scholarly journals The Ablation Casting Process

2009 ◽  
Vol 618-619 ◽  
pp. 591-594 ◽  
Author(s):  
John Grassi ◽  
John Campbell ◽  
Martin Hartlieb ◽  
Fred Major

A new patented casting process is described, based on a precision aggregate mold, bonded with a water-soluble binder. For the first time the twin functions of the mold (i) defining shape and (ii) providing cooling have been successfully separated allowing the production of castings of all sizes and shapes (thin and thick walls) for all Al and Mg alloys. Because solidification and cooling are separately controlled by the application of water a number of advantages follow immediately. The mold is ablated (i.e. eroded) away by the water without fume or dust and the ‘air gap’ is eliminated by direct contact with the water, enhancing the rate of solidification to levels normally unattainable, resulting in significantly enhanced properties. The unusual microstructures of Al-Si alloys having large DAS but micron-sized eutectic silicon indicates, in agreement with earlier predictions, that DAS per se does not control strength or ductility. The process is currently proving itself in commercial operation, having the additional advantages of modest start-up and tooling costs as well as low competitive piece part costs because of the use of low cost materials and the recycling of aggregate and water.

2020 ◽  
Vol 49 (1) ◽  
pp. 19-25
Author(s):  
Hamid Javaherian Naghash ◽  
Ali Amiri

Purpose This paper aims to improve some properties of poly (methyl methacrylate) by copolymerization with butyl acrylate (BA) monomer along with the incorporation of the stable and economical synthesized silicone-containing monomer hexamethyldisilazanomethacryloxyphenyl ketone (HDMK) into the copolymer matrix. Design/methodology/approach For this target solution copolymerization of methyl methacrylate (MMA), BA and HDMK were carried out using a 250 mL four-necked round-bottom flask. Before solution polymerization start-up, the reaction vessel was first charged with 34.8 mL toluene and heated to 170 °C with stirring and reflux cooling. A monomer mixture of 25.86 g (260 mmol) MMA, 26.40 g (200 mmol) BA, 3.00 g (8.60 mmol) HDMK and 0.45 g (2.00 mmol) dibenzoyl peroxide was added continuously from the dropping funnel over a period of 4 h. Findings The HDMK was successfully synthesized and the water resistance of acrylic resins was improved because of the existence of HDMK. Research limitations/implications The materials that were used in this research paper had a reasonably low cost. Also, the procedures for synthesis of monomers and polymers were extremely easy because there was no need for high pressure or temperature and no dangerous solvents were used. Practical implications The acrylic resin that contained HDMK was used to synthesis a white architectural paint for exterior coating. Examining the paint characteristics has shown acceptable washing and abrasion resistance, good brushing, excellent storage stability and great surface coating. Originality/value HDMK was synthesized for the first time.


1968 ◽  
Vol 20 (03/04) ◽  
pp. 588-595 ◽  
Author(s):  
E. B Goodsell ◽  
R. A Krause ◽  
E. T Kimura

SummaryUbiquin (oligo-3-(N-methylmorpholinium)-l,2-propylene oxide chloride) is a stable, water soluble, active heparin antagonist producing prompt neutralization when administered in a 1:1 ratio to rats and dogs. Initial studies indicate that it is devoid of any effect on coagulation per se; nor are there any obvious side effects manifested during the process of neutralization. The acute toxicity is less than that of other compounds in use: toluidine blue, protamine and hexadimethrine.


2019 ◽  
Vol 1 (1) ◽  
pp. 89-92
Author(s):  
José Luis Albites Sanabria

John Mullins is a researcher, teacher and one of the world’s foremost thought leaders in entrepreneurship. Over the years, John has been hailed as an inspiration for entrepreneurs who have employed the models outlined in books such as Getting to Plan B or The Customer-Funded Business, in order to transform their ideas into global startup companies. Now in its 5th edition, The New Business Road Test guides the reader through the complex yet gripping process of testing a business idea. How can you be completely sure that your list of start-up ideas is good or bad? How much time or money should you invest in each of these ideas? And, for first-time entrepreneurs, should you embark upon a start-up just because you love your idea? Should you leave a stable job and focus entirely on what feels to you like a good business idea? Mullins’ book offers thoughtful readers guidance on the thorny issues associated with entrepreneurship that you yourself may be facing even as you read this introduction. In order to fully understand the theories behind the tools and advice for testing your idea, we must start by understanding Mullins’ vision of the entrepreneurial world. The book begins by defining three elements crucial to the success of a business: the market, the industry, and the entrepreneurial team.


Author(s):  
Heinz Seltmann

AbstractThe effect of maleic hydrazide (MH) per se on bright tobacco was determined by comparing plants treated with MH to those without MH under conditions of good chemical sucker control. Sequential applications of each of five contact-type agents with MH one week later (Group I) were compared to dual applications of each of the same contact agents (Group II). In Group II suckers missed during applications were individually wetted to ensure excellent control. Sucker control was measured as 95 % for Group I and assumed to be 99 % for Group II. There were no agronomic differences between Groups I and II. In the visual warehouse appraisal, there was only a statistical difference for thin-bodied tobaccos between the two groups and a trend for slightly more heavy-bodied tobaccos in Group I. The chemical and physical analyses showed that filling value at 13 % moisture and equilibrium moisture content (EMC) measured at 60 % relative humidity were significantly lower in Group I than Group II. The result for EMC was questioned. Actual values for total alkaloids, total volatile bases minus nicotine, total ash, and alkalinity number of water-soluble ash were lower and reducing sugars were higher where MH was used. Except for EMC, the findings in this study reflected those established in studies where MH-treated and normally hand-suckered tobaccos were compared, but the differences here were generally not as great.


Author(s):  
Ole V. Petersen ◽  
Alexander P. Khomyakov ◽  
Henning Sørensen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Petersen, O. V., Khomyakov, A. P., & Henning. (2001). Natrophosphate from the Ilímaussaq alkaline complex, South Greenland. Geology of Greenland Survey Bulletin, 190, 139-141. https://doi.org/10.34194/ggub.v190.5184 _______________ The rare mineral natrophosphate has been identified for the first time in the Ilímaussaq alkaline complex in a drill core from the Kvanefjeld area. It occurs sparsely in zoned veinlets with cores of natrophosphate and borders of fibrous trona. The natrophosphate is more or less smoky, transparent and unaltered. The refractive index n = 1.448 ± 0.005 is low compared to that given for the material from the type locality, Khibina alkaline complex, Kola Peninsula; the unit cell parameter a = 27.76 ± 0.05 Å is in excellent agreement with that given for the material from the type locality. The veins occur in hyper-agpaitic naujakasite lujavrite; villiaumite is an associated mineral. Only a few water-soluble minerals have so far been found in the Ilímaussaq alkaline complex compared to the wealth of such minerals in the Khibina and Lovozero alkaline complexes. This is possibly at least partly due to lack of necessary precautions during sampling.


Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.


Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 1977
Author(s):  
Ricardo Oliveira ◽  
Liliana M. Sousa ◽  
Ana M. Rocha ◽  
Rogério Nogueira ◽  
Lúcia Bilro

In this work, we demonstrate for the first time the capability to inscribe long-period gratings (LPGs) with UV radiation using simple and low cost amplitude masks fabricated with a consumer grade 3D printer. The spectrum obtained for a grating with 690 µm period and 38 mm length presented good quality, showing sharp resonances (i.e., 3 dB bandwidth < 3 nm), low out-of-band loss (~0.2 dB), and dip losses up to 18 dB. Furthermore, the capability to select the resonance wavelength has been demonstrated using different amplitude mask periods. The customization of the masks makes it possible to fabricate gratings with complex structures. Additionally, the simplicity in 3D printing an amplitude mask solves the problem of the lack of amplitude masks on the market and avoids the use of high resolution motorized stages, as is the case of the point-by-point technique. Finally, the 3D printed masks were also used to induce LPGs using the mechanical pressing method. Due to the better resolution of these masks compared to ones described on the state of the art, we were able to induce gratings with higher quality, such as low out-of-band loss (0.6 dB), reduced spectral ripples, and narrow bandwidths (~3 nm).


AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Genan Wang ◽  
Bingyi Shi ◽  
Pan Zhang ◽  
Tingbin Zhao ◽  
Haisong Yin ◽  
...  

Abstractβ-poly(l-malic acid) (PMLA) is a water-soluble biopolymer used in medicine, food, and other industries. However, the low level of PMLA biosynthesis in microorganisms limits its further application in the biotechnological industry. In this study, corn steep liquor (CSL), which processes high nutritional value and low-cost characteristics, was selected as a growth factor to increase the PMLA production in strain, Aureobasidium melanogenum, and its metabolomics change under the CSL addition was investigated. The results indicated that, with 3 g/L CSL, PMLA production, cell growth, and yield (Yp/x) were increased by 32.76%, 41.82%, and 47.43%, respectively. The intracellular metabolites of A. melanogenum, such as amino acids, organic acids, and key intermediates in the TCA cycle, increased after the addition of CSL, and the enrichment analysis showed that tyrosine may play a major role in the PMLA biosynthesis. The results presented in this study demonstrated that the addition of CSL would be an efficient approach to improve PMLA production.


Rheumatology ◽  
1998 ◽  
Vol 37 (2) ◽  
pp. 137-142 ◽  
Author(s):  
B A Hills ◽  
M K Monds

Abstract Bovine articular cartilage and synovial fluid (SF) were co-incubated with one of three enzymes selected to destroy each of the three major contenders for the active ingredient imparting such remarkable load-bearing lubrication to the normal joint. Destroying hyaluronic acid (HA), alias hyaluronan, with hyaluronidase, both frictional and wear tests displayed no significant change in accordance with most previous studies of SF alone. Destroying surface-active phospholipid (SAPL) with phospholipase A2, there was a highly significant dose-dependent compromise of lubrication as recorded on both tests. Trypsin produced a somewhat surprising result in that lubrication of the cartilage actually improved. This result can be interpreted as indicating that lubricin is not the lubricant per se, but, as a water-soluble, macromolecular, proteinaceous carrier for phospholipid, its destruction caused more SAPL to be deposited as the true load-bearing lubricant. These results are discussed in the context that SAPL, lubricin and HA each have specific roles in a comprehensive lubrication system.


2016 ◽  
Vol 40 (5) ◽  
pp. 4756-4760 ◽  
Author(s):  
Bin Hua ◽  
Li Shao ◽  
Jiong Zhou ◽  
Guocan Yu

A water-soluble hybrid[4]arene was synthesized for the first time and its pH-responsive host–guest complexation with paraquat in water was investigated. This new host–guest recognition motif was further applied in the construction of a supra-amphiphile.


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