Browse by Author or creator

Haddrill, Penny and Nic Daeid, Niamh; (2014) Evaluating the value of Crimestoppers to Police Scotland. In: Scottish Institute for Policing Research Annual Report 2013/14. The Scottish Institute for Policing Research, Edinburgh, pp. 22-23.

Nic Daeid, Niamh and Savage, Kathleen A. and Ramsay, Donna and Holland, Ciara and Sutcliffe, Oliver B. (2014) Development of gas chromatography-mass spectrometry (GC-MS) and other rapid screening methods for the analysis of 16 'legal high' cathinone derivatives. Science and Justice, 54 (1). pp. 22-31. ISSN 1355-0306

Reed, Graham and Savage, K. and Edwards, D. and Nic Daeid, Niamh (2014) Hyperspectral imaging of gel pen inks : an emerging tool in document analysis. Science and Justice, 54 (1). 71 - 80. ISSN 1355-0306

Nic Daeid, Niamh and Jayaram, Saravana Kumar and Kerr, William (2013) Elemental profiling using ICPMS of methylamphetamine hydrochloride prepared from proprietary medication using the Moscow and hypophosphorous synthesis. Science and Justice, 53 (3). pp. 278-285. ISSN 1355-0306

Nic Daeid, Niamh and Jayaram, Saravana Kumar and Kerr, W. J. and Meier-Augenstein, Wolfram and Kemp, Helen F. (2013) Influence of precursor solvent extraction on stable isotope signatures of methylamphetamine prepared from over-the-counter medicines using the Moscow and Hypophosphorous routes. Analytical and Bioanalytical Chemistry, 405 (9). 2931–2941. ISSN 1618-2642

Walker, David and McIvor, Arthur and Nic Daeid, Niamh; (2013) The not so silent witness : developing a forensic science oral history project. In: Scottish Institute for Policing Research. Scottish Institute for Policing Research, pp. 30-31.

Nic Daeid, Niamh and Savage, Kathleen; Siegel, Jay A. and Saukko, Pekka J and Houck, Max M, eds. (2013) Classification of drugs of abuse. In: Encyclopaedia of Forensic Science. Elsevier, Amsterdam. ISBN 9780123821652

Wongniramaikul, Worawit and Choodum, Aree and Dennany, Lynn and Daeid, Niamh Nic (2012) A comprehensive chromatographic comparison of amphetamine and methylamphetamine extracted from river water using molecular imprinted polymers and without the need for sample derivatization. Journal of Separation Science, 35 (23). pp. 3332-3339. ISSN 1615-9306

Kunalan, Vanitha and Kerr, William and Nic Daeid, Niamh (2012) Clarification of route specific impurities found in methylamphetamine synthesised using the Birch method. Forensic Science International, 223 (1-3). pp. 321-329. ISSN 0379-0738

Sharkey, E. J. and Cassidy, M. and Brady, J. and Gilchrist, M. D. and NicDaeid, N. (2012) Investigation of the force associated with the formation of lacerations and skull fractures. International Journal of Legal Medicine, 126 (6). pp. 835-844. ISSN 0937-9827

Farrugia, Kevin and Riches, Philip and Bandey, H. and Savage, Kathleen and Nic Daeid, Niamh (2012) Controlling the variable of pressure in the production of test footwear impressions. Science and Justice, 52 (3). 168–176. ISSN 1355-0306

Farrugia, Kevin J. and Bandey, Helen and Dawson, Lorna and Daeid, Niamh Nic (2012) Chemical enhancement of soil based footwear impressions on fabric. Forensic Science International, 219 (1-3). 12–28. ISSN 0379-0738

Kunalan, Vanitha and Daeid, Niamh Nic and Kerr, William (2012) Investigation of the reaction impurities associated with methylamphetamine synthesized using the nagai method. Analytical Chemistry, 84 (13). pp. 5744-5752. ISSN 0003-2700

Fairley, C. and Bleay, S. M. and Sears, V. G. and NicDaeid, N. (2012) A comparison of multi-metal deposition processes utilising gold nanoparticles and an evaluation of their application to ‘low yield’ surfaces for finger mark development. Forensic Science International, 217 (1-3). pp. 5-18. ISSN 0379-0738

McGregor, Laura A. and Gauchotte-Lindsay, Caroline and Daeid, Niamh Nic and Thomas, Russell and Kalin, Robert M. (2012) Multivariate statistical methods for the environmental forensic classification of coal tars from former manufactured gas plants. Environmental Science and Technology, 46 (7). pp. 3744-3752.

Khreit, Osama I. G. and Irving, Craig and Schmidt, Elke and Parkinson, John A. and Daeid, Niamh Nic and Sutcliffe, Oliver B. (2012) Synthesis, full chemical characterisation and development of validated methods for the quantification of the components found in the evolved “legal high” NRG-2. Journal of Pharmaceutical and Biomedical Analysis, 61. pp. 122-135. ISSN 1873-264X

Hammer, Lesley and Duffy, Kate and Fraser, Jim and Nic Daeid, Niamh (2012) A study of the variability in footwear impression comparison conclusions. Journal of Forensic Identification. ISSN 0895-173X (In Press)

Daeid, Niamh Nic (2011) Onwards and upwards. Science and Justice, 51 (4). p. 149. ISSN 1355-0306

Choodum, A. and Daeid, N. N. (2011) Rapid and semi-quantitative presumptive tests for opiate drugs. Talanta, 86. pp. 284-292. ISSN 0039-9140

Mat-Desa, W. N. S. and Ismail, D. and NicDaeid, N. (2011) Classification and source determination of medium petroleum distillates by chemometric and artificial neural networks : a self organizing feature approach. Analytical Chemistry, 83 (20). pp. 7745-7754. ISSN 0003-2700

Buchanan, Hilary A. S. and Meier-Augenstein, Wolfram and Daeid, Niamh Nic and Kerr, William (2011) Organic impurities, stable isotopes, or both : a comparison of instrumental and pattern recognition techniques for the profiling of 3,4-methylenedioxymethamphetamine. Analytical Methods, 3 (10). pp. 2279-2288. ISSN 1759-9660

Santali, Eman Y. and Cadogan, Anna-Karina and Daeid, Niamh Nic and Savage, Kathleen A. and Sutcliffe, Oliver B. (2011) Synthesis, full chemical characterisation and development of validated methods for the quantification of (±)-4′-methylmethcathinone (mephedrone) : a new "legal high". Journal of Pharmaceutical and Biomedical Analysis, 56 (2). pp. 246-255. ISSN 1873-264X

Farrugia, Kevin J. and Savage, Kathleen A. and Bandey, Helen and Ciuksza, Tomasz and Daeid, Niamh Nic (2011) Chemical enhancement of footwear impressions in blood on fabric - Part 2: Peroxidase reagents. Science and Justice, 51 (3). pp. 110-121. ISSN 1355-0306

Farrugia, Kevin J. and Savage, Kathleen A. and Bandey, Helen and Daeid, Niamh Nic (2011) Chemical enhancement of footwear impressions in blood on fabric – Part 1 : protein stains. Science and Justice, 51 (3). pp. 99-109. ISSN 1355-0306

Keenan, Helen and Kates, Lisa and Kalin, Robert and Gauchotte-Lindsay, Caroline and Nic Daeid, Niamh and Knapp, Charles (2011) Environmental modelling of methylamphetamine waste. In: International Association of Forensic Sciences, 2011-09-12 - 2011-09-17. (Unpublished)

Daeid, Niamh Nic (2011) Is there a way forward for forensic science research in the UK? Science and Justice, 51 (3). pp. 89-90. ISSN 1355-0306

Sutcliffe, O. B. and Daeid, N. N. and Khreit, O. I. G. (2011) Tackling the forensic analytical challenges associated with the global increase in seizures of cathinone-derived "legal highs". Abstracts of papers - American Chemical Society, 242. 188-ANYL.

Kates, Lisa and Gauchotte-Lindsay, Caroline and Nic Daeid, Niamh and Knapp, Charles and Keenan, Helen (2011) Prediction of the environmental fate of methylamphetamine waste. In: International Network of the Environmental Forensics Conference, 2011-07-25 - 2011-07-27. (Unpublished)

McGregor, Laura A and Gauchotte-Lindsay, Caroline and Daéid, Niamh Nic and Thomas, Russell and Daly, Paddy and Kalin, Robert M (2011) Ultra resolution chemical fingerprinting of dense non-aqueous phase liquids from manufactured gas plants by reversed phase comprehensive two-dimensional gas chromatography. Journal of Chromatography A, 1218 (29). pp. 4755-4763. ISSN 0021-9673

Daeid, Niamh Nic and Meier-Augenstein, Wolfram and Kemp, Helen F. (2011) Investigating the provenance of un-dyed spun cotton fibre using multi-isotope profiles and chemometric analysis. Rapid Communications in Mass Spectrometry, 25 (13). pp. 1812-1816. ISSN 0951-4198

Choodum, Aree and Daeid, Niamh Nic (2011) Evaluating the performance of three GC columns commonly used for the analysis of ignitable liquid mixtures encountered in fire debris. Analytical Methods, 3 (7). pp. 1525-1534. ISSN 1759-9660

Kates, Lisa and Gauchotte-Lindsay, Caroline and Nic Daeid, Niamh and Kalin, Robert and Knapp, Charles and Keenan, Helen (2011) Who dumped the meth lab in the river? In: University Research Day, 2011-06-07 - 2011-06-07. (Unpublished)

Daeid, Niamh Nic (2011) The proposed Criminal Evidence (Experts) Bill......moving in the right direction..? Science and Justice, 51 (2). pp. 41-42. ISSN 1355-0306

Choodum, Aree and Daeid, Niamh Nic (2011) Development and validation of an analytical method for hydrocarbon residues using gas chromatography-mass spectrometry. Analytical Methods, 3 (5). pp. 1136-1142. ISSN 1759-9660

Choodum, Aree and Daeid, Niamh Nic (2011) Digital image-based colourimetric tests for amphetamine and methylamphetamine. Drug testing and analysis, 3 (5). pp. 277-282. ISSN 1942-7603

Aitken, Colin and Berger, Charles E. H. and Buckleton, John S. and Champod, Christophe and Curran, James and Dawid, A. P. and Evett, Ian W. and Gill, Peter and Gonzalez-Rodriguez, Joaquin and Jackson, Graham and Kloosterman, Ate and Lovelock, Tina and Lucy, David and Margot, Pierre and McKenna, Louise and Meuwly, Didier and Neumann, Cedric and Daeid, Niamh Nic and Nordgaard, Anders and Puch-Solis, Roberto and Rasmusson, Birgitta and Redmayne, Mike and Roberts, Paul and Robertson, Bernard and Roux, Claude and Sjerps, Marjan J. and Taroni, Franco and Tjin-A-Tsoi, Tjark and Vignaux, G. A. and Willis, Sheila M. and Zadora, Grzegorz (2011) Expressing evaluative opinions : a position statement. Science and Justice, 51 (1). pp. 1-2. ISSN 1355-0306

Nic Daeid, Niamh and Dzukiflee, Ismail, Fakulti Sains Kesihatan, Jabatan Sains Forensik, Universiti Sains Malaysia (USM), 16150, Malaysia. (2011) Comparison of smears of wax based products using thin layer chromatography (TLC) and microspectrophotometric (MSP) detection. Journal of Forensic Identification. ISSN 0895-173X

Dominick, Ainsley J. and Nic Daeid, Niamh and Gibson, Andrew P. and Bleay, Stephen M., Home Office Scientific Development Branch, Sandridge, UK (2011) Search results of heat-distorted fingerprints using sagem metamorpho AFIS. Journal of Forensic Identification, 61 (4). ISSN 0895-173X

Dominick, Ainsley J. and NicDaeid, Niamh and Bleay, Stephen M., Home Office Scientific Development Branch, Sandridge, UK (2011) The recoverability of fingerprints on non porous surfaces exposed to elevated temperatures. Journal of Forensic Identification. ISSN 0895-173X

Dominick, Ainsley J. and Nic Daeid, Niamh and Bleay, Stephen M. (2011) The recoverability of fingerprints on nonporous surfaces exposed to elevated temperatures. Journal of Forensic Identification, 61 (5). pp. 520-536. ISSN 0895-173X

Bhaloo, Zain M. and Yamashita, Brian and Wilkinson, Della and NicDaeid, N., RCMP, Integrated Forensic Identification Services, National Police Service, Ottawa, Ontario K1A 0R2, Canada (2011) The recovery of fingerprints from fired cartridge cases : a comparison of current methods of development with an electrostatic deposition technique. Identification Canada. ISSN 0826-8142

Farrugia, Kevin J. and NicDaeid, N. and Savage, Kathleen and Bandey, Helen, Home Office Scientific Development Branch, Fingerprint and Footwear Forensic Group (2010) Chemical enhancement of footwear impressions in blood deposited on fabric - Evaluating the use of alginate casting materials followed by chemical enhancement. Science and Justice, 50 (4). pp. 200-204. ISSN 1355-0306

NicDaeid, N. and Carey, Nicholas (2010) Arc mapping. Fire and Arson Investigator.

Kerr, William and Kunalan, Vanitha and Nic Daeid, Niamh (2010) An investigation into the ability of three analytical techniques to discriminate batches of methylamphetamine prepared by seven synthetic routes. In: 20th International Symposium on the Forensic Sciences of the Australian and New Zealand Forensic Science Society, 2010-09-05 - 2010-09-09.

Daeid, N. Nic (2010) Who speaks up for science? Science and Justice, 50 (3). pp. 111-112. ISSN 1355-0306

Mat Desa, Wan N. S. and Nic Daéid, Niamh and Ismail, Dzulkiflee and Savage, Kathleen (2010) Application of unsupervised chemometric analysis and self-organising feature map (SOFM) for the classification of lighter fuels. Analytical Chemistry, 82 (15). pp. 6395-6400.

Buchanan, Hilary A.S. and Daeid, Niamh Nic and Kerr, William J. and Carter, James F. and Hill, Jenny C. (2010) Role of five synthetic reaction conditions on the stable isotopic composition of 3,4-methylenedioxymethamphetamine. Analytical Chemistry, 82 (13). pp. 5484-5489. ISSN 0003-2700

Nic Daeid, Niamh and Buchanan, Hilary A. S. and Savage, Kathleen A. and Fraser, James G. and Cresswell, Sarah L. (2010) Recent advances in the application of stable isotope ratio analysis in forensic chemistry. Australian Journal of Chemistry, 63 (1). pp. 3-7. ISSN 0004-9425

Croft, Shiona and NicDaeid, N. and Savage, Kathleen and Vallance, Richard and Ramage, Ruth, Scottish Police Services Authority Forensic Services, Glasgow, UK (2010) The enhancement and recovery of footwear marks contaminated in soil : a feasibility study. Journal of Forensic Identification, 60 (6). pp. 718-737. ISSN 0895-173X

Dominick, Ainsley J. and NicDaeid, N. and Bleay, Stephen M., Home Office Scientific Development Branch, Sandridge, UK (2010) The recoverability of fingerprints on paper exposed to elevated temperatures - Part 1: comparison of enhancement techniques. Journal of Forensic Identification, 59 (3). pp. 325-339. ISSN 0895-173X

Dominick, Ainsley J. and NicDaeid, N. and Bleay, Stephen M. and Sears, Vaughn G., Home Office Scientific Development Branch, Sandridge, UK (2010) The recoverability of fingerprints on paper exposed to elevated temperatures - Part 2: natural fluorescence. Journal of Forensic Identification, 59 (3). pp. 340-355. ISSN 0895-173X

NicDaeid, N. and Nic Daeid, Niamh (2009) Forensic Science in Scotland-alive and well. Science and Justice, 49 (4). p. 229. ISSN 1355-0306

Daeid, N.N. and McColl, D. and Ballany, J. (2009) The level of random background glass recovered from fleece jackets of individuals who worked in law enforcement or related professions. Forensic Science International, 191 (1-3). pp. 19-23. ISSN 0379-0738

Kunalan, Vanitha and Nic Daeid, Niamh and Kerr, W.J. and Buchanan, Hilary A.S. and McPherson, Allan R. (2009) Characterization of route specific impurities found in methamphetamine synthesized by the Leuckart and reductive amination methods. Analytical Chemistry, 81 (17). pp. 7342-7348. ISSN 0003-2700

Farmer, N. and Curran, J. and Lucy, D. and NicDaeid, N. and Meier-Augenstein, W. (2009) Stable isotope profiling of burnt wooden safety matches. Science and Justice, 49 (2). pp. 107-113. ISSN 1355-0306

Daeid, N. Nic (2009) Lessons from the past. Science and Justice, 49 (1). p. 11. ISSN 1355-0306

Tobe, S.S. and Daeid, N.N. (2009) Comparison of presumptive blood test kits including Hexagon OBTI. Journal of Forensic Sciences, 54 (1). p. 239.

Dominick, Ainsley and Welch, Lindsey and Nic Daeid, Niamh and Bleay, Stephen M. (2009) Is there a relationship between fingerprint donation and DNA shedding? Journal of Forensic Identification, 59 (2). p. 133. ISSN 0895-173X

NicDaeid, N. and Whitehead, L. and Allen, M. (2008) Examining the effects of paper type, pen type, writing pressure and angle of intersection on white and dark dominance in ESDA impressions of sequenced strokes-an application of the likelihood ratio. Forensic Science International, 181 (1-3). pp. 32-35. ISSN 0379-0738

NicDaeid, N. and Hayes, K. and Allen, M. (2008) Investigations into factors affecting the cascade developer used in ESDA-a review. Forensic Science International, 181 (1-3). pp. 1-9. ISSN 0379-0738

NicDaeid, N. and Cassidy, M. and McHugh, S. (2008) An investigation into the correlation of knife damage in clothing and the lengths of skin wounds. Forensic Science International, 179 (2-3). pp. 107-110. ISSN 0379-0738

Daeid, Niamh Nic (2008) Educating the next generation. Science and Justice, 48 (2). pp. 59-60. ISSN 1355-0306

Wakelin, D. and Doyle, S. and Andrews, C. and Mountford, S. and NicDaeid, N. (2008) Network developing forensic applications of stable isotope ratio mass spectrometry conference 2005. Science and Justice, 48 (2). pp. 79-90. ISSN 1355-0306

Taylor, E. and Carter, James F. and Hill, Jenny C. and Morton, Carolyn and NicDaeid, N. and Sleeman, R. (2008) Stable isotope ratio mass spectrometry and physical comparison for the forensic examination of grip-seal plastic bags. Forensic Science International, 177 (2-3). pp. 214-220. ISSN 0379-0738

Buchanan, Hilary A.S. and Daeid, N.N. and Meier-Augenstein, Wolfram and Kemp, Helen F. and Kerr, W.J. and Middleditch, Michael (2008) Emerging use of isotope ratio mass spectrometry as a tool for discrimination of 3,4-methylenedioxymethamphetamine by synthetic route. Analytical Chemistry, 80 (9). pp. 3350-3356. ISSN 0003-2700

NicDaeid, N. and Meier-Augenstein, W. (2008) Feasibility of source identification of seized street drug samples by exploiting differences in isotopic composition at natural abundance level by gc/ms as compared to isotope ratio mass spectrometry (irms). Forensic Science International, 174 (2-3). pp. 259-261. ISSN 0379-0738

de Korompay, A. and Hill, J.C. and Carter, J.F. and NicDaeid, N. and Sleeman, R. (2008) Supported liquid-liquid extraction of the active ingredient (3,4-methylenedioxymethylamphetamine) from ecstasy tablets for isotopic analysis. Journal of Chromatography A, 1178 (1-2). pp. 1-8. ISSN 0021-9673

Daeid, N. Nic (2007) DNA - what's next? Science and Justice, 47 (4). p. 149. ISSN 1355-0306

Daeid, N. Nic (2007) CPD, an effective means of professional development... or is it? Science and Justice, 47 (3). pp. 109-110. ISSN 1355-0306

Daeid, Niamh Nic (2007) Size isn't everything. Science and Justice, 47 (1). p. 11. ISSN 1355-0306

Tobe, S.S. and Watson, N.D. and Nic Daeid, N. (2007) An evaluation of six presumptive tests for blood, their specificity, sensitivity and effect on high molecular weight DNA. Journal of Forensic Sciences, 52 (1). pp. 102-109.

Daeid, N. Nic (2006) It's a big world out there. Science and Justice, 46 (3). p. 133. ISSN 1355-0306

Daeid, N. Nic (2006) All's fair in love and war. Science and Justice, 46 (2). p. 63. ISSN 1355-0306

Daeid, N. Nic (2006) Lies, damn lies and statistics. Science and Justice, 46 (1). p. 12. ISSN 1355-0306

Nic Daeid, N. (2005) The analytical and chemometric procedures used to profile illicit drug seizures - a review. Talanta, 67 (2). pp. 280-285. ISSN 0039-9140

Waddell, R.J.H. and Nic Daeid, N. and Littlejohn, D. (2004) Classification of ecstasy tablets using trace metal analysis with the application of chemometric procedures and artificial neural network algorithms. Analyst, 129. pp. 235-240. ISSN 0003-2654

Cresswell, S.L. and Cunningham, D. and NicDaeid, N. (2003) Textile fibre survey of cinema seats in Glasgow. Forensic Science International, 136 (Supp. ). p. 117. ISSN 0379-0738

NicDaeid, N. and Cresswell, S.L. and Dzukiflee, I. (2003) Variations in the organic impurity profile in Leuckary synthesised amphetamine sulphate by the same chemist. Forensic Science International, 136 (Supp. ). p. 89. ISSN 0379-0738

Waddell, R J H and Littlejohn, D and Nic Daeid, Niamh (2002) Organic and inorganic impurity profiling in illicit ecstasy seizures with the application of principle component analysis. Abstracts of papers - American Chemical Society, 224. U122-U123. ISSN 0065-7727

Daeid, N N and Thain, E (2002) Measurement of temperature rise over time for commercially available night lights (tea lights). Fire Safety Journal, 37 (3). pp. 329-336. ISSN 0379-7112

Nic Daeid, N. and Waddell, R.J.H. and Littlejohn, D. (2002) Preliminary studies identifying and quantifying trace metal impurities in illicit ecstasy tablets using atomic spectrometry techniques. Problems of Forensic Science, 42 (XLVII). pp. 413-417.

Nic Daeid, N. and Carter, K.C. and Finnon, Y.S. and Waddell, R.J.H. and Robson, D.C. (2002) The effect of nitrostyrene on cell proliferation and macrophage immune responses. Immunopharmacology and Immunotoxicology, 24 (2). pp. 187-197. ISSN 0892-3973

Daeid, N N (2001) The development of interactive World Wide Web based teaching material in Forensic Science. British Journal of Educational Technology, 32 (1). pp. 105-108. ISSN 0007-1013

Daeid, N N and Thorpe, J (1999) Teaching lawyers about forensic science. Forensic Science International, 100 (1-2). pp. 149-151. ISSN 0379-0738

Daeid, N N and Lynch, J and Wideman, D A (1998) Statistical differences between offender groups. Forensic Science International, 98 (3). pp. 151-156. ISSN 0379-0738

Daeid, N N and Lynch, J (1998) Statistical analysis of sexual offenders - a preliminary study. Forensic Science International, 91 (2). pp. 153-161. ISSN 0379-0738

Daeid, N N (1997) Differences in offender profiling in the United States of America and the United Kingdom. Forensic Science International, 90 (1-2). pp. 25-31. ISSN 0379-0738

Daeid, N N (1997) Suicide in Ireland - 1982 to 1992. Archives of Suicide Research, 3 (1). pp. 31-42. ISSN 1381-1118

GONZALEZ, E B and DAEID, N N and NOLAN, K B (1994) Complex formation between transition metal ions and salicylglycine, a metabolite of aspirin. Polyhedron, 13 (10). pp. 1495-1499. ISSN 0277-5387

DAEID, N N and NOLAN, K B (1993) Oxidised metallophenolicporphyrins as models for compound I of the peroxidases. Reduction of oxidised iron(III), nickel(II) and zinc(II) complexes of meso-tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)prophyrin by the peroxidase substrate p-cresol. Inorganica Chimica Acta, 211 (1). pp. 55-60. ISSN 0020-1693

DAEID, N N and ATKINSON, S T and NOLAN, K B (1993) Synthetic Porphyrins/Metalloporphyrins Which Mimic States in Catalytic Cycle of Cytochrome P-450 and Peroxidases. Pure and Applied Chemistry, 65 (7). pp. 1541-1548. ISSN 0033-4545

DAEID, N N and NOLAN, K B and RYAN, L P (1991) Copper(II) complexes of hydrolysis products of the anticancer bis(3,5-dioxopiperazin-1-yl)alkanes. Displacement of co-ordinated carboxylate ligands by deprotonated amide groups in basic solution. Journal of the Chemical Society, Dalton Transactions (9). pp. 2301-2304. ISSN 0300-9246