2,812 research outputs found
Tube-to-header joint for bimetallic construction
Design advantages of bimetallic construction enables an all-welded bimetallic joint to be made from the accessible header side of the tube-to-header joint. In the two-piece header design the weld joints completely seal the tube-header plate crevice and prevent crevice and stringer corrosion
Determination of the weldability and elevated temperature stability of refractory metal alloys quarterly report no. 6, 21 sep. - 20 dec. 1964
Determination of weldability and elevated temperature stability of refractory metal alloy
Joining refractory/austenitic bimetal tubing Supplemental report
Joining bimetal tubing consisting of austenitic stainless steel with inner lining of niobium or tantalu
Determination of the weldability and elevated temperature stability of refractory metal alloys Ninth quarterly report, 21 Jun. - 20 Sep. 1965
Tensile strength and thermostability of welded refractory metal joint
Determination of the weldability and elevated temperature stability of refractory metal alloys seventh quarterly report, dec. 21, 1964 - mar. 20, 1965
Weldability and elevated temperature stability of refractory metal alloy
Determination of the weldability and elevated temperature stability of refractory metal alloys Tenth quarterly report, 21 Sep. - 20 Dec. 1965
Weldability and long time elevated temperature stability of refractory metal alloys for advanced alkali-metal space electric power system
Estrogenic chemicals often leach from BPA-free plastic products that are replacements for BPA-containing polycarbonate products
Background: Xenobiotic chemicals with estrogenic activity (EA), such as bisphenol A (BPA), have been reported to
have potential adverse health effects in mammals, including humans, especially in fetal and infant stages. Concerns
about safety have caused many manufacturers to use alternatives to polycarbonate (PC) resins to make hard and
clear, reusable, plastic products that do not leach BPA. However, no study has focused on whether such BPA-free
PC-replacement products, chosen for their perceived higher safety, especially for babies, also release other chemicals
that have EA.
Methods: We used two, well-established, mammalian cell-based, assays (MCF-7 and BG1Luc) to assess the EA of
chemicals that leached into over 1000 saline or ethanol extracts of 50 unstressed or stressed (autoclaving,
microwaving, and UV radiation) BPA-free PC-replacement products. An EA antagonist, ICI 182,780, was used to confirm
that agonist activity in leachates was due to chemicals that activated the mammalian estrogen receptor.
Results: Many unstressed and stressed, PC-replacement-products made from acrylic, polystyrene, polyethersulfone, and
Tritan™ resins leached chemicals with EA, including products made for use by babies. Exposure to various forms of UV
radiation often increased the leaching of chemicals with EA. In contrast, some BPA-free PC-replacement products made
from glycol-modified polyethylene terephthalate or cyclic olefin polymer or co-polymer resins did not release chemicals
with detectable EA under any conditions tested.
Conclusions: This hazard assessment survey showed that many BPA-free PC- replacement products still leached
chemicals having significant levels of EA, as did BPA-containing PC counterparts they were meant to replace. That is,
BPA-free did not mean EA-free. However, this study also showed that some PC-replacement products did not leach
chemicals having significant levels of EA. That is, EA-free PC-replacement products could be made in commercial
quantities at prices that compete with PC-replacement products that were not BPA-free. Since plastic products often
have advantages (price, weight, shatter-resistance, etc.) compared to other materials such as steel or glass, it is not
necessary to forgo those advantages to avoid release into foodstuffs or the environment of chemicals having EA that
may have potential adverse effects on our health or the health of future generations.This work was supported by the following NIH/NIEHS grants: R44 ES011469,
01–03 (CZY); 1R43/44 ES014806, 01–03 (CZY); subcontract (CZY, PI) on
an NIH Grant 01–03 43/44ES018083-01 to PlastiPure (DK, SY PIs).Neuroscienc
Development of large diameter T-111 /Ta-8W-2Hf/ tubing Final report
Large diameter T-111 tubing processed from seamless and welded tube shell
The Interaction of Nitrogen and Moisture on Crop Yield and Water Use
In recent years, a subject of considerable speculation among South Dakota farmers is whether or not the use of nitrogenous fertilizers is profitable under conditions of dryland farming. There has been a prejudice against the use of nitrogenous fertilizers as giving a leafy, succulent growth, liable to drought damage. Frequent claims are that additions of nitrogen result in “burning” of crops when moisture conditions become unfavorable, and that under these conditions yields are often better without the use of fertilizer. A common explanation is that fertilized crops use more water than unfertilized crops and this results in the fertilized crops having less chance to reach maturity when the moisture is limited. The objectives of this study were to determine the effect if nitrogenous fertilizer applications on the yield and moisture use of crops grown under various conditions of moisture supply. These objectives were pursued in experiments conducted in the field where it was anticipated that considerable natural moisture stress would occur, and in the greenhouse, some with no control over moisture conditions and others with controlled moisture. In some experiments, partial biochemical analysis of plants were made in an endeavor to find a physiochemical basis for observed results. It is hoped that the results of this investigation will serve in the aid in making better recommendations with regard to the application of nitrogenous fertilizers to crops under conditions of limited moisture
Validity of the scattering length approximation in strongly interacting Fermi systems
We investigate the energy spectrum of systems of two, three and four spin-1/2
fermions with short range attractive interactions both exactly, and within the
scattering length approximation. The formation of molecular bound states and
the ferromagnetic transition of the excited scattering state are examined
systematically as a function of the 2-body scattering length. Identification of
the upper branch (scattering states) is discussed and a general approach valid
for systems with many particles is given. We show that an adiabatic
ferromagnetic transition occurs, but at a critical transition point kF a much
higher than predicted from previous calculations, almost all of which use the
scattering length approximation. In the 4-particle system the discrepancy is a
factor of 2. The exact critical interaction strength calculated in the
4-particle system is consistent with that reported by experiment. To make
comparisons with the adiabatic transition, we study the quench dynamics of the
pairing instability using the eigenstate wavefunctions.Comment: 7 pages, 7 figure
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