Coleg Gwyddoniaeth a Pheirianneg

  1. Erthygl › Ymchwil › Adolygwyd gan gymheiriaid
  2. Cyhoeddwyd

    'Jack of all trades'? The negotiation of interdisciplinarity within geography.

    Pasquini, M., Lau, L. & Pasquini, M. W., 1 Maw 2008, Yn: Geoforum. 39, 2, t. 552-560

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  3. Cyhoeddwyd

    'On-farm' seed priming with zinc in chickpea and wheat in Pakistan.

    Harris, D., Rashid, A., Miraj, M. & Yunas, M., 1 Ebr 2008, Yn: Plant and Soil. 306, 1-2, t. 3-10

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  4. Cyhoeddwyd

    'On-farm' seed priming with zinc sulphate solution - a cost-effective way to increase the maize yields of resource-poor farmers.

    Harris, D., Rashid, A., Miraj, G., Arif, M. & Shah, H., 5 Meh 2007, Yn: Field Crops Research. 102, 2, t. 119-127

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  5. Cyhoeddwyd

    (E)-4-[2-(bis(octadecylsulfanyl)tetrathiafulvalenyl)ethenyl]-1-methylpyridinium iodide: synthesis and characterisation of its Langmuir-Blodgett films

    Andreu, R., Garin, J., Orduna, J., Ashwell, G. J., Amiri, M. A. & Hamilton, R., 3 Ebr 2002, Yn: Thin Solid Films. 407, 1-2, t. 236-239

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  6. Cyhoeddwyd

    1,1,2 Tribromocyclopropanecarboxylic Acid and Derivatives Valuable Intermediates for Four Carbon Cyclopropane and Cyclopropene Synthons

    Al-Dulayymi, A., Al-Dulayymi, J., Baird, M., Gerrard, M. E., Koza, G., Harkins, S. & Roberts, E., 1996, Yn: Tetrahedron. 52, t. 3409

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  7. Cyhoeddwyd

    1,1′,2,2′-Tetralithioferrocene and 1,1′,2,2′,3,3′-Hexalithioferrocene: Useful Additions to Ferrocene Precursor Compounds

    Butler, I., Evans, D., Horton, P., Coles, S. & Murphy, P., 8 Maw 2021, Yn: Organometallics. 40, 5, t. 600-605 6 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  8. Cyhoeddwyd

    1-GHz all-optical flip-flop operation of conventional cylindrical-shaped single-mode VCSELs under low-power optical injection.

    Lee, S. H., Jung, H. W., Kim, K. H., Lee, M. H., Yo, B. S., Roh, J. & Shore, K. A., 1 Rhag 2010, Yn: IEEE Photonics Technology Letters. 22, 23, t. 1759-1761

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  9. Cyhoeddwyd

    100 years of anthropogenic impact causes changes in freshwater functional biodiversity

    Eastwood, N., Zhou, J., Derelle, R., Abdallah, M.A.-E., Stubbings, W. A., Jia, Y., Crawford, S. E., Davidson, T. A., Colbourne, J. K., Creer, S., Bik, H., Hollert, H. & Orsini, L., 7 Tach 2023, Yn: Elife. 12

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  10. Cyhoeddwyd
  11. Cyhoeddwyd

    150,000-year palaeoclimate record from northern Ethiopia supports early, multiple dispersals of modern humans from Africa

    Lamb, H., Bates, R., Bryant, C., Davies, S., Huws, D., Marshall, M. & Roberts, H., 18 Ion 2018, Yn: Scientific Reports. 8, 1077.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  12. Cyhoeddwyd

    2 Synthetic methods. Part (iii) Heteroatom methods

    Murphy, P. J. & Thomas, D. A., 2000, Yn: Annual Reports on the Progress of Chemistry - Section B. 2000, 96, t. 39-63 25 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  13. Cyhoeddwyd

    2 Synthetic methods: Part (iv) Heteroatom methods

    Murphy, P. J., 1998, Yn: Annual Reports on the Progress of Chemistry - Section B. 94, t. 51-75 25 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  14. Cyhoeddwyd

    2 Vinyl 1 1,1,2 trihalocyclopropanes Valuable Five Carbon Cyclopropane and Cyclopropene Synthetic Intermediates

    Al-Dulayymi, A., Al-Dulayymi, J. & Baird, M., 1996, Yn: Tetrahedron. 52, 33, t. 10955

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  15. Cyhoeddwyd

    2-Ethyl 5-methyl 3-hydroxythiophene-2,5-dicarboxylate.

    Coles, S. J., Guthmann, H., Hursthouse, M. B. & Murphy, P. J., 1 Hyd 2001, Yn: Acta Crystallographica Section E: Structure Reports Online. 57, 10, t. o976-o977

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  16. Cyhoeddwyd

    2-groupoid enrichments in homotopy theory and algebra.

    Kamps, K. H. & Porter, T., 1 Ebr 2002, Yn: K-Theory. 25, 4, t. 373-409

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  17. Cyhoeddwyd

    2.2 Mb of contiguous nucleotide sequence from chromosome III of C. elegans

    Wilson, R., Ainscough, R., Anderson, K., Baynes, C., Berks, M., Bonfield, J., Burton, J., Connell, M., Copsey, T., Cooper, J., Coulson, A., Craxton, M., Dear, S., Du, Z., Durbin, R., Favello, A., Fraser, A., Fulton , L., Gardner, A., Green, P., Hawkins, T., Hillier, L., Jier, M., Johnston, L., Jones, M., Kershaw, J., Kirsten, J., Laisstert, N., Latreille, P., Lightning, J., Lloyd, C., Mortimore, B., O'Callaghan, M., Parsons, J., Percy , C., Rifken, L., Roopra, A., Saunders, D., Shownkeen, R., Sims, M., Smaldon, N., Smith, A., Smith, M., Sonnhammer, E., Staden, R., Sulston, J., Thierry-Mieg, J., Thomas, K., Vaudin, M., Vaughan, K., Waterston, R., Watson, A., Weinstock, L., Wilkinson-Sproatt, J. & Wohldman, P., 3 Maw 1994, Yn: Nature. 368, 6466, t. 32-8 7 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  18. Cyhoeddwyd

    200 Gb/s/ λ Bidirectional Coherent PON Solutions Demonstrated over Field Installed Fiber

    Kovacs, I. B., Faruk, M. S. & Savory, S. J., 1 Medi 2024, Yn: IEEE Photonics Technology Letters. 36, 17, t. 1089-1092 4 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  19. Cyhoeddwyd

    25.25-Gb/s Real-Time Multi-Band Optical OFDM Transmission Over 300-m MMFs With IQ Modulated Passband

    Giddings, R. P., Hugues-Salas, E., Zhang, Q. W., Zhang, J. J., Wang, M. & Tang, J. M., 2013, Yn: IEEE Photonics Technology Letters. 25, 21, t. 2123-2125 3 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  20. Cyhoeddwyd

    2DV modelling of sediment transport processes over full-scale ripples in regular asymmetric oscillatory flow.

    Van Der Werf, J. J., Magar, V., Malarkey, J., Guizien, K. & O'Donoghue, T., 15 Mai 2008, Yn: Continental Shelf Research. 28, 8, t. 1040-1056

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  21. Cyhoeddwyd

    3,4-Phenylenedioxythiophenes (PheDOTs) functionalized with electron-withdrawing groupsand their analogs for organic electronics. Remarkably efficient tuning the energy levels in flatconjugated polymers

    Krompiec, M. P., Baxter, S., Klimareva, E. L., Yufit, D. S., Congrave, D. G., Britten, T. K. & Perepichka, I., 14 Ebr 2018, Yn: Journal of Materials Chemistry C. 6, 14, t. 3746-3756

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  22. Cyhoeddwyd

    3.5-GHz signal transmission in an all-optical chaotic communication scheme using 1550-nm diode lasers.

    Paul, J., Lee, M. W. & Shore, K. A., 1 Ebr 2005, Yn: IEEE Photonics Technology Letters. 17, 4, t. 920-922

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  23. Cyhoeddwyd

    30-Gb/s signal transmission over 40-km directly modulated DFB-laser-based single-mode-fiber links without optical amplification and dispersion compensation.

    Tang, J. M. & Shore, K. A., 1 Meh 2006, Yn: Journal of Lightwave Technology. 24, 6, t. 2318-2327

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  24. Cyhoeddwyd

    30-Gb/s signal transmission over 40-km directly modulated DFB-laser-based single-mode-fibre links without optical amplification and dispersion compensation

    Tang, J., Tang, J. M. & Shore, K. A., 1 Meh 2006, Yn: Journal of Lightwave Technology. 24, 6, t. 2318-2327

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  25. Cyhoeddwyd

    36 year trends in dissolved organic carbon export from Finnish rivers to the Baltic Sea

    Raike, A., Kortelainen, P., Mattsson, T. & Thomas, D. N., 1 Hyd 2012, Yn: Science of the Total Environment. 435, t. 188-201

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  26. Cyhoeddwyd

    4,4-Dimethyl-3,5,8,10-tetraoxatricyclo[5.2.1.0(2,6)] decane.

    Light, M. E., Murphy, P. J., Brown, P. M. & Hursthouse, M. B., 1 Mai 2002, Yn: Acta Crystallographica Section E: Structure Reports Online. 58, 5, t. o560-o561

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  27. Cyhoeddwyd

    4,4′,5,5′-Tetrakis(2-thienyl)tetrathiafulvalene [TT-TTF]: synthesis and first X-ray crystal structure of a thiophene-substituted TTF electron donor

    Charlton, A., Underhill, A. E., Williams, G., Kalaji, M., Murphy, P. J., Hibbs, D. E., Hursthouse, M. B. & Malik, K. M. A., 1996, Yn: Chemical Communications. 1996, 21, t. 2423-2424 2 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  28. Cyhoeddwyd

    4,5,4 ' 5 '-Tetrakis(2-methyl-thiopen-3-yl)-[2,2 ']bi[[1,3]dithiolylidene]

    Gelbrich, T., Roberts-Bleming, S. J., Kalaji, M., Murphy, P. J. & Hursthouse, M. B., 1 Rhag 2001, Yn: Acta Crystallographica Section E: Structure Reports Online. 57, 12, t. o1143-o1144

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  29. Cyhoeddwyd

    4,5-Diazafluorene co-oligomers as electrondeficientlight-emitting materials and selectivefluorescence sensors for mercury(II) cations

    Ghosh, S., Alghunaim, A. S., AL-Mashhadani, M., Krompiec, M. P., Hallett, M. & Perepichka, I., 14 Ebr 2018, Yn: Journal of Materials Chemistry C. 6, 14, t. 3762-3773

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  30. Cyhoeddwyd

    40 Gb/s quantum random number generation based on optically sampled amplified spontaneous emission

    Guo, Y., Cai, Q., Li, P., Jia, Z., Xu, B., Zhang, Q., Zhang, Y., Zhang, R., Gao, Z., Shore, K. A. & Wang, Y., 1 Meh 2021, Yn: APL Photonics. 6, 6, t. 066105 1 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  31. Cyhoeddwyd

    800 nm WDM interrogation system for strain, temperature, and refractive index sensing based on tilted fiber Bragg grating

    Suo, R., Chen, X., Zhou, K., Zhang, L. & Bennion, I., 1 Gorff 2008, Yn: IEEE Sensors Journal. 8, 7, t. 1273-1279

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  32. Cyhoeddwyd

    A 11B NMR study of zwitterionic and cationic monoborate complexes with cationic 1,2-diol ligands

    Beckett, M. A., Bland, C. C. & Varma, K. S., 26 Meh 2008, Yn: Polyhedron. 27, 9-10, t. 2226-2230

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  33. Cyhoeddwyd

    A 26,000-year integrated record of marine and terrestrial environmental change off Gabon, west equatorial Africa

    Kim, S. Y., Scourse, J. D. & Marret, F., 1 Ion 2010, Yn: Palaeogeography, Palaeoclimatology, Palaeoecology. 297, t. 428-438

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  34. Cyhoeddwyd

    A 30,000 yr record of land–ocean interaction in the eastern Gulf of Guinea

    Marret, F., Kim, S. Y. & Scourse, J. D., 1 Gorff 2013, Yn: Quarternary Research. 80, 1, t. 1-8

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  35. Cyhoeddwyd

    A Bound on Kappa-Error Diagrams for Analysis of Classifier Ensembles

    Kuncheva, L. I., 1 Maw 2013, Yn: IEEE Transactions on Knowledge and Data Engineering. 25, 3, t. 494-501

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  36. Cyhoeddwyd

    A Circular AC Magnetohydrodynamic Micropump for Chromatographic Applications

    Burt, J., Eijkel, J. C., Dalton, C., Hayden, C. J., Burt, J. P. & Manz, A., 1 Gorff 2003, Yn: Sensors and Actuators B - Chemical. 92, 1-2, t. 215-221

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  37. Cyhoeddwyd

    A Clock-gating-based Energy-efficient Scheme for ONUs in Real-time IMDD OFDM-PONs

    Zhang, J., Zhao, J., Huang, H., Ye, N., Giddings, R., Li, Z., Qin, D., Zhang, Q. & Tang, J., 15 Gorff 2020, Yn: Journal of Lightwave Technology. 38, 14, t. 3573-3583

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  38. Cyhoeddwyd

    A Collaboratively-Derived Science-Policy Research Agenda

    Sutherland, W. J., Bellingan, L., Bellingham, J. R., Blackstock, J. J., Bloomfield, R. M., Bravo, M., Cadman, V. M., Cleevely, D. D., Clements, A., Cohen, A. S., Cope, D. R., Daemmrich, A. A., Devecchi, C., Anadon, L. D., Denegri, S., Doubleday, R., Dusic, N. R., Evans, R. J., Feng, W. Y., Godfray, H. C. J., Harris, P., Hartley, S. E., Hester, A. J., Holmes, J., Hughes, A., Hulme, M., Irwin, C., Jennings, R. C., Kass, G. S., Littlejohns, P., Marteau, T. M., McKee, G., Millstone, E. P., Nuttall, W. J., Owens, S., Parker, M. M., Pearson, S., Petts, J., Ploszek, R., Pullin, A. S., Reid, G., Richards, K. S., Robinson, J. G., Shaxson, L., Sierra, L., Smith, B. G., Spiegelhalter, D. J., Stilgoe, J., Stirling, A., Tyler, C. P., Winickoff, D. E. & Zimmern, R. L., 9 Maw 2012, Yn: PLoS ONE. 7, 3

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  39. Cyhoeddwyd

    A Comparison of Stochastic and Deterministic Downscaling in Eddy Resolving Ocean Modelling: The Lakshadweep Sea Case Study

    Shapiro, G., Ondina, J., Poovadiyil, S. & Tu, J., 6 Chwef 2023, Yn: Journal of Marine Science and Engineering . 11, 2

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  40. Cyhoeddwyd

    A Comparison of Tidal Conversion Parameterizations for Tidal Models

    Green, J. A. & Nycander, J., 1 Ion 2013, Yn: Journal of Physical Oceanography. 43, 1, t. 104-119

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  41. Cyhoeddwyd

    A Comprehensive Assessment of Climate Change and Coastal Inundation through Satellite-Derived Datasets: A Case Study of Sabang Island, Indonesia

    Kantamaneni , K., Christie, D., Lyddon, C., Huang, P., Nizar, M., Balasubramani, K., Ravichandran, V., Prasad, K. A., Pushparaj, R. R. B., Robins, P. & Panneer, S., 15 Meh 2022, Yn: Remote Sensing. 14, 12, 2857.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  42. Cyhoeddwyd

    A Compression-Based Toolkit for Modelling and Processing Natural Language Text

    Teahan, W., 22 Tach 2018, Yn: Information. 9, 294, t. 1-29 29 t., 9, 294.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  43. Cyhoeddwyd

    A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits

    Stoddart, J., Almeida, D., Silva, C. A., Gorgens, E. B., Keller, M. & Valbuena, R., 15 Chwef 2022, Yn: Remote Sensing. 14, 4

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  44. Cyhoeddwyd

    A DNA-Based Approach for the Forensic Identification of Asiatic Black Bear (Ursus thibetanus) in a Traditional Asian Medicine.

    Peppin, L., McEwing, R., Carvalho, G. R. & Ogden, R., 1 Tach 2008, Yn: Journal of Forensic Sciences. 53, 6, t. 1358-1362

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  45. Cyhoeddwyd

    A Decision Support System for Drinking Water Production Integrating Health Risks Assessment

    Delpla, I., Monteith, D. T., Freeman, C., Haftka, J., Hermens, J., Jones, T. G., Baures, E., Jung, A. & Thomas, O., 18 Gorff 2014, Yn: International Journal of Environmental Research and Public Health. 11, 7, t. 7354-7375

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  46. Cyhoeddwyd

    A Facile Synthetic Route to a Family of Mn(III) Monomers and their Structural, Magnetic and Spectroscopic Studies

    Jones, L., Barra, A.-L., Ryder, A. G., Brechin, E. K., Collison, D., Innes, E. J. L., Sanz, S., Kelly, B. & Houton, E., Tach 2016, Yn: European Journal of Inorganic Chemistry . 2016, 32, t. 5123-5131

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  47. Cyhoeddwyd

    A GAL4-Driver Line Resource for Drosophila Neurobiology

    Jenett, A., Rubin, G., Ngo, T. T. B., Shepherd, D., Murphy, C., Dionne, H., Pfeiffer, B., Cavallaro, A., Hall, D., Jeter, J., Iyer, N., Fetter, D., Hausenfluck, J., Peng, H., Trautman, E. T., Svirskas, R. R., Meyers, E. W., Iwinski, Z. R., Aso, Y., DePasquale, G. M., Enos, A., Hulamm, P., Lam, S. C. B., Li, H.-H., Laverty, T., Long, F., Qu, L., Murphy, S. D., Rokicki, C., Safford, T., Shaw, K., Simpson, J. H., Sowell, A., Tae, S., Yu, Y. & Zugates, C. T., 11 Hyd 2012, Yn: Cell Reports. 2, 4, t. 991-1001 10 t.

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  48. Cyhoeddwyd

    A Gel Filtration-Based Method for the Purification of Infectious Rotavirus Particles for Environmental Research Applications

    Farkas, K., Pang, L., Lin, S., Williamson, W., Easingwood, R., Fredericks, R., Jaffer, M. A. & Varsani, A., 1 Rhag 2013, Yn: Food and Environmental Virology. 5, 4, t. 231-235

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  49. Cyhoeddwyd

    A Heart That Beats for 500 Years: Age-Related Changes in Cardiac Proteasome Activity, Oxidative Protein Damage and Expression of Heat Shock Proteins, Inflammatory Factors, and Mitochondrial Complexes in Arctica islandica, the Longest-Living Noncolonial Animal

    Sosnowska, D., Richardson, C. A., Sonntag, W. E., Csiszar, A., Ungvari, Z. & Ridgway, I. D., 17 Rhag 2013, Yn: Journals of Gerontology, Series A. 69, 12, t. 1448-1461

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  50. Cyhoeddwyd

    A Heuristic Approach for Optical Transceiver Placement to Optimize SNR and Illuminance Uniformities of an Optical Body Area Network

    Masroor, K., Jeoti, V., Drieberg, M., Cheab, S. & Rajbhandari, S., 22 Ebr 2021, Yn: Sensors. 21, 9

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid

  51. Cyhoeddwyd

    A Label Free Colorimetric Assay for the Detection of Active Botulinum Neurotoxin Type A by SNAP-25 Conjugated Colloidal Gold

    Halliwell, J. H., Halliwell, J. & Gwenin, C. D., 6 Awst 2013, Yn: Toxins. 5, 8, t. 1381-1391

    Allbwn ymchwil: Cyfraniad at gyfnodolynErthygladolygiad gan gymheiriaid