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Terahertz Applications Group

Department of Chemical Engineering and Biotechnology

Studying at Cambridge




D. Markl, P. Wang, C. Ridgway, A.-P. Karttunen, M. Chakraborty, P. Bawuah, P. Pääkkönen, P. Gane, J. Ketolainen, K. Peiponen and J.A. Zeitler, Characterisation of the pore structure of functionalised calcium carbonate tablets by terahertz time-domain spectroscopy and x-ray computed microtomography, Journal of Pharmaceutical Sciences, accepted (2017)

D. Markl and J.A. Zeitler, A Review of Disintegration Mechanisms and Measurement Techniques, Pharmaceutical Research, in press, doi:10.1007/s11095-017-2129-z (2017). oalogo.jpg

D. Markl, J. Sauerwein, D.J. Goodwin, S. van den Ban and J.A. Zeitler, Non-destructive determination of disintegration time and dissolution in immediate release  tablets by terahertz transmission measurements, Pharmaceutical Research, in press, doi:10.1007/s11095-017-2108-4 (2017). oalogo.jpg

D. Markl, J.A. Zeitler, C. Rasch, M.H. Michaelsen, A. Müllertz, J. Rantanen, T. Rades, J. Bøtker, Analysis of 3D Prints by X-ray microtomography and terahertz pulsed imaging, Pharmaceutical Research, in press, doi:10.1007/s11095-016-2083-1 (2017). oalogo.jpg

H. Lin, Y. Dong, D. Markl, B.M. Williams, Y. Zheng, Y.C. Shen and J.A. Zeitler, Measurement of the inter-tablet coating uniformity of a pharmaceutical pan coating process with combined terahertz and optical coherence tomography in-line sensing, Journal of Pharmaceutical Sciences, in press, doi:10.1016/j.xphs.2016.12.012 (2017). oalogo.jpg

M. Alhijjaj, S. Yassin, M. Reading, J.A. Zeitler, P. Belton and S. Qi, Characterization of heterogeneity and spatial distribution of phases in complex solid dispersions by thermal analysis by structural characterization and X-ray micro computed tomography, Pharmaceutical Research, in press, doi:10.1007/s11095-016-1923-3 (2017). oalogo.jpg

Y. Dong, H. Lin, V. Abolghasemi, L. Gan, J.A. Zeitler and Y.C. Shen, Investigating intra-tablet coating uniformity with spectral-domain optical coherence tomography, Journal of Pharmaceutical Sciences, 106, 546-553, doi:10.1016/j.xphs.2016.09.021 (2017). oalogo.jpg

S. Dhillon, M. Vitiello, E. Linfield, A. Davis, M. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. Williams, E. Castro-Camus, D. Cumming, F. Simoens, I. Escorcia Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. Schmuttenmaer, T. Cocker, R. Huber, A. Markelz, Z. Taylor, V. Wallace, J.A. ZeitlerJ. Sibik, T.M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. Cooper, R. Appleby, D. Pardo, P. Huggard, V. Krozer, H. Shams, M. Fice,  C. Renaud, A. Seeds, A. Stoehr, M. Naftaly, N. Ridler, R. Clarke, J. Cunningham, M. Johnston, The 2017 terahertz science and technology roadmap, Journal of Physics D: Applied Physics, 50, 043001, doi:10.1088/1361-6463/50/4/043001 (2017). oalogo.jpg


M.T. Ruggiero, J.A. Zeitler. Resolving the Origins of Crystalline Anharmonicity Using Terahertz Time-Domain Spectroscopy and ab initio Simulations. Journal of Physical Chemistry B. 120 (45), 11733-11739, doi:10.1021/acs.jpcb.6b10248 (2016). oalogo.jpg

M.T. Ruggiero, J. Sibik, J.A. Zeitler, T.M. Korter. Examination of L-Glutamic Acid Polymorphs by Solid-State Density Functional Theory and Terahertz Spectroscopy, Journal of Physical Chemistry A, 120 (38), 7490-7495, doi:10.1021/acs.jpca.6b05702 (2016). oalogo.jpg

R. Degl'Innocenti, L. Xiao, D.S. Jessop, S.J. Kindness, Y. Ren, H. Lin, J.A. Zeitler, J.A. Alexander-Webber, H.J. Joyce, P. Braeuninger-Weimer, S. Hofmann, H. Beere and D.A. Ritchie, Fast room temperature detection of terahertz quantum cascade lasers with graphene loaded bow-tie plasmonic antenna arrays, ACS Photonics, 3, 1747-1753, doi:10.1021/acsphotonics.6b00405 (2016). oalogo.jpg

P. Bawuah, N. Tan, S.N.A. Tweneboah, T. Ervasti, J.A. Zeitler, J. Ketolainen and K.-E. Peiponen, Terahertz study on porosity and mass fraction of active pharmaceutical ingredient of pharmaceutical tablets, European Journal of Pharmaceutics and Biopharmaceutics, 105, 122-133, doi:10.1016/j.ejpb.2016.06.007 (2016).

P. Bawuah, N. Tan, T. Ervasti, J.A. Zeitler, J. Ketolainen, K.-E. Peiponen, Noninvasive porosity measurement of biconvex tablets using terahertz pulses, International Journal of Pharmaceutics, 509, 439-443, doi:10.1016/j.ijpharm.2016.06.023 (2016).

E. Rees, K. Su and J.A. Zeitler, Terahertz correlation spectroscopy infers particle velocity and rheological properties, Optics Letters, 41, 3289-3292, doi:10.1364/OL.41.003289 (2016). oalogo.jpg

K.P. Nartowski, D. Malhotra, L.E. Hawarden, J. Sibik, D. Iuga, J.A. Zeitler, L. Fábián, Y.Z. Khimyak, 19F NMR as a highly sensitive probe towards understanding and direct monitoring of confined crystallisation within nanoporous materials, accepted, Angewandte Chemie Int. Ed., 55, 8904-8908, doi:10.1002/anie.201602936 (2016).

D.S. Jessop, S.J. Kindness, L. Xiao, P. Braeuninger-Weimer, H. Lin, Y. Ren, C.X. Ren, S. Hofmann, J.A. Zeitler, H.E. Beere, D.A. Ritchie and R. Degl'Innocenti, Graphene based plasmonic terahertz amplitude modulator operating above 100 MHz, accepted, Applied Physics Letters, 108, 171101, doi:10.1063/1.4947596 (2016). oalogo.jpg

P. Bawuah, M. Chakraborty, T. Ervasti, J.A. Zeitler, J. Ketolainen, P.A.C. Gane, K.-E. Peiponen, A structure parameter for porous pharmaceutical tablets obtained with the aid of Wiener bounds for effective permittivity and terahertz time-delay measurement, International Journal of Pharmaceuticsdoi:10.1016/j.ijpharm.2016.04.026 (2016)

M.T. Ruggiero, J. Sibik, R. Orlando, J.A. Zeitler and T.M. Korter, Measuring the elasticities of poly-L-proline helices with terahertz spectroscopy, Angewandte Chemie Int. Ed., 128, 6991-6995, doi:10.1002/ange.201602268 (2016). oalogo.jpg

M. Chakraborty, P. Bawuah, N.Y. Tan, T. Ervasti, P. Pääkkönen, J.A. Zeitler, J. Ketolainen and K.-E. Peiponen, On the correlation of effective terahertz refractive index and average surface roughness of pharmaceutical tablets, Journal of Infrared, Millimeter, and Terahertz Wavesdoi:10.1007/s10762-016-0262-0, in press (2016).

R. Degl'Innocenti, D. Jessop, C. Sol, L. Xiao, S. Kindness, H. Lin, J.A. Zeitler, P. Braeuninger-Weimer, S. Hofmann, Y. Ren, V. Kamboj, J. Griffiths, H. Beere and D.A. Ritchie, Fast modulation of terahertz quantum cascade lasers using graphene loaded plasmonic antennas, ACS Photonics, 3, 464-470, doi:10.1021/acsphotonics.5b00672 (2016).

X. Li, N.Y. Tan, M. Pivnenko, J. Sibik, J.A. Zeitler and D. Chu*, High-birefringence nematic liquid crystal for broadband THz applications, Liquid Crystals, doi:10.1080/02678292.2016.1153732, in press (2016).

J. Sibik and J.A. Zeitler, Direct measurement of molecular mobility and crystallisation of amorphous pharmaceuticals using terahertz spectroscopy,  Advanced Drug Delivery Reviews, 100, 147-157, doi:10.1016/j.addr.2015.12.021, (2016).

J. Sibik and J.A. Zeitler, Terahertz response of organic amorphous systems: experimental concerns and perspectives, Philosophical Magazine, 96,  842-853, doi:10.1080/14786435.2015.1111528, (2016).

S. Gomez Sanz, L. McMillan, J. McGregor, J.A. Zeitler, N. Al-Yassir, S. Al-Khattaf and L.F. Gladden, The enhancement of the catalytic performance of CrOx/Al2O3 catalysts for ethylbenzene dehydrogenation through tailored coke deposition, Catalysis Science and Technology, 6, 1120-1133, doi:10.1039/C5CY01157D, (2016).


J. McGregor, R. Li, J.A. Zeitler, C. D'Agostino, J.H.P. Collins, M.D. Mantle, H. Manyar, J.D. Holbrey, M. Falkowska, T.G.A. Youngs, C. Hardacre, E.H. Stitt and L.F. Gladden, Structure and dynamics of aqueous 2-propanol mixtures: a THz-TDS, NMR and neutron diffraction study, Physical Chemistry Chemical Physics, 17, 30481-30491, doi:10.1039/C5CP01132A, (2015).

P. Marizza, L. Pontoni, T. Rindzevicius, J.F. Alopaeus, K. Su, J.A. Zeitler, S.S. Keller, I. Kikic, M. Moneghini, N. De Zordi, D. Solinas, A. Cortesi and A. Boisen, Supercritical impregnation of polymer matrices spatially confined in microcontainers for oral drug delivery: effect of temperature, pressure and time, Journal of Supercritical Fluids, 107, 145-152, doi:10.1016/j.supflu.2015.08.023, (2015).

N.Y. Tan, M.T. Ruggiero, C. Orellana-Tavra, T. Tian, A.D. Bond, T.M. Korter, D. Fairen- Jimenez and J.A. Zeitler, Investigation of the terahertz vibrational modes of ZIF-8 and ZIF-90 with terahertz time-domain spectroscopy, Chemical Communications, 51, 16037-16040, doi:10.1039/C5CC06455D (2015). 

V.P. Wallace, D. Ferachou, P. Ke, K. Day, S. Uddin, J. Casas-Finet, C.F. van der Walle, R.J. Falconer and J.A. Zeitler, Modulation of the hydration water around monoclonal antibodies on addition of excipients detected by terahertz time-domain spectroscopy, Journal of Pharmaceutical Sciences, 104, 4025-4033, doi:10.1002/jps.24630  (2015).

A.-K. Vynckier, H. Lin, J.A. Zeitler, J.-F. Willart, E. Bongaers, J. Voorspoels, J.P. Remon and C. Vervaet, Calendering as a direct shaping tool for the continuous production of fixed-dose combination products via co-extrusion, European Journal of Pharmaceutics and Biopharmaceutics, 96, 125–131 doi:10.1016/j.ejpb.2015.07.023 (2015).

J. Sibik, K. Löbmann, T. Rades and J.A. Zeitler, Predicting Crystallisation of Amorphous Drugs With Terahertz Spectroscopy, Molecular Pharmaceutics, 12, 3062-3068, doi:10.1021/acs.molpharmaceut.5b00330 (2015). oalogo.jpg

D.Y.S. Chau, A.R. Dennis, H. Lin, J.A. Zeitler and A. Tunnacliffe, Determination of water content in dehydrated mammalian cells using terahertz pulsed imaging: a feasibility study, Current Pharmaceutical Biotechnology, 17, 200-207 (2015). oalogo.jpg

S. Gomez Sanz, L. McMillan, J. McGregor, J.A. Zeitler, N. Al-Yassir, S. Khalif and L.F. Gladden, A new perspective on catalytic dehydrogenation of ethylbenzene: the influence of side-reactions on catalytic performance, Catalysis Science and Technology, 5, 3782-3797, doi:10.1039/c5cy00457h  (2015).

S. Yassin, D. Goodwin, A. Anderson, J. Sibik, D.I. Wilson, L.F. Gladden and J.A. Zeitler, The disintegration process in microcrystalline cellulose based tablets I.: influence of temperature, porosity and superdisintegrants, Journal of Pharmaceutical Sciences, 104, 3440-3450, doi:10.1002/jps.24544 (2015). oalogo.jpg

H. Lin, Y. Dong, Y.C. Shen and J.A. Zeitler, Quantifying pharmaceutical film coating with optical coherence tomography and terahertz pulsed imaging: an evaluation, Journal of Pharmaceutical Sciencesdoi:10.1002/jps.24535 (2015). oalogo.jpg

H. Lin, R.K. May, M. Evans, S. Zhong, L.F. Gladden, Y.C. Shen and J.A. Zeitler, Impact of processing conditions on inter-tablet coating thickness variations measured by terahertz in-line sensing, Journal of Pharmaceutical Sciences, 104, 2513-2522, doi:10.1002/jps.24503 (2015). oalogo.jpg

K.-E. Peiponen, P. Bawuah, M. Chakraborty, M. Juuti, J.A. Zeitler and J. Ketolainen, Estimation of Young’s modulus of pharmaceutical tablet obtained by terahertz time-delay measurement, International Journal of Pharmaceutics, 489, 100-105, doi:10.1016/j.ijpharm.2015.04.068 (2015).

B. Freireich, R. Kumar, W. Ketterhagen, K. Su, C. Wassgren and J.A. Zeitler, Comparisons of intra-tablet coating variability using DEM simulations, asymptotic limit models and experiments, Chemical Engineering Science, doi:10.1016/j.ces.2015.03.013, 131, 197-212  (2015).oalogo.jpg

N. Y. Tan, R. Li, P. Bräuer, C. D'Agostino, L.F. Gladden and J.A. Zeitler, Probing hydrogen-bonding in binary liquid mixtures with terahertz time-domain spectroscopy: a comparison of Debye and absorption analysis, Physical Chemistry Chemical Physics, doi:10.1039/C4CP04477K, 17, 5999-6008 (2015).oalogo.jpg

N.Y. Tan and J.A. Zeitler, Probing phase transitions in simvastatin with terahertz time-domain spectroscopy, Molecular Pharmaceutics, doi:10.1021/mp500649q, 12, 810–815 (2015).oalogo.jpg

S. Yassin, K. Su, H. Lin, L.F. Gladden and J.A. Zeitler, Diffusion and swelling measurements in pharmaceutical powder compacts using terahertz pulsed imaging, Journal of Pharmaceutical Sciences, doi:10.1002/jps.24376, 104, 1658–1667 (2015).oalogo.jpg

New Review:


E.P.J. Parrott and J.A. Zeitler, Terahertz time-domain and low-frequency Raman spectroscopy of organic materials, Applied Spectroscopy, doi:10.1366/14-07707, 69, 1-25 (2015).oalogo.jpg


P. Bawuah, P. Silfsten, T. Ervasti, J. Ketolainen, J.A. Zeitler, K.-E. Peiponen, Non-contact weight measurement of flat-faced pharmaceutical tablets using terahertz transmission pulse delay measurements, International Journal of Pharmaceutics, doi:10.1016/j.ijpharm.2014.09.027, 476, 16-22 (2014).

R. Li, C. D'Agostino, J. McGregor, M.D. Mantle, J.A. Zeitler, and L.F. Gladden, Mesoscopic Structuring and Dynamics of Alcohol/Water Solutions Probed by Terahertz Time-domain Spectroscopy and Pulsed Field Gradient Nuclear Magnetic Resonance, Journal of Physical Chemistry B, doi:10.1021/jp502799x,  118, 10156-10166 (2014).oalogo.jpg

D. Brock, J.A. Zeitler, A. Funke, K. Knop, P. Kleinebudde, Evaluation of critical process parameters for inter-tablet coating uniformity of active-coated GITS using terahertz pulsed imaging, European Journal of Pharmaceutics and Biopharmaceutics, doi:10.1016/j.ejpb.2014.06.016  (2014).

J. Sibik, S.R. Elliott, and J.A. Zeitler, Thermal decoupling of molecular-relaxation processes from the vibrational density of states at terahertz frequencies in supercooled hydrogen-bonded liquids, Journal of Physical Chemistry Letters, doi:10.1021/jz5007302, 5, 1968–1972 (2014).oalogo.jpg

K. Su, Y.C. Shen, and J.A. Zeitler, Terahertz sensor for non-contact thickness and quality measurement of automobile paints of varying complexity, IEEE Transactions of Terahertz Science and Technologydoi:10.1109/TTHZ.2014.2325393,  4, 432-439 (2014).oalogo.jpg

R. Degl'Innocenti, D.S. Jessop, Y.D. Shah, J. Sibik, J.A. Zeitler, P.R. Kidambi, S. Hofmann, H.E. Beere, and D.A. Ritchie, Terahertz optical modulator based on metamaterial split-ring resonators and graphene, Optical Engineering, doi:10.1117/1.OE.53.5.057108, 53, 057108 (2014).

J. Sibik, M.J. Sargent, M. Franklin, and J.A. Zeitler, Crystallisation and phase changes in paracetamol from the amorphous solid to the liquid phase, Molecular Pharmaceutics, doi:10.1021/mp400768m, 11, 1326–1334 (2014).oalogo.jpg

R. Degl'Innocenti, D.S. Jessop, Y.D. Shah, J. Sibik, J.A. Zeitler, P.R. Kidambi, S. Hofmann, H.E. Beere, and D.A. Ritchie
Low-Bias THz Amplitude Modulator Based on Split-Ring Resonators and Graphene, ACS Nano, doi:10.1021/nn406136c, 8, 2548–2554 (2014).

P. Bawuah, A. Mendia, P. Silfsten, P. Pääkkönen, T. Ervasti, J. Ketolainen, J.A. Zeitler, and K.-E. Peiponen, Detection of porosity of pharmaceutical compacts by terahertz radiation transmission and light reflection measurement techniques, International Journal of Pharmaceutics, doi:10.1016/j.ijpharm.2014.02.011, 465, 70-75 (2014). 

J. Bye, S. Meliga, D. Ferachou, G. Cinque, J.A. Zeitler, and R. Falconer, Analysis of the hydration water around bovine serum albumin using terahertz coherent synchrotron radiation, Journal of Physical Chemistry Adoi:10.1021/jp407410g, 118, 83-88 (2014).

E.P.J. Parrott, N.Y. Tan, R.R. Hu, J.A. Zeitler, B.Z. Tang and E. Pickwell-MacPherson, Revealing the mechanism of aggregation-induced emission using temperature resolved terahertz time-domain spectroscopy, Materials Horizonsdoi:10.1039/C3MH00078H, 1, 251-258 (2014).

C. Li, J.A. Zeitler, Y. Dong and Y.-C. Shen, Nondestructive evaluation of polymer coating structures on pharmaceutical pellets using full field optical coherence tomography, Journal of Pharmaceutical Sciencesdoi:10.1002/jps.23764, 103, 161-166 (2014).

New Book: Terahertz Spectroscopy and Imaging


K.-E. Peiponen, J.A. Zeitler, and M. Kuwata-Gonokami (eds.), Terahertz Spectroscopy and Imaging, Springer Series in Optical Sciences 171, DOI:10.1007/978-3-642-29564-5, 641 p., Springer Berlin Heidelberg 2013.

More information on


Q. Zhang, L.F. Gladden, P. Avalle, J.A. Zeitler and M.D. Mantle, Terahertz Pulsed Imaging and Magnetic Resonance Imaging as Tools to Probe Formulation Stability, Pharmaceutics, doi:10.3390/pharmaceutics5040591, 5, 591-608 (2013).oalogo.jpg

S. Badhwar, J. Sibik, P.D. Kidambi, H.E. Beere, J.A. Zeitler, S. Hofmann, and D.A. Ritchie, Intrinsic terahertz plasmon signatures in chemical vapour deposited graphene, Applied Physics Lettersdoi:10.1063/1.4821157, 103, 121110 (2013)

D. Brock, J.A. Zeitler, A. Funke, K. Knop, P. Kleinebudde, Evaluation of critical process parameters for intra-tablet coating uniformity using terahertz pulsed imaging, European Journal of Pharmaceutics and Biopharmaceutics, doi:10.1016/j.ejpb.2013.07.004, 85, 1122-1129 (2013).

J. Sibik, E.Y. Shalaev and J.A. Zeitler, Glassy dynamics of sorbitol solutions at terahertz frequencies, Physical Chemistry Chemical Physicsdoi:10.1039/C3CP51936H, 15, 11931-11942 (2013).oalogo.jpg

K.-E. Peiponen, E.M. Vartialainen, T. Unuma, J.A. Zeitler, P. Silfsten, T. Venäläinen and H. Kishida, Dispersion relations for evaluating the complex refractive index of medium without the information of its thickness, Applied Physics Lettersdoi:10.1063/1.4804610, 102, 181110 (2013).

R.K. May, K. Su, L. Han, S. Zhong, J.A. Elliott, L.F. Gladden, M. Evans, Y.C. Shen and J.A. Zeitler, Hardness and density distributions of pharmaceutical tablets measured by terahertz pulsed imaging, Journal of Pharmaceutical Sciences, 102, 2179-2186 doi:10.1002/jps.23560 (2013).

M. Haaser, K.C. Gordon, M. Pepper, T. Rades, J. Rantanen, C.J. Strachan, P.F. Taday, J.A. Zeitler and K. Naelapää, Evaluating the effect of coating equipment on tablet film quality using terahertz pulsed imaging, European Journal of Pharmaceutics and Biopharmaceuticsdoi:10.1016/j.ejpb.2013.03.019, 85, 1095-1102 (2013)

D. BrockJ.A. Zeitler, A. Funke, K. Knop, P. Kleinebudde, Critical factors in the measurement of tablet film coatings using terahertz pulsed imaging, Journal of Pharmaceutical Sciencesdoi:10.1002/jps.23521, 102, 1813–1824 (2013).

E.P.J. Parrott, B.M. Fischer, L.F. GladdenJ.A. Zeitler, and P.U. Jepsen, Terahertz spectroscopy of crystalline and non-crystalline solids, inTerahertz Spectroscopy and Imaging, edited by K.-E. Peiponen, J.A. Zeitler, and M. Kuwata-Gonokami (Springer, Berlin, Heidelberg, 2012),doi:10.1007/978-3-642-29564-5_8, pp. 191–227.

J.A. Zeitler and Y.-C. Shen, Industrial Applications of Terahertz Imaging, in Terahertz Spectroscopy and Imaging, edited by K.-E. Peiponen, J.A. Zeitler, and M. Kuwata-Gonokami (Springer, Berlin, Heidelberg, 2012), doi:10.1007/978-3-642-29564-5_18 pp. 451–489.


I.S. Russe, D. Brock, K. Knop, P. Kleinebudde and J.A. Zeitler, Validation of terahertz coating thickness measurements using X-ray microtomography, Molecular Pharmaceuticsdoi:10.1021/mp300383y, 9, 3551-3559 (2012).

D. BrockJ.A. Zeitler, A. Funke, K. Knop, P. Kleinebudde, A comparison of quality control methods for active coating processes, International Journal of Pharmaceutics, doi:10.1016/j.ijpharm.2012.09.021, 439, 289-295 (2012).

S. Badhwar, R. Puddy, P.R. Kidambi, J. Sibik, A. Brewer, J.R. Freeman, H.E. Beere, S. Hofmann, J.A. Zeitler, and D.A. Ritchie, Indirect Modulation of a Terahertz Quantum Cascade Laser Using Gate Tunable Graphene, IEEE Photonics Journal,doi:10.1109/JPHOT.2012.2215312, 4, 1776-1782 (2012).

B.S. Akpa, C. D’Agostino, L.F. Gladden, K. Hindle, H. Manyar, J. McGregor, R. Li, M. Neurock, N. Sinha, E.H. Stitt, D. Weber, J.A. Zeitler, D.W. Rooney, Solvent effects in the hydrogenation of 2-butanone, Journal of Catalysisdoi:10.1016/j.jcat.2012.01.011, 289, 30-41 (2012).

J. Muller, D. Brock, K. Knop, J.A. Zeitler and P. Kleinebudde, Prediction of dissolution time and coating thickness of sustained release formulations using Raman spectroscopy and terahertz pulsed imaging, European Journal of Pharmaceutics and Biopharmaceuticsdoi:10.1016/j.ejpb.2011.12.003, 80, 690-697 (2012).


A.J. Baragwanath, J.R. Freeman, A.J. Gallant, J.A. Zeitler, H.E. Beere, D.A. Ritchie and J.M. Chamberlain, Terahertz near-field imaging using subwavelength plasmonic apertures and a quantum cascade laser source, Optics Lettersdoi:10.1364/OL.36.002393, 36, 2393-2395 (2011).

S. Zhong, Y.C. Shen, L. Ho, R.K. May, J.A. Zeitler, M. Evans, P.F. Taday, M. Pepper, T. Rades, K.C. Gordon, R. Muller and P. Kleinebudde, Non-destructive quantification of pharmaceutical tablet coatings using terahertz pulsed imaging and optical coherence tomography, Optics and Lasers in Engineeringdoi:10.1016/j.optlaseng.2010.11.003, 49, 361-365 (2011).

R.K. May, M.J. Evans, S. Zhong, I. Warr, L.F. Gladden, Y.C. Shen and J.A. Zeitler, Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time, Journal of Pharmaceutical Sciences, doi:10.1002/jps.22359, 100, 1525-1544 (2011).

P. Parasoglou, E.P.J. Parrott, J.A. Zeitler, J. Rasburn, H. Powell, L.F. Gladden and M.L. Johns, Quantitative water content measurements in food wafers using terahertz radiation, Terahertz Science and Technology, 3, 172-182 (2011).


T. Ding, R. LiJ.A. Zeitler, T.L. Huber, L.F. Gladden, A.P.J. Middelberg and R.J. Falconer, Terahertz and far infrared spectroscopy of alanine-rich peptides having variable ellipicity, Optics Expressdoi:10.1364/OE.18.027431, 18, 27431-27444 (2010).

E.P.J. ParrottJ.A. Zeitler, G. Simon,  B. Hehlen, L.F. Gladden, S.N. Taraskin and S.R. Elliott, Atomic charge distribution in sodo-silicate glasses from terahertz time-domain spectroscopy, Physical Review Bdoi:10.1103/PhysRevB.82.140203, 82, 140203(R) (2010).

O. Trushkevych, H. Xu, T. Lu, J.A. Zeitler, R. Rungsawang, F. Golden, N. Collings and W.A. Crossland, Broad spectrum measurement of the birefringence of an isothiocyanate based liquid crystal, Applied Opticsdoi:10.1364/AO.49.005212, 49, 5212-5216 (2010).

R. Arrigo, M. Havecker, S. Wrabetz, R. Blume, M. Lerch, J. McGregor, E.P.J. Parrott, J.A. Zeitler, L.F. Gladden, A. Knop-Gericke, R. Schlogl and D.S. Su, Tuning the acid/base properties of nanotubes by functionalisation via amination, Journal of the American Chemical Societydoi:10.1021/ja910169v, 132, 9616-9630 (2010).

R. LiJ.A. Zeitler, D. Tomerini, E.P.J. ParrottL.F. Gladden and G.M. Day, A study into the effect of subtle structural details and disorder on the terahertz spectrum of crystalline benzoic acid, Physical Chemistry Chemical Physicsdoi:10.1039/B926536H, 12, 5329-5340 (2010).

K.A. Graeser, J.E. Patterson, J.A. Zeitler and T. Rades, The role of configurational entropy in amorphous systems, Pharmaceutics, doi:10.3390/pharmaceutics2020224, 2, 224-244 (2010).

H. Tuononen, E. Gornov, J.A. Zeitler, J. Aaltonen and K.E. Peiponen, Using modified Kramers-Kronig relations to test transmission spectra of porous media in THz-TDS, Optics Letters, doi:10.1364/OL.35.000631, 35, 631-633 (2010).

J. McGregor, Z. HuangE.P.J. ParrottJ.A. ZeitlerK.L. Nguyen, J.M. Rawson, A. Carley, T.W. Hansen, J.P. Tessonier, D.S. Su, D. Teschner, E.M. Vass, A. Knop-Gericke, R. Schlogl and L.F. Gladden, Active coke: Carbonaceous  materials as catalysts for alkane dehydrogenation, Journal of Catalysis, doi:10.1016/j.jcat.2009.11.016, 269, 329-339 (2010).

L. Ho, R. Müller, C. Krüger, K.C. Gordon, P. Kleinebudde, M. Pepper, T. Rades, Y.C. Shen, P.F. Taday and J.A. Zeitler, Investigating dissolution performance critical areas on coated tablets: a case study using terahertz pulsed imaging, Journal of Pharmaceutical Sciences,doi:10.1002/jps.21845, 99, 392-402 (2010). 


Y.C. Shen, L. Gan, M. Stringer, A. Burnett, K. Tych, H. Shen, J.E. Cunningham, E.P.J. ParrottJ.A. ZeitlerL.F. Gladden, E.H. Linfield and A.G. Davies, Terahertz pulsed spectroscopic imaging using optimized binary masks, Applied Physics Letters,doi:10.1063/1.3271030, 95, 231112 (2009).

E.P.J. ParrottJ.A. Zeitler, and L.F. Gladden, Accurate determination of optical coefficients from chemical samples using terahertz time-domain spectroscopy and effective medium theory, Optics Lettersdoi:10.1364/OL.34.003722, 34, 3722-3724 (2009).

E.P.J. ParrottJ.A. ZeitlerJ. McGregor, S.P. Oei, H.E. Unalan, W.I. Milne, J.P. Tessonnier, D. Su, R. Schlögl and L.F. Gladden, The use of terahertz spectroscopy as a sensitive probe in discriminating the electronic properties of structurally similar multi-walled carbon nanotubes, Advanced Materialsdoi:10.1002/adma.200900941, 21, 3953-3957 (2009).

E.P.J. ParrottJ.A. ZeitlerL.F. Gladden, S.N. Taraskin and S.R. Elliott, Extracting accurate optical parameters from glasses using terahertz time-domain spectroscopy, Journal of Non-Crystalline Solidsdoi:10.1016/j.jnoncrysol.2009.04.071, 355, 1824-1827 (2009).

E.P.J. ParrottJ.A. ZeitlerJ. McGregor, S.P. Oei, H.E. Unalan, S.C. Tan, W.I. Milne, M. Pepper, J.P. Tessonnier, R. Schlögl and L.F. Gladden, Understanding the dielectric properties of heat treated carbon nanofibres at THz frequencies, Journal of Physical Chemistry C,doi:10.1021/jp811226d, 113, 10554–10559 (2009). 

L. Ho, R. Müller, K.C. Gordon, P. Kleinebudde, M. Pepper, T. Rades, Y.C. Shen, P.F. Taday and J.A. Zeitler, Monitoring the film coating unit operation and predicting the dissolution performance using terahertz pulsed imaging, Journal of Pharmaceutical Sciences,doi:10.1002/jps.21766, 98, 4866-4876 (2009). 

K.A. Graeser, J.E. Patterson, J.A. Zeitler, K.C. Gordon and T. Rades, Correlating thermodynamic and kinetic parameters with amorphous stability, European Journal of Pharmaceutical Sciences,doi:10.1016/j.ejps.2009.04.005, 37, 492-498 (2009).

E.P.J. ParrottJ.A. Zeitler, T. Friš?i?, G.M. Day, L.F. Gladden, M. Pepper and W. Jones, Testing the sensitivity of terahertz spectroscopy to changes in molecular and supramolecular structure: A study of structurally similar cocrystals, Crystal Growth and Design,doi:10.1021/cg8008893, 9, 1452-1460 (2009). 

J.A. Zeitler and L.F. Gladden, In-vitro tomography and non-destructive imaging at depth of pharmaceutical solid dosage forms, invited review in  European Journal of Pharmaceutics and Biopharmaceuticsdoi:10.1016/j.ejpb.2008.08.012, 71, 2-22 (2009). 

L. Ho, R. Müller, K.C. Gordon, P. Kleinebudde, M. Pepper, T. Rades, Y.C. Shen, P.F. Taday and J.A. Zeitler, Terahertz pulsed imaging as a process analytical tool for sustained-release tablet film coating, European Journal of Pharmaceutics and Biopharmaceutics,doi:10.1016/j.ejpb.2008.06.023, 71, 117-123 (2009). 


V.P. Wallace, E. MacPherson, J.A. Zeitler and C. Reid, Three-Dimensional imaging of optically opaque materials using terahertz radiation,Journal of the Optical Society of America Adoi:10.1364/JOSAA.25.003120, 25, 3120-3133 (2008). 

D.G. Allis, J.A. Zeitler, P.F. Taday and T.M. Korter, Theoretical analysis of the solid-state terahertz spectrum of the high explosive RDX,Chemical Physics Lettersdoi:10.1016/j.cplett.2008.08.014, 463, 84-89 (2008). 

D.X. Zhou, E.P.J Parrott, D. Paul and J.A. Zeitler, Determination of complex refractive index of thin metal films from terahertz time-domain spectroscopy, Journal of Applied Physicsdoi:10.1063/1.2970161, 104, 053110-9 (2008). 

K. Kogermann, J.A. Zeitler, C.J. Strachan, T. Rades, P.F. Taday and M. Pepper, J. Heinämäki and J. Rantanen, Investigating dehydration from compacts using terahertz pulsed, Raman and near-infrared spectroscopy, Applied Spectroscopy,doi:10.1366/000370207783292136, 61, 1265-1274 (2008).

L. Ho, R. Müller, K.C. Gordon, P. Kleinebudde, M. Pepper, T. Rades, Y.C. Shen, P.F. Taday and J.A. Zeitler, Applications of terahertz pulsed imaging to tablet coating quality assessment and dissolution performance, Journal of Controlled Release,doi:10.1016/j.jconrel.2008.01.002, 127, 79-87 (2008).

O. Hirsch, P. Alexander and L.F. Gladden, Techniques for cancellation of interfering multiple reflections in terahertz time-domain measurements, Microelectronics Journaldoi:10.1016/j.mejo.2008.01.001, 39, 841-848 (2008).


J. ObradovicJ.H.P. CollinsO. Hirsch, M.D. Mantle, M.L. Johns and L.F. Gladden, The use of THz time-domain reflection measurements to investigate solvent diffusion in polymers, Polymerdoi:10.1016/j.polymer.2007.04.010, 48, 3494-3503 (2007).

K.L Nguyen, T. Friscic, G.M. Day, L.F. Gladden and W. Jones, Terahertz time-domain spectroscopy and the quantitative monitoring of mechanochemical cocrystal formation, Nature Materialsdoi:10.1038/nmat1848, 6, 206-209 (2007).

J.A. Zeitler, P.F. Taday, K.C. Gordon, M. Pepper and T. Rades, Solid-state transition mechanism in carbamazepine polymorphs by time-resolved terahertz spectroscopy, ChemPhysChem, doi:10.1002/cphc.200700261, 8, 1924-1927 (2007).

J.A. Zeitler, P.F. Taday, M. Pepper, and T. Rades, Relaxation and crystallization of amorphous carbamazepine studied by terahertz pulsed spectroscopy, Journal of Pharmaceutical Sciences, doi:10.1002/jps.20908, 96, 2703-2709 (2007).

L. Ho, R. Müller, M. Römer, K.C. Gordon, J. Heinämäki, P. Kleinebudde, M. Pepper, T. Rades, Y.C. Shen, C.J. Strachan, P.F. Taday, and J.A. Zeitler, The analysis of sustained-release tablet film coats using terahertz pulsed imaging, Journal of Controlled Release,doi:10.1016/j.jconrel.2007.03.011, 119, 253-261 (2007).

F. Tian, D.J. Saville, K.C. Gordon, C.J. Strachan, J.A. Zeitler, and T. Rades, The influence of various excipients on the conversion kinetics of carbamazepine polymorphs in aqueous suspension, Journal of Pharmacy and Pharmacologydoi:10.1211/jpp.59.2.0006, 59, 193-201 (2007).

J.A. Zeitler, Y.C. Shen, C. Baker, P.F. Taday, M. Pepper, and T. Rades, Analysis of coating structures and interfaces in solid oral dosage forms by three dimensional terahertz pulsed imaging, Journal of Pharmaceutical Sciences, doi:10.1002/jps.20789, 96, 330-340 (2007).

J.A. Zeitler, K. Kogermann, J. Rantanen, T. Rades, P.F. Taday, M. Pepper, J. Aaltonen, and C.J. Strachan, Drug Hydrate Systems and Dehydration Processes Studied by Terahertz Pulsed Spectroscopy, International Journal of Pharmaceutics,doi:10.1016/j.ijpharm.2006.10.027, 334, 78-84 (2007).

J.A. Zeitler, P.F. Taday, D.A. Newnham, M. Pepper, K.C. Gordon, and T. Rades, Terahertz pulsed spectroscopy and imaging in the pharmaceutical setting, Journal of Pharmacy and Pharmacology, doi:10.1211/jpp.59.2.0008, 59, 209-223 (2007).


P.C. Upadhya, K.L. Nguyen, Y.C. Shen, J. Obradovic, K. Fukushige, R. Griffiths, L.F. Gladden, A.G. Davies and E.H. Linfield, Characterization of crystalline phase-transformations in theophylline by time-domain terahertz spectroscopy, Spectroscopy Letters,doi:10.1080/00387010600636916, 39, 215-224 (2006).

K.L. NguyenM.L. JohnsL.F. Gladden, C.H. Worrall, P. Alexander, H.E. Beere, M. Pepper, D.A. Ritchie, J. Alton, S. Barbieri and E.H. Linfield, Three-dimensional imaging with a terahertz quantum cascade laser, Optics Expressdoi:10.1364/OE.14.002123, 14, 2123-2129 (2006).oalogo.jpg

J.A. Zeitler, D.A. Newnham, P.F. Taday, T.L. Threlfall, R.W. Lancaster, R.W. Berg, C.J. Strachan, M. Pepper, K.C. Gordon, and T. Rades, Characterization of temperature induced phase transitions in the five polymorphic forms of sulfathiazole studied by terahertz pulsed spectroscopy and differential scanning calorimetry, Journal of Pharmaceutical Sciencesdoi:10.1002/jps.20719, 95, 2486-2498 (2006).

G.M. Day, J.A. Zeitler, W. Jones, T. Rades, and P.F. Taday 2006. Understanding the influence of polymorphism on phonon spectra: lattice dynamics calculations and terahertz spectroscopy of carbamazepine, Journal of Physical Chemistry Bdoi:10.1021/jp055439y, 110, 447-456 (2006).

F. Tian, J.A. Zeitler, C.J. Strachan, D.J. Saville, K.C. Gordon, and T. Rades, Characterizing the transformation kinetics of carbamazepine polymorphs to the dihydrate using Raman spectroscopy, Journal of Pharmaceutical and Biomedical Analysis,doi:10.1016/j.jpba.2005.07.030, 40, 271-280 (2006).

C.M. McGoverin, L.C.H. Ho, J.A. Zeitler, C.J. Strachan, K.C. Gordon, and T. Rades, Quantification of binary mixtures of ranitidine hydrochloride using NIR spectroscopy, Vibrational Spectroscopydoi:10.1016/j.vibspec.2006.04.026, 41, 225-231 (2006).



J.A. Zeitler, D.A. Newnham, P.F. Taday, C.J. Strachan, M. Pepper, K.C. Gordon, and T. Rades, Temperature dependent terahertz pulsed spectroscopy of carbamazepine, Thermochimica Actadoi:10.1016/j.tca.2005.07.006, 436, 71-77 (2005).

C.J. Strachan, P.F. Taday, D.A. Newnham, K.C. Gordon, J.A. Zeitler, M. Pepper, and T. Rades, Using terahertz pulsed spectroscopy to quantify pharmaceutical polymorphism and crystallinity, Journal of Pharmaceutical Sciencesdoi:10.1002/jps.20281, 94, 837-846 (2005).