Research Line Manager
Research Line Manager


Dr. Nancy Hess is the Environmental Transformations and Interactions group leader in PNNL’s Environmental Molecular Sciences Division and the Environmental Molecular Sciences Laboratory (EMSL) user program. Hess develops and implements the science strategy for EMSL’s Environmental Transformations and Interactions Science Area. She is responsible for calls for proposals and user portfolio management for the science area. She identifies specific objectives/targets and guides the assembly of the needed computational and experimental platforms to implement the vision. She engages the research community in these activities by holding workshops and organizing summer schools and sessions at national meetings. She is also facilitating user access to multiple U.S. Department of Energy (DOE) user facilities through a single user proposal via the Facilities Integrating Collaborations for User Science program. 

The thrust of Hess's current research is the application of high-resolution mass spectrometry to understand the molecular identity of natural organic matter and its transformation by microbial and physiochemical processes in the natural environment. Previous research background includes the application of molecular level spectroscopic techniques, such as X-ray absorption spectroscopy, neutron scattering and diffraction, in situ Raman, and time-resolved fluorescence spectroscopies. She has contributed to DOE’s Basic Energy Sciences Hydrogen Storage program and worked on programs studying radiation effects in ceramics, the optical properties of dielectric thin films, and the development of rare-earth based optical sensors. She has led several DOE Environmental Remediation Sciences Program (ERSP) studies on technetium chemistry in high-level waste and the vadose zone, and she has contributed to several other ERSP programs at PNNL. She has participated in structural biology research on DNA repair proteins and environmental restoration characterization tasks, including actinide speciation in geological environments and Hanford tank sludge and supernate.  

Research Interest

  • Natural organic matter molecular identity and transformation 

  • X-ray absorption spectroscopy 

  • Time-resolved fluorescence spectroscopies 


  • PhD in Mineral Physics, University of Washington, 1990 

  • MS in Economic Geology, University of Arizona, 1986 

  • BS in Geology, University of California, Davis 1981 

Affiliations and Professional Service

  • NanoEarth Science Advisory Panel 

  • American Geophysical Union 

  • Chair, Los Alamos Neutron Science Center User Group (2010-2011) 

  • Vice-Chair, Los Alamos Neutron Science Center User Group (2009-2010) 

Awards and Recognitions

  • John C. Jamieson Award for Outstanding Student Contribution to High-Pressure Research (1990)



Hawkes, J. A., J. D'Andrilli, J. N. Agar, M. P. Barrow, S. M. Berg, N. Catalán, H. Chen, R. K. Chu, R. B. Cole, T. Dittmar, R. Gavard, G. Gleixner, P. G. Hatcher, C. He, N. J. Hess, R. H. S. Hutchins, A. Ijaz, H. E. Jones, W. Kew, M. Khaksari, D. C. Palacio Lozano, J. Lv, L. R. Mazzoleni, B. E. Noriega-Ortega, H. Osterholz, N. Radoman, C. K. Remucal, N. D. Schmitt, S. K. Schum, Q. Shi, C. Simon, G. Singer, R. L. Sleighter, A. Stubbins, M. J. Thomas, N. Tolic, S. Zhang, P. Zito, and D. C. Podgorski. 2020. “An International Laboratory Comparison of Dissolved Organic Matter Composition by High Resolution Mass Spectrometry: Are We Getting the Same Answer?” Limnology and Oceanography: Methods 18 (6): 235-258.  

Čapek, P., R. Starke, K. S. Hofmockel, B. Bond-Lamberty, and N. Hess. 2019. “Apparent Temperature Sensitivity of Soil Respiration Can Result from Temperature Driven Changes in Microbial Biomass.” Soil Biology and Biochemistry 135: 286-293.  


Fudyma, J. D., J. Lyon, R. AminiTabrizi, H. Gieschen, R. K. Chu, D. W. Hoyt, J. E. Kyle, J. Toyoda, N. Tolic, H. M. Heyman, N. J. Hess, T. O. Metz, and M. M. Tfaily. 2019. “Untargeted Metabolomic Profiling of Sphagnum fallax Reveals Novel Antimicrobial Metabolites.” Plant Direct 3 (11).  

Müller, K., H. Foerstendorf, R. Steudtner, S. Tsushima, M. U. Kumke, G. Lefèvre, J. Rothe, H. Mason, Z. Szabó, P. Yang, C. K. R. Adam, R. André, K. Brennenstuhl, I. Chiorescu, H. M. Cho, G. Creff, F. Coppin, K. Dardenne, C. Den Auwer, B. Drobot, S. Eidner, N. J. Hess, P. Kaden, A. Kremleva, J. Kretzschmar, S. Krüger, J. A. Platts, P. J. Panak, R. Polly, B. A. Powell, T. Rabung, R. Redon, P. E. Reiller, N. Rösch, A. Rossberg, A. C. Scheinost, B. Schimmelpfennig, G. Schreckenbach, A. Skerencak-Frech, V. Sladkov, P. L. Solari, Z. Wang, N. M. Washton, and X. Zhang. 2019. “Interdisciplinary Round-Robin Test on Molecular Spectroscopy of the U(VI) Acetate System.” ACS Omega 4 (5): 8167-8177.  

Ohno, T., N. J. Hess, and N. P. Qafoku. 2019. “Current Understanding of the Use of Alkaline Extractions of Soils to Investigate Soil Organic Matter and Environmental Processes.” Journal of Environmental Quality 48 (6): 1561-1564.  

Shen, Y., R. Zhao, N. Tolić, M. M. Tfaily, E. W. Robinson, R. Boiteau, L. Paša-Tolić, and N. J. Hess. 2019. “Online Supercritical Fluid Extraction Mass Spectrometry (SFE-LC-FTMS) for Sensitive Characterization of Soil Organic Matter.” Faraday Discussions 218: 157-171.  


Tfaily, M. M., N. J. Hess, A. Koyama, and R. D. Evans. 2018. “Elevated [CO2] Changes Soil Organic Matter Composition and Substrate Diversity in an Arid Ecosystem.” Geoderma 330: 1-8.  

Wu, X., L. Wu, Y. Liu, P. Zhang, Q. Li, J. Zhou, N. J. Hess, T. C. Hazen, W. Yang, and R. Chakraborty. 2018. “Microbial Interactions with Dissolved Organic Matter Drive Carbon Dynamics and Community Succession.” Frontiers in Microbiology 9 (JUN).  


Conradson, S. D., D. A. Andersson, K. S. Boland, J. A. Bradley, D. D. Byler, T. Durakiewicz, S. M. Gilbertson, S. A. Kozimor, K. O. Kvashnina, D. Nordlund, G. Rodriguez, G. T. Seidler, P. S. Bagus, S. M. Butorin, D. R. Conradson, F. J. Espinosa-Faller, N. J. Hess, J. J. Kas, J. S. Lezama-Pacheco, P. Martin, M. B. Martucci, J. J. Rehr, J. A. Valdez, A. R. Bishop, G. Baldinozzi, D. L. Clark, and A. Tayal. 2017. “Closure of the Mott Gap and Formation of a Superthermal Metal in the Fröhlich-Type Nonequilibrium Polaron Bose-Einstein Condensate in UO2+x.” Physical Review B 96 (12).  

Hess, N. J., L. Paša-Tolić, V. L. Bailey, and A. C. Dohnalkova. 2017. “New Understanding of Rhizosphere Processes Enabled by Advances in Molecular and Spatially Resolved Techniques.” Rhizosphere 3: 209-211.  

Stegen, J. C., C. G. Anderson, B. Bond-Lamberty, A. R. Crump, X. Chen, and N. Hess. 2017. “Soil Respiration across a Permafrost Transition Zone: Spatial Structure and Environmental Correlates.” Biogeosciences 14 (18): 4341-4354.  

Tfaily, M. M., R. K. Chu, J. Toyoda, N. Tolić, E. W. Robinson, L. Paša-Tolić, and N. J. Hess. 2017. “Sequential Extraction Protocol for Organic Matter from Soils and Sediments Using High Resolution Mass Spectrometry.” Analytica Chimica Acta 972: 54-61.  

Tolić, N., Y. Liu, A. Liyu, Y. Shen, M. M. Tfaily, E. B. Kujawinski, K. Longnecker, L. J. Kuo, E. W. Robinson, L. Paša-Tolić, and N. J. Hess. 2017. “Formularity: Software for Automated Formula Assignment of Natural and Other Organic Matter from Ultrahigh-Resolution Mass Spectra.” Analytical Chemistry 89 (23): 12659-12665.  

Walker, L. R., M. M. Tfaily, J. B. Shaw, N. J. Hess, L. Paša-Tolić, and D. W. Koppenaal. 2017. “Unambiguous Identification and Discovery of Bacterial Siderophores by Direct Injection 21 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.” Metallomics 9 (1): 82-92.  


Moran, M. A., E. B. Kujawinski, A. Stubbins, R. Fatland, L. I. Aluwihare, A. Buchan, B. C. Crump, P. C. Dorrestein, S. T. Dyhrman, N. J. Hess, B. Howe, K. Longnecker, P. M. Medeiros, J. Niggemann, I. Obernosterer, D. J. Repeta, and J. R. Waldbauer. 2016. “Deciphering Ocean Carbon in a Changing World.” Proceedings of the National Academy of Sciences of the United States of America 113 (12): 3143-3151.  

Oostrom, M., Y. Mehmani, P. Romero-Gomez, Y. Tang, H. Liu, H. Yoon, Q. Kang, V. Joekar-Niasar, M. T. Balhoff, T. Dewers, G. D. Tartakovsky, E. A. Leist, N. J. Hess, W. A. Perkins, C. L. Rakowski, M. C. Richmond, J. A. Serkowski, C. J. Werth, A. J. Valocchi, T. W. Wietsma, and C. Zhang. 2016. “Pore-Scale and Continuum Simulations of Solute Transport Micromodel Benchmark Experiments.” Computational Geosciences 20 (4): 857-879.  

Stegen, J. C., A. H. Hurlbert, B. Bond-Lamberty, X. Chen, C. G. Anderson, R. K. Chu, F. Dini-Andreote, S. J. Fansler, N. J. Hess, and M. Tfaily. 2016. “Aligning the Measurement of Microbial Diversity with Macroecological Theory.” Frontiers in Microbiology 7 (SEP).  


Tfaily, M. M., R. K. Chu, N. Tolić, K. M. Roscioli, C. R. Anderton, L. Paša-Tolić, E. W. Robinson, and N. J. Hess. 2015. “Advanced Solvent Based Methods for Molecular Characterization of Soil Organic Matter by High-Resolution Mass Spectrometry.” Analytical Chemistry 87 (10): 5206-5215.  


Bowden, M. E., K. J. Alvine, J. L. Fulton, J. P. Lemmon, X. Lu, B. J. Webb-Robertson, S. M. Heald, M. Balasubramanian, D. R. Mortensen, G. T. Seidler, and N. J. Hess. 2014. “X-Ray Absorption Measurements on Nickel Cathode of Sodium-Beta Alumina Batteries: Fe-Ni-Cl Chemical Associations.” Journal of Power Sources 247: 517-526.  

Boyd, V., H. Yoon, C. Zhang, M. Oostrom, N. Hess, B. Fouke, A. J. Valocchi, and C. J. Werth. 2014. “Influence of Mg2+ on CaCO3 Precipitation During Subsurface Reactive Transport in a Homogeneous Silicon-Etched Pore Network.” Geochimica et Cosmochimica Acta 135: 321-335.  

Conradson, S. D., N. Bock, J. M. Castro, D. R. Conradson, L. E. Cox, W. Dmowski, D. E. Dooley, T. Egami, F. J. Espinosa-Faller, F. J. Freibert, A. J. Garcia-Adeva, N. J. Hess, E. Holmström, R. C. Howell, B. A. Katz, J. C. Lashley, R. J. Martinez, D. P. Moore, L. A. Morales, J. D. Olivas, R. A. Pereyra, M. Ramos, J. H. Terry, and P. M. Villella. 2014. “Intrinsic Nanoscience of δ Pu-Ga Alloys: Local Structure and Speciation, Collective Behavior, Nanoscale Heterogeneity, and Aging Mechanisms.” Journal of Physical Chemistry C 118 (16): 8541-8563.  

Conradson, S. D., N. Bock, J. M. Castro, D. R. Conradson, L. E. Cox, W. Dmowski, D. E. Dooley, T. Egami, F. J. Espinosa-Faller, F. J. Freibert, A. J. Garcia-Adeva, N. J. Hess, E. K. Holmström, R. C. Howell, B. Katz, J. C. Lashley, R. J. Martinez, D. P. Moore, L. A. Morales, J. D. Olivas, R. A. Pereyra, M. Ramos, S. P. Rudin, and P. M. Villella. 2014. “Nanoscale Heterogeneity, Premartensitic Nucleation, and a New Plutonium Structure in Metastable δ fcc Pu-Ga Alloys.” Physical Review B - Condensed Matter and Materials Physics 89 (22).  

Qafoku, O., J. Hu, N. J. Hess, M. Y. Hu, E. S. Ilton, J. Feng, B. W. Arey, and A. R. Felmy. 2014. “Formation of Submicron Magnesite During Reaction of Natural Forsterite in H2O-Saturated Supercritical CO2.” Geochimica et Cosmochimica Acta 134: 197-209.  

Szecsody, J. E., D. P. Jansik, J. P. McKinley, and N. J. Hess. 2014. “Influence of Alkaline Co-Contaminants on Technetium Mobility in Vadose Zone Sediments.” Journal of Environmental Radioactivity 135: 147-160.  


Arey, B. W., L. Kovarik, O. Qafoku, Z. Wang, N. J. Hess, and A. R. Felmy. 2013. “Identification of Fragile Microscopic Structures During Mineral Transformations in Wet Supercritical CO2.” Microscopy and Microanalysis 19 (2): 268-275.  

Conradson, S. D., T. Durakiewicz, F. J. Espinosa-Faller, Y. Q. An, D. A. Andersson, A. R. Bishop, K. S. Boland, J. A. Bradley, D. D. Byler, D. L. Clark, D. R. Conradson, L. L. Conradson, A. L. Costello, N. J. Hess, G. H. Lander, A. Llobet, M. B. Martucci, J. Mustre De Leon, D. Nordlund, J. S. Lezama-Pacheco, T. E. Proffen, G. Rodriguez, D. E. Schwarz, G. T. Seidler, A. J. Taylor, S. A. Trugman, T. A. Tyson, and J. A. Valdez. 2013. “Possible Bose-Condensate Behavior in a Quantum Phase Originating in a Collective Excitation in the Chemically and Optically Doped Mott-Hubbard System UO2+x.” Physical Review B - Condensed Matter and Materials Physics 88 (11).  

Fanizza, M. F., H. Yoon, C. Zhang, M. Oostrom, T. W. Wietsma, N. J. Hess, M. E. Bowden, T. J. Strathmann, K. T. Finneran, and C. J. Werth. 2013. “Pore-Scale Evaluation of Uranyl Phosphate Precipitation in a Model Groundwater System.” Water Resources Research 49 (2): 874-890.  


Felmy, A. R., O. Qafoku, B. W. Arey, J. Z. Hu, M. Hu, H. Todd Schaef, E. S. Ilton, N. J. Hess, C. I. Pearce, J. Feng, and K. M. Rosso. 2012. “Reaction of Water-Saturated Supercritical CO2 with Forsterite: Evidence for Magnesite Formation at Low Temperatures.” Geochimica et Cosmochimica Acta 91: 271-282.  

Webb-Robertson, B. J. M., V. L. Bailey, S. J. Fansler, M. J. Wilkins, and N. J. Hess. 2012. “Spectral Signatures for the Classification of Microbial Species Using Raman Spectra.” Analytical and Bioanalytical Chemistry 404 (2): 563-572.  


Shaw, W. J., M. Bowden, A. Karkamkar, C. J. Howard, D. J. Heldebrant, N. J. Hess, J. C. Linehan, and T. Autrey. 2010. “Characterization of a New Phase of Ammonia Borane.” Energy and Environmental Science 3 (6): 796-804.  

Zhang, C., K. Dehoff, N. Hess, M. Oostrom, T. W. Wietsma, A. J. Valocchi, B. W. Fouke, and C. J. Werth. 2010. “Pore-Scale Study of Transverse Mixing Induced CaCO3 Precipitation and Permeability Reduction in a Model Subsurface Sedimentary System.” Environmental Science and Technology 44 (20): 7833-7838.  


Hess, N. J., G. K. Schenter, M. R. Hartman, L. L. Daemen, T. Proffen, S. M. Kathmann, C. J. Mundy, M. Hartl, D. J. Heidebrant, A. C. Stowe, and T. Autrey. 2009. “Neutron Powder Diffraction and Molecular Simulation Study of the Structural Evolution of Ammonia Borane from 15 to 340 K.” Journal of Physical Chemistry A 113 (19): 5723-5735.  

Karkamkar, A., S. M. Kathmann, G. K. Schenter, D. J. Heldebrant, N. Hess, M. Gutowski, and T. Autrey. 2009. “Thermodynamic and Structural Investigations of Ammonium Borohydride, a Solid with a Highest Content of Thermodynamically and Kinetically Accessible Hydrogen.” Chemistry of Materials 21 (19): 4356-4358.  

Kathmann, S. M., V. Parvanov, G. K. Schenter, A. C. Stowe, L. L. Daemen, M. Hartl, J. Linehan, N. J. Hess, A. Karkamkar, and T. Autrey. 2009. “Experimental and Computational Studies on Collective Hydrogen Dynamics in Ammonia Borane: Incoherent Inelastic Neutron Scattering.” Journal of Chemical Physics 130 (2).  


Cho, H., W. J. Shaw, V. Parvanov, G. K. Schenter, A. Karkamkar, N. J. Hess, C. Mundy, S. Kathmann, J. Sears, A. S. Lipton, P. D. Ellis, and S. Thomas Autrey. 2008. “Molecular Structure and Dynamics in the Low Temperature (Orthorhombic) Phase of NH3BH3.” Journal of Physical Chemistry A 112 (18): 4277-4283.  

Heldebrant, D. J., A. Karkamkar, N. J. Hess, M. Bowden, S. Rassat, Z. Feng, K. Rappe, and T. Autrey. 2008. “The Effects of Chemical Additives on the Induction Phase in Solid-State Thermal Decomposition of Ammonia Borane.” Chemistry of Materials 20 (16): 5332-5336.  

Hess, N. J., M. E. Bowden, V. M. Parvanov, C. Mundy, S. M. Kathmann, G. K. Schenter, and T. Autrey. 2008. “Spectroscopic Studies of the Phase Transition in Ammonia Borane: Raman Spectroscopy of Single Crystal NH3BH3 as a Function of Temperature from 88 to 330 K.” Journal of Chemical Physics 128 (3).  

Hess, N. J., M. R. Hartman, C. M. Brown, E. Mamontov, A. Karkamkar, D. J. Heldebrant, L. L. Daemen, and T. Autrey. 2008. “Quasielastic Neutron Scattering of - NH3 and - BH3 Rotational Dynamics in Orthorhombic Ammonia Borane.” Chemical Physics Letters 459 (1-6): 85-88.  

Hess, N. J., O. Qafoku, Y. Xia, D. A. Moore, and A. R. Felmy. 2008. “Thermodynamic Model for the Solubility of TcO2·xH2O in Aqueous Oxalate Systems.” Journal of Solution Chemistry 37 (11): 1471-1487.  

Parvanov, V. M., G. K. Schenter, N. J. Hess, L. L. Daemen, M. Hartl, A. C. Stowe, D. M. Camaioni, and T. Autrey. 2008. “Materials for Hydrogen Storage: Structure and Dynamics of Borane Ammonia Complex.” Journal of the Chemical Society. Dalton Transactions (33): 4514-4522.  


Rai, D., D. A. Moore, N. J. Hess, K. M. Rosso, L. Rao, and S. M. Heald. 2007. “Chromium(III) Hydroxide Solubility in the Aqueous K+-H+-OH--CO2-HCO3 - -CO32- -H2O System: A Thermodynamic Model.” Journal of Solution Chemistry 36 (10): 1261-1285.  


Brown, C. M., T. L. Jacques, N. J. Hess, L. L. Daemen, E. Mamontov, J. C. Linehan, A. C. Stowe, and T. Autrey. 2006. “Dynamics of Ammonia Borane Using Neutron Scattering.” Physica B: Condensed Matter 385-386 I: 266-268.  

Ding, M., J. L. Conca, C. Den Auwer, R. I. Gabitov, N. J. Hess, P. Paviet-Hartmann, P. D. Palmer, V. LoPresti, and S. D. Conradson. 2006. “Chemical Speciation of Heterogeneously Reduced Pu in Synthetic Brines.” Radiochimica Acta 94 (5): 249-259.  

Felmy, A. R., H. Cho, D. A. Dixon, Y. Xia, N. J. Hess, and Z. Wang. 2006. “The Aqueous Complexation of Thorium with Citrate under Neutral to Basic Conditions.” Radiochimica Acta 94 (4): 205-212.  

Xia, Y., N. J. Hess, and A. R. Felmy. 2006. “Stability Constants of Technetium(IV) Oxalate Complexes as a Function of Ionic Strength.” Radiochimica Acta 94 (3): 137-141.  


Conradson, S. D., B. D. Begg, D. L. Clark, C. Den Auwer, M. Ding, P. K. Dorhout, F. J. Espinosa-Faller, P. L. Gordon, R. G. Haire, N. J. Hess, R. F. Hess, D. W. Keogh, G. H. Lander, D. Manara, L. A. Morales, M. P. Neu, P. Paviet-Hartmann, J. Rebizant, V. V. Rondinella, W. Runde, C. D. Tait, D. K. Veirs, P. M. Villella, and F. Wastin. 2005. “Charge Distribution and Local Structure and Speciation in the UO2+x and PuO2+x Binary Oxides for x≤0.25.” Journal of Solid State Chemistry 178 (2 SPEC. ISS.): 521-535.  

Rai, D., Y. Xia, L. Rao, N. J. Hess, A. R. Felmy, D. A. Moore, and D. E. McCready. 2005. “Solubility of (UO2)3(PO4)2·4H2O in H+-Na+-OH--H2PO-4-HPO2- 4-PO3-4-H2O and Its Comparison to the Analogous PuO2+2 System.” Journal of Solution Chemistry 34 (4): 469-498.  

Rai, D., M. Yui, N. J. Hess, A. R. Felmy, and D. A. Moore. 2005. “Thorium Reactions in Borosilicate-Glass/Water Systems.” Radiochimica Acta 93 (8): 443-455.  

Wester, D. W., and N. J. Hess. 2005. “Bond-Valence Sums for Tc-O Systems from EXAFS Data.” Inorganica Chimica Acta 358 (4): 865-874.  


Conradson, S. D., K. D. Abney, B. D. Begg, E. D. Brady, D. L. Clark, C. Den Auwer, M. Ding, P. K. Dorhout, F. J. Espinosa-Faller, P. L. Gordon, R. G. Haire, N. J. Hess, R. F. Hess, D. W. Keogh, G. H. Lander, A. J. Lupinetti, L. A. Morales, M. P. Neu, P. D. Palmer, P. Paviet-Hartmann, S. D. Reilly, W. H. Runde, C. D. Tait, D. K. Veirs, and F. Wastin. 2004. “Higher Order Speciation Effects on Plutonium L3 X-Ray Absorption near Edge Spectra.” Inorganic Chemistry 43 (1): 116-131.  

Conradson, S. D., B. D. Begg, D. L. Clark, C. Den Auwer, M. Ding, P. K. Dorhout, F. J. Espinosa-Faller, P. L. Gordon, R. G. Haire, N. J. Hess, R. F. Hess, D. W. Keogh, L. A. Morales, M. P. Neu, P. Paviet-Hartmann, W. Runde, C. D. Tait, D. K. Veirs, and P. M. Villella. 2004. “Local and Nanoscale Structure and Speciation in the PuO2+x-y(OH)2y·zH2O System.” Journal of the American Chemical Society 126 (41): 13443-13458.  

Hess, N. J., Y. Xia, D. Rai, and S. D. Conradson. 2004. “Thermodynamic Model for the Solubility of TcO2·xH2O(am) in the Aqueous Tc(IV) - Na+ - Cl- - H+ - OH- - H2O System.” Journal of Solution Chemistry 33 (2): 199-226.  

Rai, D., N. J. Hess, M. Yui, A. R. Felmy, and D. A. Moore. 2004. “Thermodynamics and Solubility of (UxNp1-x)O2(am) Solid Solution in the Carbonate System.” Radiochimica Acta 92 (9-11): 527-535.  

Rai, D., D. A. Moore, N. J. Hess, L. Rao, and S. B. Clark. 2004. “Chromium(III) Hydroxide Solubility in the Aqueous Na+- OH--H2PO-4-HPO2-4 -PO3-4-H2O System: A Thermodynamic Model.” Journal of Solution Chemistry 33 (10): 1213-1242.  

Wildung, R. E., S. W. Li, C. J. Murray, K. M. Krupka, Y. Xie, N. J. Hess, and E. E. Roden. 2004. “Technetium Reduction in Sediments of a Shallow Aquifer Exhibiting Dissimilatory Iron Reduction Potential.” FEMS microbiology ecology 49 (1): 151-162.  


Cho, H., D. Rai, N. J. Hess, Y. Xia, and L. Rao. 2003. “Acidity and Structure of Isosaccharinate in Aqueous Solution: A Nuclear Magnetic Resonance Study.” Journal of Solution Chemistry 32 (8): 691-702.  

Conradson, S. D., B. D. Begg, D. L. Clark, C. Den Auwer, F. J. Espinosa-Faller, P. L. Gordon, N. J. Hess, R. Hess, D. W. Keogh, L. A. Morales, M. P. Neu, W. Runde, C. D. Tait, D. K. Veirs, and P. M. Villella. 2003. “Speciation and Unusual Reactivity in PuO2+x.” Inorganic Chemistry 42 (12): 3715-3717.  

Rai, D., N. J. Hess, Y. Xia, L. Rao, H. M. Cho, R. C. Moore, and L. R. Van Loon. 2003. “Comprehensive Thermodynamic Model Applicable to Highly Acidic to Basic Conditions for Isosaccharinate Reactions with Ca(II) and Np(IV).” Journal of Solution Chemistry 32 (8): 665-689.  

Xia, Y., A. R. Felmy, L. Rao, Z. Wang, and N. J. Hess. 2003. “Thermodynamic Model for the Solubility of ThO2(am) in the Aqueous Na+-H+-OH--NO3--H2O-EDTA System.” Radiochimica Acta 91 (12): 751-760.  


Hess, N. J., B. D. Begg, S. D. Conradson, D. E. McCready, P. L. Gassman, and W. J. Weber. 2002. “Spectroscopic Investigations of the Structural Phase Transition in Gd2(Ti1-yZry)2O7 Pyrochlores.” Journal of Physical Chemistry B 106 (18): 4663-4677.  

Rai, D., A. R. Felmy, N. J. Hess, V. L. LeGore, and D. E. McCready. 2002. “Thermodynamics of the U(VI)-Ca2+-Cl--OH--H2O System: Solubility Product of Becquerelite.” Radiochimica Acta 90 (9-11): 495-503.  

Rai, D., N. J. Hess, L. Rao, Z. Zhang, A. R. Felmy, D. A. Moore, S. B. Clark, and G. J. Lumetta. 2002. “Thermodynamic Model for the Solubility of Cr(OH)3(am) in Concentrated NaOH and NaOH-NaNO3 Solutions.” Journal of Solution Chemistry 31 (5): 343-367.  

Rao, L., Z. Zhang, J. I. Friese, B. Ritherdon, S. B. Clark, N. J. Hess, and D. Rai. 2002. “Oligomerization of Chromium(III) and Its Impact on the Oxidation of Chromium(III) by Hydrogen Peroxide in Alkaline Solutions.” Journal of the Chemical Society, Dalton Transactions (2): 267-274.  


Begg, B. D., N. J. Hess, D. E. McCready, S. Thevuthasan, and W. J. Weber. 2001. “Heavy-Ion Irradiation Effects in Gd2(Ti2-xZrx)O7 Pyrochlores.” Journal of Nuclear Materials 289 (1-2): 188-193.  

Begg, B. D., N. J. Hess, W. J. Weber, R. Devanathan, J. P. Icenhower, S. Thevuthasan, and B. P. McGrail. 2001. “Heavy-Ion Irradiation Effects on Structures and Acid Dissolution of Pyrochlores.” Journal of Nuclear Materials 288 (2-3): 208-216.  

Hess, N. J., Y. Su, and M. L. Balmer. 2001. “Evidence of Edge-Sharing TiO5 Polyhedra in Ti-Substituted Pollucite, CsTixAl1-xSi2O6+x/2.” Journal of Physical Chemistry B 105 (29): 6805-6811.  

Rai, D., Bolton H, Jr., D. A. Moore, N. J. Hess, and G. R. Choppin. 2001. “Thermodynamic Model for the Solubility of PuO2(am) in the Aqueous Na+-H+-OH--Cl--H2O- ethylenediaminetetraacetate System.” Radiochimica Acta 89 (2): 67-74.  

Rai, D., Y. Xia, N. J. Hess, D. M. Strachan, and B. P. McGrail. 2001. “Hydroxo and Chloro Complexes/Ion Interactions of Hf4+ and the Solubility Product of HfO2(am).” Journal of Solution Chemistry 30 (11): 949-967.  


Begg, B. D., N. J. Hess, W. J. Weber, S. D. Conradson, M. J. Schweiger, and R. C. Ewing. 2000. “XAS and XRD Study of Annealed 238Pu- and 239Pu-Substituted Zircons (Zr0.92Pu0.08SiO4).” Journal of Nuclear Materials 278 (2): 212-224.  

Buchko, G. W., N. J. Hess, V. Bandaru, S. S. Wallace, and M. A. Kennedy. 2000. “Spectroscopic Studies of Zinc(II)- and Cobalt(II)-Associated Escherichia coli Formamidopyrimidine - DNA Glycosylase: Extended X-Ray Absorption Fine Structure Evidence for a Metal-Binding Domain.” Biochemistry 39 (40): 12441-12449.  

Buchko, G. W., N. J. Hess, and M. A. Kennedy. 2000. “Cadmium Mutagenicity and Human Nucleotide Excision Repair Protein XPA: CD, EXAFS and 1H/15N-NMR Spectroscopic Studies on the Zinc(II)- and Cadmium(II)-Associated Minimal DNA-Binding Domain (M98-F219).” Carcinogenesis 21 (5): 1051-1057.  

Hess, N. J., F. J. Espinosa, S. D. Conradson, and W. J. Weber. 2000. “Beta Radiation Effects in 137Cs-Substituted Pollucite.” Journal of Nuclear Materials 281 (1): 22-33.  

Wildung, R. E., Y. A. Gorby, K. M. Krupka, N. J. Hess, S. W. Li, A. E. Plymale, J. P. McKinley, and J. K. Fredrickson. 2000. “Effect of Electron Donor and Solution Chemistry on Products of Dissimilatory Reduction of Technetium by Shewanella putrefaciens.” Applied and Environmental Microbiology 66 (6): 2451-2460.  

Williford, R. E., B. D. Begg, W. J. Weber, and N. J. Hess. 2000. “Computer Simulation of Pu3+ and Pu4+ Substitutions in Zircon.” Journal of Nuclear Materials 278 (2): 207-211.  


Buchko, G. W., L. M. Iakoucheva, M. A. Kennedy, E. J. Ackerman, and N. J. Hess. 1999. “Extended X-Ray Absorption Fine Structure Evidence for a Single Metal Binding Domain in Xenopus Laevis Nucleotide Excision Repair Protein XPA.” Biochemical and Biophysical Research Communications 254 (1): 109-113.  

Rai, D., N. J. Hess, A. R. Felmy, D. A. Moore, and M. Yui. 1999. “A Thermodynamic Model for the Solubility of NpO2(am) in the Aqueous K+- HCO3--CO32--OH--H2O System.” Radiochimica Acta 84 (3): 159-169.  

Rai, D., N. J. Hess, A. R. Felmy, D. A. Moore, M. Yui, and P. Vitorge. 1999. “A Thermodynamic Model for the Solubility of PuO2(am) in the Aqueous K+- HCO3--CO32--OH--H2O System.” Radiochimica Acta 86 (3-4): 89-100.  


Conradson, S. D., I. Al Mahamid, D. L. Clark, N. J. Hess, E. A. Hudson, M. P. Neu, P. D. Palmer, W. H. Runde, and C. D. Tait. 1998. “Oxidation State Determination of Plutonium Aquo Ions Using X-Ray Absorption Spectroscopy.” Polyhedron 17 (4): 599-602.  

Hess, N. J., G. W. Buchko, S. D. Conradson, F. J. Espinosa, S. Ni, B. D. Thrall, and M. A. Kennedy. 1998. “Human Nucleotide Excision Repair Protein XPA: Extended X-Ray Absorption Fine-Structure Evidence for a Metal-Binding Domain.” Protein Science 7 (9): 1970-1975.  

Hess, N. J., W. J. Weber, and S. D. Conradson. 1998. “U and Pu Liii XAFS of Pu-Doped Glass and Ceramic Waste Forms.” Journal of Alloys and Compounds 271-273: 240-243.  

Hess, N. J., W. J. Weber, and S. D. Conradson. 1998. “X-Ray Absorption Fine Structure of Aged, Pu-Doped Glass and Ceramic Waste Forms.” Journal of Nuclear Materials 254 (2-3): 175-184.  

Rai, D., A. R. Felmy, N. J. Hess, D. A. Moore, and M. Yui. 1998. “A Thermodynamic Model for the Solubility of UO2(Am) in the Aqueous K+-Na+-HCO3--CO32--OH--H2O System.” Radiochimica Acta 82 (1): 17-25.   

Weber, W. J., L. M. Wang, N. Yu, and N. J. Hess. 1998. “Structure and Properties of Ion-Beam-Modified (6H) Silicon Carbide.” Materials Science and Engineering A 253 (1-2): 62-70.  


Felmy, A. R., D. Rai, S. M. Sterner, M. J. Mason, N. J. Hess, and S. D. Conradson. 1997. “Thermodynamic Models for Highly Charged Aqueous Species: Solubility of Th(IV) Hydrous Oxide in Concentrated NaHCO3 and Na2CO3 Solutions.” Journal of Solution Chemistry 26 (3): 233-248.  

Hess, N. J., M. L. Balmer, B. C. Bunker, and S. D. Conradson. 1997. “Ti XAS of a Novel Cs-Ti Silicate.” Journal of Solid State Chemistry 129 (2): 206-213.  

Weber, W. J., N. Yu, L. M. Wang, and N. J. Hess. 1997. “Temperature and Dose Dependence of Ion-Beam-Induced Amorphization in α-SiC.” Journal of Nuclear Materials 244 (3): 258-265.  


Clark, D. L., S. D. Conradson, S. A. Ekberg, N. J. Hess, D. R. Janecky, M. P. Neu, P. D. Palmer, and C. D. Tait. 1996. “A Multi-Method Approach to Actinide Speciation Applied to Pentavalent Neptunium Carbonate Complexation.” New Journal of Chemistry 20 (2): 211-220.  

Clark, D. L., S. D. Conradson, S. A. Ekberg, N. J. Hess, M. P. Neu, P. D. Palmer, W. Runde, and C. Drew Tait. 1996. “EXAFS Studies of Pentavalent Neptunium Carbonato Complexes. Structural Elucidation of the Principal Constituents of Neptunium in Groundwater Environments.” Journal of the American Chemical Society 118 (8): 2089-2090.  

Exarhos, G. J., and N. J. Hess. 1996. “Phase Transformation Dynamics, Melting and Stress Evolution in Dielectric Films and at Surfaces.” Journal of Raman Spectroscopy 27 (10): 765-774.<765::AID-JRS29>3.0.CO;2-8.  


Hess, N. J., and G. J. Exarhos. 1994. “Pressure-Temperature Sensors: Solution Deposition of Rare-Earth-Doped Garnet Films.” Journal of Non-Crystalline Solids 178 (C): 91-97.  

Hess, N. J., G. D. Maupin, L. A. Chick, D. S. Sunberg, D. E. McCreedy, and T. R. Armstrong. 1994. “Synthesis and Crystallization of Yttrium-Aluminium Garnet and Related Compounds.” Journal of Materials Science 29 (7): 1873-1878.  


Exarhos, G. J., and N. J. Hess. 1993. “Deposition and Characterization of Multicomponent Oxide Films and Multilayers from Aqueous Solution.” Thin Solid Films 236 (1-2): 51-57.  

Weber, W. J., and N. J. Hess. 1993. “Ion Beam Modification of Gd2Ti2O7.” Nuclear Inst. and Methods in Physics Research, B 80-81 (PART 2): 1245-1248.  


Bozlee, B., B. Lian, J. Kahn, R. L. Garrell, T. Herne, A. Leiden, P. Palko, N. Hess, and G. Exarhos. 1992. “Characterization of Alkali-Metal Sols in Diethyl Ether. Visible Extinction and Surface-Enhanced Raman Spectra.” Chemical Physics Letters 196 (5): 437-444.  

Exarhos, G. J., and N. J. Hess. 1992. “Spectroscopic Measurements of Stress Relaxation During Thermally Induced Crystallization of Amorphous Titania Films.” Thin Solid Films 220 (1-2): 254-260.  

Exarhos, G. J., N. J. Hess, and S. Wood. 1992. “Transient Stress Evolution and Crystallization in Laser-Irradiated Amorphous Titania Sol-Gel Films.”  

Hess, N. J., and D. Schiferl. 1992. “Comparison of the Pressure-Induced Frequency Shift of Sm:YAG to the Ruby and Nitrogen Vibron Pressure Scales from 6 to 820 K and 0 to 25 GPa and Suggestions for Use as a High-Temperature Pressure Calibrant.” Journal of Applied Physics 71 (5): 2082-2086.  

Weber, W. J., N. J. Hess, and G. D. Maupin. 1992. “Amorphization in Gd2Ti2O7 and CaZrTi2O7 Irradiated with 3 MeV Argon Ions.” Nuclear Inst. and Methods in Physics Research, B 65 (1-4): 102-106.  


Hess, N. J., and D. Schiferl. 1990. “Pressure and Temperature Dependence of Laser-Induced Fluorescence of Sm: YAG to 100 kbar and 700°C and an Empirical Model.” Journal of Applied Physics 68 (5): 1953-1960.  

Hess, N. J., and G. J. Exarhos. 1989. “Temperature and Pressure Dependence of Laser Induced Fluorescence in Sm:YAG --a New Pressure Calibrant.” High Pressure Research 2 (1): 57-64.