Optimal Contract Selection for the Global Supply and Distribution of Raw Materials

2007 ◽  
Vol 46 (20) ◽  
pp. 6522-6539 ◽  
Author(s):  
Mukta Bansal ◽  
I. A. Karimi ◽  
Rajagopalan Srinivasan
2021 ◽  
Author(s):  
Amaury Borges-Miranda ◽  
Francisco José Silva-Mata ◽  
Isneri Talavera-Bustamante ◽  
Juan Jiménez-Chacón ◽  
Manuel Álvarez-Prieto ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 909
Author(s):  
Vladimir V. Popov ◽  
Maria Luisa Grilli ◽  
Andrey Koptyug ◽  
Lucyna Jaworska ◽  
Alexander Katz-Demyanetz ◽  
...  

The term “critical raw materials” (CRMs) refers to various metals and nonmetals that are crucial to Europe’s economic progress. Modern technologies enabling effective use and recyclability of CRMs are in critical demand for the EU industries. The use of CRMs, especially in the fields of biomedicine, aerospace, electric vehicles, and energy applications, is almost irreplaceable. Additive manufacturing (also referred to as 3D printing) is one of the key enabling technologies in the field of manufacturing which underpins the Fourth Industrial Revolution. 3D printing not only suppresses waste but also provides an efficient buy-to-fly ratio and possesses the potential to entirely change supply and distribution chains, significantly reducing costs and revolutionizing all logistics. This review provides comprehensive new insights into CRM-containing materials processed by modern additive manufacturing techniques and outlines the potential for increasing the efficiency of CRMs utilization and reducing the dependence on CRMs through wider industrial incorporation of AM and specifics of powder bed AM methods making them prime candidates for such developments.


Omega ◽  
2019 ◽  
Vol 86 ◽  
pp. 198-217 ◽  
Author(s):  
Yong-Wu Zhou ◽  
Xiaogang Lin ◽  
Yuanguang Zhong ◽  
Wei Xie

Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.


Author(s):  
Chung-kook Lee ◽  
Yolande Berta ◽  
Robert F. Speyer

Barium hexaferrite (BaFe12O19) is a promising candidate for high density magnetic recording media due to its superior magnetic properties. For particulate recording media, nano-sized single crystalline powders with a narrow size distribution are a primary application requirement. The glass-crystallization method is preferred because of the controllability of crystallization kinetics, hence, particle size and size distribution. A disadvantage of this method is the need to melt raw materials at high temperatures with non-reactive crucibles, e.g. platinum. However, in this work, we have shown that crystal growth of barium hexaferrite occurred during low temperature heat treatment of raw batches.


2019 ◽  
Vol 28 (3) ◽  
pp. 1000-1009
Author(s):  
Allison Bean ◽  
Lindsey Paden Cargill ◽  
Samantha Lyle

Purpose Nearly 50% of school-based speech-language pathologists (SLPs) provide services to school-age children who use augmentative and alternative communication (AAC). However, many SLPs report having insufficient knowledge in the area of AAC implementation. The objective of this tutorial is to provide clinicians with a framework for supporting 1 area of AAC implementation: vocabulary selection for preliterate children who use AAC. Method This tutorial focuses on 4 variables that clinicians should consider when selecting vocabulary: (a) contexts/environments where the vocabulary can be used, (b) time span during which the vocabulary will be relevant, (c) whether the vocabulary can elicit and maintain interactions with other people, and (d) whether the vocabulary will facilitate developmentally appropriate grammatical structures. This tutorial focuses on the role that these variables play in language development in verbal children with typical development, verbal children with language impairment, and nonverbal children who use AAC. Results Use of the 4 variables highlighted above may help practicing SLPs select vocabulary that will best facilitate language acquisition in preliterate children who use AAC.


2013 ◽  
Vol 22 (1) ◽  
pp. 4-15 ◽  
Author(s):  
Laura J. Ball ◽  
Joanne Lasker

Abstract For adults with acquired communication impairment, particularly those who have communication disorders associated with stroke or neurodegenerative disease, communication partners play an important role in establishing and maintaining communicative competence. In this paper, we assemble some evidence on this topic and integrate it with current preferred practice patterns (American Speech-Language-Hearing Association, 2004). Our goals are to help speech-language pathologists (SLPs) identify and describe partner-based communication strategies for adults with acquired impairment, implement evidence-based approaches for teaching strategies to communication partners, and employ a Personnel Framework (Binger et al., 2012) to clarify partners? roles in acquiring and supporting communication tools for individuals with acquired impairments. We offer specific guidance about AAC techniques and message selection for communication partners involved with chronic, degenerative, and end of life communication. We discuss research and provide examples of communication partner supports for person(s) with aphasia and person(s) with amyotrophic lateral sclerosis who have complex communication needs.


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