneous mix on thermonuclear burn for comparison to a probability distribution function (PDF) burn model. MARBLE utilizes plastic capsules filled with deuterated plastic foam and tritium gas. The ratio of DT to DD neutron yield is indicative of the degree to which the foam and the gas atomically mix. Platform development experiments have been performed to understand the behavior of the foam and of the gas separately using two types of capsule. The first experiments using deuterated foam and tritium gas have been performed. Results of these experiments, and the implications for our understanding of thermonuclear burn in heterogeneously mixed separated reactant experiments will be discussed. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

Salmonella transfer during pilot plant scale washing and roller conveying of tomatoes.

PubMed

Wang, Haiqiang; Ryser, Elliot T

2014-03-01

Salmonella transfer during washing and roller conveying of inoculated tomatoes was quantified using a pilot scale tomato packing line equipped with plastic, foam, or brush rollers. Red round tomatoes (2.3 kg) were dip inoculated with Salmonella enterica serovar Typhimurium LT2 (avirulent) (4 log CFU/g), air dried for 2 h, and then washed in sanitizer-free water for 2 min. Inoculated tomatoes were then passed single file over a 1.5-m conveyor equipped with plastic, foam, or brush rollers followed by 25 previously washed uninoculated tomatoes. Tomato samples were collected after 2 min of both washing and roller conveying, with all 25 uninoculated tomatoes collected individually after conveying. Roller surface samples were collected before and after conveying the uninoculated tomatoes. Both tomato and surface samples were quantitatively examined for Salmonella by direct plating or membrane filtration using xylose lysine Tergitol 4 agar. Regardless of the roller type, Salmonella populations on inoculated tomatoes did not significantly (P < 0.05) decrease during contact with the roller conveyors. After conveying uninoculated tomatoes over contaminated foam rollers, 96% of the 25 tomatoes were cross-contaminated with Salmonella at >100 CFU per tomato. With plastic rollers, 24 and 76% of tomatoes were cross-contaminated with Salmonella at 10 to 100 and 1 to 10 CFU per tomato, respectively. In contrast, only 8% of 25 tomatoes were cross-contaminated with brush rollers with Salmonella populations of 1 to 10 CFU per tomato. Overall, cross-contamination was greatest with foam, followed by plastic and brush rollers (P < 0.05). Adding peroxyacetic acid or chlorine to the wash water significantly decreased cross-contamination during tomato conveying, with chlorine less effective in controlling Salmonella on foam compared with plastic and brush rollers.

Experimental and numerical characterisation of the elasto-plastic properties of bovine trabecular bone and a trabecular bone analogue.

PubMed

Kelly, Nicola; McGarry, J Patrick

2012-05-01

The inelastic pressure dependent compressive behaviour of bovine trabecular bone is investigated through experimental and computational analysis. Two loading configurations are implemented, uniaxial and confined compression, providing two distinct loading paths in the von Mises-pressure stress plane. Experimental results reveal distinctive yielding followed by a constant nominal stress plateau for both uniaxial and confined compression. Computational simulation of the experimental tests using the Drucker-Prager and Mohr-Coulomb plasticity models fails to capture the confined compression behaviour of trabecular bone. The high pressure developed during confined compression does not result in plastic deformation using these formulations, and a near elastic response is computed. In contrast, the crushable foam plasticity models provide accurate simulation of the confined compression tests, with distinctive yield and plateau behaviour being predicted. The elliptical yield surfaces of the crushable foam formulations in the von Mises-pressure stress plane accurately characterise the plastic behaviour of trabecular bone. Results reveal that the hydrostatic yield stress is equal to the uniaxial yield stress for trabecular bone, demonstrating the importance of accurate characterisation and simulation of the pressure dependent plasticity. It is also demonstrated in this study that a commercially available trabecular bone analogue material, cellular rigid polyurethane foam, exhibits similar pressure dependent yield behaviour, despite having a lower stiffness and strength than trabecular bone. This study provides a novel insight into the pressure dependent yield behaviour of trabecular bone, demonstrating the inadequacy of uniaxial testing alone. For the first time, crushable foam plasticity formulations are implemented for trabecular bone. The enhanced understanding of the inelastic behaviour of trabecular bone established in this study will allow for more realistic simulation of orthopaedic device implantation and failure. Copyright © 2011 Elsevier Ltd. All rights reserved.

Persistent organic pollutants in plastic marine debris found on beaches in San Diego, California.

PubMed

Van, Almira; Rochman, Chelsea M; Flores, Elisa M; Hill, Kish L; Vargas, Erica; Vargas, Serena A; Hoh, Euhna

2012-01-01

Plastic debris were collected from eight beaches around San Diego County, California. Debris collected include: pre-production pellets and post-consumer plastics including fragments, polystyrene (PS) foam, and rubber. A total of n = 2453 pieces were collected ranging from <5 mm to 50 mm in size. The plastic pieces were separated by type, location, and appearance and analyzed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and its breakdown products, and chlordanes. PAH concentrations ranged from 30 ng g(-1) to 1900 ng g(-1), PCBs from non-detect to 47 ng g(-1), chlordanes from 1.8 ng g(-1) to 60 ng g(-1), and DDTs from non-detect to 76 ng g(-1). Consistently higher PAH concentrations found in PS foam samples (300-1900 ng g(-1)) led us to examine unexposed PS foam packaging materials and PS virgin pellets. Unexposed PS foam contained higher concentrations of PAHs (240-1700 ng g(-1)) than PS virgin pellets (12-15 ng g(-1)), suggesting that PAHs may be produced during manufacturing. Temporal trends of debris were investigated at one site, Ocean Beach, where storm events and beach maintenance were found to be important variables influencing debris present at a given time. Copyright © 2011 Elsevier Ltd. All rights reserved.

Results from and Plans for the Development of the MARBLE Platform for Studying Thermonuclear Burn in the Presence of Heterogeneous Mix on OMEGA and the National Ignition Facility

NASA Astrophysics Data System (ADS)

Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; Cobble, J. A.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Olson, R. E.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

2015-11-01

Work is underway to develop the MARBLE ICF platform for use on OMEGA and NIF in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. Experiments have been performed on OMEGA and are planned for NIF to develop techniques and verify that with uniform fine-pore foam, these implosions behave like atomically mixed plastic and gas. Results will be reviewed and future experiments discussed. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

33 CFR 183.552 - Plastic encased fuel tanks: Installation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Plastic encased fuel tanks... § 183.552 Plastic encased fuel tanks: Installation. (a) Each fuel tank encased in cellular plastic foam or in fiber reinforced plastic must have the connections, fittings, and labels accessible for...

33 CFR 183.552 - Plastic encased fuel tanks: Installation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Plastic encased fuel tanks... § 183.552 Plastic encased fuel tanks: Installation. (a) Each fuel tank encased in cellular plastic foam or in fiber reinforced plastic must have the connections, fittings, and labels accessible for...

33 CFR 183.552 - Plastic encased fuel tanks: Installation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Plastic encased fuel tanks... § 183.552 Plastic encased fuel tanks: Installation. (a) Each fuel tank encased in cellular plastic foam or in fiber reinforced plastic must have the connections, fittings, and labels accessible for...

33 CFR 183.552 - Plastic encased fuel tanks: Installation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Plastic encased fuel tanks... § 183.552 Plastic encased fuel tanks: Installation. (a) Each fuel tank encased in cellular plastic foam or in fiber reinforced plastic must have the connections, fittings, and labels accessible for...

33 CFR 183.552 - Plastic encased fuel tanks: Installation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Plastic encased fuel tanks... § 183.552 Plastic encased fuel tanks: Installation. (a) Each fuel tank encased in cellular plastic foam or in fiber reinforced plastic must have the connections, fittings, and labels accessible for...

Resonance Tests on Glass Reinforced Plastic Composite Panels.

DTIC Science & Technology

1981-04-01

glass -- fibre woven roving and glass - fibre chopped strand mat. BP Cellobond A2785-CV resin was used to bond the glass fibre layers to the foam. A rib was...foam slabs were filled with putty. The differences between the panels were the number of layers of glass fibre used on each side, the density of the...ORGANISATION AERONAUTICAL RESEARCH LABORATORIES MELBOURNE, VICTORIA Structures Technical Memorandum 329 RESONANCE TESTS O GLASS REINFORCED PLASTIC

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Foam § 160.053-3 Materials, construction and workmanship. (a) General. Except as otherwise specifically... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements...

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Foam § 160.053-3 Materials, construction and workmanship. (a) General. Except as otherwise specifically... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements...

The performance of lightweight plastic foams developed for fire safety

NASA Technical Reports Server (NTRS)

Fish, R. H.

1971-01-01

The use of a low density, polyurethane based foam to suppress a fire and to provide protection for the structure of an aircraft or spacecraft is discussed. The mechanism by which foams provide protection from heat and create a nonflammable surface is described. Various materials and their application to specific types of structures are examined.

46 CFR 160.010-1 - Incorporation by reference.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (Polystyrene Foam, Expanded Bead), (July 10, 1970), IBR approved for § 160.010-5 (“MIL-P-19644C”). (2) MIL-P-21929B, Military Specification, Plastic Material, Cellular Polyurethane, Foam-In-Place, Rigid (2 and 4...

Foam For Filtering

NASA Technical Reports Server (NTRS)

1978-01-01

Like nature's honeycomb, foam is a structure of many-sided cells, apparently solid but actually only three percent material and 97 percent air. Foam is made by a heat-producing chemical reaction which expands a plastic material in a manner somewhat akin to the heat-induced rising of a loaf of bread. The resulting structure of interconnected cells is flexible yet strong and extremely versatile in applicati6n. Foam can, for example, be a sound absorber in one form, while in another it allows sound to pass through it. It can be a very soft powder puff material and at the same time a highly abrasive scrubber. A sampling of foam uses includes stereo speaker grilles, applying postage meter ink, filtering lawnmower carburetor air; deadening noise in trucks and tractors, applying cosmetics, releasing fabric softener and antistatic agents in home clothes dryers, painting, filtering factory heating and ventilating systems, shining shoes, polishing cars, sponge-mopping floors, acting as pre-operative surgical scrubbers-the list is virtually limitless. The process by which foam is made produces "windows," thin plastic membranes connecting the cell walls. Windowed foam is used in many applications but for certain others-filtering, for example-it is desirable to have a completely open network. Scott Paper Company's Foam Division, Chester, Pennsylvania, improved a patented method of "removing the windows," to create an open structure that affords special utility in filtering applications. NASA technology contributed to Scott's improvement.

Cooling Device for Combat Vehicle Crew Drinking Water. Phase 1.

DTIC Science & Technology

1988-03-21

stainless steel . A third concept, in which the water container is plastic and the vacuum space is replaced by plastic foam, was also considered. The glass...Btu/ftO/=F/hr Glass Thermos 0.0905 Stainless Steel Thermos 0.1724 Foam Insulated Thermos 0.527 16 5.2. Thermal Electric Cooler Evaluation The TEC is... stainless steel thermos, which has a heat transfer coefficient approximately twice that of the glass thermos, is preferred for the vehicular use because it

A Polymer "Pollution Solution" Classroom Activity.

ERIC Educational Resources Information Center

Helser, Terry L.

1996-01-01

Explains an approach to presenting polymer chemistry to nonmajors that employs polystyrene foam, foam peanuts made from water soluble starch, and water soluble plastic bags. Students are presented with a pollution scenario and are guided to the discovery of solutions. (DDR)

Simple shearing flow of dry soap foams with TCP structure[Tetrahedrally Close-Packed

DOE Office of Scientific and Technical Information (OSTI.GOV)

REINELT,DOUGLAS A.; KRAYNIK,ANDREW M.

2000-02-16

The microrheology of dry soap foams subjected to large, quasistatic, simple shearing deformations is analyzed. Two different monodisperse foams with tetrahedrally close-packed (TCP) structure are examined: Weaire-Phelan (A15) and Friauf-Laves (C15). The elastic-plastic response is evaluated by calculating foam structures that minimize total surface area at each value of strain. The minimal surfaces are computed with the Surface Evolver program developed by Brakke. The foam geometry and macroscopic stress are piecewise continuous functions of strain. The stress scales as T/V{sup 1/3} where T is surface tension and V is cell volume. Each discontinuity corresponds to large changes in foam geometrymore » and topology that restore equilibrium to unstable configurations that violate Plateau's laws. The instabilities occur when the length of an edge on a polyhedral foam cell vanishes. The length can tend to zero smoothly or abruptly with strain. The abrupt case occurs when a small increase in strain changes the energy profile in the neighborhood of a foam structure from a local minimum to a saddle point, which can lead to symmetry-breaking bifurcations. In general, the new foam topology associated with each stable solution branch results from a cascade of local topology changes called T1 transitions. Each T1 cascade produces different cell neighbors, reduces surface energy, and provides an irreversible, film-level mechanism for plastic yield behavior. Stress-strain curves and average stresses are evaluated by examining foam orientations that admit strain-periodic behavior. For some orientations, the deformation cycle includes Kelvin cells instead of the original TCP structure; but the foam does not remain perfectly ordered. Bifurcations during subsequent T1 cascades lead to disorder and can even cause strain localization.« less

Synthetic scaffolds with full pore interconnectivity for bone regeneration prepared by supercritical foaming using advanced biofunctional plasticizers.

PubMed

Salerno, Aurelio; Diéguez, Sara; Diaz-Gomez, Luis; Gómez-Amoza, José L; Magariños, Beatriz; Concheiro, Angel; Domingo, Concepción; Alvarez-Lorenzo, Carmen; García-González, Carlos A

2017-06-30

Supercritical foaming allows for the solvent-free processing of synthetic scaffolds for bone regeneration. However, the control on the pore interconnectivity and throat pore size with this technique still needs to be improved. The use of plasticizers may help overcome these limitations. Eugenol, a GRAS natural compound extracted from plants, is proposed in this work as an advanced plasticizer with bioactive properties. Eugenol-containing poly(ε-caprolactone) (PCL) scaffolds were obtained by supercritical foaming (20.0 MPa, 45 °C, 17 h) followed by a one or a two-step depressurization profile. The effects of the eugenol content and the depressurization profile on the porous structure of the material and the physicochemical properties of the scaffold were evaluated. The combination of both processing parameters was successful to simultaneously tune the pore interconnectivity and throat sizes to allow mesenchymal stem cells infiltration. Scaffolds with eugenol were cytocompatible, presented antimicrobial activity preventing the attachment of Gram positive (S. aureus, S. epidermidis) bacteria and showed good tissue integration.

Elemental concentrations and bioaccessibilities in beached plastic foam litter, with particular reference to lead in polyurethane.

PubMed

Turner, Andrew; Lau, Kwan S

2016-11-15

Seventy samples of foamed plastic collected from a high-energy, sandy beach in SW England have been characterised by FTIR and XRF. Most samples were polyurethane (PU; n=39) or polystyrene (PS; n=27) that were associated with variable concentrations of Br-Cl, Fe and Zn, indicative of the presence of halogenated flame retardants, iron oxides and Zn-based additives, respectively. Many samples of rigid PU contained Pb, historically used as a catalyst, at concentrations of up to 16,000μgg -1 . A physiological extraction test that simulates the conditions in the gizzard of plastic-ingesting seabirds was applied to selected samples and results revealed that while Br and Zn were not measurably bioaccessible, Pb mobilisation progressed logarithmically over a period of time with maximum accessibilities after 220h of ~10% of total metal. Foamed PU is a source of bioaccessible Pb in the marine environment that has not previously been documented. Copyright © 2016 Elsevier Ltd. All rights reserved.

Catalytic thermal cracking of post-consumer waste plastics to fuels: Part 1 - Kinetics and optimization

USDA-ARS?s Scientific Manuscript database

Thermogravimetric analysis (TGA) was used to investigate thermal and catalytic pyrolysis of waste plastics such as prescription bottles (polypropylene/PP), high density polyethylene, landfill liners (polyethylene/PE), packing materials (polystyrene/PS), and foams (polyurethane/PU) into crude plastic...

Mechanical Properties of 17-4PH Stainless Steel Foam Panels

NASA Technical Reports Server (NTRS)

Raj, S. V.; Ghosn, L. J.; Lerch, B. a.; Hebsur, M.; Cosgriff, L. M.; Fedor, J.

2007-01-01

Rectangular 17-4PH stainless steel sandwiched foam panels were fabricated using a commercial manufacturing technique by brazing two sheets to a foam core. Microstructural observations and ultrasonic nondestructive evaluation of the panels revealed large variations in the quality of the brazed areas from one panel to the next as well as within the same panel. Shear tests conducted on specimens machined from the panels exhibited failures either in the brazed region or in the foam core for the poorly brazed and well-brazed samples, respectively. Compression tests were conducted on the foam cores to evaluate their elastic and plastic deformation behavior. These data were compared with published data on polymeric and metallic foams, and with theoretical deformation models proposed for open cell foams.

U.S. Navy Shipboard-Generated Plastic Waste Pilot Recycling Program

DTIC Science & Technology

1991-03-01

2: Recyclable Plastic Items Collected from Lexington Waste at Escambia County MRF Shampoo containers Plastic garbage bags Tyvek suit Shower thongs...bale consisted of polystyrene foam cups, bread bags, bottles, disposable razors, latex gloves, shampoo bottles, and othermiscellaneous items listed in...recent csws telephone survey of recycling firms involved in the separation of mixed 46 plastic bottles, the cost of sorting plastic bottles is

Simple shearing flow of dry soap foams with tetrahedrally close-packed structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinelt, Douglas A.; Kraynik, Andrew M.

2000-05-01

The microrheology of dry soap foams subjected to quasistatic, simple shearing flow is analyzed. Two different monodisperse foams with tetrahedrally close-packed (TCP) structure are examined: Weaire-Phelan (A15) and Friauf-Laves (C15). The elastic-plastic response is evaluated by using the Surface Evolver to calculate foam structures that minimize total surface area at each value of strain. The foam geometry and macroscopic stress are piecewise continuous functions of strain. The stress scales as T/V{sup 1/3}, where T is surface tension and V is cell volume. Each discontinuity corresponds to large changes in foam geometry and topology that restore equilibrium to unstable configurations thatmore » violate Plateau's laws. The instabilities occur when the length of an edge on a polyhedral foam cell vanishes. The length can tend to zero smoothly or abruptly with strain. The abrupt case occurs when a small increase in strain changes the energy profile in the neighborhood of a foam structure from a local minimum to a saddle point, which can lead to symmetry-breaking bifurcations. In general, the new structure associated with each stable solution branch results from an avalanche of local topology changes called T1 transitions. Each T1 cascade produces different cell neighbors, reduces surface energy, and provides an irreversible, film-level mechanism for plastic yield behavior. Stress-strain curves and average stresses are evaluated by examining foam orientations that admit strain-periodic behavior. For some orientations, the deformation cycle includes Kelvin cells instead of the original TCP structure; but the foam does not remain perfectly ordered. Bifurcations during subsequent T1 cascades lead to disorder and can even cause strain localization. (c) 2000 Society of Rheology.« less

Methods of Responsibly Managing End-of-Life Foams and Plastics Containing Flame Retardants: Part II.

PubMed

Lucas, Donald; Petty, Sara M; Keen, Olya; Luedeka, Bob; Schlummer, Martin; Weber, Roland; Yazdani, Ramin; Riise, Brian; Rhodes, James; Nightingale, Dave; Diamond, Miriam L; Vijgen, John; Lindeman, Avery; Blum, Arlene; Koshland, Catherine P

2018-06-01

This is Part II of a review covering the wide range of issues associated with all aspects of the use and responsible disposal of foam and plastic wastes containing toxic or potentially toxic flame retardants. We identify basic and applied research needs in the areas of responsible collection, pretreatment, processing, and management of these wastes. In Part II, we explore alternative technologies for the management of halogenated flame retardant (HFR) containing wastes, including chemical, mechanical, and thermal processes for recycling, treatment, and disposal.

Development of fine-celled bio-fiber composite foams using physical blowing agents and nano-particles

NASA Astrophysics Data System (ADS)

Guo, Gangjian

As one of eco-friendly bio-fibers, wood-fiber has been incorporated in plastics to make wood-fiber/plastic composites (WPC) with an increased stiffness, durability and lowered cost. However, these improvements are usually accompanied by loss in the ductility and impact strength of the composites. These shortcomings can be significantly improved by incorporating a fine-cell foam structure in the composites. This thesis presents the development of the foaming technology for the manufacture of fine-cell WPC foams with environmentally benign physical blowing agents (PBAs), and focuses on the elucidation of the fundamental foaming mechanisms and the related issues involved. One critical issue comes from the volatiles evolved from the wood-fiber during high temperature processing. The volatiles, as a blowing agent, can contribute to the foaming process. However, they lead to gross deterioration of the cell structure of WPC foams. The presence of volatiles makes foaming of WPC "a poorly understood black art". With the use of PBAs, a strategy of lowering processing temperature becomes feasible, to suppress the generation of volatiles. A series of PBA-based experiments were designed using a statistical design of experiments (DOE) technique, and were performed to establish the relationship of processing and material variables with the structure of WPC foams. Fundamental foaming behaviors for two different PBAs and two different polymer systems were identified. WPC foams with a fine-cell morphology and a desired density were successfully obtained at the optimized conditions. Another limitation for the wider application of WPC is their flammability. Innovative use of a small amount of nano-clay in WPC significantly improved the flame-retarding property of WPC, and the key issue was to achieve a high degree of exfoliation of nano-particles in the polymer matrix, to achieve a desired flammability reduction. The synergistic effects of nano-particles in foaming of WPC were identified as well.

Hydrodynamics of wet foams

NASA Astrophysics Data System (ADS)

Langevin, Dominique; Saint-Jalmes, Arnaud; Marze, Sébastien; Cox, Simon; Hutzler, Stefan; Drenckhan, Wiebke; Weaire, Denis; Caps, Hervé; Vandewalle, Nicolas; Adler, Micheàle; Pitois, Olivier; Rouyer, Florence; Cohen-Addad, Sylvie; Höhler, Reinhard; Ritacco, Hernan

2005-10-01

Foams and foaming pose important questions and problems to the chemical industry. As a material, foam is unusual in being a desired product while also being an unwanted byproduct within industry. Liquid foams are an essential part of gas/liquid contacting processes such as distillation and absorption, but over-production of foam in these processes can lead to downtime and loss of efficiency. Solid polymeric foams, such as polystyrene and polyurethane, find applications as insulation panels in the construction industry. Their combination of low weight and unique elastic/plastic properties make them ideal as packing and cushioning materials. Foams made with proteins are extensively used in the food industry. Despite the fact that foam science is a rapidly maturing field, critical aspects of foam physics and chemistry remain unclear. Several gaps in knowledge were identified to be tackled as the core of this MAP project. In addition, microgravity affords conditions for extending our understanding far beyond the possibilities offered by ground-based investigation. This MAP project addresses the challenges posed by the physics of foams under microgravity.

Arts & Crafts for Everyone.

ERIC Educational Resources Information Center

Crane, Diane, Ed.

1982-01-01

Five different art activities, using different media, are described: (1) "mystery molds," using plaster and discarded packaging materials; (2) "calico cottages," using boxes and fabric; (3) "foam friends," using plastic foam packing pieces; (4) "bauble boxes," using spray can tops and papier mache; and (5) "soft stuff," using old clothing. (CJ)

Mechanisms of nanoclay-enhanced plastic foaming processes: effects of nanoclay intercalation and exfoliation

NASA Astrophysics Data System (ADS)

Wong, Anson; Wijnands, Stephan F. L.; Kuboki, Takashi; Park, Chul B.

2013-08-01

The foaming behaviors of high-density polypropylene-nanoclay composites with intercalated and exfoliated nanoclay particles blown with carbon dioxide were examined via in situ observation of the foaming processes in a high-temperature/high-pressure view-cell. The intercalated nanoclay particles were 300-600 nm in length and 50-200 nm in thickness, while the exfoliated nanoclay particles were 100-200 nm in length and 1 nm in thickness. Contrary to common belief, it was discovered that intercalated nanoclay yielded higher cell density than exfoliated nanoclay despite its lower particle density. This was attributed to the higher tensile stresses generated around the larger and stiffer intercalated nanoclay particles, which led to increase in supersaturation level for cell nucleation. Also, the coupling agent used to exfoliate nanoclay would increase the affinity between polymer and surface of nanoclay particles. Consequently, the critical work needed for cell nucleation would be increased; pre-existing microvoids, which could act as seeds for cell nucleation, were also less likely to exist. Meanwhile, exfoliated nanoclay had better cell stabilization ability to prevent cell coalescence and cell coarsening. This investigation clarifies the roles of nanoclay in plastic foaming processes and provides guidance for the advancement of polymer nanocomposite foaming technology.

Exploratory development of foams from liquid crystal polymers

NASA Technical Reports Server (NTRS)

Chung, T. S.

1985-01-01

Two types of liquid crystal polymer (LCP) compositions were studied and evaluated as structural foam materials. One is a copolymer of 6-hydroxy-2-naphthoic acid, terephthalic acid, and p-acetoxyacetanilide (designed HNA/TA/AAA), and the other is a copolymer of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid (designated HBA/HNA). Experimental results showed that the extruded HNA/TA/AA foams have better mechanical quality and appearance than HBA/HNA foams. Heat treatment improved foam tensile strength and break elongation, but reduced their modulus. The injection molding results indicated that nitrogen foaming agents with a low-pressure process gave better void distribution in the injection molded LCP foams than those made by the conventional injection-molding machine and chemical blowing agents. However, in comparing LCP foams with other conventional plastic foams, HBA/HNA foams have better mechanical properties than foamed ABS and PS, but are comparable to PBT and inferior to polycarbonate foams, especially in heat-deflection temperature and impact resistance energy. These deficiencies are due to LCP molecules not having been fully oriented during the Union-Carbide low-pressure foaming process.

Innovative energy absorbing devices based on composite tubes

NASA Astrophysics Data System (ADS)

Tiwari, Chandrashekhar

Analytical and experimental study of innovative load limiting and energy absorbing devices are presented here. The devices are based on composite tubes and can be categorized in to two groups based upon the energy absorbing mechanisms exhibited by them, namely: foam crushing and foam fracturing. The device based on foam crushing as the energy absorbing mechanism is composed of light weight elastic-plastic foam filling inside an angle ply composite tube. The tube is tailored to have a high Poisson’s ratio (>20). Upon being loaded the device experiences large transverse contraction resulting in rapid decrease in diameter. At a certain axial load the foam core begins to crush and energy is dissipated. This device is termed as crush tube device. The device based upon foam shear fracture as the energy absorbing mechanism involves an elastic-plastic core foam in annulus of two concentric extension-twist coupled composite tubes with opposite angles of fibers. The core foam is bonded to the inner and outer tube walls. Upon being loaded axially, the tubes twist in opposite directions and fracture the core foam in out of plane shear and thus dissipate the energy stored. The device is termed as sandwich core device (SCD). The devices exhibit variations in force-displacement characteristics with changes in design and material parameters, resulting in wide range of energy absorption capabilities. A flexible matrix composite system was selected, which was composed of high stiffness carbon fibers as reinforcements in relatively low stiffness polyurethane matrix, based upon large strain to failure capabilities and large beneficial elastic couplings. Linear and non-linear analytical models were developed encapsulating large deformation theory of the laminated composite shells (using non-linear strain energy formulation) to the fracture mechanics of core foam and elastic-plastic deformation theory of the foam filling. The non-linear model is capable of including material and geometric nonlinearities that arise from large deformation and fiber reorientation. Developed non-linear analysis predicts the behavior of extension-twist coupled and angle ply flexible matrix composite tubes under multi-axial loadings. The predicted results show close correlation with experimental findings. It was also found that these devices exhibit variations with respect to rate of loading. It was found that the novel energy absorbing devices are capable of providing 4-5 times higher specific energy absorption (SEA) than currently used devices for similar purposes (such as wire bender which has SEA of 3.6 J/g).

Elastic-Plastic Behaviour of Ultrasonic Assisted Compression of Polyvinyl Chloride (PVC) Foam

NASA Astrophysics Data System (ADS)

Muhalim, N. A. D.; Hassan, M. Z.; Daud, Y.

2018-04-01

The present study aims to investigate the elastic-plastic behaviour of ultrasonic assisted compression of PVC closed-cell foam. A series of static and ultrasonic compression test of PVC closed-cell foam were conducted at a constant cross head speed of 30 mm/min on dry surface condition. For quasi-static test, specimen was compressed between two rigid platens using universal testing machine. In order to evaluate the specimen behavior under ultrasonic condition, specimen was placed between a specifically design double-slotted block horn and rigid platen. The horn was designed and fabricated prior to the test as a medium to transmit the ultrasonic vibration from the ultrasonic transducer to the working specimen. It was tuned to a frequency of 19.89 kHz in longitudinal mode and provided an average oscillation amplitude at 6 µm on the uppermost surface. Following, the characteristics of stress-strain curves for quasi-static and ultrasonic compression tests were analyzed. It was found that the compressive stress was significantly reduced at the onset of superimposed ultrasonic vibration during plastic deformation.

Biodegradable baked foam made with chayotextle starch mixed with plantain flour and wood fiber

USDA-ARS?s Scientific Manuscript database

New renewable materials are needed to reduce petroleum-based plastic packaging. The effect of plantain flour (PF) and wood fiber (WF) on the properties of starch-based foams (SBFs) were investigated. The SBFs were characterized using physical, thermal, and mechanical methods to better understand the...

Feasibility of Use of Plastic Foams for Small Vessel Flotation Devices.

DTIC Science & Technology

1976-01-01

waterproofing agents, namely, Dow Corning Silicone 200 fluid, zinc stearate, sodium silicate, Fisher Bath Wax , Carnauba wax , and paraffin wax . Some of...these materials (e.g., waxes ) did not mix well with the foam solution. None of these materials was effective in preventing water absorption by polystyrene

An investigation of the inelastic behaviour of trabecular bone during the press-fit implantation of a tibial component in total knee arthroplasty.

PubMed

Kelly, N; Cawley, D T; Shannon, F J; McGarry, J P

2013-11-01

The stress distribution and plastic deformation of peri-prosthetic trabecular bone during press-fit tibial component implantation in total knee arthroplasty is investigated using experimental and finite element techniques. It is revealed that the computed stress distribution, implantation force and plastic deformation in the trabecular bone is highly dependent on the plasticity formulation implemented. By incorporating pressure dependent yielding using a crushable foam plasticity formulation to simulate the trabecular bone during implantation, highly localised stress concentrations and plastic deformation are computed at the bone-implant interface. If the pressure dependent yield is neglected using a traditional von Mises plasticity formulation, a significantly different stress distribution and implantation force is computed in the peri-prosthetic trabecular bone. The results of the study highlight the importance of: (i) simulating the insertion process of press-fit stem implantation; (ii) implementing a pressure dependent plasticity formulation, such as the crushable foam plasticity formulation, for the trabecular bone; (iii) incorporating friction at the implant-bone interface during stem insertion. Simulation of the press-fit implantation process with an appropriate pressure dependent plasticity formulation should be implemented in the design and assessment of arthroplasty prostheses. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

Properties of foam and composite materials made o starch and cellulose fiber

USDA-ARS?s Scientific Manuscript database

Composite materials were made of starch and cellulose fibers. Pre-gelatinized starch was effective in dispersing pulp fiber in a starch matrix to form a viscous starch/fiber dough. The starch/fiber dough was a useful feedstock for various composite foam and plastic materials. Viscous blends of star...

Thermal conductivity and combustion properties of wheat gluten foams.

PubMed

Blomfeldt, Thomas O J; Nilsson, Fritjof; Holgate, Tim; Xu, Jianxiao; Johansson, Eva; Hedenqvist, Mikael S

2012-03-01

Freeze-dried wheat gluten foams were evaluated with respect to their thermal and fire-retardant properties, which are important for insulation applications. The thermal properties were assessed by differential scanning calorimetry, the laser flash method and a hot plate method. The unplasticised foam showed a similar specific heat capacity, a lower thermal diffusivity and a slightly higher thermal conductivity than conventional rigid polystyrene and polyurethane insulation foams. Interestingly, the thermal conductivity was similar to that of closed cell polyethylene and glass-wool insulation materials. Cone calorimetry showed that, compared to a polyurethane foam, both unplasticised and glycerol-plasticised foams had a significantly longer time to ignition, a lower effective heat of combustion and a higher char content. Overall, the unplasticised foam showed better fire-proof properties than the plasticized foam. The UL 94 test revealed that the unplasticised foam did not drip (form droplets of low viscous material) and, although the burning times varied, self-extinguished after flame removal. To conclude both the insulation and fire-retardant properties were very promising for the wheat gluten foam. © 2012 American Chemical Society

Laser Irradiated Foam Targets: Absorption and Radiative Properties

NASA Astrophysics Data System (ADS)

Salvadori, Martina; Luigi Andreoli, Pier; Cipriani, Mattia; Consoli, Fabrizio; Cristofari, Giuseppe; De Angelis, Riccardo; di Giorgio, Giorgio; Giulietti, Danilo; Ingenito, Francesco; Gus'kov, Sergey Yu.; Rupasov, Alexander A.

2018-01-01

An experimental campaign to characterize the laser radiation absorption of foam targets and the subsequent emission of radiation from the produced plasma was carried out in the ABC facility of the ENEA Research Center in Frascati (Rome). Different targets have been used: plastic in solid or foam state and aluminum targets. The activated different diagnostics allowed to evaluate the plasma temperature, the density distribution, the fast particle spectrum and the yield of the X-Ray radiation emitted by the plasma for the different targets. These results confirm the foam homogenization action on laser-plasma interaction, mainly attributable to the volume absorption of the laser radiation propagating in such structured materials. These results were compared with simulation absorption models of the laser propagating into a foam target.

Effect of the chemical structure of the polymer matrix on the properties of foam polyurethanes at low temperatures

NASA Astrophysics Data System (ADS)

Yakushin, V. A.; Stirna, U. K.; Zhmud', N. P.

1999-07-01

The dependence of physical and mechanical properties of oligoether-based foam polyurethanes on the molecular mass (Mc) of polymer chains between the nodes of the polymer network and on the content of rigid segments in the polymer is investigated at 293 and 98K. The values of Mc at which the foam plastics have the best mechanical properties at low temperatures are determined. The content of rigid segments in the polymer at which foam polyurethanes have the best combination of the linear thermal expansion coefficient and mechanical properties in tension at a temperature of 98K is found.

Starch-based Foam Composite Materials: processing and bioproducts

USDA-ARS?s Scientific Manuscript database

Starch is an abundant, biodegradable, renewable and low-cost commodity that has been explored as a replacement for petroleum-based plastics. By itself, starch is a poor replacement for plastics because of its moisture sensitivity and brittle properties. Efforts to improve starch properties and funct...

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements.... All components used in the construction of work vests must meet the applicable requirements of subpart...

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements.... All components used in the construction of work vests must meet the applicable requirements of subpart...

46 CFR 160.053-3 - Materials, construction and workmanship.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic... workmanship of unicellular plastic foam work vests specified by this subpart shall conform to the requirements.... All components used in the construction of work vests must meet the applicable requirements of subpart...

Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

NASA Astrophysics Data System (ADS)

Rapp, F.; Schneider, A.; Elsner, P.

2014-05-01

Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO2 balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry), melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength).

Microcellular foaming of arabinoxylan and PEGylated arabinoxylan with supercritical CO2.

PubMed

Härdelin, Linda; Ström, Anna; Di Maio, Ernesto; Iannace, Salvatore; Larsson, Anette

2018-02-01

In this study, arabinoxylan extracted from barley husks was reacted with polyethylene glycol (PEG) of various molecular weights to introduce an internal plasticizer into the polymer matrix. A successful PEGylation reaction was identified using FTIR and elemental analysis. Thermal and mechanical properties were studied using dynamic mechanical analysis, which revealed that the attachment of PEG chains reduced the glass transition temperature by up to 25°C. Foaming experiments were conducted under different test conditions in a batch foaming process with supercritical CO 2 in a thermoregulated and pressurized cylinder. The foams were evaluated using SEM by studying the morphology of the samples foamed at different temperatures. The unmodified arabinoxylan sample was found to produce the best foam morphology, though the PEGylated samples could be produced at lower temperatures than could the unmodified arabinoxylan. This was interpreted as due to the decrease in the glass transition temperature. Copyright © 2017. Published by Elsevier Ltd.

Relative merits of polystyrene foam and paper in hot drink cups: Implications for packaging

NASA Astrophysics Data System (ADS)

Hocking, Martin B.

1991-11-01

An analysis of the overall relative merits of the use of uncoated paper vs molded polystyrene bead foam in single-use 8-oz cups is described here as a manageable example of the use of paper vs plastics in packaging. In raw material requirements the paper cup required about 2.5 times its finished weight of raw wood and about the same hydrocarbon fueling requirement as is needed for the polystyrene foam cup. To process the raw materials about six times as much steam, 13 times as much electric power, and twice as much cooling water are consumed to produce the paper cup as compared to the polystyrene foam cup. Emission rates to air are similar and to water are generally higher for the paper cup. Virtually all primary use factors favor polystyrene foam over paper. Once used both cup types may be recycled. Landfill disposal of the two items under dry conditions will occupy similar landfill volumes after compaction and will confer similarly slow to nonexistent decomposition to either option. Under wet conditions polystyrene foam will not readily degrade, but may help other materials to do so. Paper under wet conditions will biodegrade to produce methane, a significant greenhouse gas, biochemical oxygen demand to any leachate, and instability to the land surface during the process. Both materials can be incinerated cleanly in a municipal waste stream with the option of energy recovery, to yield an ash volume of 2% 5% of the incoming waste volume. Overall this analysis would suggest that polystyrene foam, with an extension to plastics in general, should be given more evenhanded consideration relative to paper in packaging applications than is currently the case.

Absolute Hugoniot measurements for CH foams in the 2–9 Mbar range

DOE PAGES

Aglitskiy, Y.; Velikovich, A. L.; Karasik, M.; ...

2018-03-19

Absolute Hugoniot measurements for empty plastic foams at ~10% of solid polystyrene density and supporting rad-hydro simulation results are reported. Planar foam slabs, ~400 μm thick and ~500 μm wide, some of which were covered with a 10 μm solid plastic ablator, were directly driven by 4 ns long Nike krypton-fluoride 248 nm wavelength laser pulses that produced strong shock waves in the foam. The shock and mass velocities in our experiments were up to 104 km/s and 84 km/s, respectively, and the shock pressures up to ~9 Mbar. The motion of the shock and ablation fronts was recorded usingmore » side-on monochromatic x-ray imaging radiography. Here, the steadiness of the observed shock and ablation fronts within ~1% has been verified. The Hugoniot data inferred from our velocity measurements agree with the predictions of the SESAME and CALEOS equation-of-state models near the highest pressure ~9 Mbar and density compression ratio ~5. In the lower pressure range 2–5 Mbar, a lower shock density compression is observed than that predicted by the models. Possible causes for this discrepancy are discussed.« less

Absolute Hugoniot measurements for CH foams in the 2-9 Mbar range

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Velikovich, A. L.; Karasik, M.; Schmitt, A. J.; Serlin, V.; Weaver, J. L.; Oh, J.; Obenschain, S. P.; Cochrane, K. R.

2018-03-01

Absolute Hugoniot measurements for empty plastic foams at ˜10% of solid polystyrene density and supporting rad-hydro simulation results are reported. Planar foam slabs, ˜400 μm thick and ˜500 μm wide, some of which were covered with a 10 μm solid plastic ablator, were directly driven by 4 ns long Nike krypton-fluoride 248 nm wavelength laser pulses that produced strong shock waves in the foam. The shock and mass velocities in our experiments were up to 104 km/s and 84 km/s, respectively, and the shock pressures up to ˜9 Mbar. The motion of the shock and ablation fronts was recorded using side-on monochromatic x-ray imaging radiography. The steadiness of the observed shock and ablation fronts within ˜1% has been verified. The Hugoniot data inferred from our velocity measurements agree with the predictions of the SESAME and CALEOS equation-of-state models near the highest pressure ˜9 Mbar and density compression ratio ˜5. In the lower pressure range 2-5 Mbar, a lower shock density compression is observed than that predicted by the models. Possible causes for this discrepancy are discussed.

A disposable insulated container for rearing fall webworm larvae in the laboratory

Treesearch

William N., Jr. Cannon

1970-01-01

Plastic-foam cups with plastic lids were found to be more suitable for rearing larvae of the fall webworm, Hyphantria cunea Drury, than other types of containers tested. These cups are inexpensive, lightweight, rigid, and translucent; and they protect the contents from rapid fluctuations in temperature.

Specifications and Other Standardization Documents Involving Cellular Plastics (Plastic Foams), Cushioning and Related Materials

DTIC Science & Technology

1976-07-01

FOR MEDICAL MATERIAL REQUIRING CONTROLLED TEMPERATURE RANGES 258 PPP-C-1683(1) 8135 69 10 Oct 73 CUSHIONING MATERIAL, EXPANDED POLYSTYRENE LOOSE FILL...Liquid immersion effect on properties of elastoaeric vulcanizates - 45 Lead deflection characteristics - 264 Loose-fill expanded polystyrene - 25f

Functional Performances of CuZnAl Shape Memory Alloy Open-Cell Foams

NASA Astrophysics Data System (ADS)

Biffi, C. A.; Casati, R.; Bassani, P.; Tuissi, A.

2018-01-01

Shape memory alloys (SMAs) with cellular structure offer a unique mixture of thermo-physical-mechanical properties. These characteristics can be tuned by changing the pore size and make the shape memory metallic foams very attractive for developing new devices for structural and functional applications. In this work, CuZnAl SMA foams were produced through the liquid infiltration of space holder method. In comparison, a conventional CuZn brass alloy was foamed trough the same method. Functional performances were studied on both bulk and foamed SMA specimens. Calorimetric response shows similar martensitic transformation (MT) below 0 °C. Compressive response of CuZnAl revealed that mechanical behavior is strongly affected by sample morphology and that damping capacity of metallic foam is increased above the MT temperatures. The shape memory effect was detected in the CuZnAl foams. The conventional brass shows a compressive response similar to that of the martensitic CuZnAl, in which plastic deformation accumulation occurs up to the cellular structure densification after few thermal cycles.

Size selective isocyanate aerosols personal air sampling using porous plastic foams

NASA Astrophysics Data System (ADS)

Khanh Huynh, Cong; Duc, Trinh Vu

2009-02-01

As part of a European project (SMT4-CT96-2137), various European institutions specialized in occupational hygiene (BGIA, HSL, IOM, INRS, IST, Ambiente e Lavoro) have established a program of scientific collaboration to develop one or more prototypes of European personal samplers for the collection of simultaneous three dust fractions: inhalable, thoracic and respirable. These samplers based on existing sampling heads (IOM, GSP and cassettes) use Polyurethane Plastic Foam (PUF) according to their porosity to support sampling and separator size of the particles. In this study, the authors present an original application of size selective personal air sampling using chemical impregnated PUF to perform isocyanate aerosols capturing and derivatizing in industrial spray-painting shops.

Density and temperature characterization of long-scale length, near-critical density controlled plasma produced from ultra-low density plastic foam

PubMed Central

Chen, S. N.; Iwawaki, T.; Morita, K.; Antici, P.; Baton, S. D.; Filippi, F.; Habara, H.; Nakatsutsumi, M.; Nicolaï , P.; Nazarov, W.; Rousseaux, C.; Starodubstev, M.; Tanaka, K. A.; Fuchs, J.

2016-01-01

The ability to produce long-scale length (i.e. millimeter scale-length), homogeneous plasmas is of interest in studying a wide range of fundamental plasma processes. We present here a validated experimental platform to create and diagnose uniform plasmas with a density close or above the critical density. The target consists of a polyimide tube filled with an ultra low-density plastic foam where it was heated by x-rays, produced by a long pulse laser irradiating a copper foil placed at one end of the tube. The density and temperature of the ionized foam was retrieved by using x-ray radiography and proton radiography was used to verify the uniformity of the plasma. Plasma temperatures of 5–10 eV and densities around 1021 cm−3 are measured. This well-characterized platform of uniform density and temperature plasma is of interest for experiments using large-scale laser platforms conducting High Energy Density Physics investigations. PMID:26923471

HLH Rotor Blade Manufacturing Technology Development Report

DTIC Science & Technology

1977-09-01

30 Tool Design and Fabrication . . . . . .. 30 Tool Concepts and Materials . . . . . . . 30 Autoclave Cure - Plastic Molds . . . 30...Materials Autoclave Cure - Plastic MoiJ.- The Double Coke Bottle specimen (Figure 13) was layed-up on a bean bag and cured in a fiberglass tool in...lower airfoil) was made from a foam material, mounted on a common base, and covered with plastic coating to give a hard working surface. This is

Plastic debris in the coastal environment: The invincible threat? Abundance of buried plastic debris on Malaysian beaches.

PubMed

Fauziah, S H; Liyana, I A; Agamuthu, P

2015-09-01

Studies on marine debris have gained worldwide attention since many types of debris have found their way into the food chain of higher organisms. Thus, it is crucial that more focus is given to this area in order to curb contaminations in sea food. This study was conducted to quantify plastic debris buried in sand at selected beaches in Malaysia. Marine debris was identified according to size range and distribution, and this information was related to preventive actions to improve marine waste issues. For the purpose of this study, comparison of plastic waste abundance between a recreational beach and fish-landing beaches was also carried out, since the different beach types represent different activities that produce debris. Six beaches along the Malaysian coastline were selected for this study. The plastic types in this study were related to the functions of the beach. While recreational beaches have abundant quantities of plastic film, foamed plastic including polystyrene, and plastic fragment, fish-landing beaches accumulated line and foamed plastic. A total of 2542 pieces (265.30 g m(-2)) of small plastic debris were collected from all six beaches, with the highest number from Kuala Terengganu, at 879 items m(-2) on Seberang Takir Beach, followed by Batu Burok Beach with 780 items m(-2). Findings from studies of Malaysian beaches have provided a clearer understanding of the distribution of plastic debris. This demonstrates that commitments and actions, such as practices of the 'reduce, reuse, recycle' (3R) approach, supporting public awareness programmes and beach clean-up activities, are essential in order to reduce and prevent plastic debris pollution. © The Author(s) 2015.

Biopolymer foams - Relationship between material characteristics and foaming behavior of cellulose based foams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rapp, F., E-mail: florian.rapp@ict.fraunhofer.de, E-mail: anja.schneider@ict.fraunhofer.de; Schneider, A., E-mail: florian.rapp@ict.fraunhofer.de, E-mail: anja.schneider@ict.fraunhofer.de; Elsner, P., E-mail: peter.elsner@ict.fraunhofer.de

2014-05-15

Biopolymers are becoming increasingly important to both industry and consumers. With regard to waste management, CO{sub 2} balance and the conservation of petrochemical resources, increasing efforts are being made to replace standard plastics with bio-based polymers. Nowadays biopolymers can be built for example of cellulose, lactic acid, starch, lignin or bio mass. The paper will present material properties of selected cellulose based polymers (cellulose propionate [CP], cellulose acetate butyrate [CAB]) and corresponding processing conditions for particle foams as well as characterization of produced parts. Special focus is given to the raw material properties by analyzing thermal behavior (differential scanning calorimetry),more » melt strength (Rheotens test) and molecular weight distribution (gel-permeation chromatography). These results will be correlated with the foaming behavior in a continuous extrusion process with physical blowing agents and underwater pelletizer. Process set-up regarding particle foam technology, including extrusion foaming and pre-foaming, will be shown. The characteristics of the resulting foam beads will be analyzed regarding part density, cell morphology and geometry. The molded parts will be tested on thermal conductivity as well as compression behavior (E-modulus, compression strength)« less

Modeling of skeletal members using polyurethane foam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sena, J.M.F.; Weaver, R.W.

1983-11-01

At the request of the University of New Mexico's Maxwell Museum of Anthropology, members of the Plastic Section in the Process Development Division at SNLA undertook the special project of the Chaco Lady. The project consisted of polyurethane foam casting of a disinterred female skull considered to be approximately 1000 years old. Rubber latex molds, supplied by the UNM Anthropology Department, were used to produce the polymeric skull requested. The authors developed for the project a modified foaming process which will be used in future polyurethane castings of archaeological artifacts and contemporary skeletal members at the University.

Temper Foam

NASA Technical Reports Server (NTRS)

1981-01-01

Fabricated by Expanded Rubber & Plastics Corporation, Temper Foam provides better impact protection for airplane passengers and enhances passenger comfort on long flights because it distributes body weight and pressure evenly over the entire contact area. Called a "memory foam" it matches the contour of the body pressing against it and returns to its original shape once the pressure is removed. As a shock absorber, a three-inch foam pad has the ability to absorb the impact of a 10-foot fall by an adult. Applications include seat cushioning for transportation vehicles, padding for furniture and a variety of athletic equipment medical applications including wheelchair padding, artificial limb socket lining, finger splint and hand padding for burn patients, special mattresses for the bedridden and dental stools. Production and sales rights are owned by Temper Foam, Inc. Material is manufactured under license by the Dewey and Almy Division of Grace Chemical Corporation. Distributors of the product are Kees Goebel Medical Specialties, Inc. and Alimed, Inc. They sell Temper Foam in bulk to the fabricators who trim it to shapes required by their customers.

Foam injection molding of thermoplastic elastomers: Blowing agents, foaming process and characterization of structural foams

NASA Astrophysics Data System (ADS)

Ries, S.; Spoerrer, A.; Altstaedt, V.

2014-05-01

Polymer foams play an important role caused by the steadily increasing demand to light weight design. In case of soft polymers, like thermoplastic elastomers (TPE), the haptic feeling of the surface is affected by the inner foam structure. Foam injection molding of TPEs leads to so called structural foam, consisting of two compact skin layers and a cellular core. The properties of soft structural foams like soft-touch, elastic and plastic behavior are affected by the resulting foam structure, e.g. thickness of the compact skins and the foam core or density. This inner structure can considerably be influenced by different processing parameters and the chosen blowing agent. This paper is focused on the selection and characterization of suitable blowing agents for foam injection molding of a TPE-blend. The aim was a high density reduction and a decent inner structure. Therefore DSC and TGA measurements were performed on different blowing agents to find out which one is appropriate for the used TPE. Moreover a new analyzing method for the description of processing characteristics by temperature dependent expansion measurements was developed. After choosing suitable blowing agents structural foams were molded with different types of blowing agents and combinations and with the breathing mold technology in order to get lower densities. The foam structure was analyzed to show the influence of the different blowing agents and combinations. Finally compression tests were performed to estimate the influence of the used blowing agent and the density reduction on the compression modulus.

Continuous microcellular foaming of polylactic acid/natural fiber composites

NASA Astrophysics Data System (ADS)

Diaz-Acosta, Carlos A.

Poly(lactic acid) (PLA), a biodegradable thermoplastic derived from renewable resources, stands out as a substitute to petroleum-based plastics. In spite of its excellent properties, commercial applications are limited because PLA is more expensive and more brittle than traditional petroleum-based resins. PLA can be blended with cellulosic fibers to reduce material cost. However, the lowered cost comes at the expense of flexibility and impact strength, which can be enhanced through the production of microcellular structures in the composite. Microcellular foaming uses inert gases (e.g., carbon dioxide) as physical blowing agents to make cellular structures with bubble sizes of less than 10 microm and cell-population densities (number of bubbles per unit volume) greater than 109 cells/cm³. These unique characteristics result in a significant increase in toughness and elongation at break (ductility) compared with unfoamed parts because the presence of small bubbles can blunt the crack-tips increasing the energy needed to propagate the crack. Microcellular foams have been produced through a two step batch process. First, large amounts of gas are dissolved in the solid plastic under high pressure (sorption process) to form a single-phase solution. Second, a thermodynamic instability (sudden drop in solubility) triggers cell nucleation and growth as the gas diffuses out of the plastic. Batch production of microcellular PLA has addressed some of the drawbacks of PLA. Unfortunately, the batch foaming process is not likely to be implemented in the industrial production of foams because it is not cost-effective. This study investigated the continuous microcellular foaming process of PLA and PLA/wood-fiber composites. The effects of the processing temperature and material compositions on the melt viscosity, pressure drop rate, and cell-population density were examined in order to understand the nucleation mechanisms in neat and filled PLA foams. The results indicated that the processing temperature had a strong effect of the rheology of the melt and cell morphology. Processing at a lower temperature significantly increased the cell nucleation rate of neat PLA (amorphous and semi-crystalline) because of the fact that a high melt viscosity induced a high pressure drop rate in the polymer/gas solution. The presence of nanoclay did not affect the homogeneous nucleation but increased the heterogeneous nucleation, allowing both nucleation mechanisms to occur during the foaming process. The effect of wood-flour (0-30 wt.%) and rheology modifier contents on the melt viscosity and cell morphology of microcellular foamed composites was investigated. The viscosity of the melt increased with wood-flour content and decreased with rheology modifier content, affecting the processing conditions (i.e., pressure drop and pressure drop rate) and foamability of the composites. Matching the viscosity of the composites with that of neat PLA resulted in the best cell morphologies. Physico-mechanical characterization of microcellular foamed PLA as a function of cell morphology was performed to establish process-morphology-property relationships. The processing variables, i.e., amount of gas injected, flow rate, and processing temperature affected the development of the cellular structure and mechanical properties of the foams.

Collisions of plastic and foam laser-driven foils studied by orthogonal x-ray imaging.

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Metzler, N.; Karasik, M.; Serlin, V.; Obenschain, S. P.; Schmitt, A. J.; Velikovich, A. L.; Zalesak, S. T.; Gardner, J. H.; Weaver, J.; Oh, J.; Harding, E. C.

2007-11-01

We report an experimental study of hydrodynamic Rayleigh-Taylor and Richtmyer-Meshkov-type instabilities developing at the material interface produced in double-foil collisions. Our double-foil targets consist of a plastic foil irradiated by the 4 ns Nike KrF laser pulse at ˜50 TW/cm^2 and accelerated toward a stationary plastic or foam foil. Either the rear side of the front foil or the front side of the rear foil is rippled. Orthogonal imaging, i. e., a simultaneous side-on and face-on x-ray radiography of the targets has been used in these experiments to observe the process of collision and the evolution of the areal mass amplitude modulation. Its observed evolution is similar to the case of the classical RM instability in finite thickness targets first studied by Y. Aglitsky et al., Phys. Plasmas 13, 80703 (2006). Our data are favorably compared with 1D and 2D simulation results.

Plastic Foam Porosity Characterization by Air-Borne Ultrasound

NASA Astrophysics Data System (ADS)

Hoffrén, H.; Karppinen, T.; Hæggström, E.

2006-03-01

We continue to develop an ultrasonic burst-reflection method for estimating porosity and tortuosity of solid materials. As a first step we report on method design considerations and measurements on polyurethane foams (Sylomer® vibration dampener) with well-defined porosity. The ultrasonic method is experimentally tested by measuring 235 kHz and 600 kHz air-borne ultrasound reflection from a foam surface at two incidence angles. The reflected sound wave from different foam samples (32% - 64% porosity) was compared to a wave that had traveled from the transmitter to the detector without reflection. The ultrasonically estimated sample porosities coincided within 8% with the porosity estimates obtained by a gravimetric reference method. This parallels the uncertainty of the gravimetric method, 8%. The repeatability of the ultrasonic porosity measurements was better than 5%.

Endovascular embolization

MedlinePlus

... plastic particles, glue, metal coils, foam, or a balloon through it to seal off the faulty blood vessel. (If coils are used, it is called coil embolization.) This procedure can take several hours.

High Temperature Structural Foam

NASA Technical Reports Server (NTRS)

Weiser, Erik S.; Baillif, Faye F.; Grimsley, Brian W.; Marchello, Joseph M.

1997-01-01

The Aerospace Industry is experiencing growing demand for high performance polymer foam. The X-33 program needs structural foam insulation capable of retaining its strength over a wide range of environmental conditions. The High Speed Research Program has a need for low density core splice and potting materials. This paper reviews the state of the art in foam materials and describes experimental work to fabricate low density, high shear strength foam which can withstand temperatures from -220 C to 220 C. Commercially available polymer foams exhibit a wide range of physical properties. Some with densities as low as 0.066 g/cc are capable of co-curing at temperatures as high as 182 C. Rohacell foams can be resin transfer molded at temperatures up to 180 C. They have moduli of elasticity of 0.19 MPa, tensile strengths of 3.7 Mpa and compressive strengths of 3.6 MPa. The Rohacell foams cannot withstand liquid hydrogen temperatures, however Imi-Tech markets Solimide (trademark) foams which withstand temperatures from -250 C to 200 C, but they do not have the required structural integrity. The research activity at NASA Langley Research Center focuses on using chemical blowing agents to produce polyimide thermoplastic foams capable of meeting the above performance requirements. The combination of blowing agents that decompose at the minimum melt viscosity temperature together with plasticizers to lower the viscosity has been used to produce foams by both extrusion and oven heating. The foams produced exhibit good environmental stability while maintaining structural properties.

Preparation, testing, and delivery of low density polyimide foam panels

NASA Technical Reports Server (NTRS)

Ball, G. L., III; Post, L. K.; Salyer, I. O.

1975-01-01

Plastic foams based on polyimide resins were shown to be stable at relatively high temperatures, and to possess very low flame spread and smoke generation characteristics. A system and process were developed to prepare low-density polyimide foam from a liquid formulation. The system is based on the reaction of micropulverized grade pyromellitic dianhydride with a polymeric diisocyanate. The panels produced were postcured at elevated temperatures to achieve maximum thermal and fire resistance, and incorporation of a fire retardant into the formulation was considered. The effects of a flame retardant (Flameout 5600B1) were investigated, but eliminated in preference to the postcuring approach.

Demonstration/Validation of Hazardous Air Pollutant-Free Adhesive Replacement for Federal Specification MMM-A-121 on the Stryker Infantry Carrier Vehicle

DTIC Science & Technology

2013-06-01

high-performance contact adhesive (baseline) can be used to bond most rubber, cloth, metal, wood , foamed glass, paper honeycomb, decorative plastic ...and gasket adhesive (baseline) may be used to bond metal, wood , most plastics , neoprene, SBR, and butyl rubber (11). Key features are high immediate...nitrile rubber, most plastics and gasketing materials to a variety of substrates (13). This product contains 0% HAPs (14) and has been added to the

Size distribution of stranded small plastic debris on the coast of Guangdong, South China.

PubMed

Fok, Lincoln; Cheung, Pui Kwan; Tang, Guangda; Li, Wai Chin

2017-01-01

Beach environments are known to be conducive to fragmentation of plastic debris, and highly fragmented plastic particles can interact with smaller organisms. Even through stranded plastic debris may not interact directly with marine organisms, backwash processes may transport this debris back to coastal waters, where it may affect a wide range of marine life at different trophic levels. This study analysed the size distribution of stranded plastic debris (<10 mm) collected from eight coastal beaches in Guangdong Province, China. Polystyrene (PS) foams and fragments smaller than 7 mm were increasingly abundant in the smaller size classes, whereas resin pellets remained in their production sizes (∼3 mm). Microplastics (<5 mm) accounted for over 98% of the total plastic debris by abundance and 71% by weight, indicating that the plastic debris on these coastal beaches was highly fragmented and the majority of the plastic masses belonged to the microplastic size range. The observed size distributions of PS foams and fragments are believed to result from continued fragmentation. Previous studies found that the residence time of beached debris was less than one year on average, and no sign of plastic accumulation with depth in beach sediment was observed. Therefore, coastal beaches may represent a reservoir of highly fragmented and degraded microplastics that may be mobilised and returned to the sea during storm events. Further research on the dynamics and longevity of microplastics on beaches will help reveal the mass balance of microplastics on the shoreline and determine whether shorelines are sinks or sources of microplastics. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigation of in-situ poly(lactic acid)/soy protein concentrate composites: Composite preparation, properties and foam application development

NASA Astrophysics Data System (ADS)

Liu, Bo

2011-12-01

In this study, soy protein (SP), the residue of oil crushing, was used for preparation of value-added thermoplastics. Novel poly(lactic acid) (PLA)/soy protein concentrate (SPC) blends were investigated and foaming of the resulting blends was developed. PLA/SPC blends were prepared by twin-screw extrusion and test specimens by injection molding. Unlike the practice elsewhere SP was used as a filler in mixing with other polymers, SPC was processed as a plastic component in blending process in this work. Processing SPC as plastic component, water played an important role in terms of the deformability and the morphology of SP thus the properties of the blends. Plasticization of SP, compatibilization of the blends and structure-property relationship of the PLA/SPC blends were studied. In the literature water and glycerol were often used together in preparing SP plastics or plastic blends, but this study found that this traditional combination did not provide the best results in terms of morphology and mechanical properties. Water is only recommended in plasticizing SP in the blends. This study showed water as a plasticizer was a domain factor on control of morphology and properties of PLA/SPC blends. The due to the evaporation of water after extrusion, SP domain lost its deformability thus resulted in in-situ composites. Interconnected SPC phase structure was achieved by control water content in the pre-formulated SPC and SPC content in the blends. A novel dual compatibilization method was developed to improve the properties of PLA/SPC blends. Poly(2-ethyl-2-oxazoline) was used to improve the dispersion of SPC in the blending stage, and polymeric methylene diphenyl diisocyanate was used to improve the interfacial adhesion between SPC and PLA in the subsequent processing. The result showed excellent mechanical properties and improved thermal properties of PLA/SPC blends. Using processing aids is an effective way to decrease processing temperature and thermal degradation of PLA/SPC blends. Interfacial adhesion and chemical blowing agent (CBA) played important roles in extrusion foaming PLA/SPC blends. The interconnected SPC particles provided a convenient passage for gas escape due to the weak adhesion between PLA melt and SPC, especially when CBA content was high. Strong interfacial adhesion is necessary to prevent gas escape and get low density foam at low CBA content. The new findings in this work contribute to the knowledgebase of polymer blends and composites. The findings in this work and implementation of the investigation of preparation and properties of PLA/SP blends set up a framework for future research and development of similar natural polymer blends and will contribute to the commercialization of natural polymer based polymer blends such as starch and sugar beet pulp.

Structure and Compressive Properties of Invar-Cenosphere Syntactic Foams.

PubMed

Luong, Dung; Lehmhus, Dirk; Gupta, Nikhil; Weise, Joerg; Bayoumi, Mohamed

2016-02-18

The present study investigates the mechanical performance of syntactic foams produced by means of the metal powder injection molding process having an Invar (FeNi36) matrix and including cenospheres as hollow particles at weight fractions (wt.%) of 5 and 10, respectively, corresponding to approximately 41.6 and 60.0 vol.% in relation to the metal content and at 0.6 g/cm³ hollow particle density. The synthesis process results in survival of cenospheres and provides low density syntactic foams. The microstructure of the materials is investigated as well as the mechanical performance under quasi-static and high strain rate compressive loads. The compressive stress-strain curves of syntactic foams reveal a continuous strain hardening behavior in the plastic region, followed by a densification region. The results reveal a strain rate sensitivity in cenosphere-based Invar matrix syntactic foams. Differences in properties between cenosphere- and glass microsphere-based materials are discussed in relation to the findings of microstructural investigations. Cenospheres present a viable choice as filler material in iron-based syntactic foams due to their higher thermal stability compared to glass microspheres.

The deformation and failure response of closed-cell PMDI foams subjected to dynamic impact loading

DOE PAGES

Koohbor, Behrad; Mallon, Silas; Kidane, Addis; ...

2015-04-07

The present work aims to investigate the bulk deformation and failure response of closed-cell Polymeric Methylene Diphenyl Diisocyanate (PMDI) foams subjected to dynamic impact loading. First, foam specimens of different initial densities are examined and characterized in quasi-static loading conditions, where the deformation behavior of the samples is quantified in terms of the compressive elastic modulus and effective plastic Poisson's ratio. Then, the deformation response of the foam specimens subjected to direct impact loading is examined by taking into account the effects of material compressibility and inertia stresses developed during deformation, using high speed imaging in conjunction with 3D digitalmore » image correlation. The stress-strain response and the energy absorption as a function of strain rate and initial density are presented and the bulk failure mechanisms are discussed. As a result, it is observed that the initial density of the foam and the applied strain rates have a substantial influence on the strength, bulk failure mechanism and the energy dissipation characteristics of the foam specimens.« less

Shock Isolation Elements Testing for High Input Loadings. Volume II. Foam Shock Isolation Elements.

DTIC Science & Technology

SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*EXPANDED PLASTICS, (*SHOCK(MECHANICS), REDUCTION), TEST METHODS, SHOCK WAVES, STRAIN(MECHANICS), LOADS(FORCES), MATHEMATICAL MODELS, NUCLEAR EXPLOSIONS, HARDENING.

Characterization of compressive and short beam shear strength of bamboo opened cell foam core sandwich composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Setyawan, Paryanto Dwi, E-mail: paryanto-ds@yahoo.com; Sugiman,; Saputra, Yudhi

The paper presents the compressive and the short beam shear strength of a sandwich composite with opened cell foam made of bamboo fiber as the core and plywood as the skins. The core thickness was varied from 10 mm to 40 mm keeping the volume fraction of fiber constant. Several test s were carried out including the core density, flatwise compressive and the short beam shear testing in three point bending. The results show that the density of bamboo opened cell foam is comparable with commercial plastic foam, such as polyurethane foam. The compressive strength tends to increase linearly with increasing themore » core thickness. The short beam shear failure load of the sandwich composite increases with the increase of core thickness, however on the contrary, the short beam shear strength which tends to sharply decrease from the thickness of 10 mm to 30 mm and then becomes flat.« less

Fire Hazard Assessment of Shipboard Plastic Waste Processing Systems

DTIC Science & Technology

1994-02-28

cm 1.6 Wood panel (S178M) 1.6 Plastic wage (processed) 1.65 Hardboard, gloss paint, 3.4 mm 1.7 Mineral wool , textile paper (S160M) 1.7 Hardboard...1.27 cm 390 Chipboard (Si 18M) 390 Plywood, plain, 0.635 cm 390 Foam, flexible, 2.54 cm 390 GRP, 2.24 mm 390 Pha waste -(ressed 400 Mineral wool , textile

Streaked x-ray backlighting with twin-slit imager for study of density profile and trajectory of low-density foam target filled with deuterium liquid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiraga, H.; Mahigashi, N.; Yamada, T.

2008-10-15

Low-density plastic foam filled with liquid deuterium is one of the candidates for inertial fusion target. Density profile and trajectory of 527 nm laser-irradiated planer foam-deuterium target in the acceleration phase were observed with streaked side-on x-ray backlighting. An x-ray imager employing twin slits coupled to an x-ray streak camera was used to simultaneously observe three images of the target: self-emission from the target, x-ray backlighter profile, and the backlit target. The experimentally obtained density profile and trajectory were in good agreement with predictions by one-dimensional hydrodynamic simulation code ILESTA-1D.

Plastic debris in 29 Great Lakes tributaries: Relations to watershed attributes and hydrology

USGS Publications Warehouse

Baldwin, Austin K.; Corsi, Steven; Mason, Sherri A.

2016-01-01

Plastic debris is a growing contaminant of concern in freshwater environments, yet sources, transport, and fate remain unclear. This study characterized the quantity and morphology of floating micro- and macroplastics in 29 Great Lakes tributaries in six states under different land covers, wastewater effluent contributions, population densities, and hydrologic conditions. Tributaries were sampled three or four times each using a 333 μm mesh neuston net. Plastic particles were sorted by size, counted, and categorized as fibers/lines, pellets/beads, foams, films, and fragments. Plastics were found in all 107 samples, with a maximum concentration of 32 particles/m3 and a median of 1.9 particles/m3. Ninety-eight percent of sampled plastic particles were less than 4.75 mm in diameter and therefore considered microplastics. Fragments, films, foams, and pellets/beads were positively correlated with urban-related watershed attributes and were found at greater concentrations during runoff-event conditions. Fibers, the most frequently detected particle type, were not associated with urban-related watershed attributes, wastewater effluent contribution, or hydrologic condition. Results from this study add to the body of information currently available on microplastics in different environmental compartments, including unique contributions to quantify their occurrence and variability in rivers with a wide variety of different land-use characteristics while highlighting differences between surface samples from rivers compared with lakes.

Plastic Debris in 29 Great Lakes Tributaries: Relations to Watershed Attributes and Hydrology.

PubMed

Baldwin, Austin K; Corsi, Steven R; Mason, Sherri A

2016-10-04

Plastic debris is a growing contaminant of concern in freshwater environments, yet sources, transport, and fate remain unclear. This study characterized the quantity and morphology of floating micro- and macroplastics in 29 Great Lakes tributaries in six states under different land covers, wastewater effluent contributions, population densities, and hydrologic conditions. Tributaries were sampled three or four times each using a 333 μm mesh neuston net. Plastic particles were sorted by size, counted, and categorized as fibers/lines, pellets/beads, foams, films, and fragments. Plastics were found in all 107 samples, with a maximum concentration of 32 particles/m 3 and a median of 1.9 particles/m 3 . Ninety-eight percent of sampled plastic particles were less than 4.75 mm in diameter and therefore considered microplastics. Fragments, films, foams, and pellets/beads were positively correlated with urban-related watershed attributes and were found at greater concentrations during runoff-event conditions. Fibers, the most frequently detected particle type, were not associated with urban-related watershed attributes, wastewater effluent contribution, or hydrologic condition. Results from this study add to the body of information currently available on microplastics in different environmental compartments, including unique contributions to quantify their occurrence and variability in rivers with a wide variety of different land-use characteristics while highlighting differences between surface samples from rivers compared with lakes.

46 CFR 160.060-5 - Construction-standard vests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... arranged and distributed so as to provide the flotation characteristics and buoyancy required to hold the... drawings. (c) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as...

Terahertz inline wall thickness monitoring system for plastic pipe extrusion

NASA Astrophysics Data System (ADS)

Hauck, J.; Stich, D.; Heidemeyer, P.; Bastian, M.; Hochrein, T.

2014-05-01

Conventional and commercially available inline wall thickness monitoring systems for pipe extrusion are usually based on ultrasonic or x-ray technology. Disadvantages of ultrasonic systems are the usual need of water as a coupling media and the high damping in thick walled or foamed pipes. For x-ray systems special safety requirements have to be taken into account because of the ionizing radiation. The terahertz (THz) technology offers a novel approach to solve these problems. THz waves have many properties which are suitable for the non-destructive testing of plastics. The absorption of electrical isolators is typically very low and the radiation is non-ionizing in comparison to x-rays. Through the electromagnetic origin of the THz waves they can be used for contact free measurements. Foams show a much lower absorption in contrast to acoustic waves. The developed system uses THz pulses which are generated by stimulating photoconductive switches with femtosecond laser pulses. The time of flight of THz pulses can be determined with a resolution in the magnitude of several ten femtoseconds. Hence the thickness of an object like plastic pipes can be determined with a high accuracy by measuring the time delay between two reflections on materials interfaces e.g. at the pipe's inner and outer surface, similar to the ultrasonic technique. Knowing the refractive index of the sample the absolute layer thickness from the transit time difference can be calculated easily. This method in principle also allows the measurement of multilayer systems and the characterization of foamed pipes.

Building under Cold Climates and on Permafrost. Collection of Papers from a US-Soviet Joint Seminar, Leningrad USSR.

DTIC Science & Technology

1980-12-01

The panels are insulated with PSBS polyurethane foam, FRP-I. and mineral wool . In recent years, several dozen such buildings have been constructed in...vulnerable points in the walls. 37 Different plastic foams and also mineral wool sheets with synthetic binding are used in the USSR for insulating the...middle layer of the panels. Mineral wool sheets are used in the wall panels of buildings having high fire safety requirements (children’s and medical

Conversion of "Waste Plastic" into Photocatalytic Nanofoams for Environmental Remediation.

PubMed

de Assis, Geovania C; Skovroinski, Euzébio; Leite, Valderi D; Rodrigues, Marcelo O; Galembeck, André; Alves, Mary C F; Eastoe, Julian; de Oliveira, Rodrigo J

2018-03-07

Plastic debris is a major environmental concern, and to find effective ways to reuse polystyrene (PS) presents major challenges. Here, it is demonstrated that polystyrene foams impregnated with SnO 2 are easily generated from plastic debris and can be applied to photocatalytic degradation of dyes. SnO 2 nanoparticles were synthesized by a polymeric precursor method, yielding specific surface areas of 15 m 2 /g after heat treatment to 700 °C. Crystallinity, size, and shape of the SnO 2 particles were assessed by X-ray diffraction (XRD) and transmission electron microscopy (TEM), demonstrating the preparation of crystalline spherical nanoparticles with sizes around 20 nm. When incorporated into PS foams, which were generated using a thermally induced phase separation (TIPS) process, the specific surface area increased to 48 m 2 /g. These PS/SnO 2 nanofoams showed very good efficiency for photodegradation of rhodamine B, under UV irradiation, achieving up to 98.2% removal. In addition the PS/SnO 2 nanofoams are shown to retain photocatalytic activity for up to five reuse cycles.

Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

NASA Astrophysics Data System (ADS)

Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; Olson, R. E.; Cobble, J. A.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Parra-Vasquez, N. A. G.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

2016-05-01

Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Work is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. The ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.

Methods for Aircraft State and Parameter Identification

DTIC Science & Technology

1975-05-01

fast heat exchange with the air. The isolation of the flask was improved by plastic foam. See Fig. 5. A small electric heater mounted inside the...flight tests is necessary to have a check on possible changes in the caracteristics of the transducers. If Kalman filtering or corresponding techniques...negates the need for transparent plastic overlays of the flight data. thereby eliminating the coneiderable amount of parallax and distortion which is

Shock-induced perturbation evolution in planar laser targets

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Karasik, M.; Velikovich, A. L.; Serlin, V.; Weaver, J. L.; Kessler, T. J.; Schmitt, A. J.; Obenschain, S. P.; Metzler, N.; Oh, J.

2013-10-01

Experimental studies of hydrodynamic perturbation evolution triggered by a laser-driven shock wave in a planar target done on the KrF Nike laser facility are reported. The targets were made of solid plastic and/or plastic foam with single mode sinusoidal perturbation on the front or back surface or plastic/foam interface. Two specific cases are discussed. When a planar solid plastic target rippled at the front side is irradiated with a 350 ps long laser pulse, ablative Richtmyer-Meshkov (RM) oscillation of its areal mass modulation amplitude is detected while the laser is on, followed by observed strong oscillations of the areal mass in the unsupported shock flow after the laser pulse ends. When the target is rippled at the rear side, the nature of the perturbation evolution after the shock breakout is determined by the strength of the laser-driven shock wave. At pressure below 1 Mbar shock interaction with rear-surface ripples produces planar collimated jets manifesting the development of a classical RM instability in a weakly compressible shocked fluid. At shock pressure ~ 8 Mbar sufficient for vaporizing the shocked target material we observed instead the strong areal mass oscillations characteristic of a rippled centered rarefaction wave. Work supported by US DOE, Defense Programs.

Fully recoverable rigid shape memory foam based on copper-catalyzed azide-alkyne cycloaddition (CuAAC) using a salt leaching technique.

PubMed

Alzahrani, Abeer A; Saed, Mohand; Yakacki, Christopher M; Song, Han Byul; Sowan, Nancy; Walston, Joshua J; Shah, Parag K; McBride, Matthew K; Stansbury, Jeffrey W; Bowman, Christopher N

2018-01-07

This study is the first to employ the use of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) polymerization to form a tough and stiff, porous material from a well-defined network possessing a high glass transition temperature. The effect of the network linkages formed as a product of the CuAAC reaction, i.e., the triazoles, on the mechanical behavior at high strain was evaluated by comparing the CuAAC foam to an epoxy-amine-based foam, which consisted of monomers with similar backbone structures and mechanical properties (i.e., T g of 115 °C and a rubbery modulus of 1.0 MPa for the CuAAC foam, T g of 125 °C and a rubbery modulus of 1.2 MPa for the epoxy-amine foam). When each foam was compressed uniformly to 80% strain at ambient temperature, the epoxy-amine foam was severely damaged after only reaching 70% strain in the first compression cycle with a toughness of 300 MJ/m 3 . In contrast, the CuAAC foam exhibited pronounced ductile behavior in the glassy state with three times higher toughness of 850 MJ/m 3 after the first cycle of compression to 80% strain. Additionally, when the CuAAC foam was heated above T g after each of five compression cycles to 80% strain at ambient temperature, the foam completely recovered its original shape while exhibiting a gradual decrease in mechanical performance over the multiple compression cycles. The foam demonstrated almost complete shape fixity and recovery ratios even through five successive cycles, indicative of "reversible plasticity", making it highly desirable as a glassy shape memory foams.

Extracting material response from simple mechanical tests on hardening-softening-hardening viscoplastic solids

NASA Astrophysics Data System (ADS)

Mohan, Nisha

Compliant foams are usually characterized by a wide range of desirable mechanical properties. These properties include viscoelasticity at different temperatures, energy absorption, recoverability under cyclic loading, impact resistance, and thermal, electrical, acoustic and radiation-resistance. Some foams contain nano-sized features and are used in small-scale devices. This implies that the characteristic dimensions of foams span multiple length scales, rendering modeling their mechanical properties difficult. Continuum mechanics-based models capture some salient experimental features like the linear elastic regime, followed by non-linear plateau stress regime. However, they lack mesostructural physical details. This makes them incapable of accurately predicting local peaks in stress and strain distributions, which significantly affect the deformation paths. Atomistic methods are capable of capturing the physical origins of deformation at smaller scales, but suffer from impractical computational intensity. Capturing deformation at the so-called meso-scale, which is capable of describing the phenomenon at a continuum level, but with some physical insights, requires developing new theoretical approaches. A fundamental question that motivates the modeling of foams is `how to extract the intrinsic material response from simple mechanical test data, such as stress vs. strain response?' A 3D model was developed to simulate the mechanical response of foam-type materials. The novelty of this model includes unique features such as the hardening-softening-hardening material response, strain rate-dependence, and plastically compressible solids with plastic non-normality. Suggestive links from atomistic simulations of foams were borrowed to formulate a physically informed hardening material input function. Motivated by a model that qualitatively captured the response of foam-type vertically aligned carbon nanotube (VACNT) pillars under uniaxial compression [2011,"Analysis of Uniaxial Compression of Vertically Aligned Carbon Nanotubes," J. Mech.Phys. Solids, 59, pp. 2227--2237, Erratum 60, 1753-1756 (2012)], the property space exploration was advanced to three types of simple mechanical tests: 1) uniaxial compression, 2) uniaxial tension, and 3) nanoindentation with a conical and a flat-punch tip. The simulations attempt to explain some of the salient features in experimental data, like 1) The initial linear elastic response. 2) One or more nonlinear instabilities, yielding, and hardening. The model-inherent relationships between the material properties and the overall stress-strain behavior were validated against the available experimental data. The material properties include the gradient in stiffness along the height, plastic and elastic compressibility, and hardening. Each of these tests was evaluated in terms of their efficiency in extracting material properties. The uniaxial simulation results proved to be a combination of structural and material influences. Out of all deformation paths, flat-punch indentation proved to be superior since it is the most sensitive in capturing the material properties.

The effect of moisture absorption on the physical properties of polyurethane shape memory polymer foams.

PubMed

Yu, Ya-Jen; Hearon, Keith; Wilson, Thomas S; Maitland, Duncan J

2011-08-01

The effect of moisture absorption on the glass transition temperature (T(g)) and stress/strain behavior of network polyurethane shape memory polymer (SMP) foams has been investigated. With our ultimate goal of engineering polyurethane SMP foams for use in blood contacting environments, we have investigated the effects of moisture exposure on the physical properties of polyurethane foams. To our best knowledge, this study is the first to investigate the effects of moisture absorption at varying humidity levels (non-immersion and immersion) on the physical properties of polyurethane SMP foams. The SMP foams were exposed to differing humidity levels for varying lengths of time, and they exhibited a maximum water uptake of 8.0% (by mass) after exposure to 100% relative humidity for 96 h. Differential scanning calorimetry results demonstrated that water absorption significantly decreased the T(g) of the foam, with a maximum water uptake shifting the T(g) from 67 °C to 5 °C. Samples that were immersed in water for 96 h and immediately subjected to tensile testing exhibited 100% increases in failure strains and 500% decreases in failure stresses; however, in all cases of time and humidity exposure, the plasticization effect was reversible upon placing moisture-saturated samples in 40% humidity environments for 24 h.

The effect of moisture absorption on the physical properties of polyurethane shape memory polymer foams

PubMed Central

Yu, Ya-Jen; Hearon, Keith; Wilson, Thomas S.; Maitland, Duncan J.

2011-01-01

The effect of moisture absorption on the glass transition temperature (Tg) and stress/strain behavior of network polyurethane shape memory polymer (SMP) foams has been investigated. With our ultimate goal of engineering polyurethane SMP foams for use in blood contacting environments, we have investigated the effects of moisture exposure on the physical properties of polyurethane foams. To our best knowledge, this study is the first to investigate the effects of moisture absorption at varying humidity levels (non-immersion and immersion) on the physical properties of polyurethane SMP foams. The SMP foams were exposed to differing humidity levels for varying lengths of time, and they exhibited a maximum water uptake of 8.0% (by mass) after exposure to 100% relative humidity for 96 h. Differential scanning calorimetry results demonstrated that water absorption significantly decreased the Tg of the foam, with a maximum water uptake shifting the Tg from 67 °C to 5 °C. Samples that were immersed in water for 96 h and immediately subjected to tensile testing exhibited 100% increases in failure strains and 500% decreases in failure stresses; however, in all cases of time and humidity exposure, the plasticization effect was reversible upon placing moisture-saturated samples in 40% humidity environments for 24 h. PMID:21949469

The effect of moisture absorption on the physical properties of polyurethane shape memory polymer foams

NASA Astrophysics Data System (ADS)

Yu, Ya-Jen; Hearon, Keith; Wilson, Thomas S.; Maitland, Duncan J.

2011-08-01

The effect of moisture absorption on the glass transition temperature (Tg) and the stress/strain behavior of network polyurethane shape memory polymer (SMP) foams has been investigated. With our ultimate goal of engineering polyurethane SMP foams for use in blood-contacting environments, we have investigated the effects of moisture exposure on the physical properties of polyurethane foams. To the best of our knowledge, this study is the first to investigate the effects of moisture absorption at varying humidity levels (non-immersion and immersion) on the physical properties of polyurethane SMP foams. The SMP foams were exposed to differing humidity levels for varying lengths of time, and they exhibited a maximum water uptake of 8.0% (by mass) after exposure to 100% relative humidity for 96 h. Differential scanning calorimetry results demonstrated that water absorption significantly decreased the Tg of the foam, with a maximum water uptake shifting the Tg from 67 to 5 °C. Samples that were immersed in water for 96 h and immediately subjected to tensile testing exhibited 100% increases in failure strains and 500% decreases in failure stresses; however, in all cases of time and humidity exposure, the plasticization effect was reversible upon placing moisture-saturated samples in 40% humidity environments for 24 h.

The Effect of Matrix Composition on the Deformation and Failure Mechanisms in Metal Matrix Syntactic Foams during Compression

PubMed Central

Kádár, Csilla; Máthis, Kristián; Knapek, Michal; Chmelík, František

2017-01-01

The influence of the matrix material on the deformation and failure mechanisms in metal matrix syntactic foams was investigated in this study. Samples with commercially pure Al (Al) and Al-12 wt % Si (AlSi12) eutectic aluminum matrix, reinforced by hollow ceramic spheres, were compressed at room temperature. Concurrently, the acoustic emission response and the strain field development on the surface were monitored in-situ. The results indicate that the plastic deformation of the cell walls is the governing mechanism in the early stage of straining for both types of foams. At large stresses, deformation bands form both in the Al and AlSi12 foam. In Al foam, cell walls collapse in a large volume. In contrast, the AlSi12 foam is more brittle; therefore, the fracture of precipitates and the crushing of the matrix take place within a distinctive deformation band, along with an occurrence of a significant stress drop. The onset stress of ceramic sphere failure was shown to be not influenced by the matrix material. The in-situ methods provided complementary data which further support these results. PMID:28772556

The Effect of Matrix Composition on the Deformation and Failure Mechanisms in Metal Matrix Syntactic Foams during Compression.

PubMed

Kádár, Csilla; Máthis, Kristián; Knapek, Michal; Chmelík, František

2017-02-17

The influence of the matrix material on the deformation and failure mechanisms in metal matrix syntactic foams was investigated in this study. Samples with commercially pure Al (Al) and Al-12 wt % Si (AlSi12) eutectic aluminum matrix, reinforced by hollow ceramic spheres, were compressed at room temperature. Concurrently, the acoustic emission response and the strain field development on the surface were monitored in-situ. The results indicate that the plastic deformation of the cell walls is the governing mechanism in the early stage of straining for both types of foams. At large stresses, deformation bands form both in the Al and AlSi12 foam. In Al foam, cell walls collapse in a large volume. In contrast, the AlSi12 foam is more brittle; therefore, the fracture of precipitates and the crushing of the matrix take place within a distinctive deformation band, along with an occurrence of a significant stress drop. The onset stress of ceramic sphere failure was shown to be not influenced by the matrix material. The in-situ methods provided complementary data which further support these results.

The influence of geometric imperfections on the stability of three-layer beams with foam core

NASA Astrophysics Data System (ADS)

Wstawska, Iwona

2017-01-01

The main objective of this work is the numerical analysis (FE analysis) of stability of three-layer beams with metal foam core (alumina foam core). The beams were subjected to pure bending. The analysis of the local buckling was performed. Furthermore, the influence of geometric parameters of the beam and material properties of the core (linear and non-linear model) on critical loads values and buckling shape were also investigated. The calculations were made on a family of beams with different mechanical properties of the core (elastic and elastic-plastic material). In addition, the influence of geometric imperfections on deflection and normal stress values of the core and the faces has been evaluated.

Fire resistant aircraft seat program

NASA Technical Reports Server (NTRS)

Fewell, L. A.

1979-01-01

Foams, textiles, and thermoformable plastics were tested to determine which materials were fire retardant, and safe for aircraft passenger seats. Seat components investigated were the decorative fabric cover, slip covers, fire blocking layer, cushion reinforcement, and the cushioning layer.

Process Development and Micro-Machining of MARBLE Foam-Cored Rexolite Hemi-Shell Ablator Capsules

DOE PAGES

Randolph, Randall Blaine; Oertel, John A.; Schmidt, Derek William; ...

2016-06-30

For this study, machined CH hemi-shell ablator capsules have been successfully produced by the MST-7 Target Fabrication Team at Los Alamos National Laboratory. Process development and micro-machining techniques have been developed to produce capsules for both the Omega and National Ignition Facility (NIF) campaigns. These capsules are gas filled up to 10 atm and consist of a machined plastic hemi-shell outer layer that accommodates various specially engineered low-density polystyrene foam cores. Machining and assembly of the two-part, step-jointed plastic hemi-shell outer layer required development of new techniques, processes, and tooling while still meeting very aggressive shot schedules for both campaigns.more » Finally, problems encountered and process improvements will be discussed that describe this very unique, complex capsule design approach through the first Omega proof-of-concept version to the larger NIF version.« less

Numerical Simulation and Experimental Verification of Hollow and Foam-Filled Flax-Fabric-Reinforced Epoxy Tubular Energy Absorbers Subjected to Crashing

NASA Astrophysics Data System (ADS)

Sliseris, J.; Yan, L.; Kasal, B.

2017-09-01

Numerical methods for simulating hollow and foam-filled flax-fabric-reinforced epoxy tubular energy absorbers subjected to lateral crashing are presented. The crashing characteristics, such as the progressive failure, load-displacement response, absorbed energy, peak load, and failure modes, of the tubes were simulated and calculated numerically. A 3D nonlinear finite-element model that allows for the plasticity of materials using an isotropic hardening model with strain rate dependence and failure is proposed. An explicit finite-element solver is used to address the lateral crashing of the tubes considering large displacements and strains, plasticity, and damage. The experimental nonlinear crashing load vs. displacement data are successfully described by using the finite-element model proposed. The simulated peak loads and absorbed energy of the tubes are also in good agreement with experimental results.

Supercritical CO2 foaming of thermoplastic materials derived from maize: proof-of-concept use in mammalian cell culture applications.

PubMed

Trujillo-de Santiago, Grissel; Portales-Cabrera, Cynthia Guadalupe; Portillo-Lara, Roberto; Araiz-Hernández, Diana; Del Barone, Maria Cristina; García-López, Erika; Rojas-de Gante, Cecilia; de Los Angeles De Santiago-Miramontes, María; Segoviano-Ramírez, Juan Carlos; García-Lara, Silverio; Rodríguez-González, Ciro Ángel; Alvarez, Mario Moisés; Di Maio, Ernesto; Iannace, Salvatore

2015-01-01

Foams are high porosity and low density materials. In nature, they are a common architecture. Some of their relevant technological applications include heat and sound insulation, lightweight materials, and tissue engineering scaffolds. Foams derived from natural polymers are particularly attractive for tissue culture due to their biodegradability and bio-compatibility. Here, the foaming potential of an extensive list of materials was assayed, including slabs elaborated from whole flour, the starch component only, or the protein fraction only of maize seeds. We used supercritical CO2 to produce foams from thermoplasticized maize derived materials. Polyethylene-glycol, sorbitol/glycerol, or urea/formamide were used as plasticizers. We report expansion ratios, porosities, average pore sizes, pore morphologies, and pore size distributions for these materials. High porosity foams were obtained from zein thermoplasticized with polyethylene glycol, and from starch thermoplasticized with urea/formamide. Zein foams had a higher porosity than starch foams (88% and 85%, respectively) and a narrower and more evenly distributed pore size. Starch foams exhibited a wider span of pore sizes and a larger average pore size than zein (208.84 vs. 55.43 μm2, respectively). Proof-of-concept cell culture experiments confirmed that mouse fibroblasts (NIH 3T3) and two different prostate cancer cell lines (22RV1, DU145) attached to and proliferated on zein foams. We conducted screening and proof-of-concept experiments on the fabrication of foams from cereal-based bioplastics. We propose that a key indicator of foamability is the strain at break of the materials to be foamed (as calculated from stress vs. strain rate curves). Zein foams exhibit attractive properties (average pore size, pore size distribution, and porosity) for cell culture applications; we were able to establish and sustain mammalian cell cultures on zein foams for extended time periods.

Supercritical CO2 Foaming of Thermoplastic Materials Derived from Maize: Proof-of-Concept Use in Mammalian Cell Culture Applications

PubMed Central

Trujillo-de Santiago, Grissel; Portales-Cabrera, Cynthia Guadalupe; Portillo-Lara, Roberto; Araiz-Hernández, Diana; Del Barone, Maria Cristina; García-López, Erika; Rojas-de Gante, Cecilia; de los Angeles De Santiago-Miramontes, María; Segoviano-Ramírez, Juan Carlos; García-Lara, Silverio; Rodríguez-González, Ciro Ángel; Alvarez, Mario Moisés; Di Maio, Ernesto; Iannace, Salvatore

2015-01-01

Background Foams are high porosity and low density materials. In nature, they are a common architecture. Some of their relevant technological applications include heat and sound insulation, lightweight materials, and tissue engineering scaffolds. Foams derived from natural polymers are particularly attractive for tissue culture due to their biodegradability and bio-compatibility. Here, the foaming potential of an extensive list of materials was assayed, including slabs elaborated from whole flour, the starch component only, or the protein fraction only of maize seeds. Methodology/Principal Findings We used supercritical CO2 to produce foams from thermoplasticized maize derived materials. Polyethylene-glycol, sorbitol/glycerol, or urea/formamide were used as plasticizers. We report expansion ratios, porosities, average pore sizes, pore morphologies, and pore size distributions for these materials. High porosity foams were obtained from zein thermoplasticized with polyethylene glycol, and from starch thermoplasticized with urea/formamide. Zein foams had a higher porosity than starch foams (88% and 85%, respectively) and a narrower and more evenly distributed pore size. Starch foams exhibited a wider span of pore sizes and a larger average pore size than zein (208.84 vs. 55.43 μm2, respectively). Proof-of-concept cell culture experiments confirmed that mouse fibroblasts (NIH 3T3) and two different prostate cancer cell lines (22RV1, DU145) attached to and proliferated on zein foams. Conclusions/Significance We conducted screening and proof-of-concept experiments on the fabrication of foams from cereal-based bioplastics. We propose that a key indicator of foamability is the strain at break of the materials to be foamed (as calculated from stress vs. strain rate curves). Zein foams exhibit attractive properties (average pore size, pore size distribution, and porosity) for cell culture applications; we were able to establish and sustain mammalian cell cultures on zein foams for extended time periods. PMID:25859853

The Temperature Effect on the Compressive Behavior of Closed-Cell Aluminum-Alloy Foams

NASA Astrophysics Data System (ADS)

Movahedi, Nima; Linul, Emanoil; Marsavina, Liviu

2018-01-01

In this research, the mechanical behavior of closed-cell aluminum (Al)-alloy foams was investigated at different temperatures in the range of 25-450 °C. The main mechanical properties of porous Al-alloy foams are affected by the testing temperature, and they decrease with the increase in the temperature during uniaxial compression. From both the constant/serrated character of stress-strain curves and macro/microstructural morphology of deformed cellular structure, it was found that Al foams present a transition temperature from brittle to ductile behavior around 192 °C. Due to the softening of the cellular structure at higher temperatures, linear correlations of the stress amplitude and that of the absorbed energy with the temperature were proposed. Also, it was observed that the presence of inherent defects like micropores in the foam cell walls induced further local stress concentration which weakens the cellular structure's strength and crack propagation and cell-wall plastic deformation are the dominant collapse mechanisms. Finally, an energy absorption study was performed and an optimum temperature was proposed.

Elasto-Plastic Behavior of Aluminum Foams Subjected to Compression Loading

NASA Astrophysics Data System (ADS)

Silva, H. M.; Carvalho, C. D.; Peixinho, N. R.

2017-05-01

The non-linear behavior of uniform-size cellular foams made of aluminum is investigated when subjected to compressive loads while comparing numerical results obtained in the Finite Element Method software (FEM) ANSYS workbench and ANSYS Mechanical APDL (ANSYS Parametric Design Language). The numerical model is built on AUTODESK INVENTOR, being imported into ANSYS and solved by the Newton-Raphson iterative method. The most similar conditions were used in ANSYS mechanical and ANSYS workbench, as possible. The obtained numerical results and the differences between the two programs are presented and discussed

46 CFR 160.060-5 - Construction-standard vests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... drawings. (c) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as.... Two pieces of fabric shall be cut to the pattern shown on Dwg. No. 160.060-1, Sheet 1 for the adult...

46 CFR 160.060-5 - Construction-standard vests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... drawings. (c) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as.... Two pieces of fabric shall be cut to the pattern shown on Dwg. No. 160.060-1, Sheet 1 for the adult...

46 CFR 160.060-5 - Construction-standard vests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... drawings. (c) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as.... Two pieces of fabric shall be cut to the pattern shown on Dwg. No. 160.060-1, Sheet 1 for the adult...

46 CFR 160.060-5 - Construction-standard vests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... drawings. (c) Buoyant inserts. The unicellular plastic foam buoyant inserts shall be cut and formed as.... Two pieces of fabric shall be cut to the pattern shown on Dwg. No. 160.060-1, Sheet 1 for the adult...

Portable flooring protects finished surfaces, is easily moved

NASA Technical Reports Server (NTRS)

Carmody, R. J.

1964-01-01

To protect curved, finished surface and provide support for workmen, portable flooring has been made from rigid plastic foam blocks, faced with aluminum strips. Held together by nylon webbing, the flooring can be rolled up for easy carrying.

Castable plastic mold with electroplatable base

DOEpatents

Domeier, Linda A.; Morales, Alfredo M.; Gonzales, Marcela G.; Keifer, Patrick M.

2004-01-20

A sacrificial plastic mold having an electroplatable backing is provided as are methods of making such a mold via the infusion of a castable liquid formulation through a porous metal substrate (sheet, screen, mesh or foam) and into the features of a micro-scale master mold. Upon casting and demolding, the porous metal substrate is embedded within the cast formulation and projects a plastic structure with features determined by the mold tool. The plastic structure provides a sacrificial plastic mold mechanically bonded to the porous metal substrate, which provides a conducting support suitable for electroplating either contiguous or non-contiguous metal replicates. After electroplating and lapping, the sacrificial plastic can be dissolved, leaving the desired metal structure bonded to the porous metal substrate. Optionally, the electroplated structures may be debonded from the porous substrate by selective dissolution of the porous substrate or a coating thereon.

Rigid polyurethane/oil palm fibre biocomposite foam

NASA Astrophysics Data System (ADS)

Alis, Adilah; Majid, Rohah A.; Nasir, Izzah Athirah Ahmad; Mustaffa, Nor Syatika; Hassan, Wan Hasamuddin Wan

2017-07-01

Rigid polyurethane (PU) biocomposite foam had been successfully prepared by reacting palm oil-derived polyol (PO-p) with polymeric 4, 4-diphenylmethane diisocynate (p-MDI). Two types of alkali-treated oil palm fibres namely, empty fruit bunch (EFB) and palm pressed fibre (PPF) were used as fillers to be incorporated into PU foam at 2.5 wt%, 5 wt% and 7.5 wt% fibre loadings. The effects of these fibres on surface morphology, compressive strength and thermal transition behaviours of biocomposite foams were investigated. Fourier transform infra-red (FTIR) analysis confirmed the formation of urethane linkages (-NHCOO) in all samples at 1530-1540 cm-1. Differential scanning calorimetry (DSC) analysis showed the average melting peak temperature (Tm) of biocomposite foams (132°C) were lower Tm than that of pure PU foam (161.67°C) and the increase amount of fibres did not give significant effect on the Tm of both biocomposite systems. Meanwhile, the microscopic images of PU-PPF foams exhibited smaller and uniform cell size morphologies compared with the PU-EFB foams that had coarse and irregular cell sizes, especially at 7.5wt% EFB. These findings were manifested with the gradually increase of compressive strength of PU-PPF at all PPF ratios while for PU-EFB system, the compressive strength increased up to 5 wt% before reduced at 7.5 wt% loading. It was thought due to the residual oil in PPF fibre had plasticized the PU matrix to a little extent, thus helping the dispersion of PPF fibre across the matrix.

Methods of Responsibly Managing End-of-Life Foams and Plastics Containing Flame Retardants: Part I.

PubMed

Lucas, Donald; Petty, Sara M; Keen, Olya; Luedeka, Bob; Schlummer, Martin; Weber, Roland; Barlaz, Morton; Yazdani, Ramin; Riise, Brian; Rhodes, James; Nightingale, Dave; Diamond, Miriam L; Vijgen, John; Lindeman, Avery; Blum, Arlene; Koshland, Catherine P

2018-06-01

Flame retardants (FRs) are added to foams and plastics to comply with flammability standards and test requirements in products for household and industrial uses. When these regulations were implemented, potential health and environmental impacts of FR use were not fully recognized or understood. Extensive research in the past decades reveal that exposure to halogenated FRs, such as those used widely in furniture foam, is associated with and/or causally related to numerous health effects in animals and humans. While many of the toxic FRs have been eliminated and replaced by other FRs, existing products containing toxic or potentially toxic chemical FRs will remain in use for decades, and new products containing these and similar chemicals will permeate the environment. When such products reach the end of their useful life, proper disposal methods are needed to avoid health and ecological risks. To minimize continued human and environmental exposures to hazardous FR chemicals from discarded products, waste management technologies and processes must be improved. This review discusses a wide range of issues associated with all aspects of the use and responsible disposal of wastes containing FRs, and identifies basic and applied research needs in the areas of responsible collection, pretreatment, processing, and management of these wastes.

Refractory Ceramic Foams for Novel Applications

NASA Technical Reports Server (NTRS)

Stackpoole, M.

2008-01-01

Workers at NASA Ames Research center are endeavoring to develop durable, oxidation-resistant, foam thermal protection systems (TPSs) that would be suitable for covering large exterior spacecraft surfaces, would have low to moderate densities, and would have temperature capabilities comparable to those of carbon-based TPSs [reusable at 3,000 F (.1,650 C)] with application of suitable coatings. These foams may also be useful for repairing TPSs while in orbit. Moreover, on Earth as well as in outer space, these foams might be useful as catalyst supports and filters. Preceramic polymers are obvious candidates for use in making the foams in question. The use of these polymers offers advantages over processing routes followed in making conventional ceramics. Among the advantages are the ability to plastically form parts, the ability to form pyrolized ceramic materials at lower temperatures, and the ability to form high-purity microstructures having properties that can be tailored to satisfy requirements. Heretofore, preceramic polymers have been used mostly in the production of such low-dimensional products as fibers because the loss of volatiles during pyrolysis of the polymers leads to porosity and large shrinkage (in excess of 30 percent). In addition, efforts to form bulk structures from preceramic polymers have resulted in severe cracking during pyrolysis. However, because the foams in question would consist of networks of thin struts (in contradistinction to nonporous dense solids), these foams are ideal candidates for processing along a preceramic-polymer route.

Prediction of the Stress-Strain Behavior of Open-Cell Aluminum Foam under Compressive Loading and the Effects of Various RVE Boundary Conditions

NASA Astrophysics Data System (ADS)

Hamidi Ghaleh Jigh, Behrang; Farsi, Mohammad Ali; Hosseini Toudeshky, Hossein

2018-05-01

The prediction of the mechanical behavior of metallic foams with realistic microstructure and the effects of various boundary conditions on the mechanical behavior is an important and challenging issue in modeling representative volume elements (RVEs). A numerical investigation is conducted to determine the effects of various boundary conditions and cell wall cross sections on the compressive mechanical properties of aluminum foam, including the stiffness, plateau stress and onset strain of densification. The open-cell AA6101-T6 aluminum foam Duocel is used in the analyses in this study. Geometrical characteristics including the cell size, foam relative density, and cross-sectional shape and thickness of the cell walls are extracted from images of the foam. Then, the obtained foam microstructure is analyzed as a 2D model. The ligaments are modeled as shear deformable beams with elastic-plastic material behavior. To prevent interpenetration of the nodes and walls inside the cells with large deformations, self-contact-type frictionless interaction is stipulated between the internal surfaces. Sensitivity analyses are performed using several boundary conditions and cells wall cross-sectional shapes. The predicted results from the finite element analyses are compared with the experimental results. Finally, the most appropriate boundary conditions, leading to more consistent results with the experimental data, are introduced.

Prediction of the Stress-Strain Behavior of Open-Cell Aluminum Foam under Compressive Loading and the Effects of Various RVE Boundary Conditions

NASA Astrophysics Data System (ADS)

Hamidi Ghaleh Jigh, Behrang; Farsi, Mohammad Ali; Hosseini Toudeshky, Hossein

2018-04-01

The prediction of the mechanical behavior of metallic foams with realistic microstructure and the effects of various boundary conditions on the mechanical behavior is an important and challenging issue in modeling representative volume elements (RVEs). A numerical investigation is conducted to determine the effects of various boundary conditions and cell wall cross sections on the compressive mechanical properties of aluminum foam, including the stiffness, plateau stress and onset strain of densification. The open-cell AA6101-T6 aluminum foam Duocel is used in the analyses in this study. Geometrical characteristics including the cell size, foam relative density, and cross-sectional shape and thickness of the cell walls are extracted from images of the foam. Then, the obtained foam microstructure is analyzed as a 2D model. The ligaments are modeled as shear deformable beams with elastic-plastic material behavior. To prevent interpenetration of the nodes and walls inside the cells with large deformations, self-contact-type frictionless interaction is stipulated between the internal surfaces. Sensitivity analyses are performed using several boundary conditions and cells wall cross-sectional shapes. The predicted results from the finite element analyses are compared with the experimental results. Finally, the most appropriate boundary conditions, leading to more consistent results with the experimental data, are introduced.

46 CFR 160.055-8 - Marking.

Code of Federal Regulations, 2010 CFR

2010-10-01

... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for... persons weighing over 90 pounds); or (2) Child (for persons weighing less than 90 pounds). (b) In letters...

Novel phosphonates triazine derivative as economic flame retardant for cotton

USDA-ARS?s Scientific Manuscript database

Phosphorous-containing flame retardants are widely used in standard and engineering plastics, polyurethane foams, thermosets, coatings, and textiles. Organophosphorous flame retardants have been known to be more effective when used in conjunction with nitrogen-containing systems. Their mixture produ...

JPRS Report, Soviet Union, Military Affairs

DTIC Science & Technology

1990-12-17

connection with the fact that they Irkutsk began throwing stones, bottles , and smoke bombs onto Lt Gen N. Kozlov, chief of the Central Food Directorate of the...elevators. The missile’s body is manufactured from fiber plastic (injection molded mate- The AGM-88B’s homing head is equipped with a rial) and consists...spiral antennas installed in a foam plastic radar and the same dimensions as the Martel. The new missile absorbing fairing which support operation of

Plastic ingestion by Black-footed Albatross Phoebastria nigripes from Kure Atoll, Hawai'i: Linking chick diet remains and parental at-sea foraging distributions

USGS Publications Warehouse

Hyrenbach, K. David; Hester, Michelle M.; Adams, Josh; Titmus, Andrew J.; Michael, Pam; Wahl, Travis; Chang, Chih-Wei; Marie, Amarisa; Vanderlip, Cynthia

2017-01-01

We quantified the incidence (percentage of samples with plastic) and loads (mass, volume) of four plastic types (fragments, line, sheet, foam) ingested by Black-footed Albatross Phoebastria nigripes chicks raised on Kure Atoll, the westernmost Hawaiian colony. All 25 samples contained plastic, mostly in the form of foam and line. On average (± SD), boluses and stomachs contained 28.2 ± 14.3 g and 40.3 ± 29.0 g of plastic, respectively. Plastic was the dominant indigestible material in the boluses and the stomach samples, accounting for 48.8%-89.7% of the bolus mass (mean 67.4 ± 12.1%, median 67.5%, n = 20), and for 18.2%-94.1% of the stomach content mass (mean 70.0 ± 30.3%, median 75.6%, n = 5). Although the ingested plastic fragments ranged widely in size, most (92% in boluses, 91% in stomachs) were mesoplastics (5-25 mm), followed by macroplastics (>25 mm; 7% in boluses, 6% in stomachs), and microplastics (1-5 mm; 1% in boluses, 4% in stomachs). Yet the two fragment size distributions were significantly different, with more small-sized items (3-8 mm) in stomachs and with more large-sized items (46-72 mm) in boluses. To investigate where albatross parents collect this material, we tracked seven provisioning adults during 14 foraging trips using satellite-linked transmitters. The tracked birds foraged west of Kure Atoll (180–150°E, 30-40°N) and spent most of their time over pelagic waters (>2000 m deep; averaging 89 ± 9%), with substantial time over seamounts (averaging 11 ± 7%). Together, these results indicate that Black-footed Albatross chicks at Kure Atoll ingest plastics sourced by their parents foraging in waters of the western North Pacific. Provisioning adults forage within an area of surface convergence, downstream from the Kuroshio Current, and frequently visit seamounts northwest of the Hawaiian archipelago.

Foam imbibition in a Hele-Shaw cell via laminated microfluidic ``T-junction'' device

NASA Astrophysics Data System (ADS)

Parra, Dina; Ward, Thomas

2013-11-01

In this talk we analyze experimental results of a novel microfluidic ``T-junction'' device, made from laminated plastic, that is used to produce foam in porous media. The fluids, both Newtonian and non-Newtonian liquids and air, are driven using constant-static pressure fluid pumping. For the T-junction geometry studied there are novel observations with this type of pumping: 1) at low pressure ratios there is an increase in the liquid and total flow rates and 2) at higher pressure ratios there is a decrease in the liquid flow rate. To understand this phenomenon we visualize the drop production process near the T-junction. Furthermore, flow rates for the liquid and total volume are estimated by imbibing the foam into a Hele-Shaw cell. Foam is produced by using a mixture containing aqueous polyacrylamide of concentrations ranging from 0.01-0.10% by weight and several solution also containing a sodium-lauryl-sulfate (SLS) surfactant at concentrations ranging 0.01-0.1% by weight.

Partitioned airs at microscale and nanoscale: thermal diffusivity in ultrahigh porosity solids of nanocellulose

PubMed Central

Sakai, Koh; Kobayashi, Yuri; Saito, Tsuguyuki; Isogai, Akira

2016-01-01

High porosity solids, such as plastic foams and aerogels, are thermally insulating. Their insulation performance strongly depends on their pore structure, which dictates the heat transfer process in the material. Understanding such a relationship is essential to realizing highly efficient thermal insulators. Herein, we compare the heat transfer properties of foams and aerogels that have very high porosities (97.3–99.7%) and an identical composition (nanocellulose). The foams feature rather closed, microscale pores formed with a thin film-like solid phase, whereas the aerogels feature nanoscale open pores formed with a nanofibrous network-like solid skeleton. Unlike the aerogel samples, the thermal diffusivity of the foam decreases considerably with a slight increase in the solid fraction. The results indicate that for suppressing the thermal diffusion of air within high porosity solids, creating microscale spaces with distinct partitions is more effective than directly blocking the free path of air molecules at the nanoscale. PMID:26830144

46 CFR 160.055-2 - Type and model.

Code of Federal Regulations, 2010 CFR

2010-10-01

... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for...) Model 66, child (for persons weighing less than 90 pounds); or (b) Standard, bib type, cloth covered; (1...

Migration of Organophosphate Flame Retardants from Closed Cell Foam to Settled Dust

EPA Science Inventory

Many industrial and consumer products, such as electrical and electronic products, furniture, plastics, textile, and building materials are manufactured with organophosphorus flame retardants (OPFRs). OPFRs can leach or diffuse out of the products and are released to the surround...

46 CFR 160.052-9 - Recognized laboratory.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Recognized laboratory. 160.052-9 Section 160.052-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam...

46 CFR 160.052-9 - Recognized laboratory.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Recognized laboratory. 160.052-9 Section 160.052-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam...

46 CFR 160.052-9 - Recognized laboratory.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Recognized laboratory. 160.052-9 Section 160.052-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam...

46 CFR 160.052-9 - Recognized laboratory.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Recognized laboratory. 160.052-9 Section 160.052-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam...

Other NASA-developed materials and some industrial applications

NASA Technical Reports Server (NTRS)

Radnofsky, M. I.

1971-01-01

The characteristics and applications of various materials for fireproofing aerospace vehicles are discussed. Materials described are: (1) fibrous materials, (2) nonflammable paper and paperboard, (3) elastomers, (4) foams, and (5) plastics. The suitability of the various materials for specific applications are investigated.

Sacrificial plastic mold with electroplatable base

DOEpatents

Domeier, Linda A.; Hruby, Jill M.; Morales, Alfredo M.

2002-01-01

A sacrificial plastic mold having an electroplatable backing is provided. One embodiment consists of the infusion of a softened or molten thermoplastic through a porous metal substrate (sheet, screen, mesh or foam) and into the features of a micro-scale molding tool contacting the porous metal substrate. Upon demolding, the porous metal substrate will be embedded within the thermoplastic and will project a plastic structure with features determined by the mold tool. This plastic structure, in turn, provides a sacrificial plastic mold mechanically bonded to the porous metal substrate which provides a conducting support suitable for electroplating either contiguous or non-contiguous metal replicates. After electroplating and lapping, the sacrificial plastic can be dissolved to leave the desired metal structure bonded to the porous metal substrate. Optionally, the electroplated structures may be debonded from the porous substrate by selective dissolution of the porous substrate or a coating thereon.

Sacrificial Plastic Mold With Electroplatable Base

DOEpatents

Domeier, Linda A.; Hruby, Jill M.; Morales, Alfredo M.

2005-08-16

A sacrificial plastic mold having an electroplatable backing is provided. One embodiment consists of the infusion of a softened or molten thermoplastic through a porous metal substrate (sheet, screen, mesh or foam) and into the features of a micro-scale molding tool contacting the porous metal substrate. Upon demolding, the porous metal substrate will be embedded within the thermoplastic and will project a plastic structure with features determined by the mold tool. This plastic structure, in turn, provides a sacrificial plastic mold mechanically bonded to the porous metal substrate which provides a conducting support suitable for electroplating either contiguous or non-contiguous metal replicates. After electroplating and lapping, the sacrificial plastic can be dissolved to leave the desired metal structure bonded to the porous metal substrate. Optionally, the electroplated structures may be debonded from the porous substrate by selective dissolution of the porous substrate or a coating thereon.

Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murphy, T. J.; Douglas, M. R.; Fincke, J. R.

Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Workmore » is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. Lastly, the ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.« less

Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

DOE PAGES

Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; ...

2016-05-26

Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Workmore » is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. Lastly, the ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.« less

Polyurethane rigid foam, a proven thermal insulating material for applications between +130°C and -196°C

NASA Astrophysics Data System (ADS)

Demharter, Anton

Polyurethanes are high molecular weight polymers based on the polyaddition of polyfunctional hydroxyl-group containing compounds and polyisocyanates. A wide variety of properties can be tailored to fulfil the requirements of different applications: soft to hard, plastic, elastic or thermoset, compact or foamed. Compared with other insulating materials, PUR rigid foam is highly competitive. There are five product-related advantages: lowest thermal conductivity, high mechanical and chemical properties at both high and low temperatures, all major international fire safety requirements can be satisfied, the ability to form sandwich structures with various facer materials, and the new generation of PUR is CFC-free and recyclable. Rigid polyurethane foams perform well in most areas of low-temperature insulations. Products in density ranging from approximately 30 to 200 kg m -3 withstand temperatures down to -196°C. Typical applications are: refrigerated vehicles, road and rail tankers, vessels for refrigerated cargo, pipelines, liquid gas tanks for LPG and LNG and cryogenic wind tunnels. The paper presents applications, corresponding properties of the rigid foams used, and also other insulating materials in competition to PUR are discussed.

46 CFR 160.055-6 - Construction-nonstandard, life preservers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Construction-nonstandard, life preservers. 160.055-6..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-6 Construction—nonstandard, life preservers...

46 CFR 160.055-6 - Construction-nonstandard, life preservers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Construction-nonstandard, life preservers. 160.055-6..., CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-6 Construction—nonstandard, life preservers...

46 CFR 160.049-6 - Marking.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Marking. 160.049-6 Section 160.049-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-6...

46 CFR 160.049-6 - Marking.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Marking. 160.049-6 Section 160.049-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-6...

46 CFR 160.053-5 - Marking.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Marking. 160.053-5 Section 160.053-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-5 Marking. (a...

46 CFR 160.053-5 - Marking.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Marking. 160.053-5 Section 160.053-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-5 Marking. (a...

46 CFR 160.052-8 - Marking.

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-8 Marking. (a) Each buoyant vest must have the following information clearly... vests shall be sufficiently waterproof so that after 72 hours submergence in water it will withstand...

46 CFR 160.052-8 - Marking.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-8 Marking. (a) Each buoyant vest must have the following information clearly... vests shall be sufficiently waterproof so that after 72 hours submergence in water it will withstand...

46 CFR 160.052-8 - Marking.

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-8 Marking. (a) Each buoyant vest must have the following information clearly... vests shall be sufficiently waterproof so that after 72 hours submergence in water it will withstand...

A NEW RENEWABLE POLYMER FROM BIO-OIL - PHASE I

EPA Science Inventory

The vast majority of today’s polymers, plastics, foams, synthetic fibers, adhesives, and coatings are made from oil, which is non-renewable, non-biodegradable, depends in large part on foreign sources, is highly sensitive to regional conflicts, and has a large carbon foo...

46 CFR 160.049-6 - Marking.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Marking. 160.049-6 Section 160.049-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-6...

Marine debris in five national parks in Alaska.

PubMed

Polasek, L; Bering, J; Kim, H; Neitlich, P; Pister, B; Terwilliger, M; Nicolato, K; Turner, C; Jones, T

2017-04-15

Marine debris is a management issue with ecological and recreational impacts for agencies, especially on remote beaches not accessible by road. This project was implemented to remove and document marine debris from five coastal National Park Service units in Alaska. Approximately 80km of coastline were cleaned with over 10,000kg of debris collected. Marine debris was found at all 28 beaches surveyed. Hard plastics were found on every beach and foam was found at every beach except one. Rope/netting was the next most commonly found category, present at 23 beaches. Overall, plastic contributed to 60% of the total weight of debris. Rope/netting (14.6%) was a greater proportion of the weight from all beaches than foam (13.3%). Non-ferrous metal contributed the smallest amount of debris by weight (1.7%). The work forms a reference condition dataset of debris surveyed in the Western Arctic and the Gulf of Alaska within one season. Copyright © 2017. Published by Elsevier Ltd.

An elasto-visco-plastic model for immortal foams or emulsions

NASA Astrophysics Data System (ADS)

Bénito, S.; Bruneau, C.-H.; Colin, T.; Gay, C.; Molino, F.

2008-03-01

A variety of complex fluids consists in soft, round objects (foams, emulsions, assemblies of copolymer micelles or of multilamellar vesicles--also known as onions). Their dense packing induces a slight deviation from their prefered circular or spherical shape. As a frustrated assembly of interacting bodies, such a material evolves from one conformation to another through a succession of discrete, topological events driven by finite external forces. As a result, the material exhibits a finite yield threshold. The individual objects usually evolve spontaneously (colloidal diffusion, object coalescence, molecular diffusion), and the material properties under low or vanishing stress may alter with time, a phenomenon known as aging. We neglect such effects to address the simpler behaviour of (uncommon) immortal fluids: we construct a minimal, fully tensorial, rheological model, equivalent to the (scalar) Bingham model. Importantly, the model consistently describes the ability of such soft materials to deform substantially in the elastic regime (be it compressible or not) before they undergo (incompressible) plastic creep--or viscous flow under even higher stresses.

Observation of Compressible Plasma Mix in Cylindrically Convergent Implosions

NASA Astrophysics Data System (ADS)

Barnes, Cris W.; Batha, Steven H.; Lanier, Nicholas E.; Magelssen, Glenn R.; Tubbs, David L.; Dunne, A. M.; Rothman, Steven R.; Youngs, David L.

2000-10-01

An understanding of hydrodynamic mix in convergent geometry will be of key importance in the development of a robust ignition/burn capability on NIF, LMJ and future pulsed power machines. We have made use of the OMEGA laser facility at the University of Rochester to investigate directly the mix evolution in a convergent geometry, compressible plasma regime. The experiments comprise a plastic cylindrical shell imploded by direct laser irradiation. The cylindrical shell surrounds a lower density plastic foam which provides sufficient back pressure to allow the implosion to stagnate at a sufficiently high radius to permit quantitative radiographic diagnosis of the interface evolution near turnaround. The susceptibility to mix of the shell-foam interface is varied by choosing different density material for the inner shell surface (thus varying the Atwood number). This allows the study of shock-induced Richtmyer-Meshkov growth during the coasting phase, and Rayleigh-Taylor growth during the stagnation phase. The experimental results will be described along with calculational predictions using various radiation hydrodynamics codes and turbulent mix models.

The plastic-associated microorganisms of the North Pacific Gyre.

PubMed

Carson, Henry S; Nerheim, Magnus S; Carroll, Katherine A; Eriksen, Marcus

2013-10-15

Microorganisms likely mediate processes affecting the fate and impacts of marine plastic pollution, including degradation, chemical adsorption, and colonization or ingestion by macroorganisms. We investigated the relationship between plastic-associated microorganism communities and factors such as location, temperature, salinity, plankton abundance, plastic concentration, item size, surface roughness, and polymer type. Small plastic items from the surface of the North Pacific Gyre in 2011 were examined using scanning electron microscopy. Bacillus bacteria (mean 1664 ± 247 individuals mm(-2)) and pennate diatoms (1097 ± 154 mm(-2)) were most abundant, with coccoid bacteria, centric diatoms, dinoflagellates, coccolithophores, and radiolarians present. Bacterial abundance was patchy, but increased on foamed polystyrene. Diatom abundance increased on items with rough surfaces and at sites with high plastic concentrations. Morphotype richness increased slightly on larger fragments, and a biogeographic transition occurred between pennate diatom groups. Better characterizing this community will aid in understanding how it interacts with plastic pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

46 CFR 160.055-4 - Materials-nonstandard life preservers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Materials-nonstandard life preservers. 160.055-4 Section..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-4 Materials—nonstandard life preservers. All...

46 CFR 160.055-4 - Materials-nonstandard life preservers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Materials-nonstandard life preservers. 160.055-4 Section..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-4 Materials—nonstandard life preservers. All...

46 CFR 160.055-5 - Construction-standard life preservers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Construction-standard life preservers. 160.055-5 Section..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-5 Construction—standard life preservers. (a...

46 CFR 160.055-5 - Construction-standard life preservers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Construction-standard life preservers. 160.055-5 Section..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-5 Construction—standard life preservers. (a...

Occupational asthma after exposure to azodicarbonamide: report of four cases.

PubMed Central

Normand, J C; Grange, F; Hernandez, C; Ganay, A; Davezies, P; Bergeret, A; Prost, G

1989-01-01

Azodicarbonamide (Chemical Abstract Service Registry No 123.77.3) is an organic low molecular weight agent used for blowing and foaming plastics. Finely ground azodicarbonamide can be a pulmonary and sometimes a cutaneous acute sensitiser. Four cases of work related asthma are reported. PMID:2920144

46 CFR 160.049-8 - Recognized laboratory.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Recognized laboratory. 160.049-8 Section 160.049-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-8...

46 CFR 160.049-8 - Recognized laboratory.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Recognized laboratory. 160.049-8 Section 160.049-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-8...

Optimizing biomass blends for manufacturing molded packaging materials using mycelium

USDA-ARS?s Scientific Manuscript database

Polystyrene is one of the most widely used plastics and is commonly produced in three forms: 1) Extruded polystyrene – disposable utensils, CD/DVD cases, yogurt containers, smoke alarm housing, etc.; 2) Expanded polystyrene foam – molded packaging materials and packaging "peanuts"; 3) Extruded polys...

46 CFR 160.055-4 - Materials-nonstandard life preservers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Materials-nonstandard life preservers. 160.055-4 Section..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-4 Materials—nonstandard life preservers. All...

46 CFR 160.055-4 - Materials-nonstandard life preservers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Materials-nonstandard life preservers. 160.055-4 Section..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-4 Materials—nonstandard life preservers. All...

46 CFR 160.055-4 - Materials-nonstandard life preservers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Materials-nonstandard life preservers. 160.055-4 Section..., AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Life Preservers, Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-4 Materials—nonstandard life preservers. All...

Bio-composites from mycelium reinforced agricultural substrates

USDA-ARS?s Scientific Manuscript database

There is a need for biodegradable alternatives to the inert plastics and expanded foams currently used in in manufacturing processes and device components. The material focused on in this report is a bio-composite patented by Ecovative Design, LLC. The bio-composite utilizes the fungus mycelium to i...

46 CFR 160.049-8 - Recognized laboratory.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Recognized laboratory. 160.049-8 Section 160.049-8 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-8...

Stability of minoxidil in Espumil foam base.

PubMed

Geiger, Christine M; Sorenson, Bridget; Whaley, Paul A

2013-01-01

Minoxidil is a drug used to stimulate hair growth and to slow balding. It is marketed under a number of trade names, including Rogaine, and is available in varying strength dose forms from a number of generic manufacturers. Minoxidil is available in oral and topical forms. In topical form, it can be applied by a metered-spray or rub-on applicator. A hydroalcoholic compounding vehicle can minimize greasiness, itching, burning, and contact dermatitis where low concentrations of ethanol and propylene glycol are present. Espumil Foam Base contains low concentrations of these ingredients and also can form a foam on topical application. Espumil's unique delivery by foam-activating packaging assures simple application to difficult-to-treat areas, and it vanishes quickly after application, keeping it in place and avoiding health skin areas. The objective of this study was to determine the stability of minoxidil in Espumil Foam Base. The studied sample was compounded into a 50-mg/mL solution and stored in a plastic foam-activating bottle at room temperature conditions. Three samples were assayed at each time point out to 90 days by a stability-indicating high-performance liquid chromatography method. The method was validated for its specificity through forced-degradation studies. The beyond-use-date is at least 90 days, based on data collected when this formulation was stored at room temperature, protected from light.

[Wrapping of X-ray Cassette by a Plastic Bag in Portable Radiography: For Infection Prevention and Alleviation of Patient's Discomfort].

PubMed

Nakano, Tsutomu

Portable radiography is available for the patient who is postoperative, severe condition and old. As they have weak immunity, it is important to prevent from hospital infection. Wrapping of 14×14 inch or 14×17 inch X-ray cassette by a plastic (polyethylene) bag a little bit bigger than the cassette was proposed for infection prevention in portable radiography. How to wrap the cassette easily was devised using the sheath of a polyester bag cutting at the bottom. In radiography with the grid, the plastic bag fastens the X-ray grid to the cassette substantially without any other means. In addition, the wrapped cassette, or the cassette with grid covered by the foamed plastic sheet alleviates patient's discomfort.

An Integrated Inherent Optical Property Sensor for AUVs

DTIC Science & Technology

2007-09-30

handling and installation into compact platforms. Previous hard plastic shields were replaced with an EPDM foam rubber tube that slips over the laser...Schofield, O., J. Kohut, J. Kerfoot, L. Creed, C. Mugdal, S. Glenn, M. Twardowski, C. Jones, and D. Webb. 2004. Dawn in the age of ocean robots: what

46 CFR 160.049-2 - Types and sizes.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Types and sizes. 160.049-2 Section 160.049-2 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-2...

46 CFR 160.053-6 - Procedure for approval.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Procedure for approval. 160.053-6 Section 160.053-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-6 Procedure for...

46 CFR 160.053-4 - Inspections and tests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Inspections and tests. 160.053-4 Section 160.053-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-4 Inspections and...

46 CFR 160.049-5 - Inspections and tests. 1

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Inspections and tests. 1 160.049-5 Section 160.049-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-5...

46 CFR 160.053-4 - Inspections and tests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Inspections and tests. 160.053-4 Section 160.053-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-4 Inspections and...

46 CFR 160.049-5 - Inspections and tests. 1

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Inspections and tests. 1 160.049-5 Section 160.049-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-5...

46 CFR 160.053-6 - Procedure for approval.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Procedure for approval. 160.053-6 Section 160.053-6 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-6 Procedure for...

46 CFR 160.049-2 - Types and sizes.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Types and sizes. 160.049-2 Section 160.049-2 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-2...

Evaluation of select blends of cotton byproducts in the manufacture of biodegradable packaging material

USDA-ARS?s Scientific Manuscript database

Polystyrene is one of the most widely used plastics in the manufacture of packaging materials. Extruded polystyrene foam is commonly sold under the trademark name of StyrofoamTM. Polystyrene packaging is a multibillion dollar a year industry. Since polystyrene is non-biodegradable, a biodegradable m...

7 CFR 2902.17 - Plastic insulating foam for residential and commercial construction.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (Continued) OFFICE OF ENERGY POLICY AND NEW USES, DEPARTMENT OF AGRICULTURE GUIDELINES FOR DESIGNATING... weight (mass) of the total organic carbon in the finished product. (c) Preference compliance date. No... manufacturers of these qualifying biobased products provide information on the BioPreferred Web site of...

Toxicokinetics of the Sterioisomer Specific Flame Retardant Hexabromocyclododecane (HBCD) Gamma: Effect of Dose, Time, and Repeated Exposure

EPA Science Inventory

Hexabromocyclododecanes (HBCDs) are high production volume brominated aliphatic cyclic hydrocarbons used as flame-retardants in foams, plastics and textiles. Commercial HBCD is a mixture of three main stereoisomers, alpha (α), beta (β) and gamma (γ). A shift from the high percent...

46 CFR 160.053-4 - Inspections and tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-4 Inspections and.... (b) Manufacturer's inspections and tests. Manufacturers of approved work vests shall maintain quality... samples from each lot to maintain the quality of their product. (c) Lot size. A lot shall consist of not...

46 CFR 160.049-5 - Inspections and tests. 1

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-5... maintain quality control of the materials used, manufacturing methods and the finished product so as to... samples and components produced to maintain the quality of the finished product. Records of tests...

46 CFR 160.053-4 - Inspections and tests.

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-4 Inspections and.... (b) Manufacturer's inspections and tests. Manufacturers of approved work vests shall maintain quality... samples from each lot to maintain the quality of their product. (c) Lot size. A lot shall consist of not...

46 CFR 160.049-5 - Inspections and tests. 1

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-5... maintain quality control of the materials used, manufacturing methods and the finished product so as to... samples and components produced to maintain the quality of the finished product. Records of tests...

46 CFR 160.049-5 - Inspections and tests. 1

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-5... maintain quality control of the materials used, manufacturing methods and the finished product so as to... samples and components produced to maintain the quality of the finished product. Records of tests...

46 CFR 160.053-4 - Inspections and tests.

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-4 Inspections and.... (b) Manufacturer's inspections and tests. Manufacturers of approved work vests shall maintain quality... samples from each lot to maintain the quality of their product. (c) Lot size. A lot shall consist of not...

ANALYSIS AND EVALUATION OF MYCELIUM REINFORCED NATURAL FIBER BIO-COMPOSITES

USDA-ARS?s Scientific Manuscript database

There is a need for biodegradable alternatives to the inert plastics and expanded foams that are common in both the manufacturing process and device componentry. The material in this study is a bio-composite patented by Ecovative Design LLC. The manufacturer's bio-composite utilizes fungal mycelium ...

Revisit Pattern Blocks to Develop Rational Number Sense

ERIC Educational Resources Information Center

Champion, Joe; Wheeler, Ann

2014-01-01

Pattern blocks are inexpensive wooden, foam, or plastic manipulatives developed in the 1960s to help students build an understanding of shapes, proportions, equivalence, and fractions (EDC 1968). The colorful collection of basic shapes in classic pattern block kits affords opportunities for amazing puzzle-like problem-solving tasks and for…

Evaluation of mycelium reinforced agricultural fiber biocomposites for diverse applications

USDA-ARS?s Scientific Manuscript database

There is a genuine need for new biodegradable alternatives to the inert plastics and expanded foams that are common in both manufacturing processes and device componentry. The material emphasized in this report is a bio-composite patented by Ecovative Design, LLC. The bio-composite utilizes fungus m...

46 CFR 160.052-3 - Materials-standard vests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Materials-standard vests. 160.052-3 Section 160.052-3...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3 Materials—standard vests. (a) General. All components used in the...

46 CFR 160.052-2 - Size and model.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-2 Size and model. (a) A standard buoyant vest is manufactured in accordance... (for persons weighing less than 50 pounds). (b) A nonstandard buoyant vest is: (1) Manufactured in...

46 CFR 160.052-4 - Materials-nonstandard vests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Materials-nonstandard vests. 160.052-4 Section 160.052-4...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-4 Materials—nonstandard vests. (a) General. All materials used in nonstandard...

46 CFR 160.053-6 - Procedure for approval.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-6 Procedure for approval. (a) General. Work vests for use on merchant vessels are approved only by the Commandant, U.S. Coast Guard. Manufacturers seeking approval of a work vest shall follow the procedures of this section...

46 CFR 160.052-4 - Materials-nonstandard vests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Materials-nonstandard vests. 160.052-4 Section 160.052-4...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-4 Materials—nonstandard vests. (a) General. All materials used in nonstandard...

46 CFR 160.053-5 - Marking.

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-5 Marking. (a) Each work vest must have the following information clearly printed in waterproof lettering that can be... force of 171/2 lbs. Approved for use on Merchant Vessels as a work vest. U.S. Coast Guard Approval No...

46 CFR 160.052-2 - Size and model.

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-2 Size and model. (a) A standard buoyant vest is manufactured in accordance... (for persons weighing less than 50 pounds). (b) A nonstandard buoyant vest is: (1) Manufactured in...

46 CFR 160.052-4 - Materials-nonstandard vests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Materials-nonstandard vests. 160.052-4 Section 160.052-4...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-4 Materials—nonstandard vests. (a) General. All materials used in nonstandard...

46 CFR 160.053-5 - Marking.

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-5 Marking. (a) Each work vest must have the following information clearly printed in waterproof lettering that can be... force of 171/2 lbs. Approved for use on Merchant Vessels as a work vest. U.S. Coast Guard Approval No...

46 CFR 160.053-6 - Procedure for approval.

Code of Federal Regulations, 2012 CFR

2012-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-6 Procedure for approval. (a) General. Work vests for use on merchant vessels are approved only by the Commandant, U.S. Coast Guard. Manufacturers seeking approval of a work vest shall follow the procedures of this section...

46 CFR 160.053-6 - Procedure for approval.

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-6 Procedure for approval. (a) General. Work vests for use on merchant vessels are approved only by the Commandant, U.S. Coast Guard. Manufacturers seeking approval of a work vest shall follow the procedures of this section...

46 CFR 160.053-5 - Marking.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Work Vests, Unicellular Plastic Foam § 160.053-5 Marking. (a) Each work vest must have the following information clearly printed in waterproof lettering that can be... force of 171/2 lbs. Approved for use on Merchant Vessels as a work vest. U.S. Coast Guard Approval No...

46 CFR 160.052-3 - Materials-standard vests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 6 2013-10-01 2013-10-01 false Materials-standard vests. 160.052-3 Section 160.052-3...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3 Materials—standard vests. (a) General. All components used in the...

46 CFR 160.052-2 - Size and model.

Code of Federal Regulations, 2013 CFR

2013-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-2 Size and model. (a) A standard buoyant vest is manufactured in accordance... (for persons weighing less than 50 pounds). (b) A nonstandard buoyant vest is: (1) Manufactured in...

46 CFR 160.052-2 - Size and model.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-2 Size and model. (a) A standard buoyant vest is manufactured in accordance... (for persons weighing less than 50 pounds). (b) A nonstandard buoyant vest is: (1) Manufactured in...

46 CFR 160.052-3 - Materials-standard vests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 6 2011-10-01 2011-10-01 false Materials-standard vests. 160.052-3 Section 160.052-3...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3 Materials—standard vests. (a) General. All components used in the...

46 CFR 160.052-4 - Materials-nonstandard vests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Materials-nonstandard vests. 160.052-4 Section 160.052-4...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-4 Materials—nonstandard vests. (a) General. All materials used in nonstandard...

46 CFR 160.052-3 - Materials-standard vests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 6 2012-10-01 2012-10-01 false Materials-standard vests. 160.052-3 Section 160.052-3...: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3 Materials—standard vests. (a) General. All components used in the...

46 CFR 160.049-2 - Types and sizes.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 6 2014-10-01 2014-10-01 false Types and sizes. 160.049-2 Section 160.049-2 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Cushion Plastic Foam § 160.049-2...

Calibrating the Abaqus Crushable Foam Material Model using UNM Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schembri, Philip E.; Lewis, Matthew W.

Triaxial test data from the University of New Mexico and uniaxial test data from W-14 is used to calibrate the Abaqus crushable foam material model to represent the syntactic foam comprised of APO-BMI matrix and carbon microballoons used in the W76. The material model is an elasto-plasticity model in which the yield strength depends on pressure. Both the elastic properties and the yield stress are estimated by fitting a line to the elastic region of each test response. The model parameters are fit to the data (in a non-rigorous way) to provide both a conservative and not-conservative material model. Themore » model is verified to perform as intended by comparing the values of pressure and shear stress at yield, as well as the shear and volumetric stress-strain response, to the test data.« less

The Marble Experiment: Overview and Simulations

NASA Astrophysics Data System (ADS)

Douglas, M. R.; Murphy, T. J.; Cobble, J. A.; Fincke, J. R.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Olson, R. E.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

2015-11-01

The Marble ICF platform has recently been launched on both OMEGA and NIF with the goal to investigate the influence of heterogeneous mix on fusion burn. The unique separated reactant capsule design consists of an ``engineered'' CH capsule filled with deuterated plastic foam that contains pores or voids that are filled with tritium gas. Initially the deuterium and tritium are separated, but as the implosion proceeds, the D and T mix, producing a DT signature. The results of these experiments will be used to inform a probability density function (PDF) burn modelling approach for un-resolved cell morphology. Initial targets for platform development have consisted of either fine-pore foams or gas mixtures, with the goal to field the engineered foams in 2016. An overview of the Marble experimental campaign will be presented and simulations will be discussed. This work is supported by US DOE/NNSA, performed at LANL, operated by LANS LLC under contract DE-AC52-06NA25396.

IRIS Health Assessment of 2,2',4,4'-Tetrabromodiphenyl Ether (BDE-47) CASRN 5436-43-12,2',4,4',5-Pentabromodiphenyl Ether (BDE-99) CASRN 60348-60-92,2',4,4',5,5'-Hexabromodiphenyl Ether (BDE-153) CASRN 68631-49-22,2',3,3',4,4',5,5',6,6'-Decabromodiphenyl Ether (BDE-209) CASRN 1163-19-5

EPA Science Inventory

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in furniture foam (pentaBDE), plastics for TV cabinets, consumer electronics, wire insulation, and backcoatings for draperies and upholstery (decaBDE), and plastics for personal computers and small appliances (oc...

Anthropogenic marine litter composition in coastal areas may be a predictor of potentially invasive rafting fauna

PubMed Central

Borrell Pichs, Yaisel J.; García-Vazquez, Eva

2018-01-01

Anthropogenic plastic pollution is a global problem. In the marine environment, one of its less studied effects is the transport of attached biota, which might lead to introductions of non-native species in new areas or aid in habitat expansions of invasive species. The goal of the present work was to assess if the material composition of beached anthropogenic litter is indicative of the rafting fauna in a coastal area and could thus be used as a simple and cost-efficient tool for risk assessment in the future. Beached anthropogenic litter and attached biota along the 200 km coastline of Asturias, central Bay of Biscay, Spain, were analysed. The macrobiotic community attached to fouled litter items was identified using genetic barcoding combined with visual taxonomic analysis, and compared between hard plastics, foams, other plastics and non-plastic items. On the other hand, the material composition of beached litter was analysed in a standardized area on each beach. From these two datasets, the expected frequency of several rafting taxa was calculated for the coastal area and compared to the actually observed frequencies. The results showed that plastics were the most abundant type of beached litter. Litter accumulation was likely driven by coastal sources (industry, ports) and river/sewage inputs and transported by near-shore currents. Rafting vectors were almost exclusively made up of plastics and could mainly be attributed to fishing activity and leisure/ household. We identified a variety of rafting biota, including species of goose barnacles, acorn barnacles, bivalves, gastropods, polychaetes and bryozoan, and hydrozoan colonies attached to stranded litter. Several of these species were non-native and invasive, such as the giant Pacific oyster (Crassostrea gigas) and the Australian barnacle (Austrominius modestus). The composition of attached fauna varied strongly between litter items of different materials. Plastics, except for foam, had a much more diverse attached community than non-plastic materials. The predicted frequency of several taxa attached to beached litter significantly correlated with the actually observed frequencies. Therefore we suggest that the composition of stranded litter on a beach or an area could allow for predictions about the corresponding attached biotic community, including invasive species. PMID:29385195

Anthropogenic marine litter composition in coastal areas may be a predictor of potentially invasive rafting fauna.

PubMed

Rech, Sabine; Borrell Pichs, Yaisel J; García-Vazquez, Eva

2018-01-01

Anthropogenic plastic pollution is a global problem. In the marine environment, one of its less studied effects is the transport of attached biota, which might lead to introductions of non-native species in new areas or aid in habitat expansions of invasive species. The goal of the present work was to assess if the material composition of beached anthropogenic litter is indicative of the rafting fauna in a coastal area and could thus be used as a simple and cost-efficient tool for risk assessment in the future. Beached anthropogenic litter and attached biota along the 200 km coastline of Asturias, central Bay of Biscay, Spain, were analysed. The macrobiotic community attached to fouled litter items was identified using genetic barcoding combined with visual taxonomic analysis, and compared between hard plastics, foams, other plastics and non-plastic items. On the other hand, the material composition of beached litter was analysed in a standardized area on each beach. From these two datasets, the expected frequency of several rafting taxa was calculated for the coastal area and compared to the actually observed frequencies. The results showed that plastics were the most abundant type of beached litter. Litter accumulation was likely driven by coastal sources (industry, ports) and river/sewage inputs and transported by near-shore currents. Rafting vectors were almost exclusively made up of plastics and could mainly be attributed to fishing activity and leisure/ household. We identified a variety of rafting biota, including species of goose barnacles, acorn barnacles, bivalves, gastropods, polychaetes and bryozoan, and hydrozoan colonies attached to stranded litter. Several of these species were non-native and invasive, such as the giant Pacific oyster (Crassostrea gigas) and the Australian barnacle (Austrominius modestus). The composition of attached fauna varied strongly between litter items of different materials. Plastics, except for foam, had a much more diverse attached community than non-plastic materials. The predicted frequency of several taxa attached to beached litter significantly correlated with the actually observed frequencies. Therefore we suggest that the composition of stranded litter on a beach or an area could allow for predictions about the corresponding attached biotic community, including invasive species.

Absolute Hugoniot measurements for CH foams in the 1.5-8 Mbar range

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Velikovich, A. L.; Schmitt, A. J.; Karasik, M.; Serlin, V.; Weaver, J. L.; Oh, J.; Obenschain, S. P.

2016-10-01

We report the absolute Hugoniot measurements for dry CH foams at 10% of solid polystyrene density. The 400 μm thick, 500 μm wide planar foam slabs covered with a 10 μm solid plastic ablator were driven with 4 ns long Nike KrF laser pulses whose intensity was varied between 10 and 50 TW/cm2. The trajectories of the shock front and the ablative piston, as well as the rarefaction fan emerging after the shock breakout from the rear surface of the target were clearly observed using the side-on monochromatic x-ray imaging radiography. From these measurements the shock density compression ratio and the shock pressure are evaluated directly. The observed compression ratios varied between 4 and 8, and the corresponding shock pressures - between 1.5 and 8 Mbar. The data was simulated with the FASTRAD3D hydrocode, using standard models of inverse bremsstrahlung absorption, flux-limited thermal conduction, and multi-group radiation diffusion. The demonstrated diagnostics technique applied in a cryo experiment would make it possible to make the first absolute Hugoniot measurements for liquid deuterium or DT-wetted CH foams, which is relevant for designing the wetted-foam indirect-drive ignition targets for NIF. This work was supported by the US DOE/NNSA.

Structural applications of metal foams considering material and geometrical uncertainty

NASA Astrophysics Data System (ADS)

Moradi, Mohammadreza

Metal foam is a relatively new and potentially revolutionary material that allows for components to be replaced with elements capable of large energy dissipation, or components to be stiffened with elements which will generate significant supplementary energy dissipation when buckling occurs. Metal foams provide a means to explore reconfiguring steel structures to mitigate cross-section buckling in many cases and dramatically increase energy dissipation in all cases. The microstructure of metal foams consists of solid and void phases. These voids have random shape and size. Therefore, randomness ,which is introduced into metal foams during the manufacturing processes, creating more uncertainty in the behavior of metal foams compared to solid steel. Therefore, studying uncertainty in the performance metrics of structures which have metal foams is more crucial than for conventional structures. Therefore, in this study, structural application of metal foams considering material and geometrical uncertainty is presented. This study applies the Sobol' decomposition of a function of many random variables to different problem in structural mechanics. First, the Sobol' decomposition itself is reviewed and extended to cover the case in which the input random variables have Gaussian distribution. Then two examples are given for a polynomial function of 3 random variables and the collapse load of a two story frame. In the structural example, the Sobol' decomposition is used to decompose the variance of the response, the collapse load, into contributions from the individual input variables. This decomposition reveals the relative importance of the individual member yield stresses in determining the collapse load of the frame. In applying the Sobol' decomposition to this structural problem the following issues are addressed: calculation of the components of the Sobol' decomposition by Monte Carlo simulation; the effect of input distribution on the Sobol' decomposition; convergence of estimates of the Sobol' decomposition with sample size using various sampling schemes; the possibility of model reduction guided by the results of the Sobol' decomposition. For the rest of the study the different structural applications of metal foam is investigated. In the first application, it is shown that metal foams have the potential to serve as hysteric dampers in the braces of braced building frames. Using metal foams in the structural braces decreases different dynamic responses such as roof drift, base shear and maximum moment in the columns. Optimum metal foam strengths are different for different earthquakes. In order to use metal foam in the structural braces, metal foams need to have stable cyclic response which might be achievable for metal foams with high relative density. The second application is to improve strength and ductility of a steel tube by filling it with steel foam. Steel tube beams and columns are able to provide significant strength for structures. They have an efficient shape with large second moment of inertia which leads to light elements with high bending strength. Steel foams with high strength to weight ratio are used to fill the steel tube to improves its mechanical behavior. The linear eigenvalue and plastic collapse finite element (FE) analysis are performed on steel foam filled tube under pure compression and three point bending simulation. It is shown that foam improves the maximum strength and the ability of energy absorption of the steel tubes significantly. Different configurations with different volume of steel foam and composite behavior are investigated. It is demonstrated that there are some optimum configurations with more efficient behavior. If composite action between steel foam and steel increases, the strength of the element will improve due to the change of the failure mode from local buckling to yielding. Moreover, the Sobol' decomposition is used to investigate uncertainty in the strength and ductility of the composite tube, including the sensitivity of the strength to input parameters such as the foam density, tube wall thickness, steel properties etc. Monte Carlo simulation is performed on aluminum foam filled tubes under three point bending conditions. The simulation method is nonlinear finite element analysis. Results show that the steel foam properties have a greater effect on ductility of the steel foam filled tube than its strength. Moreover, flexural strength is more sensitive to steel properties than to aluminum foam properties. Finally, the properties of hypothetical structural steel foam C-channels foamed are investigated via simulations. In thin-walled structural members, stability of the walls is the primary driver of structural limit states. Moreover, having a light weight is one of the main advantages of the thin-walled structural members. Therefore, thin-walled structural members made of steel foam exhibit improved strength while maintaining their low weight. Linear eigenvalue, finite strip method (FSM) and plastic collapse FE analysis is used to evaluate the strength and ductility of steel foam C-channels under uniform compression and bending. It is found that replacing steel walls of the C-channel with steel foam walls increases the local buckling resistance and decreases the global buckling resistance of the C-channel. By using the Sobol' decomposition, an optimum configuration for the variable density steel foam C-channel can be found. For high relative density, replacing solid steel of the lips and flange elements with steel foam increases the buckling strength. On the other hand, for low relative density replacing solid steel of the lips and flange elements with steel foam deceases the buckling strength. Moreover, it is shown that buckling strength of the steel foam C-channel is sensitive to the second order Sobol' indices. In summary, it is shown in this research that the metal foams have a great potential to improve different types of structural responses, and there are many promising application for metal foam in civil structures.

Solar energy panel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyman, M.

1980-03-04

A light-weight, low-cost and high efficiency solar panel includes a light-weight rectangular wood frame which surrounds and houses a copper absorber plate. A pair of spaced glazings, formed from plastic film materials, are disposed above the absorber to define a pair of enclosed air spaces. The lower glazing is capable of withstanding high temperatures and the upper glazing material is capable of providing good weather resistance. The material of the upper glazing extends fully about the frame to protect the entire frame from weathering. Insulation is provided beneath the absorber plate. The frame rests on top of a bottom sheetmore » of insulative foam plastic which is wrapped in a plastic envelope. The surrounding film of the outer glazing is bonded securely to the envelope to encase the entire panel within a protective sealed envelope of weather-resistant plastic film.« less

Explicit 2-D Hydrodynamic FEM Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Jerry

1996-08-07

DYNA2D* is a vectorized, explicit, two-dimensional, axisymmetric and plane strain finite element program for analyzing the large deformation dynamic and hydrodynamic response of inelastic solids. DYNA2D* contains 13 material models and 9 equations of state (EOS) to cover a wide range of material behavior. The material models implemented in all machine versions are: elastic, orthotropic elastic, kinematic/isotropic elastic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, rubber, high explosive burn, isotropic elastic-plastic, temperature-dependent elastic-plastic. The isotropic and temperature-dependent elastic-plastic models determine only the deviatoric stresses. Pressure is determined by one of 9 equations of state including linear polynomial, JWL highmore » explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, and tabulated.« less

Materials Assessment of Insulating Foam in the 9977 Shipping Package for Long-Term Storage - Annual Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

McWilliams, A. J.

The 9977 shipping package is being evaluated for long-term storage applications in the K-Area Complex (KAC) with specific focus on the packaging foam material. A rigid closed cell polyurethane foam, LAST-A-FOAM® FR-3716, produced by General Plastics Manufacturing Company is sprayed and expands to fill the void between the inner container and the outer shell of the package. The foam is sealed in this annular space and is not accessible. During shipping and storage, the foam experiences higher than ambient temperatures from the heat generated by nuclear material within the package creating the potential for degradation of the foam. A seriesmore » of experiments is underway to determine the extent of foam degradation. Foam samples of three densities have been aging at elevated temperatures 160 °F, 160 °F + 50% relative humidity (RH), 185 °F, 215 °F, and 250 °F since 2014. Samples were periodically removed and tested. After approximately 80 weeks, samples conditioned at 160 °F, 160 °F + 50% RH, and 185 °F have retained initial property values while samples conditioned at 215 °F have reduced intumescence. Samples conditioned at 250 °F have shown the most degradation, loss of volume, mass, absorbed energy under compression, intumescence, and increased flammability. Based on the initial data, temperatures up to 185 °F have not yet shown an adverse effect on the foam properties and it is recommended that exposure of FR-3716 foam to temperatures in excess of 250 °F be avoided or minimized. Testing will continue beyond the 96 week mark. This will provide additional data to help define the long-term behavior for the lower temperature conditions. Additional testing will be pursued in an attempt to identify transition points (threshold times and temperatures) at the higher temperatures of interest, as well as possible benefits of aging within the relatively oxygen-free environment the foam experiences inside the 9977 shipping package.« less

Transient Thermal Response of Lightweight Cementitious Composites Made with Polyurethane Foam Waste

NASA Astrophysics Data System (ADS)

Kismi, M.; Poullain, P.; Mounanga, P.

2012-07-01

The development of low-cost lightweight aggregate (LWA) mortars and concretes presents many advantages, especially in terms of lightness and thermal insulation performances of structures. Low-cost LWA mainly comes from the recovery of vegetal or plastic wastes. This article focuses on the characterization of the thermal conductivity of innovative lightweight cementitious composites made with fine particles of rigid polyurethane (PU) foam waste. Five mortars were prepared with various mass substitution rates of cement with PU-foam particles. Their thermal conductivity was measured with two transient methods: the heating-film method and the hot-disk method. The incorporation of PU-foam particles causes a reduction of up to 18 % of the mortar density, accompanied by a significant improvement of the thermal insulating performance. The effect of segregation on the thermal properties of LWA mortars due to the differences of density among the cementitious matrix, sand, and LWA has also been quantified. The application of the hot-disk method reveals a gradient of thermal conductivity along the thickness of the specimens, which could be explained by a non-uniform repartition of fine PU-foam particles and mineral aggregates within the mortars. The results show a spatial variation of the thermal conductivity of the LWA mortars, ranging from 9 % to 19 %. However, this variation remains close to or even lower than that observed on a normal weight aggregate mortar. Finally, a self-consistent approach is proposed to estimate the thermal conductivity of PU-foam cement-based composites.

46 CFR 160.052-6 - Construction-nonstandard vests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the following volume of plastic foam buoyant material, determined by the displacement method: (1) Five... methods used for nonstandard buoyant vests must be equivalent to those requirements in § 160.052-5 for a... wearer in an upright or backward position with head and face out of water; (2) Have no tendency to turn a...

46 CFR 160.052-6 - Construction-nonstandard vests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the following volume of plastic foam buoyant material, determined by the displacement method: (1) Five... methods used for nonstandard buoyant vests must be equivalent to those requirements in § 160.052-5 for a... wearer in an upright or backward position with head and face out of water; (2) Have no tendency to turn a...

46 CFR 160.052-6 - Construction-nonstandard vests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the following volume of plastic foam buoyant material, determined by the displacement method: (1) Five... methods used for nonstandard buoyant vests must be equivalent to those requirements in § 160.052-5 for a... wearer in an upright or backward position with head and face out of water; (2) Have no tendency to turn a...

46 CFR 160.052-6 - Construction-nonstandard vests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the following volume of plastic foam buoyant material, determined by the displacement method: (1) Five... methods used for nonstandard buoyant vests must be equivalent to those requirements in § 160.052-5 for a... wearer in an upright or backward position with head and face out of water; (2) Have no tendency to turn a...

46 CFR 160.055-9 - Procedure for approval-standard and nonstandard life preservers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 6 2010-10-01 2010-10-01 false Procedure for approval-standard and nonstandard life preservers. 160.055-9 Section 160.055-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED..., Unicellular Plastic Foam, Adult and Child, for Merchant Vessels § 160.055-9 Procedure for approval—standard...

Evaluation of Biomass Residual Substrate Blends for Eco-Friendly Packaging and Insulation Sheets/Panels

USDA-ARS?s Scientific Manuscript database

Polystyrene is one of the most widely used plastics and is commonly produced in three forms: 1) Extruded polystyrene – disposable utensils, CD/DVD cases, yogurt containers, smoke alarm housing, etc.; 2) Expanded polystyrene foam – molded packaging materials and packaging "peanuts"; and 3) Extruded p...

Optimization of biomass blends in the manufacture of molded packaging materials produced using fungal mycelium

USDA-ARS?s Scientific Manuscript database

Polystyrene is one of the most widely used plastics and is commonly produced in three forms: 1) Extruded polystyrene – disposable utensils, CD/DVD cases, yogurt containers, smoke alarm housing, etc.; 2) Expanded polystyrene foam – molded packaging materials and packaging "peanuts"; 3) Extruded polys...

The Haiti earthquake: the provision of wound care for mass casualties utilizing negative-pressure wound therapy.

PubMed

Gabriel, Allen; Gialich, Shelby; Kirk, Julie; Edwards, Sheriden; Beck, Brooke; Sorocéanu, Alexandra; Nelson, Scott; Gabriel, Cassie; Gupta, Subhas

2011-10-01

Many months after the devastating earthquake in January 2010, wounds remain a major disease burden in Haiti. Since January 2010, through the efforts of corporations, nonprofit charitable organizations, and medical professionals, advanced wound care techniques, including negative-pressure wound therapy (NPWT), have been introduced into the wound care regimens of various hospitals in Haiti. In June 2010, the authors completed their second volunteer trip at a Haitian hospital specializing in orthopedic wounds. The medical team was composed of a plastic surgeon, orthopedic surgeon, anesthesiologist, medical assistant, scrub technician, and registered nurse (specializing in plastic surgery and orthopedics). The authors' team supplied NPWT devices, reticulated open-cell foam dressings, and canisters donated by Kinetic Concepts, Inc, San Antonio, Texas, for use at the hospital. This report describes the medical challenges in postearthquake Haiti (including limb salvage and infection), benefits of adjunctive use of NPWT/reticulated open-cell foam, and current wound care status in a Haitian orthopedic hospital. The future role of NPWT in Haiti and during mass catastrophe in a least-developed country is also discussed.

Production and characterization of novel starch and poly(butylene adipate-co-terephthalate)-based materials and their applications

NASA Astrophysics Data System (ADS)

Stagner, Jacqueline Ann

This work focuses on the production and characterization of blends of maleated thermoplastic starch (MTPS) and poly(butylenes adipate-co-terephthalate) and their application for use as thermoformed objects, films, and foams. First, by the production and characterization of maleated thermoplastic starch (MTPS) synthesized by reactive extrusion in a twin-screw extruder, a better understanding of MTPS was gained. This reactive thermoplastic starch was prepared with glycerol as the plasticizer, maleic anhydride (MA), and free-radical initiator, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (Luperox 101). Dynamic light scattering (DLS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), soxhlet extraction in acetone, and environmental scanning electron microscopy (ESEM) were performed to determine the effect of maleation, extrusion temperature, initiator concentration, and maleic anhydride concentration on the resulting MTPS. Next, maleated thermoplastic starch (MTPS) and thermoplastic starch (TPS) were reactively blended in a twin-screw extruder with a biodegradable polyester, poly(butylene adipate-co-terephthalate) (PBAT). The blends were extruded to produce thermoformable sheets. The mechanical properties of the sheets were characterized by tensile and puncture tests. Proof of grafting was determined by soxhlet extraction in dichloromethane and FTIR analysis. Observations of the thermal properties were made using DSC, while the surface of the sheets was imaged using ESEM. Blends of MTPS and PBAT were also extruded to produce films. Mechanical testing (tensile and puncture tests) and barrier performance testing (carbon dioxide, oxygen, and water vapor permeability) were performed on the films. Transmission electron microscopy (TEM) was used to image the blends and to view the dispersion of the various phases. Finally, blends of MTPS and PBAT were extruded with an endothermic chemical blowing agent to produce foams. The foams were characterized by measuring density, expansion ratio, specific length, compressive strength, resiliency, and moisture sorption. Also, digital light microscopy was used to image the cell structure of the foams. This work demonstrates that blends of starch and PBAT can be produced and formed into thermoformed objects, films, and foams. These objects can replace current objects made from non-biodegradable, petroleum-based plastics. By blending the starch and PBAT together, one receives advantages over using either component separately.

Coseismic microstructures of experimental fault zones in Carrara marble

NASA Astrophysics Data System (ADS)

Ree, Jin-Han; Ando, Jun-ichi; Han, Raehee; Shimamoto, Toshihiko

2014-09-01

Experimental fault zones developed in Carrara marble that were deformed at seismic slip rates (1.18-1.30 m s-1) using a high-velocity-rotary-shear apparatus exhibit very low friction (friction coefficient as low as 0.06) at steady state due to nanoparticle lubrication of the decomposition product (lime). The fault zones show a layered structure; a central slip-localization layer (5-60 μm thick) of lime nanograins mantled by gouge layers (5-150 μm thick) and a plastically deformed layer (45-500 μm thick) between the wall rock and gouge layer in the marginal portion of cylindrical specimens. Calcite grains of the wall rock adjacent to the slip zone deform by dislocation glide when subjected to frictional heating and a lower strain rate than that of the principal slip zone. The very fine (2-5 μm) calcite grains in the gouge layer show a foam structure with relatively straight grain boundaries and 120° triple junctions. This foam structure is presumed to develop by welding at high temperature and low strain once slip is localized along the central layer. We suggest that a seismic event can be inferred from deformed marbles, given: (i) the presence of welded gouge with foam structure in a fault zone where wall rocks show no evidence of thermal metamorphism and (ii) a thin plastically deformed layer immediately adjacent to the principal slip zone of a cataclastic fault zone.

Surface modification of polypropylene based particle foams

NASA Astrophysics Data System (ADS)

Schreier, P.; Trassl, C.; Altstädt, V.

2014-05-01

This paper deals with the modification of the surface properties of expanded polypropylene (EPP). EPP is a semi-hard to soft elastic thermoplastic foam. The characteristic surface of EPP shows process-related steam nozzle imprints and gussets. Therefore EPP does not satisfy the quality requirements for visible automotive applications. In order to meet these demands, plastic surfaces are usually enhanced with functional or decorative coatings, e.g. textiles, plastic films or paint. The coating of plastics with low surface energies such as PP often leads to adhesion problems by reason of the missing polar and functional groups. This paper gives an evaluation of activation and pre-treatment methods of EPP, with the aim to identify the most suitable pre-treatment method. For this purpose five typical surface treatment methods - flame treatment, corona, fluorination, atmospheric and low-pressure plasma - were performed on EPP samples. As a comparison criterion the maximum increase in the adhesion force between a polyurethane-based coating and the modified EPP substrate was selected. Moreover the influence of the selected pre-treatment method on the increase in the total surface energy and its polar component was investigated by the drop shape analysis method. The results showed that the contact angle measurement is a suitable method to determine the polar and disperse fractions of the surface tension of EPP. Furthermore, all performed methods increased the adhesion of EPP.

Sorption and vapor transmission properties of uncompressed and compressed microcellular starch foam.

PubMed

Glenn, Gregory M; Klamczynski, Artur P; Takeoka, Gary; Orts, William J; Wood, Delilah; Widmaier, Robert

2002-11-20

Microcellular starch foams (MCFs) are made by a solvent-exchange process and consist of a porous matrix with pores generally ranging from approximately 2 microm to submicrometer size. MCF may potentially be useful as a slow-release agent for volatile compounds because of its ability to sorb chemicals from the atmosphere and to absorb liquids into its porous structure, and because it can be compressed to form a starch plastic. MCF made of high-amylose corn and wheat starches was prepared with or without 2% (w/w) silicone oil (SO) or palmitic acid (PA). The MCF was loaded with 1% of various volatile compounds with vapor pressures ranging from 0.02 to 28 mm. The MCF depressed the vapor pressure from 0.37 to 37% compared to a control containing no MCF. Incorporating SO or PA in the matrix of the MCF had little effect on sorption of volatiles. Compressing MCF at 1.4, 6.9, and 69 MPa made a starch plastic with varying porosity. The vapor transmission rate of various volatile compounds through MCF was positively correlated to the vapor pressure of the test compound but was inversely proportional to the compression force used to form the starch plastic. The results indicate that uncompressed and compressed MCFs could be effective slow-release agents for a variety of volatile compounds, especially if used together.

Inertial confinement fusion and fast ignitor studies

NASA Astrophysics Data System (ADS)

Willi, O.; Barringer, L.; Bell, A.; Borghesi, M.; Davies, J.; Gaillard, R.; Iwase, A.; MacKinnon, A.; Malka, G.; Meyer, C.; Nuruzzaman, S.; Taylor, R.; Vickers, C.; Hoarty, D.; Gobby, P.; Johnson, R.; Watt, R. G.; Blanchot, N.; Canaud, B.; Croso, H.; Meyer, B.; Miquel, J. L.; Reverdin, C.; Pukhov, A.; Meyer-ter-Vehn, J.

2000-03-01

Laser imprinting has been studied and, in particular, saturation of areal density perturbations induced by near single mode laser imprinting was observed. Several issues important for the foam buffered direct drive scheme have been investigated. These studies included measurements of the absolute levels of stimulated Brillouin and Raman scattering observed from laser irradiated low density foam targets, either bare or overcoated with a thin layer of gold. A novel scheme is proposed to increase the pressure in indirectly driven targets. By heating a foam supersonically that is attached to a solid target the pressure generated is not only the ablation pressure but also the combined pressure due to ablation at the foam-foil interface and the heated foam material. Planar brominated plastic foil targets overcoated with a low density foam were irradiated by a soft X ray pulse. The pressure was obtained by comparing the rear side trajectory of the driven target observed by soft X ray radiography with one dimensional radiation hydrodynamic simulations. Observations were also carried out of the transition from supersonic to subsonic propagation of an ionization front in low density chlorinated foam targets irradiated by an intense soft X ray pulse. The diagnostic for these measurements was K shell point projection absorption spectroscopy. In the fast ignitor area the channelling and guiding of picosecond laser pulses through underdense plasmas, preformed density channels and microtubes were investigated. It was observed that a large fraction of the incident laser energy can be propagated. Megagauss magnetic fields were measured, with a polarimetric technique, during and after propagation of intense picosecond pulses in preionized plasmas. Two types of toroidal fields, of opposite orientation, were detected. In addition, the production and propagation of an electron beam through solid glass targets irradiated at intensities above 1019W/cm2 were observed using optical probing techniques.

OpenFOAM Modeling of Particle Heating and Acceleration in Cold Spraying

NASA Astrophysics Data System (ADS)

Leitz, K.-H.; O'Sullivan, M.; Plankensteiner, A.; Kestler, H.; Sigl, L. S.

2018-01-01

In cold spraying, a powder material is accelerated and heated in the gas flow of a supersonic nozzle to velocities and temperatures that are sufficient to obtain cohesion of the particles to a substrate. The deposition efficiency of the particles is significantly determined by their velocity and temperature. Particle velocity correlates with the amount of kinetic energy that is converted to plastic deformation and thermal heating. The initial particle temperature significantly influences the mechanical properties of the particle. Velocity and temperature of the particles have nonlinear dependence on the pressure and temperature of the gas at the nozzle entrance. In this contribution, a simulation model based on the reactingParcelFoam solver of OpenFOAM is presented and applied for an analysis of particle velocity and temperature in the cold spray nozzle. The model combines a compressible description of the gas flow in the nozzle with a Lagrangian particle tracking. The predictions of the simulation model are verified based on an analytical description of the gas flow, the particle acceleration and heating in the nozzle. Based on experimental data, the drag model according to Plessis and Masliyah is identified to be best suited for OpenFOAM modeling particle heating and acceleration in cold spraying.

Tube pumices as strain markers of the ductile-brittle transition during magma fragmentation

NASA Astrophysics Data System (ADS)

Martí, J.; Soriano, C.; Dingwell, D. B.

1999-12-01

Magma fragmentation-the process by which relatively slow-moving magma transforms into a violent gas flow carrying fragments of magma-is the defining feature of explosive volcanism. Yet of all the processes involved in explosively erupting systems, fragmentation is possibly the least understood. Several theoretical and laboratory studies on magma degassing and fragmentation have produced a general picture of the sequence of events leading to the fragmentation of silicic magma. But there remains a debate over whether magma fragmentation is a consequence of the textural evolution of magma to a foamed state where disintegration of walls separating bubbles becomes inevitable due to a foam-collapse criterion, or whether magma is fragmented purely by stresses that exceed its tensile strength. Here we show that tube pumice-where extreme bubble elongation is observed-is a well-preserved magmatic `strain marker' of the stress state immediately before and during fragmentation. Structural elements in the pumice record the evolution of the magma's mechanical response from viscous behaviour (foaming and foam elongation) through the plastic or viscoelastic stage, and finally to brittle behaviour. These observations directly support the hypothesis that fragmentation occurs when magma undergoes a ductile-brittle transition and stresses exceed the magma's tensile strength.

Negative pressure wound therapy and external fixation device: a simple way to seal the dressing.

PubMed

Bulla, Antonio; Farace, Francesco; Uzel, André-Pierre; Casoli, Vincent

2014-07-01

Negative pressure therapy is widely applied to treat lower limb trauma. However, sealing a negative pressure dressing in the presence of an external fixation device may be difficult and time consuming. Therefore, screws, pins, wires, etc, may preclude the vacuum, preventing the plastic drape to perfectly adhere to the foam. To maintain the vacuum, we tried to prevent air leaking around the screws putting bone wax at the junction between the pins and the plastic drape. This solution, in our hands, avoids air leakage and helps maintain vacuum in a fast and inexpensive way.

Does size and buoyancy affect the long-distance transport of floating debris?

NASA Astrophysics Data System (ADS)

Ryan, Peter G.

2015-08-01

Floating persistent debris, primarily made from plastic, disperses long distances from source areas and accumulates in oceanic gyres. However, biofouling can increase the density of debris items to the point where they sink. Buoyancy is related to item volume, whereas fouling is related to surface area, so small items (which have high surface area to volume ratios) should start to sink sooner than large items. Empirical observations off South Africa support this prediction: moving offshore from coastal source areas there is an increase in the size of floating debris, an increase in the proportion of highly buoyant items (e.g. sealed bottles, floats and foamed plastics), and a decrease in the proportion of thin items such as plastic bags and flexible packaging which have high surface area to volume ratios. Size-specific sedimentation rates may be one reason for the apparent paucity of small plastic items floating in the world’s oceans.

Community-wide patterns of plastic ingestion in seabirds breeding at French Frigate Shoals, Northwestern Hawaiian Islands.

PubMed

Rapp, Dan C; Youngren, Sarah M; Hartzell, Paula; David Hyrenbach, K

2017-10-15

Between 2006 and 2013, we salvaged and necropsied 362 seabird specimens from Tern Island, French Frigate Shoals, Northwestern Hawaiian Islands. Plastic ingestion occurred in 11 of the 16 species sampled (68.75%), representing four orders, seven families, and five foraging guilds: four plunge-divers, two albatrosses, two nocturnal-foraging petrels, two tuna-birds, and one frigatebird. Moreover, we documented the first instance of ingestion in a previously unstudied species: the Brown Booby. Plastic prevalence (percent occurrence) ranged from 0% to 100%, with no significant differences across foraging guilds. However, occurrence was significantly higher in chicks versus adult conspecifics in the Black-footed Albatross, one of the three species where multiple age classes were sampled. While seabirds ingested a variety of plastic (foam, line, sheets), fragments were the most common and numerous type. In albatrosses and storm-petrels, the plastic occurrence in the two stomach chambers (the proventriculus and the ventriculus) was not significantly different. Copyright © 2017 Elsevier Ltd. All rights reserved.

24 CFR 3280.207 - Requirements for foam plastic thermal insulating materials.

Code of Federal Regulations, 2012 CFR

2012-04-01

... include intensity of cavity fire (temperature-time) and post-test damage. (iii) Post-test damage... Technology Research Institute (IIT) Report, “Development of Mobile Home Fire Test Methods to Judge the Fire... Project J-6461, 1979” or other full-scale fire tests accepted by HUD, and it is installed in a manner...

24 CFR 3280.207 - Requirements for foam plastic thermal insulating materials.

Code of Federal Regulations, 2011 CFR

2011-04-01

... include intensity of cavity fire (temperature-time) and post-test damage. (iii) Post-test damage... Technology Research Institute (IIT) Report, “Development of Mobile Home Fire Test Methods to Judge the Fire... Project J-6461, 1979” or other full-scale fire tests accepted by HUD, and it is installed in a manner...

24 CFR 3280.207 - Requirements for foam plastic thermal insulating materials.

Code of Federal Regulations, 2010 CFR

2010-04-01

... include intensity of cavity fire (temperature-time) and post-test damage. (iii) Post-test damage... Technology Research Institute (IIT) Report, “Development of Mobile Home Fire Test Methods to Judge the Fire... Project J-6461, 1979” or other full-scale fire tests accepted by HUD, and it is installed in a manner...

24 CFR 3280.207 - Requirements for foam plastic thermal insulating materials.

Code of Federal Regulations, 2014 CFR

2014-04-01

... include intensity of cavity fire (temperature-time) and post-test damage. (iii) Post-test damage... Technology Research Institute (IIT) Report, “Development of Mobile Home Fire Test Methods to Judge the Fire... Project J-6461, 1979” or other full-scale fire tests accepted by HUD, and it is installed in a manner...

24 CFR 3280.207 - Requirements for foam plastic thermal insulating materials.

Code of Federal Regulations, 2013 CFR

2013-04-01

... include intensity of cavity fire (temperature-time) and post-test damage. (iii) Post-test damage... Technology Research Institute (IIT) Report, “Development of Mobile Home Fire Test Methods to Judge the Fire... Project J-6461, 1979” or other full-scale fire tests accepted by HUD, and it is installed in a manner...

Blind Students' Learning of Probability through the Use of a Tactile Model

ERIC Educational Resources Information Center

Vita, Aida Carvalho; Kataoka, Verônica Yumi

2014-01-01

The objective of this paper is to discuss how blind students learn basic concepts of probability using the tactile model proposed by Vita (2012). Among the activities were part of the teaching sequence "Jefferson's Random Walk", in which students built a tree diagram (using plastic trays, foam cards, and toys), and pictograms in 3D…

Design and fabrication of durable owner-built wind turbine blades

NASA Astrophysics Data System (ADS)

Queeney, R. A.

To find the configuration of materials that will produce lightweight, durable wind tubine blades, a composite material blade consisting of an aluminum tubing spar, a foam insulating filler and a glass reinforced plastic skin was analyzed. Various tensile and creep tests were conducted on model blades, and a computer analysis determined the best configuration for the blade.

46 CFR 160.052-7 - Inspections and tests-standard and nonstandard vests. 1

Code of Federal Regulations, 2014 CFR

2014-10-01

... Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-7 Inspections and tests—standard and...) Maintain quality control of the materials used, the manufacturing methods and workmanship, and the finished... scale in such a manner that the basket can be weighed while it is completely under water. In order to...

46 CFR 160.052-7 - Inspections and tests-standard and nonstandard vests. 1

Code of Federal Regulations, 2012 CFR

2012-10-01

... Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-7 Inspections and tests—standard and...) Maintain quality control of the materials used, the manufacturing methods and workmanship, and the finished... scale in such a manner that the basket can be weighed while it is completely under water. In order to...

46 CFR 160.052-7 - Inspections and tests-standard and nonstandard vests. 1

Code of Federal Regulations, 2013 CFR

2013-10-01

... Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-7 Inspections and tests—standard and...) Maintain quality control of the materials used, the manufacturing methods and workmanship, and the finished... scale in such a manner that the basket can be weighed while it is completely under water. In order to...

Estimation of human percutaneous uptake for two novel brominated flame retardants, 2-ethylhexyl tetrabromobenzoate (TBB) and bis(2-ethylhexyl) tetrabromophthalate (TBPH) using the parallelogram method

EPA Science Inventory

2-ethylhexyl- tetrabromobenzoate (TBB) and bis(2-ethylhexyl)-tetrabromobenzoate (TBPH) are novel brominated flame retardants (FRs). TBPH is used as a plasticizer or with TBB in polyurethane foam FRs. TBB & TBPH have been detected in both indoor and outdoor environmental sampl...

Effect of pH on the functional properties of Arthrospira (Spirulina) platensis protein isolate.

PubMed

Benelhadj, Sonda; Gharsallaoui, Adem; Degraeve, Pascal; Attia, Hamadi; Ghorbel, Dorra

2016-03-01

In the present study, a protein isolate extracted from Arthrospira platensis by isoelectric precipitation was evaluated for its functional properties. The maximum nitrogen solubility was 59.6±0.7% (w/w) at pH 10. The A. platensis protein isolate (API) showed relatively high oil (252.7±0.3g oil/100g API) and water (428.8±15.4g of water/100g of API at pH 10) absorption capacities. The protein zeta potential, the emulsifying capacity, the emulsion ageing stability, the emulsion microstructure and the emulsion opacity as well as the foaming capacity and the foam stability were shown to be greatly affected by pH. Especially, emulsifying and foaming capacities were positively correlated to the protein solubility. Moreover, the API was able to form films when sorbitol (30% (w/w)) was used as plasticizer and to form gels when the API concentration exceeded 12% (w/w). Copyright © 2015 Elsevier Ltd. All rights reserved.

Ablative Rayleigh-Taylor and Richtmyer-Meshkov Instabilities in Laser-Accelerated Colliding Foils

NASA Astrophysics Data System (ADS)

Aglitskiy, Y.; Metzler, N.; Karasik, M.; Serlin, V.; Weaver, J.; Obenschain, S. P.; Oh, J.; Schmitt, A. J.; Velikovich, A. L.; Zalesak, S. T.; Gardner, J. H.; Harding, E. C.

2008-11-01

In our experiments done on the Nike KrF laser, we study instability growth at shock-decelerated interfaces in planar colliding-foil experiments. We use streaked monochromatic (1.86 keV) x-ray face-on imaging diagnostics to measure the areal mass modulation growth caused by the instability. Higher x-ray energies up to 5.25 keV are used to follow the shock propagation as well as the 1D dynamics of the collision. While a laser-driven foil is accelerated towards the stationary low-density foam layer, an ablative RT instability develops. Having reached a high velocity, the foil hits the foam layer. The impact generates strong shocks in the plastic and in the foam. The reflected shock wave re-shocks the ablation front, its acceleration stops, and so does the observed RT growth. This is followed by areal mass oscillations due to the ablative RM instability and feedout mechanisms, of which the latter dominates.

Continuous microcellular foaming of polyvinyl chloride and compatibilization of polyvinyl chloride and polylactide composites

NASA Astrophysics Data System (ADS)

Shah, Bhavesh

This dissertation focuses on overcoming existing limitations of WPCs which prevent them from realizing their full market potential. These limitations include: (i) lack of a continuous extrusion process for microcellular foaming of polyvinyl chloride (PVC) and its composites using supercritical fluids to reduce the high density of the WPCs, (ii) need for an efficient coupling agent for WPCs to overcome the poor compatibility between wood and plastic, and (iii) unproven use of wood as a filler for the biopolymer polylactide (PLA) to make "green" composites. These limitations were addressed through experimentation to develop a continuous extrusion process for microcellular foaming, and through surface modification of wood flour using natural coupling agents. The effects of wood flour, acrylic modifier and plasticizer content on the rheological properties of PVC based WPCs were studied using an extrusion capillary rheometer and a two-level factorial design. Wood flour content and acrylic modifier content were the major factors affecting the die swell ratio. Addition of plasticizer decreased the true viscosity of unfilled and filled PVC, irrespective of the acrylic modifier content. However, the addition of acrylic modifier significantly increased the viscosity of unfilled PVC but decreased the composite viscosity. Results of the rheological study were used to set baseline conditions for the continuous extrusion foaming of PVC WPCs using supercritical CO 2. Effects of material composition and processing conditions on the morphology of foamed samples were investigated. Foamed samples were produced using various material compositions and processing conditions, but steady-state conditions could not be obtained for PVC. Thus the relationships could not be determined. Incompatibility between wood flour and PVC was the focus of another study. The natural polymers chitin and chitosan were used as novel coupling agents to improve interfacial adhesion between the polymer matrix and wood fiber. Results indicated that addition of chitin and chitosan significantly increased the flexural properties and storage modulus of PVC WPCs, compared to composites without coupling agent. Significant improvements were attained with 0.5 wt. % chitosan and with 6.67 wt. % chitin. Based on the efficiency of chitosan as a coupling agent for PVC based WPCs, a biodegradable composite using polylactide (PLA) and chitosan was developed. Wood flour (0--40 wt. %) was evaluated as a filler for PLA composites and its effect on mechanical, thermal and chemical properties was studied with and without chitosan (0--10 wt. %). Addition of wood flour significantly increased the flexural and storage moduli of PLA-wood flour composites, but had no effect on glass transition temperature (Tg). Chitosan had no significant effect on any of the properties of the composites studied. Development of an efficient and effective coupling agent for PVC wood composite is a significant development which will increase performance while reducing cost. Wood filled PLA composites can further expand WPCs into applications such as packaging and automotive. Results from these studies have broadened the current knowledge base for WPC products and will be useful in the continued expansion of wood composites technology into a variety of industries.

Heat shields for aircraft - A new concept to save lives in crash fires.

NASA Technical Reports Server (NTRS)

Neel, C. B.; Parker, J. A.; Fish, R. H.; Henshaw, J.; Newland, J. H.; Tempesta, F. L.

1971-01-01

A passenger compartment surrounded by a fire-retardant shell, to protect the occupants long enough for the fire to burn out or for fire-fighting equipment to reach the aircraft and extinguish it, is proposed as a new concept for saving lives in crash fires. This concept is made possible by the recent development of two new fire-retardant materials: a very lightweight foam plastic, called polyisocyanurate foam, and an intumescent paint. Exposed to heat, the intumescent paint expands to many times its original thickness and insulates the surface underneath it. Demonstration tests are illustrated, described and discussed. However, some problems, such as preventing fuselage rupture and protecting windows, must be solved before such a system can be used.

Perinatal triphenyl phosphate exposure accelerates type 2 diabetesonset and increases adipose accumulation in UCD-type 2 diabetesmellitus rats

USDA-ARS?s Scientific Manuscript database

Triphenyl phosphate (TPP) is an additive used globally to in furniture, foams, and electronics products either as a flame retardant or plasticizer and is found in household dust. We administered TPP from gestational day 8.5 to weaning and evaluated metabolic phenotypes of 3.5 month old male and fema...

21 CFR 178.3010 - Adjuvant substances used in the manufacture of foamed plastics.

Code of Federal Regulations, 2011 CFR

2011-04-01

... prescribed limitations: List of substances Limitations Azodicarbonamide For use as a blowing agent in pol... agent in polystyrene. Isopentane For use as a blowing agent in polystyrene. n-Pentane Do. 1,1,2,2-Tetra-chloroethylene For use only as a blowing agent adjuvant in polystyrene at a level not to exceed 0.3 percent by...

21 CFR 178.3010 - Adjuvant substances used in the manufacture of foamed plastics.

Code of Federal Regulations, 2012 CFR

2012-04-01

... prescribed limitations: List of substances Limitations Azodicarbonamide For use as a blowing agent in pol... agent in polystyrene. Isopentane For use as a blowing agent in polystyrene. n-Pentane Do. 1,1,2,2-Tetra-chloroethylene For use only as a blowing agent adjuvant in polystyrene at a level not to exceed 0.3 percent by...

21 CFR 178.3010 - Adjuvant substances used in the manufacture of foamed plastics.

Code of Federal Regulations, 2013 CFR

2013-04-01

... prescribed limitations: List of substances Limitations Azodicarbonamide For use as a blowing agent in pol... agent in polystyrene. Isopentane For use as a blowing agent in polystyrene. n-Pentane Do. 1,1,2,2-Tetra-chloroethylene For use only as a blowing agent adjuvant in polystyrene at a level not to exceed 0.3 percent by...

A Device for Comparing Callus Growth Rates in Vitro

PubMed Central

Krul, William R.; Combs, Michael

1975-01-01

A device to compare the kinetics of callus growth in vitro is described. Changes in volumes of callus grown in scintillation vials were monitored photometrically without removing the sample from the solid support and medium. It is shown that a fiberglass-paper solid support is superior to a plastic foam solid support for the growth of American chestnut callus. PMID:16659126

46 CFR 160.052-3a - Materials-Dee ring and snap hook assemblies and other instruments of closure for buoyant vests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... HOMELAND SECURITY (CONTINUED) EQUIPMENT, CONSTRUCTION, AND MATERIALS: SPECIFICATIONS AND APPROVAL LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3a... must be attached to a support and bear 150 pounds for an adult size and 115 pounds for a child size for...

77 FR 5091 - Certain New Chemicals; Receipt and Status Information

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-01

... identification, pass through a metal detector, and sign the EPA visitor log. All visitor bags are processed through an X-ray machine and subject to search. Visitors will be provided an EPA/DC badge that must be... clear coatings for wood, plastic and metal. P-12-0055 11/17/2011 02/14/2012 CBI (G) Foam stabilizer and...

Estimation of human percutaneous bioavailability for two novel brominated flame retardants, 2-ethylhexyl tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP), using the parallelogram approach

EPA Science Inventory

2-ethylhexyltetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) are novel brominated flame retardants (FRs). BEH-TEBP is used alone as a plasticizer or with EH-TBB in polyurethane foams; both are contaminants in the indoor and outdoor environments. In ...

Process to recycle shredder residue

DOEpatents

Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.

2001-01-01

A system and process for recycling shredder residue, in which separating any polyurethane foam materials are first separated. Then separate a fines fraction of less than about 1/4 inch leaving a plastics-rich fraction. Thereafter, the plastics rich fraction is sequentially contacted with a series of solvents beginning with one or more of hexane or an alcohol to remove automotive fluids; acetone to remove ABS; one or more of EDC, THF or a ketone having a boiling point of not greater than about 125.degree. C. to remove PVC; and one or more of xylene or toluene to remove polypropylene and polyethylene. The solvents are recovered and recycled.

Properties of Shocked Polymers: Mbar experiments on Z and multi-scale simulations

NASA Astrophysics Data System (ADS)

Mattsson, Thomas R.

2010-03-01

Significant progress has been made over the last few years in understanding properties of matter subject to strong shocks and other extreme conditions. High-accuracy multi-Mbar experiments and first-principles theoretical studies together provide detailed insights into the physics and chemistry of high energy-density matter. While comprehensive advances have been made for pure elements like deuterium, helium, and carbon, progress has been slower for equally important, albeit more challenging, materials like molecular crystals, polymers, and foams. Hydrocarbon based polymer foams are common materials and in particular they are used in designing shock- and inertial confinement fusion experiments. Depending on their initial density, foams shock to relatively higher pressure and temperature compared to shocked dense polymers/plastics. As foams and polymers are shocked, they exhibit both structural and chemical transitions. We will present experimental and theoretical results for shocked polymers in the Mbar regime. By shock impact of magnetically launched flyer plates on poly(4-methyl-1-pentene) foams, we create multi-Mbar pressures in a dense plasma mixture of hydrogen, carbon, at temperatures of several eV. Concurrently with executing experiments, we analyze the system by multi-scale simulations, from density functional theory to continuum magneto-hydrodynamics simulations. In particular, density functional theory (DFT) molecular dynamics (MD) and classical MD simulations of the principal shock Hugoniot will be presented in detail for two hydrocarbon polymers: polyethylene (PE) and poly(4-methyl-1-pentene) (PMP).

Processing and characterization of solid and microcellular biobased and biodegradable PHBV-based polymer blends and composites

NASA Astrophysics Data System (ADS)

Javadi, Alireza

Petroleum-based polymers have made a significant contribution to human society due to their extraordinary adaptability and processability. However, due to the wide-spread application of plastics over the past few decades, there are growing concerns over depleting fossil resources and the undesirable environmental impact of plastics. Most of the petroleum-based plastics are non-biodegradable and thus will be disposed in landfills. Inappropriate disposal of plastics may also become a potential threat to the environment. Many approaches, such as efficient plastics waste management and replacing petroleum-based plastics with biodegradable materials obtained from renewable resources, have been put forth to overcome these problems. Plastics waste management is at its beginning stages of development which is also more expensive than expected. Thus, there is a growing interest in developing sustainable biobased and biodegradable materials produced from renewable resources such as plants and crops, which can offer comparable performance with additional advantages, such as biodegradability, biocompatibility, and reducing the carbon footprint. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is one of the most promising biobased and biodegradable polymers, In fact many petroleum based polymers such as poly(propylene) (PP) can be potentially replaced by PHBV because of the similarity in their properties. Despite PHBV's attractive properties, there are many drawbacks such as high cost, brittleness, and thermal instability, which hamper the widespread usage of this specific polymer. The goals of this study are to investigate various strategies to address these drawbacks, including blending with other biodegradable polymers such as poly (butylene adipate-coterephthalate) (PBAT) or fillers (e.g., coir fiber, recycled wood fiber, and nanofillers) and use of novel processing technologies such as microcellular injection molding technique. Microcellular injection molding technique will not only reduce cost but also improve processability due to the use of supercritical fluid. Various material properties of the solid (without the foaming agent) and microcellular components (with foaming agent) made of PHBV-based polymer blends or composites were investigated including static mechanical properties (tensile testing), dynamic mechanical properties (dynamic mechanical analysis), thermal properties (differential scanning calorimetry and thermo gravimetric analysis), crystallinity(wide angle X-ray scattering analysis), and morphology (scanning electron microscopy and transmission electron microscopy). The composition-processing-structure-property relationship of these solid and microcellular components were established.

Plastic in surface waters of the Inside Passage and beaches of the Salish Sea in Washington State.

PubMed

Davis, Wallace; Murphy, Anne G

2015-08-15

We summarize results of two independent studies on plastic pollution in the marine environment that overlap in time and space. One study evaluated the abundance of anthropogenic debris on 37 sandy beaches bordering the Salish Sea in Washington State while the other characterized plastic debris in surface waters of the Salish Sea and the Inside Passage to Skagway, Alaska. Both studies concluded that foam, primarily expanded polystyrene was the dominant pollutant. Plastic was found in surface waters the full length of the Inside Passage but was concentrated near harbors. At the wrack line, an average square meter of Washington's 1180km of sandy beaches in the Salish Sea had 61 pieces of anthropogenic debris weighing approximately 5g. The total loading for the entire 1m wide band is estimated to be 72,000,000 pieces and 5.8metric tons. Most anthropogenic debris on beaches is generated within the region. Copyright © 2015 Elsevier Ltd. All rights reserved.

21 CFR 178.3010 - Adjuvant substances used in the manufacture of foamed plastics.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Limitations Azodicarbonamide For use as a blowing agent in pol-yethylene complying with item 2.1 in § 177.1520...-Difluoroethane (CAS Reg. No. 75-37-6) For use as a blowing agent in polystyrene. Isopentane For use as a blowing agent in polystyrene. n-Pentane Do. 1,1,2,2-Tetra-chloroethylene For use only as a blowing agent...

46 CFR 160.052-3a - Materials-Dee ring and snap hook assemblies and other instruments of closure for buoyant vests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... instruments of closure for buoyant vests. 160.052-3a Section 160.052-3a Shipping COAST GUARD, DEPARTMENT OF... LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3a Materials—Dee ring and snap hook assemblies and other instruments of closure for buoyant vests. (a...

46 CFR 160.052-3a - Materials-Dee ring and snap hook assemblies and other instruments of closure for buoyant vests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... instruments of closure for buoyant vests. 160.052-3a Section 160.052-3a Shipping COAST GUARD, DEPARTMENT OF... LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3a Materials—Dee ring and snap hook assemblies and other instruments of closure for buoyant vests. (a...

46 CFR 160.052-3a - Materials-Dee ring and snap hook assemblies and other instruments of closure for buoyant vests.

Code of Federal Regulations, 2011 CFR

2011-10-01

... instruments of closure for buoyant vests. 160.052-3a Section 160.052-3a Shipping COAST GUARD, DEPARTMENT OF... LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3a Materials—Dee ring and snap hook assemblies and other instruments of closure for buoyant vests. (a...

46 CFR 160.052-3a - Materials-Dee ring and snap hook assemblies and other instruments of closure for buoyant vests.

Code of Federal Regulations, 2012 CFR

2012-10-01

... instruments of closure for buoyant vests. 160.052-3a Section 160.052-3a Shipping COAST GUARD, DEPARTMENT OF... LIFESAVING EQUIPMENT Specification for a Buoyant Vest, Unicellular Plastic Foam, Adult and Child § 160.052-3a Materials—Dee ring and snap hook assemblies and other instruments of closure for buoyant vests. (a...

Advanced Sensors for TBI

DTIC Science & Technology

2016-12-01

SMD-VAC- GP, Virtual Industries) with plastic tip. Then the chip was covered with silicone open-cell foam (0.062” thick, HT -870, Stockwell...the build. 26 We discussed with a sub- contractor in Livermore who might be able to perform the packaging assembly work. Dr. Kotovsky...worked with the sub- contractor on practice assemblies anticipating the new upcoming build. Working through an outside contractor represents an enormous

Acoustic properties of reticulated plastic foams

NASA Astrophysics Data System (ADS)

Cummings, A.; Beadle, S. P.

1994-08-01

Some general aspects of sound propagation in rigid porous media are discussed, particularly with reference to the use of a single - dimensionless - frequency parameter and the role of this, in the light of the possibility of varying gas properties, is examined. Steady flow resistance coefficients of porous media are also considered, and simple scaling relationships between these coefficients and `system parameters' are derived. The results of a series of measurements of the bulk acoustic properties of 12 geometrically similar, fully reticulated, polyurethane foams are presented, and empirical curve-fitting coefficients are found; the curve-fitting formulae are valid within the experimental range of values of the frequency parameter. Comparison is made between the measured data and an alternative, fairly recently published, semi-empirical set of formulae. Measurements of the steady flow-resistive coefficients are also given and both the acoustical and flow-resistive data are shown to be consistent with theoretical ideas. The acoustical and flow-resistive data should be of use in predicting the acoustic bulk properties of open-celled foams of types similar to those used in the experimental tests.

Progresses in Polystyrene Biodegradation and Prospects for Solutions to Plastic Waste Pollution

NASA Astrophysics Data System (ADS)

Yang, S. S.; Brandon, A. M.; Xing, D. F.; Yang, J.; Pang, J. W.; Criddle, C. S.; Ren, N. Q.; Wu, W. M.

2018-05-01

Petroleum-based plastic pollution has been a global environmental concern for decades. The obvious contrast between the remarkable durability of the plastics and their short service time leads to the increasing accumulation of plastic wastes in the environment. A cost-effective, sustainable strategy to solve the problem should focus on source control and clean up. Polystyrene (PS) wastes, a recalcitrant plastic polymer, are among the wide spread man-made plastic pollutants. Destruction of PS wastes can be achieved using various abiotic methods such as incineration but such methods release potential air pollution and generation of hazardous by-products. Biodegradation and bioremediation has been proposed for years. Since the 1970’s, the microbial biodegradation of plastics, including PS, has been evaluated with mixed and isolated cultures from different sources such as activated sludge, trash, soil, and manure. To date, PS biodegradation by these microbial cultures is still quite slow. Recently, the larvae of yellow mealworms (Tenebrio molitor Linnaeus) have demonstrated promising PS biodegradation performance. Mealworms have demonstrated the ability to chew and ingest PS foam as food and are capable of degrading and mineralizing PS into CO2 via microbe-dependent activities within the gut in less than the 12-15 hrs gut retention time. These research results have revealed a potential for microbial biodegradation and bioremediation of plastic pollutants.

Using Sodium Hydrogen Carbonate for Foaming Polymers

NASA Astrophysics Data System (ADS)

Satin, Lukáš; Likavčan, Lukáš; Košík, Miroslav; Rantuch, Peter; Bílik, Jozef

2016-09-01

All plastics products are made of the essential polymer mixed with a complex blend of materials known collectively as additives. Without additives, plastics would not work, but with them, they can be made safer, cleaner, tougher and more colourful. Additives cost money, but by reducing production costs and making products live longer, they help us save money and conserve the world's precious raw material reserves. In fact, our world would be a lot less safe, a lot more expensive and a great deal duller without the additives that turn basic polymers into useful plastics. One of these additives is sodium bicarbonate. Influence of sodium bicarbonate on properties of the product made of polystyrene was observed in the research described in this paper. Since polystyrene is typically used as a material for electrical components, the mechanical properties of tensile strength and inflammability were measured as a priority. Inflammability parameters were measured using a cone calorimeter.

Exploratory Development of New and Improved Self-Sealing Materials for Fuel Lines

DTIC Science & Technology

1974-10-01

identify hy block number) New and improved self-sealing fuel line composites were developed under this program. Fabric reinforced plastic and nonflowering...integrated aluminum foil, fabric reinforced laminated fuel line composites employing compressed natural rubber foam as the sealant were fabricated which...successfully sealed wounds inflicted by .30 and .50 caliber projectiles. The weight of these new self-sealing fuel line composites ranged from 0.83

Forming and Bending of Metal Foams

NASA Astrophysics Data System (ADS)

Nebosky, Paul; Tyszka, Daniel; Niebur, Glen; Schmid, Steven

2004-06-01

This study examines the formability of a porous tantalum foam, known as trabecular metal (TM). Used as a bone ingrowth surface on orthopedic implants, TM is desirable due to its combination of high strength, low relative density, and excellent osteoconductive properties. This research aims to develop bend and stretch forming as a cost-effective alternative to net machining and EDM for manufacturing thin parts made of TM. Experimentally, bending about a single axis using a wiping die was studied by observing cracking and measuring springback. It was found that die radius and clearance strongly affect the springback properties of TM, while punch speed, embossings, die radius and clearance all influence cracking. Depending on the various combinations of die radius and clearance, springback factor ranged from .70-.91. To examine the affect of the foam microstructure, bending also was examined numerically using a horizontal hexagonal mesh. As the hexagonal cells were elongated along the sheet length, elastic springback decreased. This can be explained by the earlier onset of plastic hinging occurring at the vertices of the cells. While the numerical results matched the experimental results for the case of zero clearance, differences at higher clearances arose due to an imprecise characterization of the post-yield properties of tantalum. By changing the material properties of the struts, the models can be modified for use with other open-cell metallic foams.

Novel wireless health monitor with acupuncture bio-potentials obtained by using a replaceable salt-water-wetted foam-rubber cushions on RFID-tag.

PubMed

Lin, Jium-Ming; Lu, Hung-Han; Lin, Cheng-Hung

2014-01-01

This paper proposes a bio-potential measurement apparatus including a wireless device for transmitting acupuncture bio-potential information to a remote control station for health conditions analysis and monitor. The key technology of this system is to make replaceable foam-rubber cushions, double-side conducting tapes, chip and antenna on the radio frequency identification (RFID) tag. The foam-rubber cushions can be wetted with salt-water and contact with the acupuncture points to reduce contact resistance. Besides, the double-side conducting tapes are applied to fix foam-rubber cushions. Thus, one can peel the used cushions or tapes away and supply new ones quickly. Since the tag is a flexible plastic substrate, it is easy to deploy on the skin. Besides, the amplifier made by CMOS technology on RFID chip could amplify the signals to improve S/N ratio and impedance matching. Thus, cloud server can wirelessly monitor the health conditions. An example shows that the proposed system can be used as a wireless health condition monitor, the numerical method and the criteria are given to analyze eleven bio-potentials for the important acupunctures of eleven meridians on a person's hands and legs. Then a professional doctor can know the performance of an individual and the cross-linking effects of the organs.

Three-dimensional printing and deformation behavior of low-density target structures by two-photon polymerization

NASA Astrophysics Data System (ADS)

Liu, Ying; Stein, Ori; Campbell, John H.; Jiang, Lijia; Petta, Nicole; Lu, Yongfeng

2017-08-01

Two-photon polymerization (2PP), a 3D nano to microscale additive manufacturing process, is being used for the first time to fabricate small custom experimental packages ("targets") to support laser-driven high-energy-density (HED) physics research. Of particular interest is the use of 2PP to deterministically print low-density, low atomic-number (CHO) polymer matrices ("foams") at millimeter scale with sub-micrometer resolution. Deformation during development and drying of the foam structures remains a challenge when using certain commercial photo-resins; here we compare use of acrylic resins IP-S and IP-Dip. The mechanical strength of polymeric beam and foam structures is examined particularly the degree of deformation that occurs during the development and drying processes. The magnitude of the shrinkage in the two resins in quantified by printing sample structures and by use of FEA to simulate the deformation. Capillary drying forces are shown to be small and likely below the elastic limit of the core foam structure. In contrast the substantial shrinkage in IP-Dip ( 5-10%) cause large shear stresses and associated plastic deformation particularly near constrained boundaries such as the substrate and locations with sharp density variation. The inherent weakness of stitching boundaries is also evident and in certain cases can lead to delamination. Use of IP-S shows marked reduction in deformation with a minor loss of print resolution

Optimization of Design and Manufacturing Process of Metal Foam Filled Anti-Intrusion Bars

NASA Astrophysics Data System (ADS)

Villa, Andrea; Strano, Matteo; Mussi, Valerio

2011-05-01

The role of an anti-intrusion bar for automotive use is to absorb the kinetic energy of the colliding bodies that is partially converted into internal work of the bodies involved in the crash. The aim of this paper is to investigate the performances of a new kind of anti-intrusion bars for automotive use, filled with metallic foams. The reason for using a cellular material as a filler deals with its capacity to absorb energy during plastic deformation, while being lightweight. The study is the evolution of a previous paper presented by the authors at Esaform 2010 and will present new results and findings. It is conducted by evaluating some key technical issues of the manufacturing problem and by conducting experimental and numerical analyses. The evaluation of materials and shapes of the closed sections to be filled is made in the perspective of a car manufacturer (production costs, weight reduction, space availability in a car door, etc.). Experimentally, foams are produced starting from an industrial aluminium precursor with a TiH2 blowing agent. Bars are tested in three point bending, in order to evaluate their performances in terms of force-displacement response and other specific performance parameters. In order to understand the role of interface between the inner surface of the tube and the external surface of the foam, different kinds of interface are tested.

Supersonic Panel Flutter Test Results for Flat Fiber-Glass Sandwich Panels with Foamed Cores

NASA Technical Reports Server (NTRS)

Tuovila, W. J.; Presnell, John G., Jr.

1961-01-01

Flutter tests have been made on flat panels having a 1/4 inch-thick plastic-foam core covered with thin fiber-glass laminates. The testing was done in the Langley Unitary Plan wind tunnel at Mach numbers from 1.76 t o 2.87. The flutter boundary for these panels was found to be near the flutter boundary of thin metal panels when compared on the basis of an equivalent panel stiffness. The results also demonstrated that the depth of the cavity behind the panel has a pronounced influence on flutter. Changing the cavity depth from 1 1/2 inches to 1/2 inch reduced the dynamic pressure at start of flutter by 40 percent. No flutter was obtained when the spacers on the back of the panel were against the bottom of the cavity.

Fiber Reinforced Composite Cores and Panels

NASA Technical Reports Server (NTRS)

Day, Stephen W. (Inventor); Campbell, G. Scott (Inventor); Tilton, Danny E. (Inventor); Stoll, Frederick (Inventor); Sheppard, Michael (Inventor); Banerjee, Robin (Inventor)

2013-01-01

A fiber reinforced core panel is formed from strips of plastics foam helically wound with layers of rovings to form webs which may extend in a wave pattern or may intersect transverse webs. Hollow tubes may replace foam strips. Axial rovings cooperate with overlying helically wound rovings to form a beam or a column. Wound roving patterns may vary along strips for structural efficiency. Wound strips may alternate with spaced strips, and spacers between the strips enhance web buckling strength. Continuously wound rovings between spaced strips permit folding to form panels with reinforced edges. Continuously wound strips are helically wrapped to form annular structures, and composite panels may combine both thermoset and thermoplastic resins. Continuously wound strips or strip sections may be continuously fed either longitudinally or laterally into molding apparatus which may receive skin materials to form reinforced composite panels.

Causes and Control of Corrosion in Buried-Conduit Heat Distribution Systems

DTIC Science & Technology

1991-07-01

rubber , and foamed plastics such as polyurethanic anld phenolic) nominally contain 10 to 500 ppmn soluble chloide.’ Further, insulation can also become...pressure ratings. A maximum P X T limitation exists for all gasket materials. For example, the maximum temperature and pressure ratings for an EPDM ...ethylene propylene diene monomer) rubber material are, respectively, 3() ’F and 150 psi. The material, however, cannot be expected to perform

Expanded Polystyrene Re-Expansion Analysis Following Impact Compression

DTIC Science & Technology

2015-03-04

on the higher density (0.08 g/cm3) EAL used in the Sound Protective Helmet No. 4 ( SPH -4) showed a linear relationship between initial EPS...temperature on the cushioning properties of some foamed plastic materials. Packaging Technology Science. 16: 69-76. Palmer, R.P. 1991. SPH -4 aircrew...Slobodnik, B.A. 1979. SPH -4 helmet damage and head injury correlation. Aviation, Space, and Environmental Medicine. 50: 139-146. Slobodnik, B.A

Army Logistician. Volume 34, Issue 5, September-October 2002

DTIC Science & Technology

2002-10-01

ingredients of a poly bag—are porous and allow moisture to be transmitted through the material. A product wrapped in plastic, surrounded by foam, and...M. Gayagas 18 A Statement of Requirements: Ensuring the ‘Special’ in Special Operations—Major O. Shawn Cupp 20 Deploying Medical Units—Major Charles...H. Strite, Jr. 24 Situational Awareness and FSB Battle Command —Lieutenant Colonel Jeffrey S. Wilson 26 MTMC Surface Shipments Sustain Troops in

Reproductive biology of Pleurodema guayapae (Anura: Leptodactylidae: Leiuperinae).

PubMed

Valetti, Julián Alonso; Grenat, Pablo Raúl; Baraquet, Mariana; Martino, Adolfo Ludovico

2014-03-01

Pleurodema guayapae is a species that inhabits saline environments and semidesert zones from central Argentina. To date, the knowledge about the reproductive biology of this species is very poor, and our aim is to contribute to its knowledge with the description of some important reproductive aspects. For this, field work was undertaken in an area near to Patquia, La Rioja province. Sampling was undertaken during three summer periods (2006-2007; 2007-2008; 2008-2009) in Chamical-Patquia area, where we could find reproductively active populations. We observed and described breeding sites, type of clutch, process of foam nest construction, clutch and egg number and sizes, and hatching time and stage. Behaviour observations were performed from the time that males began to call until the pairs ended up the foam nests building, and layed the eggs. Additionally, one amplected pair was observed and filmed in the process of foam nest construction, and four amplectant pairs were collected and separatelly placed in plastic containers, for nests observations in the laboratory. Hatching time was based on three different foam nests of known age. We found that P. guayapae populations were acoustically active only after a rainfall. Its breeding sites were represented by ephemeral ponds of fresh water, product of rains. The males emitted their calls inside or outside these ponds. A detailed description of the foam nest construction process by both females and males was made. The clutches were in dome-shaped foam nest type of 6-9cm in diameter and 1-3cm in height, some of which were in communal nests. The nests had an average of 1 137 pigmented eggs. This species showed a short hatching time. Our results allow us to conclude that this species should be considered an extreme explosive breeder. Our results are discussed with others obtained for related species.

Measurements and empirical model of the acoustic properties of reticulated vitreous carbon.

PubMed

Muehleisena, Ralph T; Beamer, C Walter; Tinianov, Brandon D

2005-02-01

Reticulated vitreous carbon (RVC) is a highly porous, rigid, open cell carbon foam structure with a high melting point, good chemical inertness, and low bulk thermal conductivity. For the proper design of acoustic devices such as acoustic absorbers and thermoacoustic stacks and regenerators utilizing RVC, the acoustic properties of RVC must be known. From knowledge of the complex characteristic impedance and wave number most other acoustic properties can be computed. In this investigation, the four-microphone transfer matrix measurement method is used to measure the complex characteristic impedance and wave number for 60 to 300 pore-per-inch RVC foams with flow resistivities from 1759 to 10,782 Pa s m(-2) in the frequency range of 330 Hz-2 kHz. The data are found to be poorly predicted by the fibrous material empirical model developed by Delany and Bazley, the open cell plastic foam empirical model developed by Qunli, or the Johnson-Allard microstructural model. A new empirical power law model is developed and is shown to provide good predictions of the acoustic properties over the frequency range of measurement. Uncertainty estimates for the constants of the model are also computed.

Reticulated vitreous carbon: a useful material for cell adhesion and tissue invasion.

PubMed

Pec, M K; Reyes, R; Sánchez, E; Carballar, D; Delgado, A; Santamaría, J; Arruebo, M; Evora, C

2010-10-06

Diverse carbon materials have been used for tissue engineering and clinical implant applications with varying success. In this study, commercially available reticulated vitreous carbon (RVC) foams were tested in vitro and in vivo for compatibility with primary cell adhesion and tissue repair. Pores sizes were determined as 279 ± 98 μm. No hydroxyapatite deposition was detected after immersion of the foams in simulated body fluid. Nonetheless, RVC provided an excellent support for adhesion of mesenchymal stem cells (MSCs) as well as primary chondrocytes without any surface pre-treatment. Live cell quantification revealed neutral behaviour of the material with plastic adhered chondrocytes but moderate cytotoxicity with MSCs. Yet, rabbit implanted foams exhibited good integration in subcutaneous pockets and most importantly, total defect repair in bone. Probably due to the stiffness of the material, incompatibility with cartilage regeneration was found. Interestingly and in contrast to several other carbon materials, we observed a total lack of foreign body reactions. Our results and its outstanding porous interconnectivity and availability within a wide range of pore sizes convert RVC into an attractive candidate for tissue engineering applications in a variety of bone models and for ex vivo cell expansion for regenerative medical applications.

Measurements and empirical model of the acoustic properties of reticulated vitreous carbon

NASA Astrophysics Data System (ADS)

Muehleisen, Ralph T.; Beamer, C. Walter; Tinianov, Brandon D.

2005-02-01

Reticulated vitreous carbon (RVC) is a highly porous, rigid, open cell carbon foam structure with a high melting point, good chemical inertness, and low bulk thermal conductivity. For the proper design of acoustic devices such as acoustic absorbers and thermoacoustic stacks and regenerators utilizing RVC, the acoustic properties of RVC must be known. From knowledge of the complex characteristic impedance and wave number most other acoustic properties can be computed. In this investigation, the four-microphone transfer matrix measurement method is used to measure the complex characteristic impedance and wave number for 60 to 300 pore-per-inch RVC foams with flow resistivities from 1759 to 10 782 Pa s m-2 in the frequency range of 330 Hz-2 kHz. The data are found to be poorly predicted by the fibrous material empirical model developed by Delany and Bazley, the open cell plastic foam empirical model developed by Qunli, or the Johnson-Allard microstructural model. A new empirical power law model is developed and is shown to provide good predictions of the acoustic properties over the frequency range of measurement. Uncertainty estimates for the constants of the model are also computed. .

Present Status and Prospects of FIREX Project

NASA Astrophysics Data System (ADS)

Mima, K.

2008-07-01

The goal of the first phase of Fast Ignition Realization EXperiment (FIREX) project (FIREX-I) is to demonstrate ignition temperature of 5-10 keV, followed by the second phase to demonstrate ignition and burn. Since starting FIREX-I project, plasma physics study in ILE has been devoted to increase the coupling efficiency and to improve compression performance. The heating efficiency can be increased by the following two ways. 1) A previous experiments indicate that the coupling of heating laser to imploded plasmas increases with coating a low-density. foam used in the experiment, low-Z plastic foam is desired for efficient electron transport. (Lei et al. 2006). 2) Electrons generated in the inner surface of the double cone will return by sheathe potential generated between two cones. A 2-D PIC simulation indicates that hot electron confinement is improved by a factor of 1.7 (Nakamura et al. 2007). Further optimization of cone geometry by 2-D simulation will be presented in the workshop. The implosion performance can be improved by three ways. 1) Low-Z plastic layer coating on the outer surface of the cone: The 2D hydro-simulation PINOCO predicts that the target areal density increases by a factor of 2. 2) Br doped plastic layer on a fuel pellet may significantly moderate the Rayleigh-Taylor instability (Fujioka et al. 2004), making implosion more stable. 3) Reducing vapor gas pressure in a pellet is necessary to suppress strength of a jet that will destroy the cone tip. (Stephens et al. 2005). As for the cryogenic target fabrication, R&D of fabricating foam cryogenic cine shell target are under development by the joint group between Osaka Univ. and NIFS. The amplifier system of the heating laser LFEX is completed in March 2008. The amplification test has demonstrated laser energy of 3 kJ/beam at 3nm bandwidth. The equivalent 12 kJ in 4 beams meets the specification of LFEX. The large tiled gratings for pulse compressor are completed and installed. The short pulse laser will be delivered on a target in September, 2008. The fully integrated fast ignition experiments is scheduled on February 2009 until the end of 2010. If subsequent FIREX-II will start as proposed, the ignition and burn will be demonstrated in parallel to that at NIF and LMJ, providing a scientific database of both central and fast ignition.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kasparek, Eva M.; Voelzke, Holger; Scheidemann, Robert

Rigid, closed-cell polyurethane foams are frequently used as cask impact limiters in nuclear materials and hazardous waste transport due to their high energy-absorption potential. When assessing the cask integrity in accidental scenarios based on numerical simulations, a description of the foam damping properties is required for different strain rates and for a wide temperature range with respect to waste heat generation in conjunction with critical operating and environmental conditions. Implementation and adaption of a respective finite element material model strongly relies on an appropriate experimental data base. Even though extensive impact experiments were conducted e.g. in Sandia National Laboratories, Savannahmore » River National Laboratory and by Rolls Royce plc, not all relevant factors were taken into account. Hence, BAM who is in charge of the mechanical evaluation of such packages within the approval procedure in Germany, incorporated systematic test series into a comprehensive research project aimed to develop numerical methods for a couple of damping materials. In a first step, displacement driven compression tests have been performed on confined, cubic specimens at five loading rates ranging from 0.02 mm/s to 3 m/s at temperatures between +90 deg. C and -40 deg. C. Materials include two different polyurethane foam types called FR3718 and FR3730 having densities of 280 kg/m{sup 3} and 488 kg/m{sup 3} from the product line-up of General Plastics Manufacturing Company. Their data was used to adapt an advanced plasticity model allowing for reliably simulating cellular materials under multi-axial compression states. Therefore, an automated parameter identification procedure had been established by combining an artificial neural network with local optimization techniques. Currently, the selected numerical material input values are validated and optimized by means of more complex loading configurations with the prospect of establishing methods applicable to impact limiters under severe accidental conditions. The reference data base is provided by experiments, where weights between 212 kg and 1200 kg have been dropped from heights between 1.25 m and 7 m on confined 10 cm cubic foam specimens. By presenting the deviations between experimental values and the corresponding output of finite element simulations, the potentials and restrictions of the resulting models are highlighted. Systematic compression tests on polyurethane foams had been performed at BAM test site within the framework of a research project on impact limiters for handling casks for radioactive waste. The experimental results had been used to adapt numerical models for simulating the behaviour of different foam types at different temperatures. The loading speed, however, turned out to have a major influence on their flow curves that can not be captured by simple strain-rate dependent multipliers. Especially for guided drop tests that come close to real accidental scenarios there is a significant gap between experimental and numerical results even when applying such advanced material models. Hence, the extensive data base is currently deployed for expanding the standard algorithms to include adequate dynamic hardening factors. (authors)« less

Room Temperature Stabilization of Oral, Live Attenuated Salmonella enterica serovar Typhi-Vectored Vaccines

PubMed Central

Ohtake, Satoshi; Martin, Russell; Saxena, Atul; Pham, Binh; Chiueh, Gary; Osorio, Manuel; Kopecko, Dennis; Xu, DeQi; Lechuga-Ballesteros, David; Truong-Le, Vu

2011-01-01

Foam drying, a modified freeze drying process, was utilized to produce a heat-stable, live attenuated Salmonella Typhi ‘Ty21a’ bacterial vaccine. Ty21a vaccine was formulated with pharmaceutically approved stabilizers, including sugars, plasticizers, amino acids, and proteins. Growth media and harvesting conditions of the bacteria were also studied to enhance resistance to desiccation stress encountered during processing as well as subsequent storage at elevated temperatures. The optimized Ty21a vaccine, formulated with trehalose, methionine, and gelatin, demonstrated stability for approximately 12 weeks at 37°C (i.e., time required for the vaccine to decrease in potency by 1log10 CFU) and no loss in titer at 4 and 25°C following storage for the same duration. Furthermore, the foam dried Ty21a elicited a similar immunogenic response in mice as well as protection in challenge studies compared to Vivotif™, the commercial Ty21a vaccine. The enhanced heat stability of the Ty21a oral vaccine, or Ty21a derivatives expressing foreign antigens (e.g. anthrax), could mitigate risks of vaccine potency loss during long term storage, shipping, delivery to geographical areas with warmer climates or during emergency distribution following a bioterrorist attack. Because the foam drying process is conducted using conventional freeze dryers and can be readily implemented at any freeze drying manufacturing facility, this technology appears ready and appropriate for large scale processing of foam dried vaccines. PMID:21300096

The correlation of local deformation and stress-assisted local phase transformations in MMC foams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berek, H., E-mail: harry.berek@ikgb.tu-freiberg.de; Ballaschk, U.; Aneziris, C.G.

2015-09-15

Cellular structures are of growing interest for industry, and are of particular importance for lightweight applications. In this paper, a special case of metal matrix composite foams (MMCs) is investigated. The investigated foams are composed of austenitic steel exhibiting transformation induced plasticity (TRIP) and magnesia partially stabilized zirconia (Mg-PSZ). Both components exhibit martensitic phase transformation during deformation, thus generating the potential for improved mechanical properties such as strength, ductility, and energy absorption capability. The aim of these investigations was to show that stress-assisted phase transformations within the ceramic reinforcement correspond to strong local deformation, and to determine whether they canmore » trigger martensitic phase transformations in the steel matrix. To this end, in situ interrupted compression experiments were performed in an X-ray computed tomography device (XCT). By using a recently developed registration algorithm, local deformation could be calculated and regions of interest could be defined. Corresponding cross sections were prepared and used to analyze the local phase composition by electron backscatter diffraction (EBSD). The results show a strong correlation between local deformation and phase transformation. - Graphical abstract: Display Omitted - Highlights: • In situ compressive deformation on MMC foams was performed in an XCT. • Local deformation fields and their gradient amplitudes were estimated. • Cross sections were manufactured containing defined regions of interest. • Local EBSD phase analysis was performed. • Local deformation and local phase transformation are correlated.« less

OSIRIS Modeling of High Energy Electron Transport in Warm Dense Matter

NASA Astrophysics Data System (ADS)

May, J.; Yabuuchi, T.; McGuffey, C.; Wei, Ms; Beg, F.; Mori, Wb

2016-10-01

In experiments on the Omega EP laser, a high intensity laser beam (eA /me c > 1) is focused onto a gold foil, generating relativistic electrons. Behind the Au foil is a layer of plastic foam through which the electrons are allowed to transport, and on the far side of the CH from the gold is a copper foil; electron fluence is measured by recording the k- α from that foil. The foam layer is either pre-ionized via a shock launched from an ablator irradiated earlier with a beam perpendicular to the high intensity beam; or the foam is in the solid state when the high intensity beam is switched on. In the latter case the foam - which has an initial density of 200mg /cm3 - heats to a temperature of 40eV and rarifies to a density of 30mg /cm3 . Results show an order of magnitude decrease in k- α when the CH layer is pre-ionized compared to cold CH. OSIRIS simulations indicate that the primary explanation for the difference in transport seen in the experiment is the partial resistive collimation of the beam in the higher density material, caused by collisional resistivity. The effect seems to be mostly caused by the higher density itself, with temperature having minimal effect. The authors acknowledge the support of the Department of Energy under contract DE-NA 0001833 and the National Science Foundation under contract ACI 1339893.

A method of measuring the effective thermal conductivity of thermoplastic foams

NASA Astrophysics Data System (ADS)

Asséko, André Chateau Akué; Cosson, Benoit; Chaki, Salim; Duborper, Clément; Lacrampe, Marie-France; Krawczak, Patricia

2017-10-01

An inverse method for determining the in-plane effective thermal conductivity of porous thermoplastics was implemented by coupling infrared thermography experiments and numerical solution of heat transfer in straight fins having temperature-dependent convective heat transfer coefficient. The obtained effective thermal conductivity values were compared with previous results obtained using a numerical solution based on periodic homogenization techniques (NSHT) in which the microstructure heterogeneity of extruded polymeric polyethylene (PE) foam in which pores are filled with air with different levels of open and closed porosity was taken into account and Transient Plane Source Technique (TPS) in order to verify the accuracy of the proposed method. The new method proposed in the present study is in good agreement with both NSHT and TPS. It is also applicable to structural materials such as composites, e.g. unidirectional fiber-reinforced plastics, where heat transfer is very different according to the fiber direction (parallel or transverse to the fibers).

Development of on line automatic separation device for apple and sleeve

NASA Astrophysics Data System (ADS)

Xin, Dengke; Ning, Duo; Wang, Kangle; Han, Yuhang

2018-04-01

Based on STM32F407 single chip microcomputer as control core, automatic separation device of fruit sleeve is designed. This design consists of hardware and software. In hardware, it includes mechanical tooth separator and three degree of freedom manipulator, as well as industrial control computer, image data acquisition card, end effector and other structures. The software system is based on Visual C++ development environment, to achieve localization and recognition of fruit sleeve with the technology of image processing and machine vision, drive manipulator of foam net sets of capture, transfer, the designated position task. Test shows: The automatic separation device of the fruit sleeve has the advantages of quick response speed and high separation success rate, and can realize separation of the apple and plastic foam sleeve, and lays the foundation for further studying and realizing the application of the enterprise production line.

Deformation of Polymer Composites in Force Protection Systems

NASA Astrophysics Data System (ADS)

Nazarian, Oshin

Systems used for protecting personnel, vehicles and infrastructure from ballistic and blast threats derive their performance from a combination of the intrinsic properties of the constituent materials and the way in which the materials are arranged and attached to one another. The present work addresses outstanding issues in both the intrinsic properties of high-performance fiber composites and the consequences of how such composites are integrated into force protection systems. One aim is to develop a constitutive model for the large-strain intralaminar shear deformation of an ultra-high molecular weight polyethylene (UHMWPE) fiber-reinforced composite. To this end, an analytical model based on a binary representation of the constituent phases is developed and validated using finite element analyses. The model is assessed through comparisons with experimental measurements on cross-ply composite specimens in the +/-45° orientation. The hardening behavior and the limiting tensile strain are attributable to rotations of fibers in the plastic domain and the effects of these rotations on the internal stress state. The model is further assessed through quasi-static punch experiments and dynamic impact tests using metal foam projectiles. The finite element model based on this model accurately captures both the back-face deflection-time history and the final plate profile (especially the changes caused by fiber pull-in). A separate analytical framework for describing the accelerations caused by head impact during, for example, the secondary collision of a vehicle occupant with the cabin interior during an external event is also presented. The severity of impact, characterized by the Head Injury Criterion (HIC), is used to assess the efficacy of crushable foams in mitigating head injury. The framework is used to identify the optimal foam strength that minimizes the HIC for prescribed mass and velocity, subject to constraints on foam thickness. The predictive capability of the model is evaluated through comparisons with a series of experimental measurements from impacts of an instrumented headform onto several commercial foams. Additional comparisons are made with the results of finite element simulations. An analytical model for the planar impact of a cylindrical mass on a foam is also developed. This model sets a theoretical bound for the reduction in HIC by utilizing a "plate-on-foam" design. Experimental results of impact tests on foams coupled with stiff composite plates are presented, with comparisons to the theoretical limits predicted by the analytical model. Design maps are developed from the analytical models, illustrating the variations in the HIC with foam strength and impact velocity.

Physical transport properties of marine microplastic pollution

NASA Astrophysics Data System (ADS)

Ballent, A.; Purser, A.; Mendes, P. de Jesus; Pando, S.; Thomsen, L.

2012-12-01

Given the complexity of quantitative collection, knowledge of the distribution of microplastic pollution in many regions of the world ocean is patchy, both spatially and temporally, especially for the subsurface environment. However, with knowledge of typical hydrodynamic behavior of waste plastic material, models predicting the dispersal of pelagic and benthic plastics from land sources into the ocean are possible. Here we investigate three aspects of plastic distribution and transport in European waters. Firstly, we assess patterns in the distribution of plastics found in fluvial strandlines of the North Sea and how distribution may be related to flow velocities and distance from source. Second, we model transport of non-buoyant preproduction pellets in the Nazaré Canyon of Portugal using the MOHID system after assessing the density, settling velocity, critical and depositional shear stress characteristics of such waste plastics. Thirdly, we investigate the effect of surface turbulences and high pressures on a range of marine plastic debris categories (various densities, degradation states and shapes tested) in an experimental water column simulator tank and pressure laboratory. Plastics deposited on North Sea strandlines varied greatly spatially, as a function of material composition and distance from source. Model outputs indicated that such dense production pellets are likely transported up and down canyon as a function of tidal forces, with only very minor net down canyon movement. Behaviour of plastic fragments under turbulence varied greatly, with the dimensions of the material, as well as density, playing major determining roles. Pressure was shown to affect hydrodynamic behaviours of only low density foam plastics at pressures ≥ 60 bar.

A historical look at chlorofluorocarbon refrigerants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhatti, M.S.

1999-07-01

A class of chemical compounds called chlorofluorocarbon refrigerants has been in widespread use since the 1930s in such diverse applications as refrigerants for refrigerating and air-conditioning systems, blowing agents for plastic foams, solvents for microelectronic circuitry and dry cleaning, sterilants for medical instruments, aerosol propellants for personal hygiene products and pesticides, and freezants for food. This paper describes the historical development of the chlorofluorocarbon refrigerants and gives brief biographical sketches of the inventors. 85 refs., 8 figs., 4 tabs.

Utility Distribution Systems in Sweden, Finland, Norway and England

DTIC Science & Technology

1976-11-01

the duct adds to the water protection and sumps, with access for pumping, are provided -at low points. Glass wool or mineral wool insulation is placed...mm thick, is glass, mineral wool or polyurethane foam. The outer pipe is steel, polyurethane or asbestos cement coupled with O-ring seals. Asbestos...decided that asbestos cement should be replaced by less dangerous materials. Some use is made of steel, plastic or copper tubes with mineral wool or

Design Guidelines for Prevention of Corrosion in Combat and Tactical Vehicles

DTIC Science & Technology

1988-03-01

deterioration is used to describe phenomena whereby materials in general (i.e., rubber, plastics, wood ) suffer loss of ’ integrity, or contaminate other...per million, causes embrittlement of rubber tires. Microorganisms cause materials such as wood or canvas to rot, and can also promote metal corrosion...limited to the following: o Wood o Cardboard o Open-cell foams o Sponge rubber 21 The solution is to avoid placing materials ouch as these in contact with

Cryogenic Wind Tunnels.

DTIC Science & Technology

1980-07-01

CRYOGENIC ENGINEERING - II by R.G.Scurlock 3 PROPERTIES OF MATERIALS: THE PHYSICAL PROPERTIES OF METALS AND NON- METALS by D.A.Wigley 4 REAL GAS EFFECTS - i...atmosphere. Examples include plastics and synthetic polymers in solid, foam, woven or sheet form, lubricating oils and metal powders. DO NOT think that...obtained with non- metals . TABLE 5 Ultimate Yield Thermal Figure Material tensile stress cond strength mega od.t _ i t y of mega N/m 2 N/m 2 Wm K Merit

Evaluation of chemical-specific IgG antibodies in male workers from a urethane foam factory.

PubMed

Tsuji, Mayumi; Ishihara, Yasuhiro; Isse, Toyohi; Koriyama, Chihaya; Yamamoto, Megumi; Kakiuchi, Noriaki; Yu, Hsu-Sheng; Tanaka, Masayuki; Tsuchiya, Takuto; Ohta, Masanori; Tanaka, Rie; Kawamoto, Toshihiro

2018-06-19

Plastic resins are complex chemicals that contain toluene diisocyanate (TDI) and/or trimellitic anhydride (TMA), which cause occupational allergies (OA), including respiratory allergies. Serum IgGs against TDI and TMA have been suggested as potential markers of the exposure status and as exploring cause of OA. Although TDI-specific IgG has been examined for suspected OA, TMA-specific IgG is not commonly evaluated in a urethane foam factory. This study therefore investigated both TDI- and TMA-specific IgGs in suspected OA patients and to evaluate the usefulness of the measurement of multiple chemical-specific IgG measurement for practical monitoring. Blood samples were collected from two male workers who developed respiratory allergies supposedly caused by occupational exposure to TDI and/or TMA for the presence of TDI- and TMA-specific IgGs. In addition, blood samples from 75 male workers from a urethane foam factory, along with 87 male control subjects, were collected in 2014 and tested for the same IgGs in 2014. The presence and levels of TDI- and TMA-specific serum IgGs were measured using dot blot assays. We found that controls had mean concentrations of TDI- and TMA-specific IgGs of 0.98 and 2.10 μg/mL, respectively. In the two workers with respiratory allergies, the TDI-specific IgG concentrations were 15.6 and 9.51 μg/mL, and TMA-specific IgG concentrations were 4.56 and 14.4 μg/mL, which are clearly higher than those in controls. Mean concentrations of TDI- and TMA-specific IgGs in the factory workers were 1.89 and 2.41 μg/mL, respectively, and are significantly higher than those of the controls (P < 0.001 and P < 0.026 for TDI- and TMA-specific IgGs, respectively). The workers suspected of OA showed an evidently high level of TDI- and TMA-specific IgG, and these levels in workers at the urethane foam factory were also significantly higher than those in controls. In conclusion, the measurement of TDI- and TMA-specific IgG among workers using plastic resins is helpful to monitor their exposure status.

Electrical and electronic plastics waste co-combustion with municipal solid waste for energy recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vehlow, J.; Mark, F.E.

1997-12-01

The recovery or disposal of end-of-life electrical and electronic (E+E) equipment is receiving considerable attention from industry organisations such as APME in order to supply factual information which can be used in the development of a clear industry strategy. It is hoped that such information will persuade EU member states to define the best management practices for this waste stream. One of the difficulties regarding the recovery or disposal of E+E waste is a lack of data regarding its behaviour when incinerated. This lack of data has led to unfounded conclusions by sonic parties that plastic wastes contain harmful halogenatedmore » species which are difficult to treat and remove, and when incinerated contribute to the emission of halogenated species and are responsible for the major portion of emissions. APME has a comprehensive testing program investigating the impact of plastics on municipal solid waste (MSW) incineration. APME`s previous work has demonstrated the positive, beneficial effects of mixed waste plastics in the MSW energy recovery process as well as studying halogen behaviour during the combustion of packaging plastics waste and construction foam from the building industry. The current study was designed to evaluate the incineration of MSW containing typical levels of electrical and electronic (E+E) plastic waste, as well as MSW containing E+E waste in amounts up to 12%.« less

Experiments and Models for Polymeric Microsphere Foams

NASA Technical Reports Server (NTRS)

Pipes, R. Byrona; Kyu, Thein

2005-01-01

The current project was performed under the direction of Dr. Byron Pipes as its lead investigator from January 2001 to August 2004. With the permission of the NASA, the project was transferred to Dr. Thein Kyu as the principle investigator for the period of September 2004 - June 2005. There were two major thrust areas in the original proposal; (1) experimental characterization and kinematics of foam structure formation and (2) determination of the mechanical, physical, and thermal properties, although these thrust areas were further sub- divided into 7 tasks. The present project has been directed primarily to elucidate kinematics of micro-foam formation (tasks 1 and 3) and to characterize micro-foam structures, since the control of the micro-structure of these foams is of paramount importance in determining their physical, mechanical and thermal properties. The first thrust area was accomplished in a timely manner; however, the second thrust area of foam properties (tasks 2,4-7) has yet to be completed because the area of kinematics of foam structure formation turned out to be extremely complex and thus consumed more time than what have been anticipated. As will be reported in what follows, the present studies have greatly enhances the in-depth understanding of mechanisms and kinematics of the micro-foam formation from solid powders. However, in order to implement all objectives of the second thrust areas regarding investigations of mechanical, physical, and thermal properties and establishment of the correlation of structure - properties of the foams, the project needs additional time and resources. The technical highlights of the accomplishment are summarized as follows. The present study represents a first approach to understanding the complexities that act together in the powder foaming process to achieve the successful inflation of polyimide microstructures. This type of study is novel as no prior work had dissected the fundamentals that govern the inflation process in this type of systems. The systematic approach to each of the different phenomena (i.e. morphological, diffusive, kinetic and dynamic) brings into context each of them in a way that allows separate understanding and analysis. Of the different phenomena studied, probably the one that gives a higher level of control over the inflation process has been shown to be the morphological aspects of the precursor particles. It is a major contribution of the present work to isolate and identify this phenomenon and highlight the features that with careful control during the synthesis of the precursor material can lead to a highly optimized and specialized final product (neat foam or microstructure). Some of these accomplishments have been presented in various national meetings and some of which are either published in refereed journals or still in various stages of publications. One of the presentations was selected for "Best of ANTEC 2004" Online Presentation Series of the Society of Plastics Engineers (SPE) (September 2004)

Laser Imprint Reduction with a Short Shaping Laser Pulse Incident Upon a Foam-Plastic Target

DTIC Science & Technology

2002-12-01

Corporation, McLean, VA 22150, and Physics Department, Nuclear Research Center Negev , P. O. Box 9001, Beer Sheva, Israel Alexander L. Velikovich and...plasma oscillate rather than grow. Density tailoring seems to improve radiative performance of Z-pinch plasma radiation sources: For example, the cross...efficiency of the density profile shaping described above for laser imprint mitigation. We now use the the FAST2D hydrocode in a 2-D mode. The radiation

Pathfinder aircraft in flight

NASA Image and Video Library

1995-07-27

The Pathfinder research aircraft's wing structure was clearly defined as it soared under a clear blue sky during a test flight July 27, 1995, from Dryden Flight Research Center, Edwards, California. The center section and outer wing panels of the aircraft had ribs constructed of thin plastic foam, while the ribs in the inner wing panels are fabricated from lightweight composite material. Developed by AeroVironment, Inc., the Pathfinder was one of several unmanned aircraft being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program.

Dual-Mode Adhesive Pad

NASA Technical Reports Server (NTRS)

Hartz, Leslie

1994-01-01

Tool helps worker grip and move along large, smooth structure with no handgrips or footholds. Adheres to surface but easily released by actuating simple mechanism. Includes handle and segmented contact-adhesive pad. Bulk of pad made of soft plastic foam conforming to surface of structure. Each segment reinforced with rib. In sticking mode, ribs braced by side catches. In peeling mode, side catches retracted, and segmented adhesive pad loses its stiffness. Modified versions useful in inspecting hulls of ships and scaling walls in rescue operations.

The inverse problem of acoustic wave scattering by an air-saturated poroelastic cylinder.

PubMed

Ogam, Erick; Fellah, Z E A; Baki, Paul

2013-03-01

The efficient use of plastic foams in a diverse range of structural applications like in noise reduction, cushioning, and sleeping mattresses requires detailed characterization of their permeability and deformation (load-bearing) behavior. The elastic moduli and airflow resistance properties of foams are often measured using two separate techniques, one employing mechanical vibration methods and the other, flow rates of fluids based on fluid mechanics technology, respectively. A multi-parameter inverse acoustic scattering problem to recover airflow resistivity (AR) and mechanical properties of an air-saturated foam cylinder is solved. A wave-fluid saturated poroelastic structure interaction model based on the modified Biot theory and plane-wave decomposition using orthogonal cylindrical functions is employed to solve the inverse problem. The solutions to the inverse problem are obtained by constructing the objective functional given by the total square of the difference between predictions from the model and scattered acoustic field data acquired in an anechoic chamber. The value of the recovered AR is in good agreement with that of a slab sample cut from the cylinder and characterized using a method employing low frequency transmitted and reflected acoustic waves in a long waveguide developed by Fellah et al. [Rev. Sci. Instrum. 78(11), 114902 (2007)].

Modeling Transport of Relativistic Electrons through Warm-Dense Matter Using Collisional PIC

NASA Astrophysics Data System (ADS)

May, J.; McGuffey, C.; Yabuuchi, T.; Wei, Ms; Beg, F.; Mori, Wb

2017-10-01

In electron transport experiments performed on the OMEGA EP laser system, a relativistic electron beam was created by focusing a high intensity (eA /me c > 1) laser onto a gold (Au) foil. Behind the Au foil was a layer of plastic (CH) foam, with an initial density of 200mg /cm3 . Before the high intensity laser was switched on, this foam was either left unperturbed; or it was shocked using a lower intensity laser (eA /me c 10-4) with beam path perpendicular to the high intensity laser, which left the CH layer in a warm dense matter (WDM) state with temperature of 40 eV and density of 30mg /cm3 . The electron beam was imaged by observing the k- α signal from a copper foil on the far side from the Au. The result was that transport was decreased by an order of magnitude in the WDM compared to the cold foam. We have modeled this experiment using the PIC code OSIRIS, with also a Monte Carlo Coulomb collision package. Our simulations indicate that the main cause of the differences in transport is a collimating magnetic field in the higher density, cold foam, created by collisional resistivity. The plasma density of the Au layer, difficult to model fully in PIC, appears to effect the heat capacity and therefore temperature and resistivity of the target. The authors acknowledge the support of the Department of Energy under contract DE-NA 0001833 and the National Science Foundation under contract ACI 1339893.

Direct-drive inertial confinement fusion research at the Laboratory for Laser Energetics: charting the path to thermonuclear ignition

NASA Astrophysics Data System (ADS)

McCrory, R. L.; Regan, S. P.; Loucks, S. J.; Meyerhofer, D. D.; Skupsky, S.; Betti, R.; Boehly, T. R.; Craxton, R. S.; Collins, T. J. B.; Delettrez, J. A.; Edgell, D.; Epstein, R.; Fletcher, K. A.; Freeman, C.; Frenje, J. A.; Glebov, V. Yu.; Goncharov, V. N.; Harding, D. R.; Igumenshchev, I. V.; Keck, R. L.; Kilkenny, J. D.; Knauer, J. P.; Li, C. K.; Marciante, J.; Marozas, J. A.; Marshall, F. J.; Maximov, A. V.; McKenty, P. W.; Myatt, J.; Padalino, S.; Petrasso, R. D.; Radha, P. B.; Sangster, T. C.; Séguin, F. H.; Seka, W.; Smalyuk, V. A.; Soures, J. M.; Stoeckl, C.; Yaakobi, B.; Zuegel, J. D.

2005-10-01

Significant theoretical and experimental progress continues to be made at the University of Rochester's Laboratory for Laser Energetics (LLE), charting the path to direct-drive inertial confinement fusion (ICF) ignition. Direct drive offers the potential for higher-gain implosions than x-ray drive and is a leading candidate for an inertial fusion energy power plant. LLE's direct-drive ICF ignition target designs for the National Ignition Facility (NIF) are based on hot-spot ignition. A cryogenic target with a spherical DT-ice layer, within or without a foam matrix, enclosed by a thin plastic shell, will be directly irradiated with ~1.5 MJ of laser energy. Cryogenic and plastic/foam (surrogate-cryogenic) targets that are hydrodynamically scaled from these ignition target designs are imploded on the 60-beam, 30 kJ, UV OMEGA laser system to validate the key target physics issues, including energy coupling, hydrodynamic instabilities and implosion symmetry. Prospects for direct-drive ignition on the NIF are extremely favourable, even while it is in its x-ray-drive irradiation configuration, with the development of the polar-direct-drive concept. A high-energy petawatt capability is being constructed at LLE next to the existing 60-beam OMEGA compression facility. This OMEGA EP (extended performance) laser will add two short-pulse, 2.6 kJ beams to the OMEGA laser system to backlight direct-drive ICF implosions and study fast-ignition physics with focused intensities up to 6 × 1020 W cm-2.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Randolph, Randall Blaine; Oertel, John A.; Schmidt, Derek William

For this study, machined CH hemi-shell ablator capsules have been successfully produced by the MST-7 Target Fabrication Team at Los Alamos National Laboratory. Process development and micro-machining techniques have been developed to produce capsules for both the Omega and National Ignition Facility (NIF) campaigns. These capsules are gas filled up to 10 atm and consist of a machined plastic hemi-shell outer layer that accommodates various specially engineered low-density polystyrene foam cores. Machining and assembly of the two-part, step-jointed plastic hemi-shell outer layer required development of new techniques, processes, and tooling while still meeting very aggressive shot schedules for both campaigns.more » Finally, problems encountered and process improvements will be discussed that describe this very unique, complex capsule design approach through the first Omega proof-of-concept version to the larger NIF version.« less

LDRD Final Report: Advanced Hohlraum Concepts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Ogden S.

Indirect drive inertial confinement fusion (ICF) experiments to date have mostly used cylindrical, laser-heated, gas-filled hohlraums to produce the radiation drive needed to symmetrically implode DT-filled fusion capsules. These hohlraums have generally been unable to produce a symmetric radiation drive through the end of the desired drive pulse, and are plagued with complications due to laser-plasma interactions (LPI) that have made it difficult to predict their performance. In this project we developed several alternate hohlraum concepts. These new hohlraums utilize different hohlraum geometries, radiation shields, and foam materials in an attempt to improve performance relative to cylindrical hohlraums. Each alternatemore » design was optimized using radiation hydrodynamic (RH) design codes to implode a reference DT capsule with a high-density carbon (HDC) ablator. The laser power and energy required to produce the desired time-dependent radiation drive, and the resulting time-dependent radiation symmetry for each new concept were compared to the results for a reference cylindrical hohlraum. Since several of the new designs needed extra laser entrance holes (LEHs), techniques to keep small LEHs open longer, including high-Z foam liners and low-Z wires at the LEH axis, were investigated numerically. Supporting experiments and target fabrication efforts were also done as part of this project. On the Janus laser facility plastic tubes open at one end (halfraums) and filled with SiO 2 or Ta 2O 5 foam were heated with a single 2w laser. Laser propagation and backscatter were measured. Generally the measured propagation was slower than calculated, and the measured laser backscatter was less than calculated. A comparable, scaled up experiment was designed for the NIF facility and four targets were built. Since low density gold foam was identified as a desirable material for lining the LEH and the hohlraum wall, a technique was developed to produce 550 mg/cc gold foam, and a sample of this material was successfully manufactured.« less

Laser-Induced Graphene.

PubMed

Ye, Ruquan; James, Dustin K; Tour, James M

2018-06-20

Research on graphene abounds, from fundamental science to device applications. In pursuit of complementary morphologies, formation of graphene foams is often preferred over the native two-dimensional (2D) forms due to the higher available area. Graphene foams have been successfully prepared by several routes including chemical vapor deposition (CVD) methods and by wet-chemical approaches. For these methods, one often needs either high temperature furnaces and highly pure gases or large amounts of strong acids and oxidants. In 2014, using a commercial laser scribing system as found in most machine shops, a direct lasing of polyimide (PI) plastic films in the air converted the PI into 3D porous graphene, a material termed laser-induced graphene (LIG). This is a one-step method without the need for high-temperature reaction conditions, solvent, or subsequent treatments, and it affords graphene with many five-and seven-membered rings. With such an atomic arrangement, one might call LIG "kinetic graphene" since there is no annealing in the process that causes the rearrangement to the preferred all-six-membered-ring form. In this Account, we will first introduce the approaches that have been developed for making LIG and to control the morphology as either porous sheets or fibrils, and to control porosity, composition, and surface properties. The surfaces can be varied from being either superhydrophilic with a 0° contact angle with water to being superhydrophobic having >150° contact angle with water. While it was initially thought that the LIG process could only be performed on PI, it was later shown that a host of other polymeric substrates, nonpolymers, metal/plastic composites, and biodegradable and naturally occurring materials and foods could be used as platforms for generating LIG. Methods of preparation include roll-to-roll production for fabrication of in-plane electronics and two different 3D printing (additive manufacturing) routes to specific shapes of LIG monoliths using both laminated object manufacturing and powder bed fabrication methods. Use of the LIG in devices is performed very simply. This is showcased with high performance supercapacitors, fuel cell materials for oxygen reduction reactions, water splitting for both hydrogen and oxygen evolution reactions coming from the same plastic sheet, sensor devices, oil/water purification platforms, and finally applications in both passive and active biofilm inhibitors. So the ease of formation of LIG, its simple scale-up, and its utility for a range of applications highlights the easy transition of this substrate-bound graphene foam into commercial device platforms.

W-Band Transmission MeasurementS and X-Band Dielectric Properties Measurements for a Radome Material Sample

NASA Technical Reports Server (NTRS)

Cravey, Robin L.; Tiemsin, Pacita I.

1997-01-01

This paper describes measurements which were performed on a sample of radome material in the Electromagnetic Properties Measurements Laboratory (EPML). The purpose of the measurements described in this paper was to determine the one-way transmission loss through the flat panel of radome material for a frequency range of 84 to 94 GHz, for varying incidence angles. The panel, which was manufactured by Norton Performance Plastics Corporation, was provided to the EPML by TRW. The size of the panel is 40 in x 36 in x 0.422 in and consists of a foam material with one side coated with a smooth white coating (this side will be referred to as the front side). The dielectric properties of the foam material from the inside of the panel were also determined at X-band (8.2-12.4 GHz). The W-band free space measurements are presented first, followed by the X-band dielectric properties measurements.

Portable X-ray fluorescence for the detection of POP-BFRs in waste plastics.

PubMed

Sharkey, Martin; Abdallah, Mohamed Abou-Elwafa; Drage, Daniel S; Harrad, Stuart; Berresheim, Harald

2018-05-17

The purpose of this study was to establish the efficacy of portable X-ray fluorescence (XRF) instrumentation as a screening tool for a variety of end of life plastics which may contain excess amounts of brominated flame retardants (BFRs), in compliance with European Union (EU) and United Nations Environment Programme (UNEP) legislative limits (low POP concentration limits - LPCLs). 555 samples of waste plastics were collected from eight waste and recycling sites in Ireland, including waste electrical and electronic equipment (WEEE), textiles, polyurethane foams (PUFs), and expanded polystyrene foams. Samples were screened for bromine content, in situ using a Niton™ XL3T GOLDD XRF analyser, the results of which were statistically compared to mass spectrometry (MS)-based measurements of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD) and tetrabromobisphenol-A (TBBP-A) concentrations in the same samples. Regression between XRF and MS for WEEE samples shows that, despite an overall favourable trend, large deviations occur for a cluster of samples indicative of other bromine-based compounds in some samples; even compensating for false-positives due to background interference from electronic components, XRF tends to over-estimate MS-determined BFR concentrations in the 100 to 10,000 mg kg -1 range. Substantial deviations were additionally found between results for PUFs, textiles and polystyrene samples, with the XRF over-estimating BFR concentrations by a factor of up to 1.9; this is likely due to matrix effects influencing XRF measurements. However, expanded (EPS) and extruded polystyrene (XPS) yielded much more reliable estimations of BFR-content due to a dominance of HBCDD in these materials. XRF proved much more reliable as a "pass/fail" screening tool for LPCL compliance (including a prospective LPCL on Deca-BDE based on REACH). Using a conservative threshold of BFR content exceeding legislative limits (710 mg kg -1 bromine attributed to Penta-BDE), XRF mistakenly identifies only 6 % of samples (34/555) as exceeding legislative limits. Copyright © 2018 Elsevier B.V. All rights reserved.

The Effect of RDX Crystal Defect Structure on Mechanical Response of a Polymer-Bonded Explosive

DTIC Science & Technology

2015-11-09

standard geometry. From left to right there is a 5 cm steel cylinder filled with sand, a 10 cm steel cylinder filled with the PBX, and a 5 cm steel tube...third of the circumference of the cylinder was used to drive the deformation of the steel -encased Table 1. Identification of PBX, source of RDX Class I...thickness of the Semtex 10 plastic explosive layer was varied. A 4 mm thick rubber foam layer was put in be- tween the Semtex 10 layer and the steel

Impact and Blast Resistance of Sandwich Plates

NASA Astrophysics Data System (ADS)

Dvorak, George J.; Bahei-El-Din, Yehia A.; Suvorov, Alexander P.

Response of conventional and modified sandwich plate designs is examined under static load, impact by a rigid cylindrical or flat indenter, and during and after an exponential pressure impulse lasting for 0.05 ms, at peak pressure of 100 MPa, simulating a nearby explosion. The conventional sandwich design consists of thin outer (loaded side) and inner facesheets made of carbon/epoxy fibrous laminates, separated by a thick layer of structural foam core. In the three modified designs, one or two thin ductile interlayers are inserted between the outer facesheet and the foam core. Materials selected for the interlayers are a hyperelas-tic rate-independent polyurethane;a compression strain and strain rate dependent, elastic-plastic polyurea;and an elastomeric foam. ABAQUS and LS-Dyna software were used in various response simulations. Performance comparisons between the enhanced and conventional designs show that the modified designs provide much better protection against different damage modes under both load regimes. After impact, local facesheet deflection, core compression, and energy release rate of delamination cracks, which may extend on hidden interfaces between facesheet and core, are all reduced. Under blast or impulse loads, reductions have been observed in the extent of core crushing, facesheet delaminations and vibration amplitudes, and in overall deflections. Similar reductions were found in the kinetic energy and in the stored and dissipated strain energy. Although strain rates as high as 10-4/s1 are produced by the blast pressure, peak strains in the interlayers were too low to raise the flow stress in the polyurea to that in the polyurethane, where a possible rate-dependent response was neglected. Therefore, stiff polyurethane or hard rubber interlayers materials should be used for protection of sandwich plate foam cores against both impact and blast-induced damage.

Effect of blocking tactile information from the fingertips on adaptation and execution of grip forces to friction at the grasping surface.

PubMed

Bilaloglu, Seda; Lu, Ying; Geller, Daniel; Rizzo, John Ross; Aluru, Viswanath; Gardner, Esther P; Raghavan, Preeti

2016-03-01

Adaptation of fingertip forces to friction at the grasping surface is necessary to prevent use of inadequate or excessive grip forces. In the current study we investigated the effect of blocking tactile information from the fingertips noninvasively on the adaptation and efficiency of grip forces to surface friction during precision grasp. Ten neurologically intact subjects grasped and lifted an instrumented grip device with 18 different frictional surfaces under three conditions: with bare hands or with a thin layer of plastic (Tegaderm) or an additional layer of foam affixed to the fingertips. The coefficient of friction at the finger-object interface of each surface was obtained for each subject with bare hands and Tegaderm by measuring the slip ratio (grip force/load force) at the moment of slip. We found that the foam layer reduced sensibility for two-point discrimination and pressure sensitivity at the fingertips, but Tegaderm did not. However, Tegaderm reduced static, but not dynamic, tactile discrimination. Adaptation of fingertip grip forces to surface friction measured by the rate of change of peak grip force, and grip force efficiency measured by the grip-load force ratio at lift, showed a proportional relationship with bare hands but were impaired with Tegaderm and foam. Activation of muscles engaged in precision grip also varied with the frictional surface with bare hands but not with Tegaderm and foam. The results suggest that sensitivity for static tactile discrimination is necessary for feedforward and feedback control of grip forces and for adaptive modulation of muscle activity during precision grasp. Copyright © 2016 the American Physiological Society.

Plastic pollution on the Baltic beaches of Kaliningrad region, Russia.

PubMed

Esiukova, Elena

2017-01-30

Contamination of sandy beaches of the Baltic Sea in Kaliningrad region is evaluated on the base of surveys carried out from June 2015 to January 2016. Quantity of macro/meso/microplastic objects in the upper 2cm of the sandy sediments of the wrack zone at 13 sampling sites all along the Russian coast is reported. Occurrence of paraffin and amber pieces at the same sites is pointed out. Special attention is paid to microplastics (range 0.5-5mm): its content ranges between 1.3 and 36.3 items per kg dry sediment. The prevailing found type is foamed plastic. No sound differences in contamination are discovered between beaches with high and low anthropogenic load. Mean level of contamination is of the same order of magnitude as has been reported by other authors for the Baltic Sea beaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

Use of pultruded reinforced plastics in energy generation and energy related applications

NASA Astrophysics Data System (ADS)

Anderson, R.

Applications of pultrusion-formed fiber-reinforced plastics (FRP) in the wind, oil, and coal derived energy industries are reviewed. FRP is noted to be a viable alternative to wood, aluminum, and steel for reasons of availability, price, and weight. Attention is given to the development of FRP wind turbine blades for the DOE 8 kW low cost, high reliability wind turbine program. The blades feature a NACA 23112 profile with a 15 in. chord on the system which was tested at Rocky Flats, CO. Fabricating the blades involved a plus and minus 45 deg roving orientation, a heavy fiber-glass nose piece to assure blade strength, and a separately manufactured foam core. Additional uses for FRP products have been found in the structural members of coal stack scrubbers using a vinyl ester resin in a fire retardant formulation, and as low cost, light weight sucker rods for deep well oil drilling.

Teaching basic life support: a prospective randomized study on low-cost training strategies in secondary schools.

PubMed

Van Raemdonck, Veerle; Monsieurs, Koenraad G; Aerenhouts, Dirk; De Martelaer, Kristine

2014-08-01

Cardiopulmonary resuscitation (CPR) training at school is recommended. Limited school resources prevent implementation. The learning efficacy of low-cost training strategies is unknown. To evaluate the efficacy of different CPR learning strategies using low-cost didactic tools. Children (n=593, 15-16 years) were randomized to four training conditions: (1) manikin+teacher instruction (control group), (2) manikin+video instruction, (3) foam dice+plastic bag+peer training+teacher instruction, and (4) foam dice+plastic bag+peer training+video instruction. After a 50 min training, a 3 min CPR test on a manikin was performed using SkillReporting Software (Laerdal, Norway), and repeated after 6 months. The data of children without previous CPR training were analysed. Analysis of variance and the χ-test assessed differences between groups. Complete data sets were available for 165 pupils. Initially, group 3 scored lower on the mean ventilation volume (P<0.05). The control group scored better than the alternative groups (P<0.05) on the mean compression rate. After 6 months, the differences disappeared. All groups scored equally on ventilation volume (P=0.12), compression depth (P=0.11), compression rate (P=0.10), correct hand position (P=0.46) and number of correct compressions (P=0.76). Ventilation volume was sufficient in 32% of the pupils, 18% had a correct compression depth and 59% had a correct compression rate. Training efficacy with low-cost equipment was not different from training with a manikin. The outcome for all training strategies was suboptimal. The basics of CPR can be taught with alternative equipment if manikins are not available.

Development of fire resistant, nontoxic aircraft interior materials

NASA Technical Reports Server (NTRS)

Haley, G.; Silverman, B.; Tajima, Y.

1976-01-01

All available newly developed nonmetallic polymers were examined for possible usage in developing fire resistant, nontoxic nonmetallic parts or assemblies for aircraft interiors. Specifically, feasibility for the development of clear films for new decorative laminates, compression moldings, injection molded parts, thermoformed plastic parts, and flexible foams were given primary considerations. Preliminary data on the flame resistant characteristics of the materials were obtained. Preliminary toxicity data were generated from samples of materials submitted from the contractor. Preliminary data on the physical characteristics of various thermoplastic materials to be considered for either compression molded, injection molded, or thermoformed parts were obtained.

Landing Energy Dissipation for Manned Reentry Vehicles

NASA Technical Reports Server (NTRS)

Fisher, Loyd. L.

1960-01-01

The film shows experimental investigations to determine the landing-energy-dissipation characteristics for several types of landing gear for manned reentry vehicles. The landing vehicles are considered in two categories: those having essentially vertical-descent paths, the parachute-supported vehicles, and those having essentially horizontal paths, the lifting vehicles. The energy-dissipation devices include crushable materials such as foamed plastics and honeycomb for internal application in couch-support systems, yielding metal elements as part of the structure of capsules or as alternates for oleos in landing-gear struts, inflatable bags, braking rockets, and shaped surfaces for water impact.

Damage tolerance of a composite sandwich with interleaved foam core

NASA Astrophysics Data System (ADS)

Ishai, Ori; Hiel, Clement

A composite sandwich panel consisting of carbon fiber-reinforced plastic (CFRP) skins and a syntactic foam core was selected as an appropriate structural concept for the design of wind tunnel compressor blades. Interleaving of the core with tough interlayers was done to prevent core cracking and to improve damage tolerance of the sandwich. Simply supported sandwich beam specimens were subjected to low-velocity drop-weight impacts as well as high velocity ballistic impacts. The performance of the interleaved core sandwich panels was characterized by localized skin damage and minor cracking of the core. Residual compressive strength (RCS) of the skin, which was derived from flexural test, shows the expected trend of decreasing with increasing size of the damage, impact energy, and velocity. In the case of skin damage, RCS values of around 50 percent of the virgin interleaved reference were obtained at the upper impact energy range. Based on the similarity between low-velocity and ballistic-impact effects, it was concluded that impact energy is the main variable controlling damage and residual strength, where as velocity plays a minor role.

Damage tolerance of a composite sandwich with interleaved foam core

NASA Technical Reports Server (NTRS)

Ishai, Ori; Hiel, Clement

1992-01-01

A composite sandwich panel consisting of carbon fiber-reinforced plastic (CFRP) skins and a syntactic foam core was selected as an appropriate structural concept for the design of wind tunnel compressor blades. Interleaving of the core with tough interlayers was done to prevent core cracking and to improve damage tolerance of the sandwich. Simply supported sandwich beam specimens were subjected to low-velocity drop-weight impacts as well as high velocity ballistic impacts. The performance of the interleaved core sandwich panels was characterized by localized skin damage and minor cracking of the core. Residual compressive strength (RCS) of the skin, which was derived from flexural test, shows the expected trend of decreasing with increasing size of the damage, impact energy, and velocity. In the case of skin damage, RCS values of around 50 percent of the virgin interleaved reference were obtained at the upper impact energy range. Based on the similarity between low-velocity and ballistic-impact effects, it was concluded that impact energy is the main variable controlling damage and residual strength, where as velocity plays a minor role.

Large-area thermographic inspection of GRP composite marine vessel hulls

NASA Astrophysics Data System (ADS)

Jones, Thomas S.; Berger, Harold; Weaver, Elizabeth

1993-04-01

Every year there is an increase in the number of Glass Reinforced Plastic (GRP) composite vessels the Coast Guard inspects. A fast, nondestructive evaluation (NDE) technique is needed to facilitate these inspections. The technique must be suitable for use in field environments. Through a Small Business Innovation Research (SBIR) contract with the Coast Guard R&D Center, Industrial Quality, Inc. has performed a feasibility study evaluating the use of infrared thermography for such applications. The study demonstrated the ability of infrared thermography to detect hidden flaws through a variety of laminates and sandwich panel core materials. Empirical results matched well with analytical results of the sensitivity of the technique to various sizes of discontinuities at different depths. Following the successful SBIR program results, the Coast Guard R&D Center asked IQI to do a survey of the Steam Yacht Medea. The Medea had been repaired by a unique system of laying foam core and fiberglass over the ship's original steel-clad hull. The hybrid steel/foam core/GRP hull provided an additional structural configuration for the infrared thermography inspection equipment to handle.

Characterization of long-scale-length plasmas produced from plastic foam targets for laser plasma instability (LPI) research

NASA Astrophysics Data System (ADS)

Oh, Jaechul; Weaver, J. L.; Serlin, V.; Obenschain, S. P.

2017-10-01

We report on an experimental effort to produce plasmas with long scale lengths for the study of parametric instabilities, such as two plasmon decay (TPD) and stimulated Raman scattering (SRS), under conditions relevant to fusion plasma. In the current experiment, plasmas are formed from low density (10-100 mg/cc) CH foam targets irradiated by Nike krypton fluoride laser pulses (λ = 248 nm, 1 nsec FWHM) with energies up to 1 kJ. This experiment is conducted with two primary diagnostics: the grid image refractometer (Nike-GIR) to measure electron density and temperature profiles of the coronas, and time-resolved spectrometers with absolute intensity calibration to examine scattered light features of TPD or SRS. Nike-GIR was recently upgraded with a 5th harmonic probe laser (λ = 213 nm) to access plasma regions near quarter critical density of 248 nm light (4.5 ×1021 cm-3). The results will be discussed with data obtained from 120 μm scale-length plasmas created on solid CH targets in previous LPI experiments at Nike. Work supported by DoE/NNSA.

Optimization of Multilayer Laminated Film and Absorbent of Vacuum Insulation Panel for Use at High Temperature

NASA Astrophysics Data System (ADS)

Araki, Kuninari; Echigoya, Wataru; Tsuruga, Toshimitsu; Kamoto, Daigorou; Matsuoka, Shin-Ichi

For the energy saving regulation and larger capacity, Vacuum Insulation Panel (VIP) has been used in refrigerators with urethane foam in recent years. VIP for low temperature is constructed by laminated plastic film, using heat welding of each neighboring part for keeping vacuum, so that the performance decrement is very large under high temperature. But recently high efficiency insulation material is desired for high temperature water holding devices (automatic vending machine, heat pump water heater, electric hot-water pot water, etc.), and we especially focused on cost and ability of the laminated plastic film and absorbent for high temperature VIP. We measured the heatproof temperature of plastic films and checked the amount of water vapor and out coming gas on temperature-programmed adsorption in absorbent. These results suggest the suitable laminated film and absorbent system for VIP use at high temperature, and the long-term reliability was evaluated by measuring thermal conductivity of high temperature. As a result it was found that high-retort pouch of CPP (cast polypropylene film) and adding of aluminum coating are the most suitable materials for use in the welded layers of high-temperature VIPs (105°C).

Assessing the biodegradability of microparticles disposed down the drain.

PubMed

McDonough, Kathleen; Itrich, Nina; Casteel, Kenneth; Menzies, Jennifer; Williams, Tom; Krivos, Kady; Price, Jason

2017-05-01

Microparticles made from naturally occurring materials or biodegradable plastics such as poly(3-hydroxy butyrate)-co-(3-hydroxy valerate), PHBV, are being evaluated as alternatives to microplastics in personal care product applications but limited data is available on their ultimate biodegradability (mineralization) in down the drain environmental compartments. An OECD 301B Ready Biodegradation Test was used to quantify ultimate biodegradability of microparticles made of PHBV foam, jojoba wax, beeswax, rice bran wax, stearyl stearate, blueberry seeds and walnut shells. PHBV polymer was ready biodegradable reaching 65.4 ± 4.1% evolved CO 2 in 5 d and 90.5 ± 3.1% evolved CO 2 in 80 d. PHBV foam microparticles (125-500 μm) were mineralized extensively with >66% CO 2 evolution in 28 d and >82% CO 2 evolution in 80 d. PHBV foam microparticles were mineralized at a similar rate and extent as microparticles made of jojoba wax, beeswax, rice bran wax, and stearyl stearate which reached 84.8  ± 4.8, 84.9  ± 2.2, 82.7  ± 4.7, and 86.4 ± 3.2% CO 2 evolution respectively in 80 d. Blueberry seeds and walnut shells mineralized more slowly only reaching 39.3  ± 6.9 and 5.1 ± 2.8% CO 2 evolution in 80 d respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Back to the future: a 15-year experience with polyurethane foam-covered breast implants using the partial-subfascial technique.

PubMed

de la Peña-Salcedo, Jose Abel; Soto-Miranda, Miguel Angel; Lopez-Salguero, Jose Fernando

2012-04-01

Implants with a polyurethane foam cover have been used by plastic surgeons since Ashley described them in 1970. Overwhelming evidence confirms the benefits of these implants, especially the extremely low incidence of capsular contracture (grades 3 and 4, Baker classification). On the other hand, except for a transient and self-limited rash, there is no evidence that polyurethane implants present more complications than texturized or smooth gel implants. Due to concerns of polyurethane-induced cancer, these implants were withdrawn in United States after approximately 110,000 American women had received them. This fact, together with the probability that these implants will be reintroduced in the United States, suggests that continued monitoring of their long-term safety and effectiveness is mandatory. A retrospective study analyzed the outcomes of 996 implants inserted during a period of 15 years. The incidence of early and late complications was analyzed as well as the aesthetic outcome. The complications evaluated included hematoma (0.6%), infection (0.4%), seroma (0.8%), rash (4.3%), wound dehiscence (0%), capsular contracture (0.4%), implant malposition (0.8%), need for revisional surgery (1.2%), implant rupture (0.7%), rippling (1.8%), and polyurethane-related cancer (0%). Regarding the aesthetic outcome, 95% of the patients expressed satisfaction with their final result. The polyurethane foam-covered implants have been proven safe for use in breast surgery. They provide the lowest rate of capsular contracture (0.4% in the current study) and excellent aesthetic results.

Thermodynamic Investigation of the Interaction between Polymer and Gases

NASA Astrophysics Data System (ADS)

Mahmood, Syed Hassan

This thesis investigates the interaction between blowing agents and polymer matrix. Existing theoretical model was further developed to accommodate the polymer and blowing agent under study. The obtained results are not only useful for the optimization of the plastic foam fabrication process but also provides a different approach to usage of blowing agents. A magnetic suspension balance and an in-house visualizing dilatometer were used to obtain the sorption of blowing agents in polymer melts under elevated temperature and pressure. The proposed theoretical approach based on the thermodynamic model of SS-EOS is applied to understand the interaction of blowing agents with the polymer melt and one another (in the case of blend blowing agent). An in-depth study of the interaction of a blend of CO2 and DME with PS was conducted. Experimental volume swelling of the blend/PS mixture was measured and compared to the theoretical volume swelling obtained via ternary based SS-EOS, insuring the models validity. The effect of plasticization due to dissolution of DME on the solubility of CO2 in PS was then investigated by utilizing the aforementioned model. It was noted that the dissolution of DME increased the concentration of CO2 in PS and lowering the saturation pressure needed to dissolved a certain amount of CO2 in PS melt. The phenomenon of retrograde vitrification in PMMA induced due dissolution of CO2 was investigated in light of the thermodynamic properties resulting from the interaction of polymer and blowing agent. Solubility and volume swelling were measured in the pressure and temperature ranges promoting vitrification phenomenon, with relation being established between the thermodynamic properties and the vitrification process. Foaming of PMMA was conducted at various temperature values to investigate the application of this phenomenon.

Marine debris removal: one year of effort by the Georgia Sea Turtle-Center-Marine Debris Initiative.

PubMed

Martin, Jeannie Miller

2013-09-15

Once in the marine environment, debris poses a significant threat to marine life that can be prevented through the help of citizen science. Marine debris is any manufactured item that enters the ocean regardless of source, commonly plastics, metal, wood, glass, foam, cloth, or rubber. Citizen science is an effective way to engage volunteers in conservation initiatives and provide education and skill development. The Georgia Sea Turtle Center Marine Debris Initiative (GSTC-MDI) is a grant funded program developed to engage citizens in the removal of marine debris from the beaches of Jekyll Island, GA, USA and the surrounding areas. During the first year of effort, more than 200 volunteers donated over 460 h of service to the removal of marine debris. Of the debris removed, approximately 89% were plastics, with a significant portion being cigarette materials. Given the successful first year, the GSTC-MDI was funded again for a second year. Copyright © 2013 Elsevier Ltd. All rights reserved.

The production of paper soaps from coconut oil and Virgin Coconut Oil (VCO) with the addition of glycerine as plasticizer

NASA Astrophysics Data System (ADS)

Widyasanti, Asri; Miracle Lenyta Ginting, Anastasia; Asyifani, Elgina; Nurjanah, Sarifah

2018-03-01

Hand washing with soap is important because it is proven to clean hands from germs and bacteria. The paper soapswere made from coconut oil and virgin coconut oil (VCO) with the addition of glycerin as a plasticizer. The aims of this research were to determine both formulation of paper soap using coconut oil and VCO based with addition of glycerin, and to determine the quality of the paper soapswhich is a disposable hand soap. This research used laboratory experimental method using descriptive analysis. The treatments of this research were treatment A (paper soap without the addition of glycerin), treatment B (paper soap with the addition of glycerin 10% (w/w)), treatment C (paper soap with the addition of glycerin 15% (w/w)), treatment D (paper soap with the addition of glycerin of 20% (w/w)). Parameters tested were moisture content, stability of foam, pH value, insoluble material in ethanol, free alkali content, unsaponified fat, antibacterial activity test, and organoleptic test. The result of physicochemical characteristics for bothcoconut oil-paper soap and VCO-paper soap revealed that treatment C (the addition of glycerin 15% (w/w) was the best soap formulation. Coconut Oil papersoap 15% w/w glicerin had water content 13.72%, the content of insoluble material in ethanol 3.93%, the content of free alkali 0.21%, and the content of unsaponified fat 4.06%, pH value 10.78, stability of foam 97.77%, and antibacterial activity against S. aureus 11.66 mm. Meanwhile, VCO paper soap 15% w/w glicerin had the value of water content of 18.47%, the value stability of foam of 96.7%, the pH value of 10.03, the value of insoluble material in ethanol of 3.49%, the value of free alkali content 0.17%, the value of unsaponified fat 4.91%, and the value of inhibition diameter on the antibacterial activity test 15.28 mm. Based on Mandatory Indonesian National Standard of solid soap SNI 3532:2016 showed that both of paper soap had not been accorded with SNI 3532:2016, unless the value of the insoluble material in ethanol. Moreover, organoleptic tests performed that both paper soap treatment D (20% w/w glicerine) were preferred by the most panelists.

Spinoff From a Moon Suit

NASA Technical Reports Server (NTRS)

1991-01-01

Al Gross transferred expertise obtained as an ILC engineer for NASA's Apollo program to the manufacture of athletic shoes. Gross substituted DuPont's Hytrel plastic for foam materials in the shoe's midsole, eliminating cushioning loss caused by body weight. An external pressurized shell applied from space suit technology was incorporated into the shoe. Stiffness and cushioning properties of the midsole were "tuned" by varying material thickness and styling lines. A stress free "blow molding" process adapted from NASA space suit design was also utilized. The resulting compression chamber midsole performed well in tests. It allows AVIA to re-configure for specific sports and is a "first step" toward a durable, foamless, non-fatiguing midsole.

Development of a protective decorative fire resistant low smoke emitting, thermally stable coating material

NASA Technical Reports Server (NTRS)

1976-01-01

The development of suitable electrocoatings and subsequent application to nonconductive substrates are discussed. Substrates investigated were plastics or resin-treated materials such as FX-resin (phenolic-type resin) impregnated fiberglass mat, polyphenylene sulfide, polyether sulfone and polyimide-impregnated unidirectional fiberglass. Efforts were aimed at formulating a fire-resistant, low smoke emitting, thermally stable, easily cleaned coating material. The coating is to be used for covering substrate panels, such as aluminum, silicate foam, polymeric structural entities, etc., all of which are applied in the aircraft cabin interior and thus subject to the spillages, scuffing, spotting and the general contaminants which prevail in aircraft passenger compartments.

Size and density avalanche scaling near jamming.

PubMed

Arévalo, Roberto; Ciamarra, Massimo Pica

2014-04-28

The current microscopic picture of plasticity in amorphous materials assumes local failure events to produce displacement fields complying with linear elasticity. Indeed, the flow properties of nonaffine systems, such as foams, emulsions and granular materials close to jamming, that produce a fluctuating displacement field when failing, are still controversial. Here we show, via a thorough numerical investigation of jammed materials, that nonaffinity induces a critical scaling of the flow properties dictated by the distance to the jamming point. We rationalize this critical behavior by introducing a new universal jamming exponent and hyperscaling relationships, and we use these results to describe the volume fraction dependence of the friction coefficient.

Investigation of Multiscale and Multiphase Flow, Transport and Reaction in Heavy Oil Recovery Processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yortsos, Yanis C.

In this report, the thrust areas include the following: Internal drives, vapor-liquid flows, combustion and reaction processes, fluid displacements and the effect of instabilities and heterogeneities and the flow of fluids with yield stress. These find respective applications in foamy oils, the evolution of dissolved gas, internal steam drives, the mechanics of concurrent and countercurrent vapor-liquid flows, associated with thermal methods and steam injection, such as SAGD, the in-situ combustion, the upscaling of displacements in heterogeneous media and the flow of foams, Bingham plastics and heavy oils in porous media and the development of wormholes during cold production.

Research and application of high performance GPES rigid foam composite plastic insulation boards

NASA Astrophysics Data System (ADS)

sun, Hongming; xu, Hongsheng; Han, Feifei

2017-09-01

A new type of heat insulation board named GPES was prepared by several polymers and modified nano-graphite particles, injecting high-pressure supercritical CO2. Compared with the traditional thermal insulation material, GPES insulation board has higher roundness bubble and thinner bubble wall. Repeatability and reproducibility tests show that melting knot, dimensional stability, strength and other physical properties are significantly better than traditional organic heat insulation materials. Especially the lower and more stable thermal conductivity of GPES can significantly reduce thermal insulation layer thickness. Obviously GPES is the best choice of insulation materials with the implement of 75% and higher energy efficiency standard.

The radiation crosslinking process and new products

NASA Astrophysics Data System (ADS)

Ueno, Keiji

In 1988 there were over 90 EB accelerators for industrial use in Japan. The number one industrial application was Wire and Cable, the 2nd was PE foam and Curing, and the 3rd was Precure of tyre. R & D has a very high ration of EB accelerator use. Low energy industrial applications were coated steel (white board), plaster slab, coated paper, magnetic tape and floppy disks. As a new application of the radiation crosslinking process, we have studied radiation crosslinking of engineering plastics and succeeded in improving the hea tresistivity without using glass fibers. Many kinds of polyfunctional monomers used as crosslinking reagents of irradiated Nylon and PBT were studied.

A Polymer Visualization System with Accurate Heating and Cooling Control and High-Speed Imaging

PubMed Central

Wong, Anson; Guo, Yanting; Park, Chul B.; Zhou, Nan Q.

2015-01-01

A visualization system to observe crystal and bubble formation in polymers under high temperature and pressure has been developed. Using this system, polymer can be subjected to a programmable thermal treatment to simulate the process in high pressure differential scanning calorimetry (HPDSC). With a high-temperature/high-pressure view-cell unit, this system enables in situ observation of crystal formation in semi-crystalline polymers to complement thermal analyses with HPDSC. The high-speed recording capability of the camera not only allows detailed recording of crystal formation, it also enables in situ capture of plastic foaming processes with a high temporal resolution. To demonstrate the system’s capability, crystal formation and foaming processes of polypropylene/carbon dioxide systems were examined. It was observed that crystals nucleated and grew into spherulites, and they grew at faster rates as temperature decreased. This observation agrees with the crystallinity measurement obtained with the HPDSC. Cell nucleation first occurred at crystals’ boundaries due to CO2 exclusion from crystal growth fronts. Subsequently, cells were nucleated around the existing ones due to tensile stresses generated in the constrained amorphous regions between networks of crystals. PMID:25915031

Evaluation of the performance of three elastomers for non-lethal projectile applications

NASA Astrophysics Data System (ADS)

Thota, N.; Epaarachchi, J.; Lau, K. T.

2015-09-01

Less lethal kinetic ammunitions with soft noses such as eXact iMpact 1006, National Sports Spartan and B&T have been commonly used by military and law enforcement officers in the situations where lethal force is not warranted. In order to explore new materials to be used as nose in such ammunitions, a scholastic study using finite element simulations has been carried out to evaluate the effectiveness of two rubber like elastomers and a polyolefinic foam (low density, highly compressible, stiff and closed cell type of thermos plastic elastomer). State-of-the art thorax surrogate MTHOTA has been employed for the evaluation of blunt thoracic trauma. Force-rigid wall method was employed for the evaluation of head damage curves for each material. XM 1006 has been used as the benchmark projectile for the purpose of comparison. Both blunt thoracic trauma and head damage criterion point of view, both rubbers (R1 and R2) have yielded high values of VCmax and peak impact force. Polyolefinic foam (F1) considered in the study has yielded very promising VCmax values and very less peak impact force when compared with those of bench mark projectile XM 1006.

Insights on Flow Behavior of Foam in Unsaturated Porous Media during Soil Flushing.

PubMed

Zhao, Yong S; Su, Yan; Lian, Jing R; Wang, He F; Li, Lu L; Qin, Chuan Y

2016-11-01

  One-dimensional column and two-dimensional tank experiments were carried out to determine (1) the physics of foam flow and propagation of foaming gas, foaming liquid, and foam; (2) the pressure distribution along foam flow and the effect of media permeability, foam flow rate and foam quality on foam injection pressure; and (3) the migration and distribution property of foam flow in homogeneous and heterogeneous sediments. The results demonstrated that: (1) gas and liquid front were formed ahead of the foam flow front, the transport speed order is foaming gas > foaming liquid > foam flowing; (2) injection pressure mainly comes from the resistance to bubble migration. Effect of media permeability on foam injection pressure mainly depends on the physics and behavior of foam flow; (3) foam has a stronger capacity of lateral spreading, besides, foam flow was uniformly distributed across the foam-occupied region, regardless of the heterogeneity of porous media.

MRI brain in monohalomethane toxic encephalopathy: A case report.

PubMed

Deshmukh, Yogeshwari S; Atre, Ashish; Shah, Darshan; Kothari, Sudhir

2013-07-01

Monohalomethanes are alkylating agents that have been used as methylating agents, laboratory reagents, refrigerants, aerosol propellants, pesticides, fumigants, fire-extinguishing agents, anesthetics, degreasers, blowing agents for plastic foams, and chemical intermediates. Compounds in this group are methyl chloride, methyl bromide, methyl iodide (MI), and methyl fluoride. MI is a colorless volatile liquid used as a methylating agent to manufacture a few pharmaceuticals and is also used as a fumigative insecticide. It is a rare intoxicant. Neurotoxicity is known with both acute and chronic exposure to MI. We present the characteristic magnetic resonance imaging (MRI) brain findings in a patient who developed neuropsychiatric symptoms weeks after occupational exposure to excessive doses of MI.

Lattice strains and load partitioning in bovine trabecular bone.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akhtar, R.; Daymond, M. R.; Almer, J. D.

2012-02-01

Microdamage and failure mechanisms have been well characterized in bovine trabecular bone. However, little is known about how elastic strains develop in the apatite crystals of the trabecular struts and their relationship with different deformation mechanisms. In this study, wide-angle high-energy synchrotron X-ray diffraction has been used to determine bulk elastic strains under in situ compression. Dehydrated bone is compared to hydrated bone in terms of their response to load. During compression, load is initially borne by trabeculae aligned parallel to loading direction with non-parallel trabeculae deforming by bending. Ineffective load partitioning is noted in dehydrated bone whereas hydrated bonemore » behaves like a plastically yielding foam« less

CAD/CAM for development and fabrication of cosecant reflector antennas

NASA Astrophysics Data System (ADS)

Petri, U.

The application of CAD/CAM techniques to lower the cost of redesigning and manufacturing specialized cosecant reflector antennas for use in the mm-wave range is described and demonstrated. Consideration is given to the theoretical computation of reflector surfaces; the representation of a reflector surface in a CAD system; the numerically controlled milling of an Al, wood, or plastic model antenna; and the construction of the antenna (by spraying the 300-micron Sn-alloy conducting layer onto the coated model surface and then applying a 1-mm-thick epoxy-matrix GFRP layer, a 20-30-mm layer of flexible polyurethane foam, and a final GFRP layer). Diagrams and photographs are provided.

Numerically Simulating Collisions of Plastic and Foam Laser-Driven Foils

NASA Astrophysics Data System (ADS)

Zalesak, S. T.; Velikovich, A. L.; Schmitt, A. J.; Aglitskiy, Y.; Metzler, N.

2007-11-01

Interest in experiments on colliding planar foils has recently been stimulated by (a) the Impact Fast Ignition approach to laser fusion [1], and (b) the approach to a high-repetition rate ignition facility based on direct drive with the KrF laser [2]. Simulating the evolution of perturbations to such foils can be a numerical challenge, especially if the initial perturbation amplitudes are small. We discuss the numerical issues involved in such simulations, describe their benchmarking against recently-developed analytic results, and present simulations of such experiments on NRL's Nike laser. [1] M. Murakami et al., Nucl. Fusion 46, 99 (2006) [2] S. P. Obenschain et al., Phys. Plasmas 13, 056320 (2006).

Current applications of foams formed from mixed surfactant-polymer solutions.

PubMed

Bureiko, Andrei; Trybala, Anna; Kovalchuk, Nina; Starov, Victor

2015-08-01

Foams cannot be generated without the use of special foaming agents, as pure liquids do not foam. The most common foaming agents are surfactants, however often for foam stability one active agent is not enough, it is necessary to add other component to increase foam lifetime. Foams on everyday use are mostly made from mixture of different components. Properly chosen combinations of two active ingredients lead to a faster foam formation and increased foam stability. During the last decade polymers (mainly polyelectrolytes and proteins) have become frequently used additives to foaming solutions. Mixtures of surfactants and polymers often demonstrate different foaming properties in comparison to surfactant only or polymer only solutions. The nature of surfactant-polymer interactions is complicated and prediction of resulting foaming properties of such formulations is not straightforward. Properties and foaming of surfactant-polymer mixtures are discussed as well as current applications of foams and foaming agents as foams are widely used in cosmetics, pharmaceutics, medicine and the food industry. Copyright © 2014 Elsevier B.V. All rights reserved.

Structure design of and experimental research on a two-stage laval foam breaker for foam fluid recycling.

PubMed

Wang, Jin-song; Cao, Pin-lu; Yin, Kun

2015-07-01

Environmental, economical and efficient antifoaming technology is the basis for achievement of foam drilling fluid recycling. The present study designed a novel two-stage laval mechanical foam breaker that primarily uses vacuum generated by Coanda effect and Laval principle to break foam. Numerical simulation results showed that the value and distribution of negative pressure of two-stage laval foam breaker were larger than that of the normal foam breaker. Experimental results showed that foam-breaking efficiency of two-stage laval foam breaker was higher than that of normal foam breaker, when gas-to-liquid ratio and liquid flow rate changed. The foam-breaking efficiency of normal foam breaker decreased rapidly with increasing foam stability, whereas the two-stage laval foam breaker remained unchanged. Foam base fluid would be recycled using two-stage laval foam breaker, which would reduce the foam drilling cost sharply and waste disposals that adverse by affect the environment.

Improving the quality of polymer-coated urea with recycled plastic, proper additives, and large tablets.

PubMed

Yang, Yue-Chao; Zhang, Min; Li, Yuncong; Fan, Xiao-Hui; Geng, Yu-Qing

2012-11-14

Polymer-coated urea (PCU) has great potential for increasing crop production and enhancing nitrogen (N) fertilizer use efficiency, benefiting the ecosystem. However, current PCUs are used only in a limited market, and the main obstacle to the wider use of PCUs is high cost compared to that of conventional N fertilizers. In this study, the low cost PCU and large tablet polymer-coated urea (LTPCU) were prepared by using recycling polystyrene foam and various sealants as the coating materials. The structural and chemical characteristics of the coating shells of the coated fertilizers were examined. The N release characteristics of coated fertilizers were determined in 25 °C water under laboratory conditions. The relationship between the N release longevity and the amount of coating material and the percentage of different sealants were evaluated. The results indicated that recycling polystyrene foam was the ideal coating material of the controlled release fertilizer. The polyurethane that was synthesized by the reaction of castor oil and isocyanate was better than the wax as the additive to delay the N release rate of coated urea. The coating material used for LTPCU was 70-80% less than those used for commercial PCUs under the same N release longevity. The cost of the recycling polystyrene foam used for coating one ton of pure N of the LTPCU was about one-seventh to one-eighth of the cost of the traditional polymer used for the commercial PCU. The experimental data showed that the LTPCU with good controlled-release capacities, being economical and eco-friendly, could be promising for wide use in agriculture and horticulture.

Assessment of marine debris on the coastal wetland of Martil in the North-East of Morocco.

PubMed

Alshawafi, Adel; Analla, Mohamed; Alwashali, Ebrahim; Aksissou, Mustapha

2017-04-15

Plastic waste at the coastal wetland in Martil beach in the North-East of Morocco is one of the problems that have appeared recently. This study aims to characterize the marine debris in the coast of Martil during the year 2015. The sampling is seasonally by type and size. The result shows, for the macro debris, the abundance of plastic (57%), lumber and paper (21.93%), cloth and fabric (7.8%), glass (5.42%), metal (4.40%), and rubber (3.4%). Micro debris is also present in the area in several forms such as wood, plants, and others by 75,63%. This was followed by the foam (26,95%), line (7,8%), and the film (1,23%). The seasonal variation (S1: January-March and S3: July to September) are the most polluted months of the year. The sources of marine debris are mainly tourism (beach users), land (run off), and commercial fishing in the four seasons of the year. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of polylactide (PLA) and PLA nanocomposite foams in injection molding for automotive applications

NASA Astrophysics Data System (ADS)

Najafi Chaloupli, Naqi

Plastic materials are extensively used in automotive structures since they make cars more energy efficient. Recently, the automotive industry is searching for bio-based and renewable alternatives to petroleum-based plastics to reduce the dependence on fossil fuels. Among polymers originating from renewable sources, polylactide (PLA) has attracted significant interest. The use of this polymer in durable industries is promising. Fuel-efficient automobiles are nowadays demanded due to the increasing concerns about environmental and fuel issues. The automobile fuel efficiency can be improved by using a lightweight material and, thereby, reducing the automobile weight. A potential method to achieve this objective is the use of the foaming technology. Foam is a material where a gas phase is encapsulated by a solid phase. Foaming technology helps to manufacture lightweight parts with superior properties in comparison with their solid counterparts. The basic mechanisms of foaming process normally consists of gas implementation, formation of uniform polymer-gas solution, cell nucleation, cell growth and, finally, cell stabilization. PLA foaming has, however, proved to be difficult mainly due to poor rheological properties, small processing window, and slow crystallization kinetics. The ultimate purpose of this work is to reduce by 30 % the weight of polylactide (PLA)-clay based nanocomposites by manufacturing injection-molded foamed parts. To use standard processing equipment, a chemical blowing agent (CBA) was employed. The injection molding technique was utilized in this project because it is the most widely used fabrication process in industry that can produce complex shaped articles. This process, however, is more challenging than other foaming processes since it deals with many additional controlling parameters. In the first part of this project, we illustrated how long chain branching (LCB) and molecular structure impact the melt rheology, crystallization and batch foaming behavior of PLA. To this end, LCB-PLAs were prepared in the presence of a multifunctional chain extender (CE) using two different processing strategies. In the first strategy, the dried PLA was directly mixed in the molten state with various quantities of CE (the formation of LCB structure). To further examine the impact of CE and molecular topology, a LCB-PLA was also prepared using a second approach, strategy S2. In this approach, a highly branched PLA was first prepared and then mixed with the neat PLA at a weight ratio of 50:50 (the introduction of LCB structure). The steady and transient rheological properties of the linear and LCB-PLAs revealed that the LCB-PLAs exhibited an increased viscosity, shear sensitivity and longer relaxation time in comparison with the linear PLA. The presence of the LCB structure, moreover, led to a strong strain-hardening behavior in uniaxial elongational flow whereas no strain hardening was observed for the linear PLA. The batch foaming of the samples was conducted using CO2 at different foaming temperatures ranging from 130 to 155 °C. The impact of molecular structure and foaming temperature on the void fraction, cell density, and cell size were examined. It was found that the increased melt strength and elasticity, resulting from branching, strongly affected the cell uniformity, cell density and void fraction. Among the investigated compositions, LCB-PLA prepared by strategy S2 provided smaller cell size and higher cell density than the other compositions. In most polymer processing operations such as extrusion and injection molding the polymeric chains are subjected to complex flow fields (elongation, shear, and mixed flows). Shearing the molten polymer during processing plays an essential role on crystallization and, thus, on the final properties of the product. The impact of the LCB structure and shear on the isothermal shear-induced crystallization kinetics, and the crystal morphology of PLA were studied in the second part of this work. The quiescent crystallization behavior was investigated and the results were, then, used as the reference point for the study of the shear-induced crystallization. To determine the effect of shear strain, a pre-shear treatment was applied on the melt at two constant shear rates for a period of 1, 5, and 10 min. The onset time of crystallization was decreased with increasing total shear strain. Meanwhile, the impact of shear strain was more pronounced as the degree of LCB and molecular weight increased. To investigate the effect of shear rate on the induced crystallization, pre-shear was applied at three different shear rates while keeping the total strain constant. The induction time of the linear PLA and LCB-PLAs was found to reduce as the shear rate increased, even though the total strain was the same. The crystal morphology of the linear PLA and LCB-PLAs under quiescent and shear flow conditions was observed. These micrographs provided information about the spherulite density and growth rate. An increase in the spherulite density was achieved in the strained melt of both linear and LCB-PLAs, as compared with those of unstrained counterparts. A comparison of the crystal structure of linear PLA with that of LCB-PLA revealed that long chain branching significantly promoted the nucleation density, although it diminished the crystal growth rate. In the next step, the injection foam molding of the linear PLA and LCB-PLAs with different formulations was performed using a chemical blowing agent (CBA) in a conventional injection molding machine. Several factors including CBA content, degree of LCB, and injection molding processing parameters such as shot size, injection speed, back pressure, cooling time, and nozzle temperature were varied to optimize the formulation and processing conditions. The optimized formulation and processing conditions were selected for the last step of the project. In the third and last part of this work, the impact of LCB and nanoclay inclusion on the low pressure injection foaming behavior of PLA were examined. The linear PLA and LCB-PLA nanocomposites were prepared via melt compounding using a twin-screw extruder. An organo-modified clay, Cloisite 30B, at concentrations of 0.25, 0.5, and 1 wt% was used in this step. The resulting compositions were then foamed in a conventional injection molding using a CBA. The degree of crystallinity, clay dispersion, cellular morphology and mechanical properties were studied. The addition of clay increased the linear PLA crystallinity while a reverse effect was observed for the LCB-PLA. The morphological observations and quantifications revealed that a more uniform, finer, and denser cellular structure was achieved in the LCB-PLA reinforced by nanoclay. In addition, 0.5 wt % clay was found to be the optimum content for achieving a uniform morphology with high cell density and relative foam density of 0.7 in the LCB-PLA. The mechanical properties of the foamed specimens were significantly influenced by the cellular structure. A significant improvement of the mechanical properties was observed at 0.5 wt% clay loading. Finally, it is worth noting that the addition of just 0.4 wt% CE and 0.5 wt% nanoclay led to the formation of a uniform cellular structure with relative density of 0.7, 10 times increase of the cell density and improved mechanical properties if they are judiciously added to the PLA.

Positive and negative impacts of specialty malts on beer foam: a comparison of various cereal products for their foaming properties.

PubMed

Combe, Alexander L; Ang, Justin K; Bamforth, Charles W

2013-07-01

The foam stability of beer is dependent on the presence of foam-stabilizing polypeptides derived from the cereals from which it is made. It has long been argued that there is a tendency to boost the foam-stabilizing capabilities of these polypeptides at the heating stages involved in the production of the grist materials. The present study started with the intent to confirm whether these changes occurred and to assess the extent to which different cereal products differed in their foam-stabilizing tendencies. Cereal products differ enormously in their foam-stabilizing capabilities. Heavily roasted grains, notably black malt and roast barley, do have superior foaming properties. However, certain specialty malts, notably crystal malts, display inferior foam performance. The observed foaming pattern is a balance between their content of foam-positive and foam-negative components. Products such as pale malt do contain foam-negative materials but have a net balance in favour of foam-stabilizing entities. By contrast, wheat malt and especially black malt have a heavy preponderance of foam-positive components. Crystal malt displays the converse behaviour: it contains low-molecular-weight foam-negative species. Several of the cereal products appear to contain higher-molecular-weight foam inhibitors, but it appears that they are merely species that are of inherently inferior foam-stabilizing capability to the foaming polypeptides from egg white that were employed to probe the system. The foam-damaging species derived from crystal malt carried through to beers brewed from them. Intense heating in the production of cereal products does lead to enhanced foam performance in extracts of those products. However, not all speciality malts display superior foam performance, through their development of foam-negative species of lower molecular weight. © 2013 Society of Chemical Industry.

State-of-the-Art Review on the Characteristics of Surfactants and Foam from Foam Concrete Perspective

NASA Astrophysics Data System (ADS)

Sahu, Sritam Swapnadarshi; Gandhi, Indu Siva Ranjani; Khwairakpam, Selija

2018-06-01

Foam concrete finds application in many areas, generally as a function of its relatively lightweight and its beneficial properties in terms of reduction in dead load on structure, excellent thermal insulation and contribution to energy conservation. For production of foam concrete with desired properties, stable and good quality foam is the key requirement. It is to be noted that the selection of surfactant and foam production parameters play a vital role in the properties of foam which in turn affects the properties of foam concrete. However, the literature available on the influence of characteristics of foaming agent and foam on the properties of foam concrete are rather limited. Hence, a more systematic research is needed in this direction. The focus of this work is to provide a review on characteristics of surfactant (foaming agent) and foam for use in foam concrete production.

State-of-the-Art Review on the Characteristics of Surfactants and Foam from Foam Concrete Perspective

NASA Astrophysics Data System (ADS)

Sahu, Sritam Swapnadarshi; Gandhi, Indu Siva Ranjani; Khwairakpam, Selija

2018-02-01

Foam concrete finds application in many areas, generally as a function of its relatively lightweight and its beneficial properties in terms of reduction in dead load on structure, excellent thermal insulation and contribution to energy conservation. For production of foam concrete with desired properties, stable and good quality foam is the key requirement. It is to be noted that the selection of surfactant and foam production parameters play a vital role in the properties of foam which in turn affects the properties of foam concrete. However, the literature available on the influence of characteristics of foaming agent and foam on the properties of foam concrete are rather limited. Hence, a more systematic research is needed in this direction. The focus of this work is to provide a review on characteristics of surfactant (foaming agent) and foam for use in foam concrete production.

Influence of pressurized carbon dioxide on ketoprofen-incorporated hot-melt extruded low molecular weight hydroxypropylcellulose.

PubMed

A Ashour, Eman; Kulkarni, Vijay; Almutairy, Bjad; Park, Jun-Bom; Shah, Sejal P; Majumdar, Soumyajit; Lian, Zhuoyang; Pinto, Elanor; Bi, Vivian; Durig, Thomas; Martin, Scott T; Repka, Michael A

2016-01-01

The aim of the current research project was to investigate the effect of pressurized carbon dioxide (P-CO 2 ) on the physico-mechanical properties of ketoprofen (KTP)-incorporated hydroxypropylcellulose (HPC) (Klucel™ ELF, EF, and LF) produced using hot-melt extrusion (HME) techniques and to assess the plasticization effect of P-CO 2 on the various polymers tested. The physico-mechanical properties of extrudates with and without injection of P-CO 2 were examined and compared with extrudates with the addition of 5% liquid plasticizer of propylene glycol (PG). The extrudates were milled and compressed into tablets. Tablet characteristics of the extrudates with and without injection of P-CO 2 were evaluated. P-CO 2 acted as a plasticizer for tested polymers, which allowed for the reduction in extrusion processing temperature. The microscopic morphology of the extrudates was changed to a foam-like structure due to the expansion of the CO 2 at the extrusion die. The foamy extrudates demonstrated enhanced KTP release compared with the extrudates processed without P-CO 2 due to the increase of porosity and surface area of those extrudates. Furthermore, the hardness of the tablets prepared by foamy extrudates was increased and the percent friability was decreased. Thus, the good binding properties and compressibility of the extrudates were positively influenced by utilizing P-CO 2 processing.

Influence of Pressurized Carbon Dioxide on Ketoprofen-Incorporated Hot-Melt Extruded Low Molecular Weight Hydroxypropylcellulose

PubMed Central

Ashour, Eman A.; Kulkarni, Vijay; Almutairy, Bjad; Park, Jun-Bom; Shah, Sejal; Majumdar, Soumyajit; Lian, Zhuoyang; Pinto, Elanor; Bi, Yunxia; Durig, Thomas; Martin, Scott T.; Repka, Michael A.

2017-01-01

Objectives The aim of the current research project was to investigate the effect of pressurized carbon dioxide (P-CO2) on the physico-mechanical properties of Ketoprofen (KTP)-incorporated hydroxypropylcellulose (HPC) (Klucel™ ELF, EF and LF) produced using hot melt extrusion (HME) techniques and to assess the plasticization effect of P-CO2 on the various polymers tested. Methods The physico-mechanical properties of extrudates with and without injection of P-CO2 were examined and compared to extrudates with the addition of 5% liquid plasticizer of propylene glycol (PG). The extrudates were milled and compressed into tablets. Tablet characteristics of the extrudates with and without injection of P-CO2 were evaluated. Results & conclusion P-CO2 acted as a plasticizer for tested polymers, which allowed for the reduction in extrusion processing temperature. The microscopic morphology of the extrudates were changed to a foam-like structure due to expansion of the CO2 at the extrusion die. The foamy extrudates demonstrated enhanced KTP release compared to the extrudates processed without P-CO2 due to the increase of porosity and surface area of those extrudates. Furthermore, the hardness of the tablets prepared by foamy extrudates was increased and the percent friability was decreased. Thus, the good binding properties and compressibility of the extrudates were positively influenced by utilizing P-CO2 processing. PMID:25997363

Microscale synthesis and characterization of polystyrene: NSF-POLYED scholars project

NASA Technical Reports Server (NTRS)

Quaal, Karen S.; Wu, Chang-Ning

1994-01-01

Polystyrene is a familiar polymer with many commercial uses. Its applications range from the clear, high index of refraction, brittle plastic used to form audio cassette and CD cases to the foamed material used in insulated drink cups and packaging material. Polystyrene constitutes 11 percent of the plastics used in packaging with only High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE) contributing a larger share: so much polystyrene is used today, it is one of six common plastics that manufacturers have assigned an identification code. The code helps recycling efforts. Polystyrene's code is (PS code 6). During the summer and fall of 1992 several new polymeric experiments were developed by the NSF POLYED Scholars for introduction into the chemistry core curriculum. In this presentation, one such project will be discussed. This laboratory project is recommended for a first or second year laboratory course allowing the introduction of polymeric science to undergraduates at the earliest opportunity. The reliability of the experiments which make up this project and the recognition factor of polystyrene, a material we come in contact with everyday, makes the synthesis and characterization of polystyrene a good choice for the introduction of polymerization to undergraduates. This laboratory project appeals to the varied interests of students enrolled in the typical first year chemistry course and becomes an ideal way to introduce polymers to a wide variety of science and engineering students.

The IBA Easy-E-Beam™ Integrated Processing System

NASA Astrophysics Data System (ADS)

Cleland, Marshall R.; Galloway, Richard A.; Lisanti, Thomas F.

2011-06-01

IBA Industrial Inc., (formerly known as Radiation Dynamics, Inc.) has been making high-energy and medium-energy, direct-current proton and electron accelerators for research and industrial applications for many years. Some industrial applications of high-power electron accelerators are the crosslinking of polymeric materials and products, such as the insulation on electrical wires, multi-conductor cable jackets, heat-shrinkable plastic tubing and film, plastic pipe, foam and pellets, the partial curing of rubber sheet for automobile tire components, and the sterilization of disposable medical devices. The curing (polymerization and crosslinking) of carbon and glass fiber-reinforced composite plastic parts, the preservation of foods and the treatment of waste materials are attractive possibilities for future applications. With electron energies above 1.0 MeV, the radiation protection for operating personnel is usually provided by surrounding the accelerator facility with thick concrete walls. With lower energies, steel and lead panels can be used, which are substantially thinner and more compact than the equivalent concrete walls. IBA has developed a series of electron processing systems called Easy-e-Beam™ for the medium energy range from 300 keV to 1000 keV. These systems include the shielding as an integral part of a complete radiation processing facility. The basic concepts of the electron accelerator, the product processing equipment, the programmable control system, the configuration of the radiation shielding and some performance characteristics are described in this paper.

Experimental Study of Hysteresis behavior of Foam Generation in Porous Media.

PubMed

Kahrobaei, S; Vincent-Bonnieu, S; Farajzadeh, R

2017-08-21

Foam can be used for gas mobility control in different subsurface applications. The success of foam-injection process depends on foam-generation and propagation rate inside the porous medium. In some cases, foam properties depend on the history of the flow or concentration of the surfactant, i.e., the hysteresis effect. Foam may show hysteresis behavior by exhibiting multiple states at the same injection conditions, where coarse-textured foam is converted into strong foam with fine texture at a critical injection velocity or pressure gradient. This study aims to investigate the effects of injection velocity and surfactant concentration on foam generation and hysteresis behavior as a function of foam quality. We find that the transition from coarse-foam to strong-foam (i.e., the minimum pressure gradient for foam generation) is almost independent of flowrate, surfactant concentration, and foam quality. Moreover, the hysteresis behavior in foam generation occurs only at high-quality regimes and when the pressure gradient is below a certain value regardless of the total flow rate and surfactant concentration. We also observe that the rheological behavior of foam is strongly dependent on liquid velocity.

Modeling Study: Mechanism of Foam Propagation in Porous Media at Different Levels of Minimum Mobilization Pressure Gradient

NASA Astrophysics Data System (ADS)

Izadi, M.; Kam, S.

2017-12-01

Scope: Numerous laboratory and field tests revealed that foam can effectively control gas mobility and improve sweep efficiency in enhanced-oil-recovery and subsurface-remediation processes, if correctly designed. The objective of this study is to answer (i) how mechanistic foam model parameters can be determined by fitting lab experiments in a step-by-step manner; (ii) how different levels of mobilization pressure gradient for foam generation affects the fundamentals of foam propagation; and (iii) how foam propagation distance can be estimated in the subsurface. This study for the first time shows why, and by how much, supercritical CO2 foams are advantaged over other types of foams such as N2 foam. Methods: First of all, by borrowing experimental data existing in the literature, this study shows how to capture mechanistic foam model parameters. The model, then, is applied to a wide range of mobilization pressure gradient to represent different types of foams that have been applied in the field (Note that supercritical CO2 foams exhibit much lower mobilization pressure compared to other types of foams (N2, steam, air, etc.). Finally, the model and parameters are used to evaluate different types of foam injection scenarios in order to predict how far foams can propagate with what properties in the field condition. Results and Conclusions: The results show that (i) the presence of three different foam states (strong, weak, intermediate) as well as two different strong-foam flow regimes (high-quality and low-quality regimes) plays a key role in model fit and field-scale propagation prediction and (ii) the importance of complex non-Newtonian foam rheology should not be underestimated. More specifically, this study finds that (i) supercritical CO2 foams can propagate a few hundreds of feet easily, which is a few orders of magnitude higher than other foams such as N2 foams; (ii) for dry foams (or, strong foams in the high-quality regime), the higher gas fractions the less foams travel, while for wet foams (or, strong foams in the low-quality regime) the distance is not sensitive to gas fraction; and (iii) the higher injection rates (or pressures), the farther foams propagate (this effect is much more pronounced for dry foams).

The Evaluation of Foam Performance and Flooding Efficiency

NASA Astrophysics Data System (ADS)

Keliang, Wang; Yuhao, Chen; Gang, Wang; Gen, Li

2017-12-01

ROSS-Miles and spinning drop interfacial tensionmeter are used to select suitable foam system through foam composite index (FCI) and interfacial tension (IT). The selected foam system are taken to conduct further test. The further tests are evaluating the foam system resistance to adsorption with multi-round core flooding dynamic adsorption test and evaluating the performance of foam system with four kinds of different transport distance, quantitatively analyzing the foam system effective distance after dynamic adsorption. The result shows that the foaming ability and the mobilizing ability of the foam system decrease with the increase of the round of dynamic adsorption. As the transport distance increases, the foaming ability and the mobilizing ability of the foam system decrease. This result further reveals the flooding characteristics of nitrogen foam flooding, which provides a reference for the implementation of nitrogen foam flooding technology.

[Volatile organic compounds concentrations and sources inside new air-conditioned bus].

PubMed

You, Ke-Wei; Ge, Yun-Shan; Qian, Yi-Xin; Liu, Wei; Feng, Bo; Zhang, Yan-Ni; Ning, Zhan-Wu; Hu, Bin; Zhao, Shou-Tang

2008-05-01

The distributing profile and concentration level inside new air-conditioned buses with 53 seats have been determined using the method of thermal desorption-capillary GC/MS under vehicle static conditions. Compounds were identified from their mass spectral data by using US National Institute of Standards and Technology (NIST02). The total numbers of identified components were 33 inside buses, including alkenes (15,45.4%), aromatic compounds (9,27.3%), alcohols (4,12.1%), ketones (3,9.1%) and esters (2,6.1%), especially in the range of C6-C10. The top 5 compounds measured inside buses were decane (8.01 mg/m3), 3-methylhexane (7.10 mg/m3), heptane (5.10 mg/m3), isoheptane (4.20 mg/m3) and 1-Methyl-3-ethylbenzene (3.56 mg/m3), and total volatile organic compounds (TVOC) > 52.5 mg/m3. The main sources of in-vehicle hydrocarbons and aromatic compounds comes from cabin components and interior trim materials (e.g., sealants, carpets, adhesives, paints, leather, plastics, PU foam and PE foam) that may retain certain VOCs during manufacturing, and/or emit these compounds over an extended period of time from off-gassing, aging-related breakdown products, heating/cooling and so on.

Polyurethane foam-covered breast implants: a justified choice?

PubMed

Scarpa, C; Borso, G F; Vindigni, V; Bassetto, F

2015-01-01

Even if the safety of the polyurethane prosthesis has been the subject of many studies and professional and public controversies. Nowadays, polyurethane covered implants are very popular in plastic surgery for the treatment of capsular contracture. We have identified 41 papers (1 is a communication of the FDA) by using search browsers such as Pubmed, Medline, and eMedicine. Eleven manuscripts have been used for an introduction, and the remaining thirty have been subdivided into three tables whose results have been summarized in three main chapters: (1) capsular formation and contracture, (2) complications, (3) biodegradation and cancer risk. (1) The polyurethanic capsule is a well defined foreign body reaction characterized by synovial metaplasia, a thin layer of disarranged collagen fibers and a high vascularization. These features make possible a "young" capsule and a low occurrence of capsular contracture even over a long period (10 years); (2) the polyurethane implants may be difficult to remove but there is no evidence that they cause an increase in the other complications; (3) there is no evidence of polyurethane related cancer in long-term studies (after 5 years). Polyurethane foam covered breast implants remain a valid choice for the treatment of capsular contracture even if it would be very useful to verify the ease of removal of the prosthesis and to continue investigations on biodegradation products.

Organic pollutant loading and biodegradability of firefighting foam

NASA Astrophysics Data System (ADS)

Zhang, Xian-Zhong; Bao, Zhi-ming; Hu, Cheng; Li-Shuai, Jing; Chen, Yang

2017-11-01

Firefighting foam has been widely used as the high-performance extinguishing agent in extinguishing the liquid poor fire. It was concerned for its environmental impacts due to its massive usage. In this study, the organic loading level and the biodegradability of 18 firefighting foams commonly used in China were evaluated and compared. The COD and TOC of firefighting foam concentrates are extremely high. Furthermore, those of foam solutions are also much higher than regular wastewater. The COD/TOC ratio of synthetic foams are higher than protein foams. The 28-day biodegradation rates of 18 firefighting foams are all over 60%, indicating that they are all ready biodegradable. Protein foams (P, FP and FFFP) have the higher organic loading and lower 28-day biodegradation rates compared to the synthetic foams (Class A foam, AFFF and S). The short and long-term impact of protein foams on the environment are larger than synthetic foams.

A review of aqueous foam in microscale.

PubMed

Anazadehsayed, Abdolhamid; Rezaee, Nastaran; Naser, Jamal; Nguyen, Anh V

2018-06-01

In recent years, significant progress has been achieved in the study of aqueous foams. Having said this, a better understanding of foam physics requires a deeper and profound study of foam elements. This paper reviews the studies in the microscale of aqueous foams. The elements of aqueous foams are interior Plateau borders, exterior Plateau borders, nodes, and films. Furthermore, these elements' contribution to the drainage of foam and hydraulic resistance are studied. The Marangoni phenomena that can happen in aqueous foams are listed as Marangoni recirculation in the transition region, Marangoni-driven flow from Plateau border towards the film in the foam fractionation process, and Marangoni flow caused by exposure of foam containing photosurfactants under UV. Then, the flow analysis of combined elements of foam such as PB-film along with Marangoni flow and PB-node are studied. Next, we contrast the behavior of foams in different conditions. These various conditions can be perturbation in the foam structure caused by injected water droplets or waves or using a non-Newtonian fluid to make the foam. Further review is about the effect of oil droplets and particles on the characteristics of foam such as drainage, stability and interfacial mobility. Copyright © 2018 Elsevier B.V. All rights reserved.

Innovative test method for the estimation of the foaming tendency of substrates for biogas plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moeller, Lucie, E-mail: lucie.moeller@ufz.de; Eismann, Frank, E-mail: info@antoc.de; Wißmann, Daniel, E-mail: d.s.wissmann@gmx.de

2015-07-15

Graphical abstract: Display Omitted - Highlights: • Foaming in biogas plants depends on the interactions between substrate and digestate. • Foaming tests enable the evaluation of substrate foaming tendency in biogas plants. • Leipzig foam tester enables foaming tests of substrates prior to use. - Abstract: Excessive foaming in anaerobic digestion occurs at many biogas plants and can cause problems including plugged gas pipes. Unfortunately, the majority of biogas plant operators are unable to identify the causes of foaming in their biogas reactor. The occurrence of foaming is often related to the chemical composition of substrates fed to the reactor.more » The consistency of the digestate itself is also a crucial part of the foam formation process. Thus, no specific recommendations concerning substrates can be given in order to prevent foam formation in biogas plants. The safest way to avoid foaming is to test the foaming tendency of substrates on-site. A possible solution is offered by an innovative foaming test. With the help of this tool, biogas plant operators can evaluate the foaming disposition of new substrates prior to use in order to adjust the composition of substrate mixes.« less

Development of Defoamers for Confinenment Foam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, D M; Mitchell, A R

Aqueous foam concentrate (AFC) 380 foam was developed by Sandia National Laboratory as a blast mitigation foam for unexploded ordnance (UXO) and its ''engineered foam structure'' is reported to be able to ''envelop chemical or biological aerosols'' [1]. It is similar to commercial fire-fighting foams, consisting mostly of water with small amounts of two alcohols, an ether and surfactant. It also contains xanthan gum, probably, to strengthen the foam film and delay drainage. The concentrate is normally diluted in a 6:94 ratio with water for foaming applications. The diluted solution is normally foamed with air to an expansion factor ofmore » about 100 (density 0.01 g/cc), which is called ''dry'' foam. Higher density foam (0.18 > {rho} > 0.03 g/cc) was discovered which had quite different characteristics from ''dry'' foam and was called ''wet'' foam. Some characterization of these foams has also been carried out, but the major effort described in this document is the evaluation, at the small and medium scale, of chemical, mechanical and thermal approaches to defoaming AFC 380 foam. Several chemical approaches to defoaming were evaluated including oxidation and precipitation of the xanthan, use of commercial oil-emulsion or suspension defoamers, pH modification, and cation exchange with the surfactant. Of these the commercial defoamers were most effective. Two mechanical approaches to defoaming were evaluated: pressure and foam rupture with very fine particles. Pressure and vacuum techniques were considered too difficult for field applications but high surface area silica particles worked very well on dry foam. Finally simple thermal techniques were evaluated. An order-disorder transition occurs in xanthan solutions at about 60 C, which may be responsible for the effectiveness of hot air as a defoamer. During defoaming of 55 gallons of foam with hot air, after about 70% of the AFC 380 foam had been defoamed, the effectiveness of hot air was dramatically reduced. Approximately 15 gal of residual foam containing mostly small bubbles was resistant to further defoaming by methods that had been effective on the original, dry foam. In this paper the residual foam is referred to as ''wet'' and the original foam is referred to as ''dry''. Methods for generating ''wet'' foam in small to moderate quantities for defoaming experiments have been developed. Methods for defoaming wet foam are currently under study.« less

40 CFR 63.8830 - What definitions apply to this subpart?

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication... chemical substance that is applied for the purpose of bonding foam to foam, foam to fabric, or foam to any... means the process of bonding flexible foam to one or more layers of material by heating the foam surface...

40 CFR 63.8830 - What definitions apply to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication... chemical substance that is applied for the purpose of bonding foam to foam, foam to fabric, or foam to any... means the process of bonding flexible foam to one or more layers of material by heating the foam surface...

40 CFR 63.8830 - What definitions apply to this subpart?

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication... chemical substance that is applied for the purpose of bonding foam to foam, foam to fabric, or foam to any... means the process of bonding flexible foam to one or more layers of material by heating the foam surface...

40 CFR 63.8830 - What definitions apply to this subpart?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication... chemical substance that is applied for the purpose of bonding foam to foam, foam to fabric, or foam to any... means the process of bonding flexible foam to one or more layers of material by heating the foam surface...

40 CFR 63.8830 - What definitions apply to this subpart?

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants: Flexible Polyurethane Foam Fabrication... chemical substance that is applied for the purpose of bonding foam to foam, foam to fabric, or foam to any... means the process of bonding flexible foam to one or more layers of material by heating the foam surface...

Fabrication of low-crystalline carbonate apatite foam bone replacement based on phase transformation of calcite foam.

PubMed

Maruta, Michito; Matsuya, Shigeki; Nakamura, Seiji; Ishikawa, Kunio

2011-01-01

Carbonate apatite (CO(3)Ap) foam may be an ideal bone substitute as it is sidelined to cancellous bone with respect to its chemical composition and structure. However, CO(3)Ap foam fabricated using α-tricalcium phosphate foam showed limited mechanical strength. In the present study, feasibility of the fabrication of calcite which could be a precursor of CO(3)Ap was studied. Calcite foam was successfully fabricated by the so-called "ceramic foam" method using calcium hydroxide coated polyurethane foam under CO(2)+O(2) atmosphere. Then the calcite foam was immersed in Na(2)HPO(4) aqueous solution for phase transformation based on dissolution-precipitation reaction. When CaO-free calcite foam was immersed in Na(2)HPO(4) solution, low-crystalline CO(3)Ap foam with 93-96% porosity and fully interconnected porous structure was fabricated. The compressive strength of the foam was 25.6 ± 6 kPa. In light of these results, we concluded that the properties of the precursor foam were key factors for the fabrication of CO(3)Ap foams.

Efficient continuous dryer for flexible polyurethane foam and cleaning apparatus

DOEpatents

Jody, Bassam; Daniels, Edward; Libera, Joseph A.

1999-01-01

A method of cleaning polyurethane foams where the material is transported through a wash station while alternately soaking the polyurethane foam in an organic solvent and squeezing solvent from the polyurethane foam a number of times. Then the polyurethane foam is sent through a rinse or solvent transfer station for reducing the concentration of solvent in the foam. The rinsed polyurethane foam is sent to a drying station wherein the foam is repeatedly squeezed while being exposed to hot air to remove wet air from the foam.

Efficient continuous dryer for flexible polyurethane foam and cleaning apparatus

DOEpatents

Jody, B.; Daniels, E.; Libera, J.A.

1999-03-16

A method of cleaning polyurethane foams where the material is transported through a wash station while alternately soaking the polyurethane foam in an organic solvent and squeezing solvent from the polyurethane foam a number of times. Then the polyurethane foam is sent through a rinse or solvent transfer station for reducing the concentration of solvent in the foam. The rinsed polyurethane foam is sent to a drying station wherein the foam is repeatedly squeezed while being exposed to hot air to remove wet air from the foam. 4 figs.

Handbook for using foams to control vapors from hazardous spills. Report for April 1984-September 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, M.L.; Carroll, H.A.

1986-07-01

The handbook describes basic types of foams that may be used to control vapor hazards from spilled volatile chemicals. It provides a table to be used by spill-response personnel to choose an appropriate foam based on the type of chemical spill. Six general types of foams, surfactant (syndet) foams, aqueous film forming foams (AFFF), alcohol type or polar solvent type foams (ATF), and special foams such as Hazmat NF no. 1 which was developed especially for alkaline spills. The handbook provides the basis for spill responders to evaluate and select a foam for vapor control by using the test methodsmore » presented or by considering manufacturers specifications for foam-expansion ratios and quarter drainage times. The responder is encouraged to maximize the effectiveness of a foam by trying different nozzles, distances of applications, and thicknesses of the foam layers.« less

Processing Characteristics and Properties of the Cellular Products Made by Using Special Foaming Agents

NASA Astrophysics Data System (ADS)

Garbacz, Tomasz; Dulebova, Ludmila

2012-12-01

The paper describes the manufacturing process of extruded products by the cellular extrusion method, and presents specifications of the blowing agents used in the extrusion process as well as process conditions. The process of cellular extrusion of thermoplastic materials is aimed at obtaining cellular shapes and coats with reduced density, presenting no hollows on the surface of extruder product and displaying minimal contraction under concurrent maintenance of properties similar to properties of products extruded by means of the conventional method. In order to obtain cellular structure, the properties of extruded product are modified by applying suitable plastic or inserting auxiliary agents.

Forming foam structures with carbon foam substrates

DOEpatents

Landingham, Richard L.; Satcher, Jr., Joe H.; Coronado, Paul R.; Baumann, Theodore F.

2012-11-06

The invention provides foams of desired cell sizes formed from metal or ceramic materials that coat the surfaces of carbon foams which are subsequently removed. For example, metal is located over a sol-gel foam monolith. The metal is melted to produce a metal/sol-gel composition. The sol-gel foam monolith is removed, leaving a metal foam.

Technological parameters influence on the non-autoclaved foam concrete characteristics

NASA Astrophysics Data System (ADS)

Bartenjeva, Ekaterina; Mashkin, Nikolay

2017-01-01

Foam concretes are used as effective heat-insulating materials. The porous structure of foam concrete provides good insulating and strength properties that make them possible to be used as heat-insulating structural materials. Optimal structure of non-autoclaved foam concrete depends on both technological factors and properties of technical foam. In this connection, the possibility to manufacture heat-insulation structural foam concrete on a high-speed cavity plant with the usage of protein and synthetic foamers was estimated. This experiment was carried out using mathematical planning method, and in this case mathematical models were developed that demonstrated the dependence of operating performance of foam concrete on foaming and rotation speed of laboratory plant. The following material properties were selected for the investigation: average density, compressive strength, bending strength and thermal conductivity. The influence of laboratory equipment technological parameters on technical foam strength and foam stability coefficient in the cement paste was investigated, physical and mechanical properties of non-autoclaved foam concrete were defined based on investigated foam. As a result of investigation, foam concrete samples were developed with performance parameters ensuring their use in production. The mathematical data gathered demonstrated the dependence of foam concrete performance on the technological regime.

Role of foam drainage in producing protein aggregates in foam fractionation.

PubMed

Li, Rui; Zhang, Yuran; Chang, Yunkang; Wu, Zhaoliang; Wang, Yanji; Chen, Xiang'e; Wang, Tao

2017-10-01

It is essential to obtain a clear understanding of the foam-induced protein aggregation to reduce the loss of protein functionality in foam fractionation. The major effort of this work is to explore the roles of foam drainage in protein aggregation in the entire process of foam fractionation with bovine serum albumin (BSA) as a model protein. The results show that enhancing foam drainage increased the desorption of BSA molecules from the gas-liquid interface and the local concentration of desorbed molecules in foam. Therefore, it intensified the aggregation of BSA in foam fractionation. Simultaneously, it also accelerated the flow of BSA aggregates from rising foam into the residual solution along with the drained liquid. Because enhancing foam drainage increased the relative content of BSA molecules adsorbed at the gas-liquid interface, it also intensified the aggregation of BSA during both the defoaming process and the storage of the foamate. Furthermore, enhancing foam drainage more readily resulted in the formation of insoluble BSA aggregates. The results are highly important for a better understanding of foam-induced protein aggregation in foam fractionation. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced rhamnolipids production via efficient foam-control using stop valve as a foam breaker.

PubMed

Long, Xuwei; Shen, Chong; He, Ni; Zhang, Guoliang; Meng, Qin

2017-01-01

In this study, a stop valve was used as a foam breaker for dealing with the massive overflowing foam in rhamnolipid fermentation. As found, a stop valve at its tiny opening could break over 90% of the extremely stable rhamnolipid foam into enriched liquid when foam flows through the sharp gap in valve. The efficient foam-control by the stop valve considerably improved the rhamnolipid fermentation and significantly enhanced the rhamnolipid productivity by 83% compared to the regular fermentation. This efficient foam breaking was mainly achieved by a high shear rate in combination with fast separation of air from the collapsed foam. Altogether, the stop valve possessed a great activity in breaking rhamnolipid foam, and the involving mechanism holds the potential for developing efficient foam breakers for industrial rhamnolipid fermentation. Copyright © 2016. Published by Elsevier Ltd.

ZrP nanoplates based fire-fighting foams stabilizer

NASA Astrophysics Data System (ADS)

Zhang, Lecheng; Cheng, Zhengdong; Li, Hai

2015-03-01

Firefighting foam, as a significant innovation in fire protection, greatly facilitates extinguishments for liquid pool fire. Recently, with developments in LNG industry, high-expansion firefighting foams are also used for extinguishing LNG fire or mitigating LNG leakage. Foam stabilizer, an ingredient in fire-fighting foam, stabilizes foam bubbles and maintains desired foam volume. Conventional foam stabilizers are organic molecules. In this work, we developed a inorganic based ZrP (Zr(HPO4)2 .H2O, Zirconium phosphate) plates functionalized as firefighting foam stabilizer, improving firefighting foam performance under harsh conditions. Several tests were conducted to illustrate performance. The mechanism for the foam stabilization is also proposed. Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX 77843, USA. Mary Kay O'Connor Process Safety Center, Texas A&M University, College Station, TX, 77843-3122

Foam, Foam-resin composite and method of making a foam-resin composite

NASA Technical Reports Server (NTRS)

MacArthur, Doug E. (Inventor); Cranston, John A. (Inventor)

1995-01-01

This invention relates to a foam, a foam-resin composite and a method of making foam-resin composites. The foam set forth in this invention comprises a urethane modified polyisocyanurate derived from an aromatic amino polyol and a polyether polyol. In addition to the polyisocyanurate foam, the composite of this invention further contains a resin layer, wherein the resin may be epoxy, bismaleimide, or phenolic resin. Such resins generally require cure or post-cure temperatures of at least 350.degree. F.

Survey of bottled drinking water sold in Canada. Part 2. Selected volatile organic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Page, B.D.; Conacher, H.B.S.; Salminen, J.

Selected volatile organic compound (VOC) contaminants were determined in 182 samples of retail bottled waters purchased in Canada. Samples included spring water (86) packaged in containers of polyethylene or in smaller containers of transparent plastic or glass, mineral water (61) packaged only in transparent plastic or glass, and miscellaneous bottled waters (35). Analyses were performed by 3 laboratories, each using headspace sampling and capillary gas chromatography with either mass spectrometric (1 laboratory) or flame ionization detection with mass spectrometric confirmation, if required (2 laboratories). Benzene, the contaminant of primary interest, was detected in only 1 of the 182 samples atmore » 2 {mu}g/kg. Other VOC contaminants detected (number of positive samples, average, and range of positives in {mu}g/kg) included toluene (20, 6.92, 0.5-63), cyclohexane (23, 39.2, 3-108), chloroform (12, 25.8, 3.7-70), and dichloromethane (4, 59, 22-97). Cyclohexane was found in the plastic and as a migrant from the plastic in 20 samples of spring water, but it was found in only 1 of 61 mineral water samples analyzed at only 3 {mu}g/kg/. Chloroform was found almost exclusively in samples that could have been obtained from public water supplies. It was not found in mineral water samples, but it was found in 1 spring water sample at 3.7 {mu}g/kg. The source of the toluene contamination was not known. Other VOCs detected include ethanol and limonene, associated with added flavoring; pentane, as a migrant from a foamed polystyrene cap liner; and 1,1,2,2-tetra-chloroethylene in a sample of demineralized water. 10 refs., 6 tabs.« less

Espresso coffee foam delays cooling of the liquid phase.

PubMed

Arii, Yasuhiro; Nishizawa, Kaho

2017-04-01

Espresso coffee foam, called crema, is known to be a marker of the quality of espresso coffee extraction. However, the role of foam in coffee temperature has not been quantitatively clarified. In this study, we used an automatic machine for espresso coffee extraction. We evaluated whether the foam prepared using the machine was suitable for foam analysis. After extraction, the percentage and consistency of the foam were measured using various techniques, and changes in the foam volume were tracked over time. Our extraction method, therefore, allowed consistent preparation of high-quality foam. We also quantitatively determined that the foam phase slowed cooling of the liquid phase after extraction. High-quality foam plays an important role in delaying the cooling of espresso coffee.

Generation of sclerosant foams by mechanical methods increases the foam temperature.

PubMed

Tan, Lulu; Wong, Kaichung; Connor, David; Fakhim, Babak; Behnia, Masud; Parsi, Kurosh

2017-08-01

Objective To investigate the effect of agitation on foam temperature. Methods Sodium tetradecyl sulphate and polidocanol were used. Prior to foam generation, the sclerosant and all constituent equipment were cooled to 4-25℃ and compared with cooling the sclerosant only. Foam was generated using a modified Tessari method. During foam agitation, the temperature change was measured using a thermocouple for 120 s. Results Pre-cooling all the constituent equipment resulted in a cooler foam in comparison with only cooling the sclerosant. A starting temperature of 4℃ produced average foam temperatures of 12.5 and 13.2℃ for sodium tetradecyl sulphate and polidocanol, respectively. It was also found that only cooling the liquid sclerosant provided minimal cooling to the final foam temperature, with the temperature 20 and 20.5℃ for sodium tetradecyl sulphate and polidocanol, respectively. Conclusion The foam generation process has a noticeable impact on final foam temperature and needs to be taken into consideration when creating foam.

Infiltrated carbon foam composites

NASA Technical Reports Server (NTRS)

Lucas, Rick D. (Inventor); Danford, Harry E. (Inventor); Plucinski, Janusz W. (Inventor); Merriman, Douglas J. (Inventor); Blacker, Jesse M. (Inventor)

2012-01-01

An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems.

Foam property tests to evaluate the potential for longwall shield dust control.

PubMed

Reed, W R; Beck, T W; Zheng, Y; Klima, S; Driscoll, J

2018-01-01

Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration's lower coal mine respirable dust standard of 1.5 mg/m 3 . Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control.

Foam property tests to evaluate the potential for longwall shield dust control

PubMed Central

Reed, W.R.; Beck, T.W.; Zheng, Y.; Klima, S.; Driscoll, J.

2018-01-01

Tests were conducted to determine properties of four foam agents for their potential use in longwall mining dust control. Foam has been tried in underground mining in the past for dust control and is currently being reconsidered for use in underground coal longwall operations in order to help those operations comply with the Mine Safety and Health Administration’s lower coal mine respirable dust standard of 1.5 mg/m3. Foams were generated using two different methods. One method used compressed air and water pressure to generate foam, while the other method used low-pressure air generated by a blower and water pressure using a foam generator developed by the U.S. National Institute for Occupational Safety and Health. Foam property tests, consisting of a foam expansion ratio test and a water drainage test, were conducted to classify foams. Compressed-air-generated foams tended to have low expansion ratios, from 10 to 19, with high water drainage. Blower-air-generated foams had higher foam expansion ratios, from 30 to 60, with lower water drainage. Foams produced within these ranges of expansion ratios are stable and potentially suitable for dust control. The test results eliminated two foam agents for future testing because they had poor expansion ratios. The remaining two foam agents seem to have properties adequate for dust control. These material property tests can be used to classify foams for their potential use in longwall mining dust control. PMID:29416179

Multiscale Analysis of Open-Cell Aluminum Foam for Impact Energy Absorption

NASA Astrophysics Data System (ADS)

Kim, Ji Hoon; Kim, Daeyong; Lee, Myoung-Gyu; Lee, Jong Kook

2016-09-01

The energy-absorbing characteristics of crash members in automotive collision play an important role in controlling the amount of damage to the passenger compartment. Aluminum foams have high strength-to-weight ratio and high deformability, thus good crashworthiness is expected while maintaining or even saving weights when foams are implemented in crash members. In order to investigate the effect of the open-cell aluminum foam fillers on impact performance and weight saving, a multiscale framework for evaluating the crashworthiness of aluminum foam-filled members is used. To circumvent the difficulties of mechanical tests on foams, a micromechanical model of the aluminum foam is constructed using the x-ray micro tomography and virtual tests are conducted for the micromechanical model to characterize the behavior of the foam. In the macroscale, the aluminum foam is represented by the crushable foam constitutive model, which is then incorporated into the impact test simulation of the foam-filled crash member. The multiscale foam-filled crash member model was validated for the high-speed impact test, which confirms that the material model characterized by the micromechanical approach represents the behavior of the open-cell foam under impact loading well. Finally, the crash member design for maximizing the energy absorption is discussed by investigating various designs from the foam-only structure to the hollow tube structure. It was found that the foam structure absorbs more energy than the hollow tube or foam-filled structure with the same weight.

In vivo performance of novel soybean/gelatin-based bioactive and injectable hydroxyapatite foams

PubMed Central

Kovtun, Anna; Goeckelmann, Melanie J.; Niclas, Antje A.; Montufar, Edgar B.; Ginebra, Maria-Pau; Planell, Josep A.; Santin, Matteo; Ignatius, Anita

2015-01-01

Major limitations of calcium phosphate cements (CPCs) are their relatively slow degradation rate and the lack of macropores allowing the ingrowth of bone tissue. The development of self-setting cement foams has been proposed as a suitable strategy to overcome these limitations. In previous work we developed a gelatine-based hydroxyapatite foam (G-foam), which exhibited good injectability and cohesion, interconnected porosity and good biocompatibility in vitro. In the present study we evaluated the in vivo performance of the G-foam. Furthermore, we investigated whether enrichment of the foam with soybean extract (SG-foam) increased its bioactivity. G-foam, SG-foam and non-foamed CPC were implanted in a critical-size bone defect in the distal femoral condyle of New Zealand white rabbits. Bone formation and degradation of the materials were investigated after 4, 12 and 20 weeks using histological and biomechanical methods. The foams maintained their macroporosity after injection and setting in vivo. Compared to non-foamed CPC, cellular degradation of the foams was considerably increased and accompanied by new bone formation. The additional functionalization with soybean extract in the SG-foam slightly reduced the degradation rate and positively influenced bone formation in the defect. Furthermore, both foams exhibited excellent biocompatibility, implying that these novel materials may be promising for clinical application in non-loaded bone defects. PMID:25448348

In vivo performance of novel soybean/gelatin-based bioactive and injectable hydroxyapatite foams.

PubMed

Kovtun, Anna; Goeckelmann, Melanie J; Niclas, Antje A; Montufar, Edgar B; Ginebra, Maria-Pau; Planell, Josep A; Santin, Matteo; Ignatius, Anita

2015-01-01

Major limitations of calcium phosphate cements (CPCs) are their relatively slow degradation rate and the lack of macropores allowing the ingrowth of bone tissue. The development of self-setting cement foams has been proposed as a suitable strategy to overcome these limitations. In previous work we developed a gelatine-based hydroxyapatite foam (G-foam), which exhibited good injectability and cohesion, interconnected porosity and good biocompatibility in vitro. In the present study we evaluated the in vivo performance of the G-foam. Furthermore, we investigated whether enrichment of the foam with soybean extract (SG-foam) increased its bioactivity. G-foam, SG-foam and non-foamed CPC were implanted in a critical-size bone defect in the distal femoral condyle of New Zealand white rabbits. Bone formation and degradation of the materials were investigated after 4, 12 and 20weeks using histological and biomechanical methods. The foams maintained their macroporosity after injection and setting in vivo. Compared to non-foamed CPC, cellular degradation of the foams was considerably increased and accompanied by new bone formation. The additional functionalization with soybean extract in the SG-foam slightly reduced the degradation rate and positively influenced bone formation in the defect. Furthermore, both foams exhibited excellent biocompatibility, implying that these novel materials may be promising for clinical application in non-loaded bone defects. Copyright © 2014 Acta Materialia Inc. All rights reserved.

Polymer-Reinforced, Non-Brittle, Lightweight Cryogenic Insulation

NASA Technical Reports Server (NTRS)

Hess, David M.

2013-01-01

The primary application for cryogenic insulating foams will be fuel tank applications for fueling systems. It is crucial for this insulation to be incorporated into systems that survive vacuum and terrestrial environments. It is hypothesized that by forming an open-cell silica-reinforced polymer structure, the foam structures will exhibit the necessary strength to maintain shape. This will, in turn, maintain the insulating capabilities of the foam insulation. Besides mechanical stability in the form of crush resistance, it is important for these insulating materials to exhibit water penetration resistance. Hydrocarbon-terminated foam surfaces were implemented to impart hydrophobic functionality that apparently limits moisture penetration through the foam. During the freezing process, water accumulates on the surfaces of the foams. However, when hydrocarbon-terminated surfaces are present, water apparently beads and forms crystals, leading to less apparent accumulation. The object of this work is to develop inexpensive structural cryogenic insulation foam that has increased impact resistance for launch and ground-based cryogenic systems. Two parallel approaches will be pursued: a silica-polymer co-foaming technique and a post foam coating technique. Insulation characteristics, flexibility, and water uptake can be fine-tuned through the manipulation of the polyurethane foam scaffold. Silicate coatings for polyurethane foams and aerogel-impregnated polyurethane foams have been developed and tested. A highly porous aerogel-like material may be fabricated using a co-foam and coated foam techniques, and can insulate at liquid temperatures using the composite foam

A Novel Method for Preparing Auxetic Foam from Closed-cell Polymer Foam Based on Steam Penetration and Condensation (SPC) Process.

PubMed

Fan, Donglei; Li, Minggang; Qiu, Jian; Xing, Haiping; Jiang, Zhiwei; Tang, Tao

2018-05-31

Auxetic materials are a class of materials possessing negative Poisson's ratio. Here we establish a novel method for preparing auxetic foam from closed-cell polymer foam based on steam penetration and condensation (SPC) process. Using polyethylene (PE) closed-cell foam as an example, the resultant foams treated by SPC process present negative Poisson's ratio during stretching and compression testing. The effect of steam-treated temperature and time on the conversion efficiency of negative Poisson's ratio foam is investigated, and the mechanism of SPC method for forming re-entrant structure is discussed. The results indicate that the presence of enough steam within the cells is a critical factor for the negative Poisson's ratio conversion in the SPC process. The pressure difference caused by steam condensation is the driving force for the conversion from conventional closed-cell foam to the negative Poisson's ratio foam. Furthermore, the applicability of SPC process for fabricating auxetic foam is studied by replacing PE foam by polyvinyl chloride (PVC) foam with closed-cell structure or replacing water steam by ethanol steam. The results verify the universality of SPC process for fabricating auxetic foams from conventional foams with closed-cell structure. In addition, we explored potential application of the obtained auxetic foams by SPC process in the fabrication of shape memory polymer materials.

mdFoam+: Advanced molecular dynamics in OpenFOAM

NASA Astrophysics Data System (ADS)

Longshaw, S. M.; Borg, M. K.; Ramisetti, S. B.; Zhang, J.; Lockerby, D. A.; Emerson, D. R.; Reese, J. M.

2018-03-01

This paper introduces mdFoam+, which is an MPI parallelised molecular dynamics (MD) solver implemented entirely within the OpenFOAM software framework. It is open-source and released under the same GNU General Public License (GPL) as OpenFOAM. The source code is released as a publicly open software repository that includes detailed documentation and tutorial cases. Since mdFoam+ is designed entirely within the OpenFOAM C++ object-oriented framework, it inherits a number of key features. The code is designed for extensibility and flexibility, so it is aimed first and foremost as an MD research tool, in which new models and test cases can be developed and tested rapidly. Implementing mdFoam+ in OpenFOAM also enables easier development of hybrid methods that couple MD with continuum-based solvers. Setting up MD cases follows the standard OpenFOAM format, as mdFoam+ also relies upon the OpenFOAM dictionary-based directory structure. This ensures that useful pre- and post-processing capabilities provided by OpenFOAM remain available even though the fully Lagrangian nature of an MD simulation is not typical of most OpenFOAM applications. Results show that mdFoam+ compares well to another well-known MD code (e.g. LAMMPS) in terms of benchmark problems, although it also has additional functionality that does not exist in other open-source MD codes.

46 CFR 108.473 - Foam system components.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Foam system components. 108.473 Section 108.473 Shipping... EQUIPMENT Fire Extinguishing Systems Foam Extinguishing Systems § 108.473 Foam system components. (a) Each foam agent, each tank for a foam agent, each discharge outlet, each control, and each valve for the...

46 CFR 108.473 - Foam system components.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Foam system components. 108.473 Section 108.473 Shipping... EQUIPMENT Fire Extinguishing Systems Foam Extinguishing Systems § 108.473 Foam system components. (a) Each foam agent, each tank for a foam agent, each discharge outlet, each control, and each valve for the...

Initial Evaluation of Burn Characteristics of Phenolic Foam Runway Brake Arrestor Material

DTIC Science & Technology

1993-12-01

foam immersed in a jet fuel fire when extinguished using 3-percent Aqueous Film Forming Foam ( AFFF ). Three pool...extinguishment time of phenolic foam immersed in a jet fuel fire, using 3-percent Aqueous Film Forming Foam ( AFFF ) extinguishing agent. The wind was negligible...percent Aqueous Film Forming Foam ( AFFF ) agent. This project is an initial assessment of the fire safety of phenolic foam

Electrostatic Safety with Explosion Suppressant Foams.

DTIC Science & Technology

1983-03-01

the foam, and (2) sorption of alkylphenol type substances, present as oxidation inhibitors in the fuel, by the foam. It had been previously reported... alkylphenol type substances. The use of antistatic ingredients in the reticulated polyurethane foam was suggested as a means of minimizing static...foam with JP-4 are: o Removal of diethylhexyl phthalate from the foam. o Sorption of alkylphenol type compounds by the foam. Tne latter of these two

Impact of foamed matrix components on foamed concrete properties

NASA Astrophysics Data System (ADS)

Tarasenko, V. N.

2018-03-01

The improvement of the matrix foam structure by means of foam stabilizing additives is aimed at solving the technology-oriented problems as well as at the further improvement of physical and mechanical properties of cellular-concrete composites. The dry foam mineralization is the mainstream of this research. Adding the concrete densifiers, foam stabilizers and mineral powders reduces the drying shrinkage, which makes the foam concrete products technologically effective.

Foam-mat drying technology: A review.

PubMed

Hardy, Z; Jideani, V A

2017-08-13

This article reviews various aspects of foam-mat drying such as foam-mat drying processing technique, main additives used for foam-mat drying, foam-mat drying of liquid and solid foods, quality characteristics of foam-mat dried foods, and economic and technical benefits for employing foam-mat drying. Foam-mat drying process is an alternative method that allows the removal of water from liquid materials and pureed materials. In this drying process, a liquid material is converted into foam that is stable by being whipped after adding an edible foaming agent. The stable foam is then spread out in sheet or mat and dried by using hot air (40-90°C) at atmospheric pressure. Methyl cellulose (0.25-2%), egg white (3-20%), maltodextrin (0.5-05%), and gum Arabic (2-9%) are the commonly utilized additives for the foam-mat drying process at the given range, either combined together for their effectiveness or individual effect. The foam-mat drying process is suitable for heat sensitive, viscous, and sticky products that cannot be dried using other forms of drying methods such as spray drying because of the state of product. More interest has developed for foam-mat drying because of the simplicity, cost effectiveness, high speed drying, and improved product quality it provides.

Application of an Elongated Kelvin Model to Space Shuttle Foams

NASA Technical Reports Server (NTRS)

Sullivan, Roy M.; Ghosn, Louis J.; Lerch, Bradley A.

2009-01-01

The space shuttle foams are rigid closed-cell polyurethane foams. The two foams used most-extensively oil space shuttle external tank are BX-265 and NCFL4-124. Because of the foaming and rising process, the foam microstructures are elongated in the rise direction. As a result, these two foams exhibit a nonisotropic mechanical behavior. A detailed microstructural characterization of the two foams is presented. Key features of the foam cells are described and the average cell dimensions in the two foams are summarized. Experimental studies are also conducted to measure the room temperature mechanical response of the two foams in the two principal material directions (parallel to the rise and perpendicular to the rise). The measured elastic modulus, proportional limit stress, ultimate tensile strength, and Poisson's ratios are reported. The generalized elongated Kelvin foam model previously developed by the authors is reviewed and the equations which result from this model are summarized. Using the measured microstructural dimensions and the measured stiffness ratio, the foam tensile strength ratio and Poisson's ratios are predicted for both foams and are compared with the experimental data. The predicted tensile strength ratio is in close agreement with the measured strength ratio for both BX-265 and NCFI24-124. The comparison between the predicted Poisson's ratios and the measured values is not as favorable.

Foam Transport in Porous Media - A Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Z. F.; Freedman, Vicky L.; Zhong, Lirong

2009-11-11

Amendment solutions with or without surfactants have been used to remove contaminants from soil. However, it has drawbacks such that the amendment solution often mobilizes the plume, and its movement is controlled by gravity and preferential flow paths. Foam is an emulsion-like, two-phase system in which gas cells are dispersed in a liquid and separated by thin liquid films called lamellae. Potential advantages of using foams in sub-surface remediation include providing better control on the volume of fluids injected, uniformity of contact, and the ability to contain the migration of contaminant laden liquids. It is expected that foam can servemore » as a carrier of amendments for vadose zone remediation, e.g., at the Hanford Site. As part of the U.S. Department of Energy’s EM-20 program, a numerical simulation capability will be added to the Subsurface Transport Over Multiple Phases (STOMP) flow simulator. The primary purpose of this document is to review the modeling approaches of foam transport in porous media. However, as an aid to understanding the simulation approaches, some experiments under unsaturated conditions and the processes of foam transport are also reviewed. Foam may be formed when the surfactant concentration is above the critical micelle concentration. There are two main types of foams – the ball foam (microfoam) and the polyhedral foam. The characteristics of bulk foam are described by the properties such as foam quality, texture, stability, density, surface tension, disjoining pressure, etc. Foam has been used to flush contaminants such as metals, organics, and nonaqueous phase liquids from unsaturated soil. Ball foam, or colloidal gas aphrons, reportedly have been used for soil flushing in contaminated site remediation and was found to be more efficient than surfactant solutions on the basis of weight of contaminant removed per gram of surfactant. Experiments also indicate that the polyhedral foam can be used to enhance soil remediation. The transport of foam in porous media is complicated in that the number of lamellae present governs flow characteristics such as viscosity, relative permeability, fluid distribution, and interactions between fluids. Hence, foam is a non-Newtonian fluid. During transport, foam destruction and formation occur. The net result of the two processes determines the foam texture (i.e., bubble density). Some of the foam may be trapped during transport. According to the impacts of the aqueous and gas flow rates, foam flow generally has two regimes – weak and strong foam. There is also a minimum pressure gradient to initiate foam flow and a critical capillary for foam to be sustained. Similar to other fluids, the transport of foam is described by Darcy’s law with the exception that the foam viscosity is variable. Three major approaches to modeling foam transport in porous media are the empirical, semi-empirical, and mechanistic methods. Mechanistic approaches can be complete in principal but may be difficult to obtain reliable parameters, whereas empirical and semi-empirical approaches can be limited by the detail used to describe foam rheology and mobility. Mechanistic approaches include the bubble population-balance model, the network/percolation theory, the catastrophe theory, and the filtration theory. Among these methods, all were developed for modeling polyhedral foam with the exception that the method based on the filtration theory was for the ball foam (microfoam).« less

Advanced nondestructive techniques applied for the detection of discontinuities in aluminum foams

NASA Astrophysics Data System (ADS)

Katchadjian, Pablo; García, Alejandro; Brizuela, Jose; Camacho, Jorge; Chiné, Bruno; Mussi, Valerio; Britto, Ivan

2018-04-01

Metal foams are finding an increasing range of applications by their lightweight structure and physical, chemical and mechanical properties. Foams can be used to fill closed moulds for manufacturing structural foam parts of complex shape [1]; foam filled structures are expected to provide good mechanical properties and energy absorption capabilities. The complexity of the foaming process and the number of parameters to simultaneously control, demand a preliminary and hugely wide experimental activity to manufacture foamed components with a good quality. That is why there are many efforts to improve the structure of foams, in order to obtain a product with good properties. The problem is that even for seemingly identical foaming conditions, the effective foaming can vary significantly from one foaming trial to another. The variation of the foams often is related by structural imperfections, joining region (foam-foam or foam-wall mold) or difficulties in achieving a complete filling of the mould. That is, in a closed mold, the result of the mold filling and its structure or defects are not known a priori and can eventually vary significantly. These defects can cause a drastic deterioration of the mechanical properties [2] and lead to a low performance in its application. This work proposes the use of advanced nondestructive techniques for evaluating the foam distribution after filling the mold to improve the manufacturing process. To achieved this purpose ultrasonic technique (UT) and cone beam computed tomography (CT) were applied on plate and structures of different thicknesses filled with foam of different porosity. UT was carried out on transmission mode with low frequency air-coupled transducers [3], in focused and unfocused configurations.

Analysis of Influence of Foaming Mixture Components on Structure and Properties of Foam Glass

NASA Astrophysics Data System (ADS)

Karandashova, N. S.; Goltsman, B. M.; Yatsenko, E. A.

2017-11-01

It is recommended to use high-quality thermal insulation materials to increase the energy efficiency of buildings. One of the best thermal insulation materials is foam glass - durable, porous material that is resistant to almost any effect of substance. Glass foaming is a complex process depending on the foaming mode and the initial mixture composition. This paper discusses the influence of all components of the mixture - glass powder, foaming agent, enveloping material and water - on the foam glass structure. It was determined that glass powder is the basis of the future material. A foaming agent forms a gas phase in the process of thermal decomposition. This aforementioned gas foams the viscous glass mass. The unreacted residue thus changes a colour of the material. The enveloping agent slows the foaming agent decomposition preventing its premature burning out and, in addition, helps to accelerate the sintering of glass particles. The introduction of water reduces the viscosity of the foaming mixture making it evenly distributed and also promotes the formation of water gas that additionally foams the glass mass. The optimal composition for producing the foam glass with the density of 150 kg/m3 is defined according to the results of the research.

Foams for barriers and nonlethal weapons

NASA Astrophysics Data System (ADS)

Rand, Peter B.

1997-01-01

Our times demand better solutions to conflict resolution than simply shooting someone. Because of this, police and military interest in non-lethal concepts is high. Already in use are pepper sprays, bean-bag guns, flash-bang grenades, and rubber bullets. At Sandia we got a head start on non- lethal weapon concepts. Protection of nuclear materials required systems that went way beyond the traditional back vault. Dispensable deterrents were used to allow a graduated response to a threat. Sticky foams and stabilized aqueous foams were developed to provide access delay. Foams won out for security systems simply because you could get a large volume from a small container. For polymeric foams the expansion ratio is thirty to fifty to one. In aqueous foams expansion ratios of one thousand to ne are easily obtained. Recent development work on sticky foams has included a changeover to environmentally friendly solvents, foams with very low toxicity, and the development of non-flammable silicone resin based foams. High expansion aqueous foams are useful visual and aural obscurants. Our recent aqueous foam development has concentrated on using very low toxicity foaming agents combined with oleoresin capsicum irritant to provide a safe but highly irritating foam.

Benefits of polidocanol endovenous microfoam (Varithena®) compared with physician-compounded foams

PubMed Central

Carugo, Dario; Ankrett, Dyan N; Zhao, Xuefeng; Zhang, Xunli; Hill, Martyn; O’Byrne, Vincent; Hoad, James; Arif, Mehreen; Wright, David DI

2015-01-01

Objective To compare foam bubble size and bubble size distribution, stability, and degradation rate of commercially available polidocanol endovenous microfoam (Varithena®) and physician-compounded foams using a number of laboratory tests. Methods Foam properties of polidocanol endovenous microfoam and physician-compounded foams were measured and compared using a glass-plate method and a Sympatec QICPIC image analysis method to measure bubble size and bubble size distribution, Turbiscan™ LAB for foam half time and drainage and a novel biomimetic vein model to measure foam stability. Physician-compounded foams composed of polidocanol and room air, CO2, or mixtures of oxygen and carbon dioxide (O2:CO2) were generated by different methods. Results Polidocanol endovenous microfoam was found to have a narrow bubble size distribution with no large (>500 µm) bubbles. Physician-compounded foams made with the Tessari method had broader bubble size distribution and large bubbles, which have an impact on foam stability. Polidocanol endovenous microfoam had a lower degradation rate than any physician-compounded foams, including foams made using room air (p < 0.035). The same result was obtained at different liquid to gas ratios (1:4 and 1:7) for physician-compounded foams. In all tests performed, CO2 foams were the least stable and different O2:CO2 mixtures had intermediate performance. In the biomimetic vein model, polidocanol endovenous microfoam had the slowest degradation rate and longest calculated dwell time, which represents the length of time the foam is in contact with the vein, almost twice that of physician-compounded foams using room air and eight times better than physician-compounded foams prepared using equivalent gas mixes. Conclusion Bubble size, bubble size distribution and stability of various sclerosing foam formulations show that polidocanol endovenous microfoam results in better overall performance compared with physician-compounded foams. Polidocanol endovenous microfoam offers better stability and cohesive properties in a biomimetic vein model compared to physician-compounded foams. Polidocanol endovenous microfoam, which is indicated in the United States for treatment of great saphenous vein system incompetence, provides clinicians with a consistent product with enhanced handling properties. PMID:26036246

Benefits of polidocanol endovenous microfoam (Varithena®) compared with physician-compounded foams.

PubMed

Carugo, Dario; Ankrett, Dyan N; Zhao, Xuefeng; Zhang, Xunli; Hill, Martyn; O'Byrne, Vincent; Hoad, James; Arif, Mehreen; Wright, David D I; Lewis, Andrew L

2016-05-01

To compare foam bubble size and bubble size distribution, stability, and degradation rate of commercially available polidocanol endovenous microfoam (Varithena®) and physician-compounded foams using a number of laboratory tests. Foam properties of polidocanol endovenous microfoam and physician-compounded foams were measured and compared using a glass-plate method and a Sympatec QICPIC image analysis method to measure bubble size and bubble size distribution, Turbiscan™ LAB for foam half time and drainage and a novel biomimetic vein model to measure foam stability. Physician-compounded foams composed of polidocanol and room air, CO2, or mixtures of oxygen and carbon dioxide (O2:CO2) were generated by different methods. Polidocanol endovenous microfoam was found to have a narrow bubble size distribution with no large (>500 µm) bubbles. Physician-compounded foams made with the Tessari method had broader bubble size distribution and large bubbles, which have an impact on foam stability. Polidocanol endovenous microfoam had a lower degradation rate than any physician-compounded foams, including foams made using room air (p < 0.035). The same result was obtained at different liquid to gas ratios (1:4 and 1:7) for physician-compounded foams. In all tests performed, CO2 foams were the least stable and different O2:CO2 mixtures had intermediate performance. In the biomimetic vein model, polidocanol endovenous microfoam had the slowest degradation rate and longest calculated dwell time, which represents the length of time the foam is in contact with the vein, almost twice that of physician-compounded foams using room air and eight times better than physician-compounded foams prepared using equivalent gas mixes. Bubble size, bubble size distribution and stability of various sclerosing foam formulations show that polidocanol endovenous microfoam results in better overall performance compared with physician-compounded foams. Polidocanol endovenous microfoam offers better stability and cohesive properties in a biomimetic vein model compared to physician-compounded foams. Polidocanol endovenous microfoam, which is indicated in the United States for treatment of great saphenous vein system incompetence, provides clinicians with a consistent product with enhanced handling properties. © The Author(s) 2015.

Research on air sprays and unique foam application methods. Phase II report. Laboratory investigation of foam systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1982-06-01

The objective of this study is to assess the effectiveness of air sprays and foam systems for dust control on longwall double-drum shearer faces. Laboratory testing has been conducted using foam systems and promising results have been obtained. Upon Bureau approval, underground testing will be scheduled to assess the effectiveness of foam systems under actual operating conditions. Laboratory testing of air sprays is being conducted at present. This report presents the results of the laboratory testing of foam systems. Specifically, the results obtained on the evaluation of selected foaming agents are presented, the feasibility investigation of flushing foam through themore » shearer-drum are demonstrated, and conceptual layout of the foam system on the shearer is discussed. The laboratory investigation of the selected foaming agents reveal that the Onyx Microfoam, Onyx Maprosyl and DeTer Microfoam foaming agents have higher expansion ratios compared to the others tested. Flushing foam through the shearer drum is entirely feasible and could be a viable technique for dust suppression on longwall faces.« less

Ocean foam generation and modeling

NASA Technical Reports Server (NTRS)

Porter, R. A.; Bechis, K. P.

1976-01-01

A laboratory investigation was conducted to determine the physical and microwave properties of ocean foam. Special foam generators were designed and fabricated, using porous glass sheets, known as glass frits, as the principal element. The glass frit was sealed into a water-tight vertical box, a few centimeters from the bottom. Compressed air, applied to the lower chamber, created ocean foam from sea water lying on the frit. Foam heights of 30 cm were readily achieved, with relatively low air pressures. Special photographic techniques and analytical procedures were employed to determine foam bubble size distributions. In addition, the percentage water content of ocean foam was determined with the aid of a particulate sampling procedure. A glass frit foam generator, with pore diameters in the range 70 - 100 micrometers, produced foam with bubble distributions very similar to those found on the surface of natural ocean foam patches.

Foam capacity and stability of Sodium Dodecyl Sulfate (SDS) on the presence of contaminant coffee and Cd ions in solution

NASA Astrophysics Data System (ADS)

Haryanto, B.; Chang, C. H.; Kuo, A. T.; Siswarni, M. Z.; Sinaga, T. M. A.

2018-02-01

In this study, the effect of the coffee colloidal particle and Cd ion contaminant on the foam capacity and stability of sodium dodecyl sulfate (SDS) solution was investigated. The foam was generated by using a foam generator. The foam capacity of SDS was first evaluated at different concentrations. After the foam capacity reaching a constant value, the foam stability was then measured by flowing to a column. The results showed that the presence the coffee colloidal particles or Cd ions in the solution would decrease the foam capacity and stability of SDS. In addition, the decreased foam capacity and stability was more pronounced in the presence of coffee colloidal particles than Cd ions. The colloidal particles may have stronger interaction with SDS and thus reduce the formation of the foam.

Fixed Combination Aerosol Foam Calcipotriene 0.005% (Cal) Plus Betamethasone Dipropionate 0.064% (BD) is More Efficacious than Cal or BD Aerosol Foam Alone for Psoriasis Vulgaris

PubMed Central

Tyring, Stephen; Bukhalo, Michael; Alonso-Llamazares, Javier; Olesen, Martin; Lowson, David; Yamauchi, Paul

2016-01-01

Objective: To evaluate the efficacy of fixed combination aerosol foam calcipotriene 0.005% (Cal) plus betamethasone dipropionate 0.064% (BD). Design: Patients were randomized (100:101:101) to receive Cal/BD foam, Cal foam, or BD foam once daily for four weeks. Setting: Twenty-eight United States centers. Participants: 302 patients (≥18 years) with Psoriasis vulgaris (plaque Psoriasis; ≥mild disease severity by physicians global assessment). Measurements: Treatment success of the body (“clear”/”almost clear” from baseline moderate/severe disease; “clear” from baseline mild disease). Involved scalp treatment success was an additional endpoint. Results: Most patients (76%) had moderate Psoriasis of the body (66% for scalp). At Week 4, 45 percent of Cal/BD foam patients achieved treatment success, significantly more than Cal foam (14.9%; OR 4.34 [95%CI 2.16,8.72] P<0.001) or BD foam (30.7%; 1.81 [1.00,3.26] P=0.047). Fifty-three percent of Cal/BD foam patients achieved treatment success of the scalp, significantly greater than Cal foam (35.6%; 1.91 [1.09,3.35] P=0.021), but not BD foam (47.5%; 1.24 [0.71,2.16] P=0.45). Mean modified Psoriasis area and severity index (population baseline 7.6) improved in all groups, with statistically significant differences in Week 4 Cal/BD foam score (2.37) versus Cal foam (4.39; mean difference -2.03 [-2.63][-1.43] P<0.001) and BD foam (3.37; -1.19 [-1.80][-0.59] P<0.001). Four (Cal/BD), 10 (Cal), and 8 (BD) adverse drug reactions were reported. Conclusion: Cal/BD foam was significantly more effective than Cal foam and BD foam in providing treatment success at Week 4 and effective on involved scalp. Trial registration: NCT01536938. PMID:27313822

Foam relaxation in fractures and narrow channels

NASA Astrophysics Data System (ADS)

Lai, Ching-Yao; Rallabandi, Bhargav; Perazzo, Antonio; Stone, Howard A.

2017-11-01

Various applications, from foam manufacturing to hydraulic fracturing with foams, involve pressure-driven flow of foams in narrow channels. We report a combined experimental and theoretical study of this problem accounting for the compressible nature of the foam. In particular, in our experiments the foam is initially compressed in one channel and then upon flow into a second channel the compressed foam relaxes as it moves. A plug flow is observed in the tube and the pressure at the entrance of the tube is higher than the exit. We measure the volume collected at the exit of the tube, V, as a function of injection flow rate, tube length and diameter. Two scaling behaviors for V as a function of time are observed depending on whether foam compression is important or not. Our work may relate to foam fracturing, which saves water usage in hydraulic fracturing, more efficient enhanced oil recovery via foam injection, and various materials manufacturing processes involving pressure-driven flow foams.

Role of Temperature and SiCP Parameters in Stability and Quality of Al-Si-Mg/SiC Foams

NASA Astrophysics Data System (ADS)

Ravi Kumar, N. V.; Gokhale, Amol A.

2018-06-01

Composites of Al-Si-Mg (A356) alloy with silicon carbide particles were synthesized in-house and foamed by melt processing using titanium hydride as foaming agent. The effects of the SiCP size and content, and foaming temperature on the stability and quality of the foam were explored. It was observed that the foam stability depended on the foaming temperature alone but not on the particle size or volume percent within the studied ranges. Specifically, foam stability was poor at 670°C. Among the stable foams obtained at 640°C, cell soundness (absence of/low defects, and collapse) was seen to vary depending on the particle size and content; For example, for finer size, lower particle contents were sufficient to obtain sound cell structure. It is possible to determine a foaming process window based on material and process parameters for good expansion, foam stability, and cell structure.

Reproducibility of Aluminum Foam by Combining Sintering and Dissolution Process with Precursor Foaming Process

NASA Astrophysics Data System (ADS)

Hangai, Yoshihiko; Matsushita, Hayato; Koyama, Shinji; Suzuki, Ryosuke; Matsubara, Masaaki

2017-07-01

A preliminary study of the reproducibility of aluminum foam was performed. Aluminum foam was fabricated by a sintering and dissolution process. It was found that aluminum foam containing a blowing agent can be fabricated without the decomposition of the blowing agent, namely, the densified aluminum foam can be used as a foamable precursor for refoaming. By heat treatment of the densified aluminum foam containing the blowing agent, pores were reproduced in the aluminum.

Synergistic effect of casein glycomacropeptide on sodium caseinate foaming properties.

PubMed

Morales, R; Martinez, M J; Pilosof, A M R

2017-11-01

Several strategies to improve the interfacial properties and foaming properties of proteins may be developed; among them, the use of mixtures of biopolymers that exhibit synergistic interactions. The aim of the present work was to evaluate the effect of casein glycomacropeptide (CMP) on foaming and surface properties of sodium caseinate (NaCas) and to establish the role of protein interactions in the aqueous phase. To this end particles size, interfacial and foaming properties of CMP, NaCas and NaCas-CMP mixtures at pH 5.5 and 7 were determined. At both pH, the interaction between CMP and NaCas induced a decrease in the aggregation state of NaCas. Single CMP foams showed the highest and NaCas the lowest foam overrun (FO) and the mixture exhibited intermediate values. CMP foam quickly drained. The drainage profile of mixed foams was closer to NaCas foams; at pH 5.5, mixed foams drained even slower than NaCas foam, exhibiting a synergistic performance. Additionally, a strong synergism was observed on the collapse of mixed foams at pH 5.5. Finally, a model to explain the synergistic effect observed on foaming properties in CMP-NaCas mixtures has been proposed; the reduced aggregation state of NaCas in the presence of CMP, made it more efficient for foam stabilization. Copyright © 2017 Elsevier B.V. All rights reserved.