01371nam a2200181 a 450000100080000000500110000800800410001910000200006024500630008026002430014352006970038665000120108365000240109565300080111965300260112770000190115370000170117213398232022-01-12       2008    bl uuuu     u00u1 u    #d1 aHAYES, M. H. B.  aBiochar and it's characterisations.h[electronic resource]  aIn: ANNUAL INTERNATIONAL MEETING OF THE INTERNATIONAL BIOCHAR INITIATIVE, 2., 2008, Newcastle. Biochar, sustainability and security in a changing climate. Newcastle: International Biochar Initiative, 2008. p. 16. Oral presentations.c2008  aNMR provides a powerful tool for studies of compositions of Biochars. However, the usual NMR procedures used for humic and SOM studies do not meet specific requirements for Biochars because pyrogenic materials present strong local magnetic susceptibility heterogeneities. Our data show that uses of CSA-filter and TOSS techniques make the pulse sequences very sensitive to imperfections in the pulses. We will show how we have used Variable Amplitude CP - (VACP)/MAS spectra and composite pulses in the CSA-filter and TOSS pulse sequences. In that way the component functionalities in a humic acid (HA) from a Terra Preta soil were successfully determined. Other techniques will be discussed.  aBiochar  aSoil organic matter  aNMR  aTerra preta de índio1 aNOVOTNY, E. H.1 aFLANAGAN, R.