scholarly journals Advanced Technology Developments for Europa Lander and other In-Situ Ocean World Missions

2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Ray Crum ◽  
Gary Bolotin ◽  
Erik Brandon ◽  
Polly Estabrook ◽  
John Gallon ◽  
...  
Keyword(s):  
Advanced Technology ◽  
World Missions

Thermodynamic Evaluation for the Synthesis of T2 Phase from Elemental Powders via In Situ Reactively Hot-Pressing

2012 ◽  
Vol 538-541 ◽  
pp. 2082-2085
Author(s):  
Lai Qi Zhang ◽  
Lei Huang ◽  
Yong Ming Hou ◽  
Jun Pin Lin
Keyword(s):  
High Temperature ◽  
Hot Pressing ◽  
Initial Temperature ◽  
Adiabatic Temperature ◽  
Advanced Technology ◽  
Thermodynamic Evaluation ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Different Temperatures

T2 phase(Mo5SiB2) is a key component of the two Mo-Si-B tri-phase alloys under hot research. However, there is little research on T2 phase, especially its mechanic characteristics, due to the difficulty of fabrication of pure T2. In this present work, the thermodynamics of an advanced technology to fabricate pure T2 phase i.e. IRHP (In-situ Reactively Hot-Pressing) using elemental powders was analyzed. Formation free enthalpies at different temperatures for the compounds in Mo-Si-B system were calculated. Adiabatic temperatures and molten fractions of T2 phase at different initial temperatures for the reaction of synthesizing T2 phase were evaluated. The results show that it is feasible to in-situ synthesize T2 phase from elemental powders. T2 phase can not be synthesized using SHS(Self-propagating High-temperature Synthesis) mode of combustion. On the contrary, the explosion mode of combustion (IRHP) is receivable. Adiabatic temperature and molten fraction of T2 phase are relevant to initial temperature.

scholarly journals In-Situ Repair Plasma-Induced Damage and Cap Dielectric Barrier for Porous Low-Dielectric-Constant Materials by HMDS Plasma Treatment

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 314
Author(s):  
Chih-Yen Lee ◽  
Chi-Yang Yan ◽  
Yi-Lung Cheng
Keyword(s):  
Dielectric Constant ◽  
Plasma Treatment ◽  
Metal Ion ◽  
Treatment Time ◽  
Advanced Technology ◽  
Low Dielectric Constant ◽  
Plasma Damage ◽  
Low Dielectric ◽  
Low K

Plasma damage and metal ion penetration are critical issues for porous low-dielectric-constant (low-k) materials used in the back-end-of-line interconnects. This study proposed a novel process with in-situ repairing plasma-induced damage and capping a barrier for porous low-k materials by Hexamethyldisilazane (HDMS) plasma treatment. For a plasma-damaged porous low-k material, its surface hydrophilic state was transformed to hydrophobic state by HDMS plasma treatment, revealing that damage was repaired. Simultaneously, a dielectric film was capped onto the porous low-k material, and displayed better barrier capability against Cu migration. Additionally, the breakdown reliability of the stacked dielectric was enhanced by the means of HDMS plasma treatment. The optimized HDMS plasma treatment time was found to be 10 s. Therefore, this proposed HDMS plasma treatment processing is a promising technique for highly applicable low-k material used for advanced technology nodes.

scholarly journals Prospects for selective-and-advanced recovery of rhenium from pregnant solutions of in-situ leaching of uranium ores at Dobrovolnoye deposit

2021 ◽  
Vol 6 (3) ◽  
pp. 158-169
Author(s):  
A. A. Rudenko ◽  
I. D. Troshkina ◽  
V. V. Danileyko ◽  
O. S. Barabanov ◽  
F. Ya. Vatsura
Keyword(s):  
Uranium Deposit ◽  
English Literature ◽  
Selective Extraction ◽  
Ammonia Solution ◽  
Product Recovery ◽  
Advanced Technology ◽  
Measuring Instruments ◽  
Ammonium Perrhenate ◽  
A Chain

Analysis of exploration materials and market conditions showed that by-product recovery of rhenium, one of the rarest strategic elements of the periodic system, was not always effective in processing the whole volume of pregnant uranium-bearing solutions. The main goal of the research was to develop an effective method for recovery rhenium from pregnant solutions in in-situ uranium leaching. The objectives of the research were as follows: evaluation of the possibility of selective-and-advanced recovery of rhenium from ores by in-situ leaching method and comparison of the technological advantages of the new proposed method with the known ones. The study involved the analysis of historical geological, mineralogical and geochemical information on the Dobrovolnoye deposit and analysis of technological aspects of by-product recovery of rhenium in the world practice. A selective-and-advanced scheme of rhenium recovery from pregnant uranium-bearing sulfate (sulfuric acid) solutions of the Dobrovolnoye deposit ISL (Russia) using mobile installations was proposed. The process has the following features: zoning of production blocks when constructing injection and extraction (pumping) wells; piping of selective extraction wells into a separate collecting pipe; implementation of advanced rhenium sorption. The process implementation makes it possible to obtain rhenium from economically viable areas of the uranium deposit. The mobile installation includes the following main units: a filter for purification (aftertreatment) to remove suspension, a chain of sorption apparatuses (sorption filters or columns), connecting fittings, control and measuring instruments. The sorption apparatuses are filled with rhenium-selective ionite (ion exchanger). As a selective sorbent for the primary concentration of rhenium from sulfate solutions (pH 2), weakly basic nitrogen-bearing ionites containing amine functional groups of various types can be used. If further concentration of rhenium is required, in order to unify the equipment used, materials with a mobile extractant phase (so-called TVEXs (solid extractants or Levextrel resins in English literature) and so-called “impregnated” or “impregnates”), such as TVEX-DIDA containing diisododecyl amine, or TAA-impregnate containing trialkylamine, can be used. Rhenium desorption from these materials is carried out by an ammonia solution, which allows producing rough ammonium perrhenate from the eluate. Economic aspects of the rhenium selective-andadvanced technology were evaluated. Implementation of the recovery selective-and-advanced technology allows obtaining rhenium from economically-viable areas of the uranium deposit.

Bronze Age: Technology, Trade, and Increasing Social Complexity

2017 ◽  
Author(s):  
Mick Atha ◽  
Kennis Yip
Keyword(s):  
Bronze Age ◽  
Local Community ◽  
Cultural Development ◽  
Advanced Technology ◽  
Social Hierarchies ◽  
Surplus Production ◽  
Fine Quartz ◽  
Trade And Exchange ◽  
Bronze Casting

Chapter 5 examines one of Sha Po’s most fascinating and important periods of cultural development, the Bronze Age, a period during which the local community was making wider and more specialised use of the coastal landscape. On the plateau there was some form of stilt-house settlement associated with the specialised manufacture of fine quartz rings, while on the backbeach we have the region’s best evidence for non-ferrous metallurgy in the form of in situ bronze casting. The evidence for craft specialisation tells us that society was undergoing change and could perhaps support the work of artisans through some form of surplus production of food. Moreover, access to more advanced technology and exotic materials are both indications of a widening of external contacts, trade, and exchange, while a heightened interest in personal ornamentation and display points towards greater competition and the emergence of social hierarchies.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

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