Spectrochemistry in the Iron Foundry: X-Ray Fluorescence vs. Optical Emission

1978 ◽  
pp. 35-42 ◽  
Author(s):  
Richard Gast
Keyword(s):  
Optical Emission ◽  
X Ray ◽  
Iron Foundry

Spectrochemistry in the Iron Foundry: X-Ray Fluorescence vs. Optical Emission

1977 ◽  
Vol 21 ◽  
pp. 35-42
Author(s):  
Richard Gast
Keyword(s):  
Chemical Process ◽  
Optical Emission ◽  
Minimal Period ◽  
Pouring Temperature ◽  
Major Objective ◽  
X Ray ◽  
Analytical Work ◽  
Iron Foundry ◽  
On Line ◽  
Casting Design

The casting of iron is largely a chemical process: that is, the chemistry of molten iron greatly influences the properties of finished castings. Other parameters - casting design, mold integrity, inoculation practice, pouring temperature, and shakeout procedure - are also vital to consistent production. But if the chemistry is wrong, the probability of defective castings is high. For this reason, control of chemical composition has long been a major objective of foundrymen.To be useful for either process control or quality assurance checking, analytical work must be reliable and accurate. Data should also be available in a minimal period of time to make possible the on-line adjustments necessary to achieve proper chemistry, and thus the desired properties, in the final castings.

scholarly journals The Effect of Mg and Zn Dopants on Pt/Al2O3 for the Dehydrogenation of Perhydrodibenzyltoluene

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 490
Author(s):  
Rudaviro Garidzirai ◽  
Phillimon Modisha ◽  
Innocent Shuro ◽  
Jacobus Visagie ◽  
Pieter van Helden ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Inductively Coupled Plasma ◽  
Flow Reactor ◽  
Plug Flow ◽  
Optical Emission ◽  
Catalytic Performance ◽  
Emission Spectrometry ◽  
Hydrogen Yield ◽  
X Ray ◽  
Temperature Programmed

The effects of Mg and Zn dopants on the catalytic performance of Pt/Al2O3 catalyst were investigated for dehydrogenation of perhydrodibenzyltoluene (H18-DBT) as a liquid organic hydrogen carrier. Al2O3 supports were modified with Mg and Zn to produce Mg-Al2O3 and Zn-Al2O3 with a target loading of 3.8 wt.% for dopants. The modified supports were impregnated with chloroplatinic acid solution to produce the catalysts Pt/Al2O3, Pt/Mg-Al2O3 and Pt/Zn-Al2O3 of 0.5 wt.% Pt loading. Thereafter, the catalysts were characterised using inductively coupled plasma- optical emission spectrometry, scanning electron microscopy-energy dispersive X-ray spectroscopy, hydrogen temperature-programmed reduction, carbon-monoxide pulse chemisorption, ammonia temperature-programmed desorption, X-ray diffraction and transmission electron microscopy. The dehydrogenation experiments were performed using a horizontal plug flow reactor system and the catalyst time-on-stream was 22 h. Pt/Mg-Al2O3 showed the highest average hydrogen flowrate of 29 nL/h, while an average of 27 nL/h was obtained for both Pt/Al2O3 and Pt/Zn-Al2O3. This has resulted in a hydrogen yield of 80% for Pt/Mg-Al2O3, 71% for Pt/Zn-Al2O3 and 73% for Pt/Al2O3. In addition, the conversion of H18-DBT ranges from 99% to 92%, Pt 97–90% and 96–90% for Pt/Mg-Al2O3, Pt/Zn-Al2O3 and Pt/Al2O3, respectively. Following the latter catalyst order, the selectivity to dibenzyltoluene (H0-DBT) ranges from 78% to 57%, 75–51% and 71–45%. Therefore, Pt/Mg-Al2O3 showed improved catalytic performance towards dehydrogenation of H18-DBT.

Theoretical and experimental investigation of point defects in cubic boron nitride

MRS Advances ◽  
2017 ◽  
Vol 2 (29) ◽  
pp. 1545-1550 ◽  
Author(s):  
Nicholas L. McDougall ◽  
Jim G. Partridge ◽  
Desmond W. M. Lau ◽  
Philipp Reineck ◽  
Brant C. Gibson ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Optical Emission ◽  
Wide Band ◽  
Wide Band Gap ◽  
Edge Structure ◽  
X Ray ◽  
Substitutional Defects ◽  
X Ray Absorption ◽  
Annealing Experiments

ABSTRACTCubic boron nitride (cBN) is a synthetic wide band gap material that has attracted attention due to its high thermal conductivity, optical transparency and optical emission. In this work, defects in cBN have been investigated using experimental and theoretical X-ray absorption near edge structure (XANES). Vacancy and O substitutional defects were considered, with O substituted at the N site (ON) to be the most energetically favorable. All defects produce unique signatures in either the B or N K-edges and can thus be identified using XANES. The calculations coupled with electron-irradiation / annealing experiments strongly suggest that ON is the dominant defect in irradiated cBN and remains after annealing. This defect is a likely source of optical emission in cBN.

Corrosion Behaviours of Mo Modified Ti6Al4V Alloy in Hank’s Solution

2009 ◽  
Vol 610-613 ◽  
pp. 1150-1154
Author(s):  
Ai Lan Fan ◽  
Cheng Gang Zhi ◽  
Lin Hai Tian ◽  
Lin Qin ◽  
Bin Tang
Keyword(s):  
Electrochemical Corrosion ◽  
Optical Emission ◽  
Ti6al4v Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Layers ◽  
Modified Layer ◽  
Surface Modified ◽  
Hank’S Solution ◽  
And Diffusion

The Mo surface modified layer on Ti6Al4V alloy was obtained by the plasma surface alloying technique. The structure and composition of the Mo modified Ti6Al4V alloy was investigated by X-ray diffraction (XRD) and glow discharge optical emission spectroscopy (GDOES). The Mo modified layer contains Mo coating on subsurface and diffusion layers between the subsurface and substrate. The X- ray diffraction analysis of the Mo modified Ti6Al4V alloy reveals that the outmost surface of the Mo modified Ti6Al4V alloy is composed of pure Mo. The electrochemical corrosion performance of the Mo modified Ti6Al4V alloy in 25°C Hank’s solution was investigated and compared with that of Ti6Al4V alloy. Results indicate that the self-corroding electric potential and the corrosion-rate of the Mo modified Ti6Al4V alloy are higher than that of Ti6Al4V alloy in 25°C Hank’s solution.

scholarly journals Using SEM-EDX and ICP-OES to Investigate the Elemental Composition of Green MacroalgaVaucheria sessilis

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Izabela Michalak ◽  
Krzysztof Marycz ◽  
Katarzyna Basińska ◽  
Katarzyna Chojnacka
Keyword(s):  
Elemental Composition ◽  
Cross Section ◽  
Inductively Coupled Plasma ◽  
Algal Biomass ◽  
Optical Emission Spectroscopy ◽  
Optical Emission ◽  
Icp Oes ◽  
X Ray ◽  
Inductively Coupled ◽  
Analytical System

The biomass ofVaucheria sessilisforms algal mats in many freshwaters. There is a need to find the method of algal biomass utilization.Vaucheria sessilisis a rich source of micro- and macronutrients and can be used as a soil amendment. In the paper, the elemental composition of enriched, via bioaccumulation process, macroalga was investigated. For this purpose, two independent techniques were used: scanning electron microscopy with an energy dispersive X-ray analytical system (SEMEDX) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The biomass was exposed to two microelemental solutions, with Cu(II) and Zn(II) ions. After two weeks of the experiment, macroalga accumulated 98.5 mg of Zn(II) ions in 1 g of dry biomass and 68.9 mg g−1of Cu(II) ions. Micrographs performed by SEM proved that bioaccumulation occurred. Metal ions were bound on the surface and in the interior of cells. Mappings of all cations showed that in the case of the surface of biomass (biosorption), the elements constituted aggregations and in the case of the cross section (bioaccumulation) they were evenly distributed. The algal biomass with permanently bound microelements can find an application in many branches of the industry (feed, natural fertilizers, etc.).

Time Evolution of Optical Emission Spectrum of a Hg-HID Lamp Exposed to X-ray

2010 ◽  
Vol 30 (4) ◽  
pp. 449-459 ◽  
Author(s):  
N. A. Harabor ◽  
A. Harabor ◽  
I. Palarie ◽  
I. M. Popescu ◽  
G. Zissis
Keyword(s):  
Emission Spectrum ◽  
Time Evolution ◽  
Optical Emission ◽  
Optical Emission Spectrum ◽  
X Ray

scholarly journals Constraining Soft and Hard X-Ray Irradiation in Ultraluminous X-Ray Sources

2021 ◽  
Vol 922 (2) ◽  
pp. 91
Author(s):  
Yanli Qiu ◽  
Hua Feng
Keyword(s):  
Optical Emission ◽  
Current Data ◽  
Compact Objects ◽  
X Rays ◽  
Optical Counterpart ◽  
X Ray ◽  
Outer Disk ◽  
Stringent Constraint ◽  
Supercritical Accretion ◽  
Key Questions

Abstract Most ultraluminous X-ray sources (ULXs) are argued to be powered by supercritical accretion onto compact objects. One of the key questions regarding these objects is whether or not the hard X-rays are geometrically beamed toward the symmetric axis. We propose testing the scenario using disk irradiation to see how much the outer accretion disk sees the central hard X-rays. We collect a sample of 11 bright ULXs with an identification of a unique optical counterpart, and model their optical fluxes considering two irradiating sources: soft X-rays from the photosphere of the optically thick wind driven by supercritical accretion, and if needed in addition, hard X-rays from the Comptonization component. Our results indicate that the soft X-ray irradiation can account for the optical emission in the majority of ULXs, and the fraction of hard X-rays reprocessed on the outer disk is constrained to be no more than ∼10−2 in general. Such an upper limit is well consistent with the irradiation fraction expected in the case of no beaming. Therefore, no stringent constraint on the beaming effect can be placed according to the current data quality.

Study of Optical Emission During Spallative Ablation Induced by Soft X-Ray Laser Pulses

2015 ◽  
pp. 405-409
Author(s):  
M. Ishino ◽  
M. Nishikino ◽  
N. Hasegawa ◽  
T. Pikuz ◽  
I. Skobelev ◽  
...  
Keyword(s):  
Optical Emission ◽  
Laser Pulses ◽  
X Ray

scholarly journals ROSAT observation of the HII region RCW 49 Possible discovery of a new Wolf-Rayet ring nebula

1995 ◽  
Vol 163 ◽  
pp. 76-77
Author(s):  
S. Mereghetti ◽  
T. Belloni
Keyword(s):  
Optical Emission ◽  
Young Star ◽  
Star Cluster ◽  
X Rays ◽  
Diffuse Emission ◽  
Hii Region ◽  
X Ray ◽  
Ring Nebula

We have observed the southern HII region RCW 49 with the ROSAT PSPC instrument. Part of the diffuse X-ray and optical emission present in this region might be associated with the X-ray selected WR star Th35-42 (WR20c). The young star cluster Westerlund 2 (which contains WR20a) is seen in X-rays as a centrally peaked, resolved source, surrounded by fainter diffuse emission.

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