Results 31 to 40 of about 2,942 (252)

Supernova Dust Synthesis—Carbonaceous Dust in the Very Early Universe

The Astrophysical Journal
Recent observations have revealed the spectral features of carbonaceous grains even in very distant galaxies. We develop a state-of-the-art dust synthesis code by self-consistently solving molecule and dust formation in supernova (SN) ejecta that contain
Gen Chiaki, Chiaki Kobayashi, Nozomu Tominaga   +2 more
doaj   +1 more source

13C-depleted moissanites in subduction-related rocks: tracers of slab fluids in the Earth’s mantle and a new diamond exploration tool [PDF]

E3S Web of Conferences, 2019
A magnesian low-Ti shoshonite dike intruding Archean Norwegian Terrane includes numerous grains of black, blue and gray moissanite (SiC). Moissanite contains inclusions of native Si, Fe and Al, Fe-Cr carbides, Fe-Cr-Mn alloys and diamond.
Kepezhinskas Pavel, Kepezhinskas Nikita
doaj   +1 more source

Sintering of Grains of Some Carbonaceous Substances

The Journal of the Society of Chemical Industry, Japan, 1957
黒鉛化容易な炭素質物質の450～700℃間における状態を推測するため,炭素質粒子間の焼結現象を中心に検討した。用いた試料のうち,サラン,セルロース,泥炭の各320℃焼成物は焼結せず,ビオラントロンおよび石油ピッチ,タール用いた試料のうち,サラン,セルロース,泥炭の各320℃焼成物は焼結せず,ビオラントロンおよび石油ピッチ,タールに述べた示差熱分析における500～700℃間の吸熱現象,さらにすでに知られているこの温度範囲におけるC0(層構の厚さ)の変化曲線等の関係からこの温度範囲の状態を次のように考えた。すなわち-O-,-C-C-結合の分裂を伴なって炭素構造に転移した後,層構造に結合する低分子量原子団および共存する低分子物質の熱振動が急速に現われ,部分的な半融状態に近い状態となり ...
openaire   +2 more sources

Microstructural Evolution and Vacancy Defect Formation in Mn–Mo–Ni RPV Steel Under Low Cycle Fatigue: Insights From EBSD and PALS

Advanced Engineering Materials, EarlyView.
Low‐cycle fatigue damage in Mn–Mo–Ni reactor pressure vessel steel is examined using a combined electron backscatter diffraction and positron annihilation lifetime spectroscopy approach. The study correlates texture evolution, dislocation substructure development, and vacancy‐type defect formation across uniform, necked, and fracture regions, providing
Apu Sarkar, Dhanadeep Dutta, G. Bharat Reddy   +2 more
wiley   +1 more source

On the Interstellar Extinction Curve toward HD 93222, a Sight Line with an Exceedingly Narrow 2175 Å Extinction Bump

The Astrophysical Journal
The 2175 Å extinction bump, the most prominent spectral feature superimposed on the interstellar extinction curve, is widely seen in the interstellar medium of the Milky Way and external galaxies, both near and far.
Qian Wang, Aigen Li, X. J. Yang
doaj   +1 more source

Creating Ti–Fe α/β Alloys by Diffusion‐Driven Solid‐State Processing

Advanced Engineering Materials, EarlyView.
This study proposes making alloys containing fast diffusing elements that are difficult to produce by ingot metallurgy, by diffusion‐driven solid‐state HIP processing of elemental powders and low‐temperature homogenisation. Here, novel Fe‐Ti α–β alloys are formed having fine α–β lamellae, a small β prior grain size without significant intermetallics ...
Jiaqi Xu, Xun Zhang, Jack M. Donoghue, Albert D. Smith, Rahul Unnikrishnan, Rhys Thomas, Vahid Nekouie, Jie Luo, Dongchen Hu, Michael Preuss, Philip J. Withers   +10 more
wiley   +1 more source

Interstellar Carbonaceous Dust Erosion Induced by X-Ray Irradiation of Water Ice in Star-forming Regions

The Astrophysical Journal, 2023
The chemical inventory of protoplanetary midplanes is the basis for forming planetesimals. Among them, solid-state reactions based on CO/CO _2 toward molecular complexity on interstellar dust grains have been studied in theoretical and laboratory work ...
K.-J. Chuang, C. Jäger, N.-E. Sie, C.-H. Huang, C.-Y. Lee, Y.-Y. Hsu, Th. Henning, Y.-J. Chen   +7 more
doaj   +1 more source

Experimental H2O formation on carbonaceous dust grains at temperatures up to 85 K

Monthly Notices of the Royal Astronomical Society, 2023
ABSTRACT Water represents the main component of the icy mantles on dust grains, it is of extreme importance for the formation of new species and it represents the main component for life. Water is observed both in the gas-phase and frozen in the interstellar medium (ISM), where the solid-phase formation route has been proven essential to
Grieco, Francesco, Dulieu, Francois, De Looze, Ilse, Baouche, S.   +3 more
openaire   +3 more sources

Affecting the Properties of Copper–Graphene Electroconductive Composite by Severe Plastic Deformation

Advanced Engineering Materials, EarlyView.
Copper‐based composites enhanced with carbon feature convenient mechanical properties and favorable electric conductivity. Processing via deformation and thermomechanical treatments can introduce advantageous microstructures further enhancing their performance. Herein, copper–graphene powder‐based composites are directly consolidated via rotary swaging
Radim Kocich, Lenka Kunčická, Pavel Czernek, Zifan Wang   +3 more
wiley   +1 more source

Chemistry in Retrieved Ryugu Asteroid Samples Revealed by Non-Invasive X-ray Microanalyses: Pink-Beam Fluorescence CT and Tender-Energy Absorption Spectroscopy

Geosciences
The Hayabusa2 space mission recently retrieved 5.4 g of material from asteroid Ryugu, providing the first direct access to pristine material from a carbonaceous asteroid. This study employs a novel combination of non-invasive synchrotron X-ray techniques
Paul Northrup, Ryan Tappero, Timothy D. Glotch, George J. Flynn, Mehmet Yesiltas, Yoko Kebukawa, Leonard Flores, Marina E. Gemma, Gavin Piccione   +8 more
doaj   +1 more source