Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Emulsions”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Formulation of Conductive Inks for DIW Printed Battery Electrodes

Ink formulations for DIW printing of Li ion battery electrodes were optimized for high conductivity, surface area and printability. Our focus is particularly on optimizing Li-ion battery electrodes for low temperature applications by 3-D printing the cathodes into high surface area shapes. The sluggish kinetics of ion transport at the solid-electrolyte phase boundary can be a major problem in batteries at low temperatures, so optimizing for ion transport can help combat these issues. Two families of DIW ink were investigated; aqueous conductive polymer suspension with graphene nano platelets (GNP) ink, and “oil in water” graphene oxide (GO) micro emulsion ink which carbonizes to an open cell graphene aerogel. By iterative formulation changes, the conductivity of PEDOT:PSS based ink was increased over tenfold, and stiffness of GO emulsion ink was increased to provide better printability without sacrificing porosity.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Chitosan Coating Incorporated with Carvacrol Improves Postharvest Guava (Psidium guajava) Quality

Guava (Psidium guajava L.) is an important economic crop grown widely in tropical and subtropical regions. Guava exhibits fast ripening and senescence as a climacteric fruit, causing a short shelf life and quality deterioration. Chitosan–essential oil nanoemulsions can be an edible coating used to improve postharvest quality attributes. In this study, chitosan was mixed with carvacrol to generate a nano-emulsoid solution containing 0.1 and 0.2% (v/v) carvacrol, using a sonic dismembrator. Guava fruit were coated with the above emulsion and postharvest quality parameters were measured during storage at 20 ± 1 °C and RH = 80 ± 5% for 8 days. The result illustrated that the particle size of the chitosan–carvacrol emulsions was nanoscale, and their high stability was demonstrated by the zeta potential and polydispersity index. Chitosan coating (2%, w/v, 310–375 kDa) containing 0.2% (v/v) carvacrol maintained postharvest quality compared to chitosan alone, with higher firmness, soluble solid content, total acid, and total phenol content, and lower weight loss and pericarp browning. The collective data were further verified by principal component analysis. A chitosan coating containing carvacrol can reduce postharvest losses. It can be applied as an effective strategy to improve postharvest fruit quality.

Agriculture↗
NASA NTRS1973

The Deuterium Puzzle in the Symmetric Universe

The examination of the experimental data concerning the reaction antiproton + He-4 yields pions + nuclei shows that the low abundance of D 2 can be explained only by assuming a low He abundance at the beginning of the radiative era. This is a completely independant confirmation of the evasion of neutrons (and antineutrons) from the emulsion before the end of the epoch where nucleogenesis might have taken place, and leads to an estimate of the size of the emulsion when T = 1 MeV.

Leroy, B.↗
NASA NTRS1972

Protective overcoating of films

Kodak Film Type SO-212 was emulsion overcoated with gelatin and lacquer to evaluate the feasibility of application of the coatings, any image degradation, and the relative protection offered against abrasion. Evaluated were: Eastman motion picture film lacquer Type 485, water solutions of Eastman purified Calfskin gelatin, and experimental Eastman gelatin stripping film of 4 and 6 microns. Conclusions reached were: (1) All coatings can be applied with relative ease with the only limitation being that of equipment. (2) None of the coatings degrade the processed image. (3) All of the coatings provide protection to the emulsion. These conclusions apply to any film which may be considered for overcoating.

Maas, K. A.↗
NASA NTRS1975

Measurement of spectra and neutron fluxes on artificial earth satellites from the Cosmos series

In 1966-1967 measurements were carried out at the altitudes of 200 to 400 km to determine the spectra and fluxes of fast neutrons inside the hermetically sealed artificial earth satellites of the Cosmos series. The detectors used were nuclear emulsions of the B9 and BR types and an emulsion of the P9 type, filled with Li and P. Spectra and fluxes of neutrons in the range of energies from thermal energies to 10 MeV are presented. Neutron doses are also estimated.

Dudkin, V. Y.↗
NASA NTRS1974

The stability of liquid dispersions in low gravity

The stability of three different dispersions of oil and water prepared on Skylab 4 is compared with the same dispersions made on earth. The stability of the emulsions has been studied by two independent optical techniques. An analysis of the data indicates that all the investigated emulsions were stable over a period of 10 hr, whereas the fluids separated completely on earth in 10 sec. This experiment indicates that the rate of coalescence in low gravity is at least 3 millionths times that on earth. A knowledge of the coalescence rate in low gravity is important in the solidification of immiscible alloys in space. The parameters obtained for this experiment are compared with those of liquid metals to determine if the same stability could be achieved with immiscible alloys.

Lacy, L. L.↗
NASA NTRS1975

Evidence for detection of a moving magnetic monopole

A very heavy particle passed through a balloon-borne stack of Cherenkov film, emulsion, and Lexan sheets. In 33 Lexan sheets it produced tracks expected of either a nucleus with Z ranging between 125 and 137 and with beta less than about 0.92 or a magnetic monopole with g = 137e. Its track structure in emulsion indicated it was moving downward with beta equal to 0.5 (plus 0.1 or minus 0.05) and was either a nucleus with Z equal to 80 or a monopole with g = 137e. These facts strongly favor identification of the particle as a magnetic monopole of strength g = 137e and mass greater than 200 times proton mass.

Price, P. B.↗
NASA NTRS1975

Intensity of primary electrons above 10 GeV

A nuclear emulsion-spark chamber-counter electron telescope has been flown on a balloon at 3.5 g/sq cm residual pressure over Palestine, Texas, where the vertical cutoff is 4.5 GeV. The spark chamber pictures permitted the elimination of about 50% of the events whose counter signatures alone would qualify them as electrons. Of those events identified as 'electron-like' by counters and spark chambers, only 43% turn out to be electrons when found in the emulsion. The resulting intensities are among the lowest currently reported and are in good agreement with earlier results. The differential intensity in the region 8-40 GeV is measured.

Freier, P.↗
NASA NTRS1975

Detection of the isotopes of heavy cosmic ray nuclei

A counter telescope designed to detect and resolve the isotopic composition of cosmic ray nuclei heavier than neon is being prepared. The telescope consists of a rather conventional charge measuring array using two scintillator elements and two solid Cerenkov radiators of differing refractive index. The mass measurement is obtained by combining the velocity information from one or both of the Cerenkov radiators operating near their threshold with residual range measured in a block of nuclear emulsion. Path length corrections and particle location in the emulsions is provided by a spark chamber fired in coincidence with potentially suitable particles. The telescope has a geometry factor of 530 sq cm sr roughly. It should be able to resolve the isotopes of iron over the energy range of 300 to 720 Mev/n and those of neon over 300 to 400 MeV/n. The expected response and characteristics of the telescope are described in detail and the sensitivity to rare isotopes discussed.

Gilman, C. M.↗
NASA NTRS1975

Correlation of individual cosmic ray nuclei with the observation of light flashes by Apollo astronauts

A nuclear emulsion detector known as the Apollo Light Flash Moving Emulsion Detector (ALFMED) was designed: (1) to record tracks of primary cosmic rays; (2) to provide time-of-passage information via a relative plate translation technique; (3) to provide particle trajectory information; and (4) to fit into a masklike device that could be located about the head and eyes of an astronaut. An ALFMED device was worn by an astronaut observing light flashes for 60 minutes on each of the last two Apollo missions. During the Apollo 17 experiment seventeen separate flashes were reported by the observer. With one-third of the total plate area completely analyzed, two definite correlations have been found between Z greater than 8 cosmic ray nuclei traversing an eye and the reports of visual sensations.

Pinsky, L. S.↗
NASA NTRS1979

Soda ash removes sulfur from fuels

Test show that adding soda ash (sodium bicarbonate) to coal/oil/water emulsion reduces 75 to 80% of sulfur dioxide gas emitted during subsequent combustion of emulsion.

Dooher, J.↗
NASA NTRS1979

Post-development image intensification by autoradiography

A method of post-development intensification of photographic images using a newly developed autoradiographic procedure is described. Radioactive Thiourea-S35 is combined with silver in the developed emulsion, which is then contact printed with a receiver emulsion. The beta decay from S35 produces an enhanced autoradiographic image. The laboratory technique is described and results of astronomical applications are presented.

Askins, B. S.↗
NASA NTRS1982

Primary proton and helium spectra in the energy range 10 to the 12th to 10 to the 14th eV

Measurements of proton and helium spectra have been made in the energy range 10 to the 12th to 10 to the 14th eV. Large area thin emulsion calorimeters were used in the Japanese American Cooperative Emulsion Experiment balloon flight series. Power indices of the integral spectra for both nuclei are consistent with published data at lower energies. Absolute intensities are also consistent for helium and proton fluxes with extrapolations of previous data. No steepening of the proton spectrum is indicated.

Gregory, J. C.↗
NASA NTRS1984

Effects of Shuttle bay environment on UV sensitive photographic film - Instrumentation for Get-Away-Special

An account is given of a Get-Away-Special experiment flown on Space Shuttles 7 and 8 investigating the effect of the space environment on Shumann emulsions. Shumann emulsions, having low gelatin content and no protective gelatin overcoating, are useful detectors of ultraviolet radiation shorter than 2200 angstroms but are extremely sensitive to environmental conditions and handling. The instrument required no interface with the Shuttle. It was turned on by an aneroid switch at an altitude of 50,000 feet. After that, its operation was controlled completely by a CMOS digital controller. Each hour, two temperatures and one voltage were read and stored in a CMOS programmable read only memory. At intervals, valves were opened and closed to expose SO 652 film strips of three sensitivities to the cargo bay environment for various time periods. The design and operation of the instrument package is described.

Kreplin, R. W.↗
NASA NTRS1985

Heavy nucleus collisions between 20 and 60 GeV/nucleon

Interest in studying relativistic nucleus-nucleus interations arises from the fact that they offer an opportunity to probe nuclear matter at high density and temperature. It is expected that under such extreme conditions a transition from hadronic matter into quark-gluon plasma occurs and that in the interactions of highly relativistic nuclei such conditions are created. Cosmic rays remain a unique source of high energy heavy nuclei. The Japanese-American Cooperative Emulsion Experiment (JACEE-3) was designed to study the collisions of heavy cosmic ray nuclei with different nuclear targets at energies beyond 20 GeV/nucleon. JACEE-3 experiment was carried out using a combined electronic counters and an emulsion chamber detector, which was exposed to the cosmic rays on a balloon at an altitude of 5 g/sq cm.

Burnett, T. H.↗
NASA NTRS1985

Characteristics of central collision events in Fe-nucleus interactions for 20 - 60 GeV/nucleon

A counter emulsion hybrid chamber in Japanese-American Cooperative Emulsion Experiment (JACEE-3) was flown on a balloon at the altitude (5.4 g/sq cm) in 1982 with the objective of probing the heavy nuclear collisions above 20 GeV per nucleon. In the energy region, it is suggested that nucleus-nucleus collisions provide dense collisions complex through compression and secondary particle production. In the lower energy region, an evidence of collective flow has been reported. And also, at higher energy region, it has been argued that nucleus has rather large stopping power. In this paper, the high multiplicity characteristics of Fe nucleus central collisions with energies 20 to 50 GeV/nucleon are presented. This is considered to be relevant to compressibility and collective flow of nuclear matter.

Burnett, T. H.↗
NASA NTRS1985

Nucleus-nucleus interaction above several hundred GeV/n

The Japanese-American Cooperative Emulsion Experiment (JACEE) have been investigating high energy nuclear interactions of cosmic ray nuclei by means of balloon-borne emulsion chamber. Current exposure parameters are listed. Analysis of the last two experiments (JACEE4 and JACEE5) are still in progress. A result of semi-inclusive analysis of a sample set of central collision events is presented here, concerning multiplicity, rapidity fluctuation for extremely high multiplicity events and correlation between transverse momentum and estimated energy density.

Burnett, T. H.↗
NASA NTRS1985

Energy spectra of proton and nuclei of primary cosmic rays in energy region 10 TeV/particle

To investigate the chemical composition of primary cosmic rays, several emulsion chambers were exposed at a 10.8 g/sq cm. depth in the stratosphere. Each chamber has the area of 0.92x0.46 sq m. and the depth of 14 c.u. The exposure time of chambers processed by now is 260 hours. The detecting layers were X-ray films and nuclear emulsions, which allowed to measure an energy of cascade and a type of primary particle. Results and techniques are described.

Mandritskaya, K. V.↗