scholarly journals Titanium Production via Titanium Sulfide

2020 ◽  
Vol 321 ◽  
pp. 07003
Author(s):  
R. O. Suzuki ◽  
Y. Yashima ◽  
N. Suzuki ◽  
E. Ahmadi ◽  
S. Natsui ◽  
...  
Keyword(s):  
Water Contamination ◽  
Gas Flow ◽  
Metallurgical Process ◽  
Mixed Gas ◽  
Low Level ◽  
Titanium Sulfide ◽  
Calciothermic Reduction ◽  
Solubility Of Oxygen ◽  
Ti Powder ◽  
Small Solubility

A new metallurgical process via titanium sulfide from ilmenite is proposed and experimentally approved: It consists of several stages; 1) The ilmenite ore is exposed to gaseous CS2 to selectively sulfurize to FeS, which is wet-chemically removed. 2) The residual oxide is again exposed to CS2 to form TiS2. 3) TiS2 is electrochemically reduced to metallic Ti using molten CaCl2-CaS as an application of OS process. TiFeO3 was exposed to Ar-CS2 mixed gas flow at 1173 K to form the mixture of FeS+TiO2. FeS was easily separated by immersing in H2SO4 solution at 313 K. After recovery of TiO2, it was converted completely to TiS2 by the second sulfurization with CS2. TiS2 could be reduced to Ti powder by calciothermic reduction and simulteneous electrolysis in a CaS-CaCl2 melt for about 6 hours at 1173 K and 3.0 V. The impurity decreased to a low level such as 0.021 mass%S due to very small solubility of S in a-Ti. However, 1.06 mass%O remained because of wide solubility of oxygen in a-Ti and water contamination in initial CaCl2.

Highly optimized CO2 capture by inexpensive nanoporous covalent organic polymers and their amine composites

2015 ◽  
Vol 183 ◽  
pp. 401-412 ◽  
Author(s):  
Hasmukh A. Patel ◽  
Cafer T. Yavuz
Keyword(s):  
Flue Gas ◽  
Gas Flow ◽  
Low Cost ◽  
High Specific Surface Area ◽  
Organic Polymers ◽  
Mixed Gas ◽  
Gas Streams ◽  
Promising Application ◽  
Adsorption Of Co ◽  
Adsorption Desorption

Carbon dioxide (CO2) storage and utilization requires effective capture strategies that limit energy penalties. Polyethylenimine (PEI)-impregnated covalent organic polymers (COPs) with a high CO2 adsorption capacity are successfully prepared in this study. A low cost COP with a high specific surface area is suitable for PEI loading to achieve high CO2 adsorption, and the optimal PEI loading is 36 wt%. Though the adsorbed amount of CO2 on amine impregnated COPs slightly decreased with increasing adsorption temperature, CO2/N2 selectivity is significantly improved at higher temperatures. The adsorption of CO2 on the sorbent is very fast, and a sorption equilibrium (10% wt) was achieved within 5 min at 313 K under the flow of simulated flue gas streams. The CO2 capture efficiency of this sorbent is not affected under repetitive adsorption–desorption cycles. The highest CO2 capture capacity of 75 mg g−1 at 0.15 bar is achieved under dry CO2 capture however it is enhanced to 100 mg g−1 in the mixed gas flow containing humid 15% CO2. Sorbents were found to be thermally stable up to at least 200 °C. TGA and FTIR studies confirmed the loading of PEIs on COPs. This sorbent with high and fast CO2 sorption exhibits a very promising application in direct CO2 capture from flue gas.

scholarly journals La Jolla Natural Radiocarbon Measurements VII

Radiocarbon ◽  
1977 ◽  
Vol 19 (1) ◽  
pp. 19-48 ◽  
Author(s):  
T W Linick
Keyword(s):  
Radiocarbon Dating ◽  
Gas Flow ◽  
Guard Ring ◽  
Low Level ◽  
Center Volume ◽  
La Jolla

Radiocarbon dating of many types of samples has continued at the La Jolla Radiocarbon Laboratory since the last date list was published (Bien and Pandolfi, 1972). Since the 1969 relocation of the laboratory to its present location on Mt Soledad, at least 5 low-level14C systems have generally been in operation. The laboratory has continued to employ acetylene gas proportional counting. Samples were usually measured for 2 to 3 days in each of 2 different detectors. The properties of the 5 counters used in the measurements of samples are as follows (background and net standard counts per minute, respectively, with acetylene of 900mmHg pressure are given in parentheses): 1) Bern counter: Oeschger-type counter-guard ring unit with 1.7L sensitive center volume (2.1, 21.5), 2) MBLE counter: Oeschger-type counter-guard ring unit with 1.6L center volume (1.3, 17.4), 3) 1L counter with separate Q-gas flow guard ring (4.2, 12.9), 4) 0.4L counter with separate guard ring (1.2, 4.2), and 0.1L counter with separate guard ring (0.7, 1.2).

The Effect of Noncondensable Gas on Film Condensation Along a Vertical Plate in an Enclosed Chamber

1977 ◽  
Vol 99 (2) ◽  
pp. 257-262 ◽  
Author(s):  
Y. Mori ◽  
K. Hijikata ◽  
K. Utsunomiya
Keyword(s):  
Gas Flow ◽  
Convective Motion ◽  
Main Flow ◽  
Film Condensation ◽  
Vapor Flow ◽  
Mixed Gas ◽  
Convective Boundary ◽  
Molecular Weights ◽  
Noncondensable Gas ◽  
Enclosed Chamber

Experiments on film condensation including noncondensable gas in an enclosed chamber have been carried out to clarify the effects of molecular weights of vapor and noncondensable gas and the convective motion induced by the vapor flow. From the experimental results of R113-air and CH3OH-mixed gas of He and Ar, it is shown that the separation of vapor and gas in the main flow is realized when the direction of gas flow in free convective boundary layer driven by concentration distribution of gas is the same as that of supplied vapor, whereas the homogeneous main flow occurs in the case of counter direction. It is also shown that in case of the separation of vapor and gas in the main flow the heat transfer coefficient is higher than that for an homogeneous main flow.

scholarly journals Optimization of Mesa Etch for a Quasi-Vertical GaN Schottky Barrier Diode (SBD) by Inductively Coupled Plasma (ICP) and Device Characteristics

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 657 ◽  
Author(s):  
Yue Sun ◽  
Xuanwu Kang ◽  
Yingkui Zheng ◽  
Ke Wei ◽  
Pengfei Li ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Inductively Coupled Plasma ◽  
Gas Flow ◽  
Reverse Current ◽  
Schottky Barrier Diode ◽  
Chamber Pressure ◽  
Mixed Gas ◽  
Inductively Coupled ◽  
Icp Etching ◽  
Etching Mask

The optimization of mesa etch for a quasi-vertical gallium nitride (GaN) Schottky barrier diode (SBD) by inductively coupled plasma (ICP) etching was comprehensively investigated in this work, including selection of the etching mask, ICP power, radio frequency (RF) power, ratio of mixed gas, flow rate, and chamber pressure, etc. In particular, the microtrench at the bottom corner of the mesa sidewall was eliminated by a combination of ICP dry etching and tetramethylammonium hydroxide (TMAH) wet treatment. Finally, a highly anisotropic profile of the mesa sidewall was realized by using the optimized etch recipe, and a quasi-vertical GaN SBD was demonstrated, achieving a low reverse current density of 10−8 A/cm2 at −10 V.

scholarly journals Influence of Gas Supply Changes on the Formation Process of Complex Mixed Gas Hydrates

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3039
Author(s):  
Mengdi Pan ◽  
Judith M. Schicks
Keyword(s):  
Gas Hydrates ◽  
Gas Hydrate ◽  
Formation Process ◽  
Gas Flow ◽  
Hydrate Formation ◽  
Experimental Investigations ◽  
Gas Composition ◽  
Mixed Gas ◽  
Hydrate Phase ◽  
Gas Supply

Natural gas hydrate occurrences contain predominantly methane; however, there are increasing reports of complex mixed gas hydrates and coexisting hydrate phases. Changes in the feed gas composition due to the preferred incorporation of certain components into the hydrate phase and an inadequate gas supply is often assumed to be the cause of coexisting hydrate phases. This could also be the case for the gas hydrate system in Qilian Mountain permafrost (QMP), which is mainly controlled by pores and fractures with complex gas compositions. This study is dedicated to the experimental investigations on the formation process of mixed gas hydrates based on the reservoir conditions in QMP. Hydrates were synthesized from water and a gas mixture under different gas supply conditions to study the effects on the hydrate formation process. In situ Raman spectroscopic measurements and microscopic observations were applied to record changes in both gas and hydrate phase over the whole formation process. The results demonstrated the effects of gas flow on the composition of the resulting hydrate phase, indicating a competitive enclathration of guest molecules into the hydrate lattice depending on their properties. Another observation was that despite significant changes in the gas composition, no coexisting hydrate phases were formed.

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