The president of the Liberia Marketing Association (LMA), Madam Lusu K. Sloan, has called on the government to address the issue of dual currency in the country. Madam Sloan made the call, recently at a roundtable symposium on the economic and constitutional implications of Liberia’s dual currency regime in Monrovia. The round table discussion was organized by the Governance Commission in partnership with the Constitution Review Committee, and it brought together several state actors from public and private sectors. According to Madam Sloan, business women and petty traders are calling for local business transactions to be done in Liberian dollars. She said local traders are not making profit because they are buying their goods in US dollars from foreign importers and selling them in Liberian dollars. As a result, the LMA president said, local traders, especially market women, are selling without adequate income from the business to better their living conditions. She stressed that dual currency is causing instability of the Liberian economy and not improving the livelihood of local marketers or the economy. The LMA boss highlighted that dual currency is increasing countless problems as many schools are charging fees in US dollars, instead of in Liberian dollars. “We actually want the government and those that are in charge to look at the situation carefully; we are selling our goods and services in Liberian dollars, but some schools are charging fees in US dollars. I don’t think it is supposed to be that way. You can’t have your school in Liberia and charge the parents in US dollars,” she said.Madam Sloan indicated that foreign importers are taking excess US dollars from Liberia to develop their countries, while Liberia remains under-developed. “Buying in US dollars from the importers, selling the goods in Liberian dollars and at the end of the day you have to change the Liberian dollars to US dollars to re-buy drops the profit margin. So you see, more money is going out of the country on a daily basis, because they come here to look for US dollars to carry it,” the LMA president asserts. She wants the government to monitor the behavior of importers toward retailers to enable the local traders to profit from their businesses. Madam Sloan said the National Legislature in collaboration with the relevant authorities should put in place policies to stabilize the Liberian dollar on the market, adding that it is losing its relevance.Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)
Research scientists have created the first non-carbon-based material with a hardness approaching that of diamond. Their work could have a significant impact on technologies and industries that rely on diamond as a cutting and drilling tool and abrasive. Extremely hard yet metallically conductive: Researchers develop novel material with high-tech prospects Explore further Citation: Scientists Create First Non-Carbon Material with Near-Diamond Hardness (2007, March 28) retrieved 18 August 2019 from https://phys.org/news/2007-03-scientists-non-carbon-material-near-diamond-hardness.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. The material is a boron nitride “nanocomposite.” This means that, rather than consisting of one large continuous crystal, it is made of crystalline boron-nitride grains that are each a few to several nanometers in size. Although research groups have previously reported boron carbonitride materials, claimed to be the second and third hardest materials after diamond, the particular versions, or “phases,” of those materials were unstable at high temperatures. In industry, this is a major drawback.“The real breakthrough would be a bulk material that is hard, tough, and thermally stable, and thus ideal for cutting and drilling. We are the first to synthesize a bulk noncarbon material that fits this description,” said Natalia Dubrovinskaia, a researcher with the University of Heidelberg and the University of Bayreuth, both in Germany, to PhysOrg.com. Dubrovinskaia is the lead author of the paper describing the new material, which appears in the March 8 edition of Applied Physics Letters.For many materials composed of crystalline grains, also referred to as polycrystalline materials, there is a grain size for which the material’s hardness is optimized. This size is often in the nanometer range.Along this line of thought, Dubrovinskaia and her colleagues synthesized and conducted several experiments on a series of polycrystalline and nanocrystalline phases of boron nitride. This characterization included measuring the samples’ “Vickers hardness,” a test that assigns a hardness value to a material based on how readily it is indented by diamond. That value can be expressed in terms of the pressure applied by the diamond – using the pressure unit “pascal” – before it makes an indentation. For very hard materials that usually means billions of pascals (gigapascals, GPa). Single-crystal diamond, the hardest type, has a hardness of about 100 GPa.The boron nitride nanocomposite synthesized by Dubrovinskaia and her group displayed a maximum hardness of 85 GPa at a grain size of about 14 nanometers, and is thermally stable up to 1600 degrees Kelvin (about 2400 degrees Fahrenheit). The material’s hardness arises from two factors: the nanoscale-grain-size effect and each grain’s two-phase composition. That is, each grain has a nanoscale crystalline structure and a sub-nanoscale structure. This complex composition significantly increases the bulk material’s mechanical strength.Prior to this research, the next hardest known material after single-crystal diamond was cubic boron nitride, a single-crystal phase of the material, which has a Vickers hardness of 50 GPa. That leaves a rather large 50 GPa gap.“This gap can be filled by boron nitride nanocomposites, particularly by tuning their grain size and the compositional structure of the grains,” says Dubrovinskaia. “These materials may come to play an important role in industry.”Citation: Natalia Dubrovinskaia, Vladimir L. Solozhenko, Nobuyoshi Miyajima, Vladimir Dmitriev, Oleksandr O. Kurakevych, and Leonid Dubrovinsky, “Superhard nanocomposite of dense polymorphs of boron nitride: Noncarbon material has reach diamond hardness.” Appl. Phys. Lett. 90, 101912 (2007)Copyright 2007 PhysOrg.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed in whole or part without the express written permission of PhysOrg.com.