Low-cost manufacturing process for nanostructured metals and alloys

2002 ◽  
Vol 17 (10) ◽  
pp. 2484-2488 ◽  
Author(s):  
Travis L. Brown ◽  
Srinivasan Swaminathan ◽  
Srinivasan Chandrasekar ◽  
W. Dale Compton ◽  
Alexander H. King ◽  
...  

In spite of their interesting properties, nanostructured materials have found limited uses because of the cost of preparation and the limited range of materials that can be synthesized. It has been shown that most of these limitations can be overcome by subjecting a material to large-scale deformation, as occurs during common machining operations. The chips produced during lathe machining of a variety of pure metals, steels, and other alloys are shown to be nanostructured with grain (crystal) sizes between 100 and 800 nm. The hardness of the chips is found to be significantly greater than that of the bulk material.

Author(s):  
Marco Vinicio Alban ◽  
Haechang Lee ◽  
Hanul Moon ◽  
Seunghyup Yoo

Abstract Thin dry electrodes are promising components in wearable healthcare devices. Assessing the condition of the human body by monitoring biopotentials facilitates the early diagnosis of diseases as well as their prevention, treatment, and therapy. Existing clinical-use electrodes have limited wearable-device usage because they use gels, require preparation steps, and are uncomfortable to wear. While dry electrodes can improve these issues and have demonstrated performance on par with gel-based electrodes, providing advantages in mobile and wearable applications; the materials and fabrication methods used are not yet at the level of disposable gel electrodes for low-cost mass manufacturing and wide adoption. Here, a low-cost manufacturing process for thin dry electrodes with a conductive micro-pyramidal array is presented for large-scale on-skin wearable applications. The electrode is fabricated using micromolding techniques in conjunction with solution processes in order to guarantee ease of fabrication, high device yield, and the possibility of mass production compatible with current semiconductor production processes. Fabricated using a conductive paste and an epoxy resin that are both biocompatible, the developed micro-pyramidal array electrode operates in a conformal, non-invasive manner, with low skin irritation, which ensures improved comfort for brief or extended use. The operation of the developed electrode was examined by analyzing electrode-skin-electrode impedance, electroencephalography, electrocardiography, and electromyography signals and comparing them with those measured simultaneously using gel electrodes.


2021 ◽  
Author(s):  
Mohammad Salman Parvez ◽  
Md. Fazlay Rubby ◽  
Shanzida Kabir ◽  
Nazmul Islam

2015 ◽  
Vol 772 ◽  
pp. 263-267 ◽  
Author(s):  
Ramanathan Arunachalam ◽  
Majid Al-Maharbi ◽  
Yahya Al Kiyumi ◽  
Elyas Aal-Thani ◽  
Mohammed Al Mafraji

Metal matrix composites (MMC's) have attracted the attention of researchers for quite some time. In the last 15 years, many studies have been reported in this field of MMC production through various routes. The most commonly used process for producing MMC is stir casting process whereby the reinforcement material is incorporated into the molten metal by stirring. It is a relatively low cost manufacturing process that is capable of producing high quality MMC. However, the process is associated with issues such as attaining uniform distribution of particles, wettability between particles and porosity in the MMCs. Because of these challenges, there has been continuous improvement in the process as well as the design of the furnace. In this research, an innovatively designed bottom tapping furnace has been used to produce the MMCs and the produced sample is characterized.


2006 ◽  
Vol 2006 ◽  
pp. 1-12
Author(s):  
A. Korobeinikov ◽  
P. Read ◽  
A. Parshotam ◽  
J. Lermit

It has been suggested that the large scale use of biofuel, that is, fuel derived from biological materials, especially in combination with reforestation of large areas, can lead to a low-cost reduction of atmospheric carbon dioxide levels. In this paper, a model of three markets: fuel, wood products, and land are considered with the aim of evaluating the impact of large scale biofuel production and forestry on these markets, and to estimate the cost of a policy aimed at the reduction of carbon dioxide in the atmosphere. It is shown that the costs are lower than had been previously expected.


2000 ◽  
Vol 2000.8 (0) ◽  
pp. 125-126
Author(s):  
Takeshi YAMADA ◽  
Takayuki TSUZUKU ◽  
Masashi HIROTA ◽  
Yukio KAWACHI ◽  
Shinichi YAMAMOTO

Author(s):  
Mohan Rao T. ◽  
K. Rajesh Kumar ◽  
G. Shyamala ◽  
R. Gobinath

With the growth of urbanization and industrialization, water bodies are getting polluted. Among various pollutants, phenol-based pollutants are common water pollutions which originate from wastewater discharged from processing manufacturing industries like petrochemical refineries, ceramic plants, textile processing, leather processing, synthetic rubbers, etc. These pollutants are toxic and have long-term ill effects on both humans and aquatic animals. Adsorption is well proven technique which is widely used for removal of pollutions from aqueous environments. But this process, is hindered due to the cost of adsorbents especially for large scale continuous processes. In this regard, adsorbents derived from waste biomass can be a great asset to reduce the cost of wastewater treatment. To meet this objective, coconut shells are chosen as biomass which is abundantly available from south east Asia. This biomass is converted into activated carbon and hence used to remove phenol from wastewater. Batch adsorption experiments were performed with different initial concentration, carbon dosage, pH and contact time. At a lower concentration of 50 mg/L of initial feed (phenol) concentration resulted in around 90% phenol removal and henceforth optimum results in phenol removal obtained in only 64%. Experimental results are in good agreement with Langmuir adsorption isotherm model and have shown a better fitting to the experimental data. These studies confirm that the coconut shell-based activated carbon could be used to effectively adsorb phenol from aqueous solutions.


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