James Martinez
A5103713252- Astro and Planetary Science
- Planetary Science and Exploration
- High-pressure geophysics and materials
- Geological and Geochemical Analysis
- Isotope Analysis in Ecology
- Technology Assessment and Management
- Geology and Paleoclimatology Research
- Electrochemical Analysis and Applications
- Analytical Chemistry and Sensors
- Tunneling and Rock Mechanics
- Spacecraft Design and Technology
- Rocket and propulsion systems research
- Education Systems and Policy
- Smart Cities and Technologies
- Advanced Battery Technologies Research
- Laser Design and Applications
- Clay minerals and soil interactions
- Semiconductor Lasers and Optical Devices
- Granular flow and fluidized beds
- Space exploration and regulation
- Thermal Radiation and Cooling Technologies
- Organizational Leadership and Management Strategies
- Impact of Light on Environment and Health
- Photocathodes and Microchannel Plates
- Radioactive element chemistry and processing
Jacobs (United States)
2010-2024
Southern University and Agricultural and Mechanical College
2023
Johnson Space Center
2015-2022
Valdosta State University
2020
National Technical Information Service
2004
Office of Scientific and Technical Information
2004
Pacific Northwest National Laboratory
2004
United States Department of Commerce
2004
A simple direct method for the rapid fabrication of zinc oxide nanotube-nanowire hybrid structure in an environmentally friendly way is described here. Zinc foils were anodized aqueous solution washing soda and baking at room temperature order to obtain architecture. At beginning process nanowires formed on substrate. The wider transformed into nanotubes about a minute grew length with time. morphological integrity was maintained upon heat treatment temperatures up melting point substrate...
Without a protective atmosphere, space-exposed surfaces of airless Solar System bodies gradually experience an alteration in composition, structure and optical properties through collective process called space weathering. The return samples from near-Earth asteroid (162173) Ryugu by Hayabusa2 provides the first opportunity for laboratory study space-weathering signatures on most abundant type inner solar system body: C-type asteroid, composed materials largely unchanged since formation...
Abstract– We performed a battery of analyses on 17 samples the Almahata Sitta meteorite, identifying three main lithologies and several minor ones present as clasts. The are (1) pyroxene‐dominated, very porous, highly reduced lithology, (2) pyroxene‐dominated compact (3) an olivine‐dominated lithology. Although it seems possible that all grade smoothly into each other at kg‐scale, g‐scale this is not apparent. meteorite polymict ureilite, with some intriguing features including exceptionally...
This paper explores how to improve the sustainability of smart cities from a design perspective, by combining concepts sustainable with Internet Things and ecosystems. The uses combination literature, cases, model building develop research. First, article analyzes six elements (human, environment, society, economy, culture) four dimensions (space, resources, management, platform) that constitute system for constructs based on this analysis; then, strategy in is discussed perspectives...
Abstract Transmission electron microscopy analyses of Hayabusa2 samples show that Ryugu organic matter exhibits a range morphologies, elemental compositions, and carbon functional chemistries consistent with those carbonaceous chondrites have experienced low‐temperature aqueous alteration. Both nanoglobules diffuse are abundant. Non‐globular particles also present, including some contain nanodiamond clusters. Diffuse is finely distributed in around phyllosilicates, forms coatings on other...
Abstract Based upon our characterization of three separate stones by electron and X‐ray beam analyses, computed microtomography, Raman microspectrometry, visible‐ IR spectrometry, Sutter's Mill is a unique regolith breccia consisting mainly various CM lithologies. Most samples resemble existing available 2 chondrites, chondrules calcium‐aluminum‐rich inclusion (CAI) set within phyllosilicate‐dominated matrix (mainly serpentine), pyrrhotite, pentlandite, tochilinite, variable amounts Ca‐Mg‐Fe...
Abstract Large amounts of nitrogen compounds, such as ammonium salts, may be stored in icy bodies and comets, but the transport these nitrogen-bearing solids into near-Earth region is not well understood. Here, we report discovery iron nitride on magnetite grains from surface C-type carbonaceous asteroid Ryugu, suggesting inorganic fixation. Micrometeoroid impacts solar wind irradiation have caused selective loss volatile species major iron-bearing minerals to form metallic iron. Iron a...
Abstract Samples returned from the carbonaceous asteroid (162173) Ryugu by Hayabusa2 mission revealed that is composed of materials consistent with CI chondrites and some types space weathering. We report detailed mineralogy fine‐grained samples allocated to our “Sand” team additional weathering features found on grains. The dominant a mixture Mg‐rich saponite serpentine, magnetite, pyrrhotite, pentlandite, dolomite, Fe‐bearing magnesite. These grains have comparable chondrites, showing...
We studied seven Itokawa particles provided by the Japan Aerospace Exploration Agency (JAXA) as first International Announcement of Opportunity (AO) study mainly using electron and synchrotron radiation X-ray beam techniques. All analyzed were collected from first-touchdown site composed olivine plagioclase with traces Ca phosphate chromite, do not contain pyroxenes. Optical microscopy these shows minor undulatory extinction plagioclase, suggesting shock metamorphism (shock stage: S2). The...
Abstract Samples were recently collected from the carbonaceous asteroid (162173) Ryugu, by Japan Aerospace Exploration Agency (JAXA) Hayabusa2 mission. They resemble CI chondrites material, thus showing clear evidence of extensive aqueous alteration attested widespread presence a mixture serpentine and saponite. We present here scanning transmission electron microscopy study Ryugu dominant lithology phyllosilicate matrix at nanometer scale, which we compare with that Orgueil chondrite. In...
Abstract We present in this study the effects of short‐term heating on organics Tagish Lake meteorite and how difference conditions can modify organic matter ( OM ) a way that complicates interpretation parent body's extent with common cosmothermometers. The kinetics its influence structure are not well understood, any is further complicated by complex alteration processes thermally metamorphosed carbonaceous chondrites—potential analogues target asteroid Ryugu Hayabusa2 mission—which had...
Life on Earth shows preference toward the set of organics with particular spatial configurations. Enantiomeric excesses have been observed for α-methyl amino acids in meteorites, which suggests that chiral asymmetry might an abiotic origin. A possible mechanism could produce meteoritic is their formation under influence asymmetric catalysts, as mineral crystallization can spatially structures. Although magnetite plaquettes proposed to be a candidate catalyst, based suggestion they spiral...
Abstract The Hayabusa2 mission from the Japan Aerospace Exploration Agency (JAXA) returned to Earth samples of carbonaceous asteroid (162173) Ryugu. This offers a unique opportunity investigate in laboratory C‐type asteroid, without physical or chemical alteration by terrestrial atmosphere. Here, we report on an investigation mineralogy and organo‐chemistry using combination micro‐ nano‐infrared spectroscopy. Particles investigated with conventional FTIR spectroscopy have spectra dominated...
Abstract The surface morphology of regolith grains from the C‐type asteroid Ryugu was studied in search evidence impact events on asteroid. Scanning electron microscopy revealed that ~8% C0105‐042 have a smooth one side grains. One these has striated linear grooves (striations) its surface. Transmission grain showed porous fine‐grained Mg‐Fe phyllosilicate assemblage, which is main component grains, compacted near with striations closely resembles slickenside, characteristic texture found...
Abstract The Almahata Sitta (AhS) meteorite is a unique polymict ureilite. Recently, carbonaceous chondritic lithologies were identified in AhS. Organic matter (OM) ubiquitously found primitive chondrites. molecular and isotopic characteristics of this OM reflect its origin parent body processes, are particularly sensitive to heating. C1 AhS 671 91A investigated, focusing mainly on the OM. We that these contains signatures, but experienced slight heating possibly by short‐term event(s)....
Abstract Our goal was to devise a bridge between shock determinations of asteroid regolith grains by standard light optical petrography, synchrotron X‐ray diffraction (SXRD), and electron backscattered (EBSD). We determined the optimal conditions under which measure stage olivine crystals in astromaterial EBSD. applied this EBSD procedure determination four from Itokawa, returned earth Hayabusa spacecraft. Interpretation these data required parallel examination three ordinary chondrite...
The ISS (International Space Station) currently lacks the capability to image and chemically analyze nano-to-micron scale particles from numerous engineering systems. To identify these particles, we must wait for a re-entry vehicle return them low earth orbit ground-based SEM (Scanning Electron Microscope) / EDS (Energy Dispersive X-Ray Spectroscopy) analysis. This may take months, potentially delaying affected system. Having an EDS-equipped (Mochii S) aboard will accelerate response time...
Journal Article Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen. Get access John Graf, Graf Crew and Thermal Systems Division, NASA-Johnson Space Center, Houston TX, USA. Search for other works by this author on: Oxford Academic Google Scholar Dale Taylor, Taylor Engineering Department, Ceramatec, Salt Lake City UT, James Martinez Structural Microscopy Microanalysis, Volume 20, Issue S3, 1 August 2014, Pages 1896–1897,...
Abstract Ryugu asteroid grains brought back to the Earth by Hayabusa2 space mission are pristine samples containing hydrated minerals and organic compounds. Here, we investigate mineralogy of their phyllosilicate‐rich matrix with four‐dimensional scanning transmission electron microscopy (4D‐STEM). We have identified mapped mineral phases at nanometer scale (serpentine, smectite, pyrrhotite), observed presence Ni‐bearing pyrrhotite, serpentine polymorph as lizardite, in agreement reported...
Abstract Regolith samples returned from asteroid 162173 Ryugu by the Hayabusa2 mission provide direct means to study how space weathering operates on surfaces of hydrous asteroids. The mechanisms weathering, its effects mineral surfaces, and characteristic time scales which alteration occurs are central understanding spectroscopic properties taxonomy asteroids in solar system. Here, we investigate behavior iron monosulfides pyrrhotite (Fe 1− x S) at earliest stages weathering. Using electron...
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An electron microscope is now, for the first time, in Earth orbit aboard International Space Station (ISS).A Mochii™ portable was delivered to ISS via Cygnus spacecraft on NASA's NG-13 commercial resupply mission (Fig. 1), and now traveling at 17,136 mph, about 250 mi above Earth's surface [1].As a new addition National Laboratory, Mochii ISS-NL will support novel in-situ microgravity science engineering low (LEO) benefit of humankind [2].