Army Corps of Engineers

The recent advances in nanotechnology and the corresponding increase in the use of nanomaterials in products in every sector of society have resulted in uncertainties regarding environmental impacts. The objectives of this review are to introduce the key aspects pertaining to nanomaterials in the environment and to discuss what is known concerning their fate, behavior, disposition, and toxicity, with a particular focus on those that make up manufactured nanomaterials. This review critiques existing nanomaterial research in freshwater, marine, and soil environments. It illustrates the paucity of existing research and demonstrates the need for additional research. Environmental scientists are encouraged to base this research on existing studies on colloidal behavior and toxicology. The need for standard reference and testing materials as well as methodology for suspension preparation and testing is also discussed.

Nanomaterials in the environment: Behavior, fate, bioavailability, and effects

https://cmapspublic3.ihmc.us/rid=1266358861321_2027852911_13457/Wound%20Healing%20Dressings%20and%20Drug%20Delivery%20Systems.pdf

Wound healing dressings and drug delivery systems: a review.

Polymers are the compounds that includes platics, artificial fibers, rubber, cellulose, and many other materials, including coatings and adhesives. This book presents key data on approximately 200 important polymers currently in industrial use or under study in industrial or academic research. No other single source covers so many polymers or offers such a depth of data. The book standardizes and makes accessible a wealth of essential data for students, teachers, researchers, and other professionals in chemistry and chemical engineering.

Polymer Data Handbook

The flow of homogeneous fluids through porous media: analogies with other physical problems

This method applies classic microchemical technique, eliminating entirely the transfer of sample materials during analysis. Respirable sized granite dust is analyzed for quartz content colorimetrically. The relative standard error of the determination of quartz in granite, using this method, is 14.7 percent. Erratum to this paper appears in 2(1)

Microchemical Determination of Quartz in Granite Dust Sampled by Size Selective Methods on Membrane Filters

The changes in the damping properties of AISI 403 with cyclical torsional fatigue stressing have been determined in order to define the cyclical stress sensitivity limit (CSSL) of the material. Comparison of the data with observations of changes in surface features and the torsional and push-pull fatigue lives shows that the CSSL is a good indication of the minimum stress which can cause permanent fatigue damage in this material. The type of test used to determine the CSSL is rapid in that less than one day's testing on one specimen is required to define it, whereas the usual fatigue limit requires testing times of several weeks and a number of different specimens. Application of the Granato-Lucke theory of dislocation damping explains many of the observations of damping and modulus changes encountered.

Correlation of Damping and Fatigue Properties of an AISI 403 Stainless Steel

A computer program has been developed to optimize hydraulic pressure system selection for use in the structural testing of aeronautical vehicles. This program will select the minimal number of pressure systems, using available hydraulic cylinders, to match all the simulated flight loads which are applied during a test. Programs were written for Fortran and Advanced Basic language users of the IBM 360/67 time-sharing system or the Varian 620/i stand-alone system. Various options are present in the programs to adjust for unique testing conditions. Since the number of pressure system combinations for large-scale testing can be astronomical, this program has eliminated what was formerly a frustrating, time-consuming, and highly subjective task.

Computer Optimization of Hydraulic System Pressure for Development and Qualification Testing

Uncoated Ta-17W and C129Y alloys and coated Ta-10W, C103, and C129Y alloys have been evaluated for short-time creep behavior at 2600 to 3200°F. The time for creep strains of up to 2 percent has been measured and the results have been used to derive empirical equations that predict short-time creep life in this temperature range. The equations give estimates of the time-to-creep strains of up to 2 percent at stress levels that will produce the maximum strain in 60 min or less. Silicide-base coatings appear to add to the creep strength of coated Ta-10W but have little added effect on the strength of the columbium-base alloys. The creep behavior of coated metals can be analyzed by the same empirical methods as those used for uncoated substrates. The results show that commercially available silicide coatings protect the substrate from oxidation with creep strains of up to 2 percent on exposures of 1 to 1½ h in this temperature range.

Short-time creep of columbium and tantalum alloys at 2600 to 3200 F

The results of experiments on Society of Automotive Engineers (SAE) 1043 steel show that the cyclic stress-strain response in small regions of a notched specimen is not necessarily the same as that obtained in tests on smooth specimens of the same metal. At the roots of notches (two different notch radii were used) plastic flow occurs at the same cyclic lives as in unnotched specimens, when the longitudinal total strains are similar. Cyclic plasticity develops in many fewer cycles near the notches than in smooth specimens under the same longitudinal total strains. The more sharply notched specimens soften more rapidly at locations near the notches than the less severely notched ones under identical longitudinal strains.

SF Etris

Papers

Microchemical Determination of Quartz in Granite Dust Sampled by Size Selective Methods on Membrane Filters

Correlation of Damping and Fatigue Properties of an AISI 403 Stainless Steel

Computer Optimization of Hydraulic System Pressure for Development and Qualification Testing

Short-time creep of columbium and tantalum alloys at 2600 to 3200 F

Cycle-Dependent Softening in Notched Steel Specimens