Ultrafast electro-optic modulation on a narrow band optical pulse is utilized to spectrally resolve coherent terahertz radiation. This technique requires no moving parts and has the potential to measure THz spectra with a resolution better than 10 GHz, limited by the bandwidth of the optical probe field or optical spectrometer. The dynamic range of this device is limited by the detection capabilities of an optical spectrometer, providing a highly efficient method of spectral reconstruction of both narrow band and broadband terahertz radiation.
Chen, Z.
Montavon, G.
Guo, Z.
Wang, X.
Razafindratsima, S.
Robinet, J.C.
Landesman, C.
Callovo-Oxfordian formation (COX) is as potential host formation for emplacement of long-term nuclear waste repositories in France. The objective of this work is to assess whether a simplified "bottom-up" approach may explain the retention of Ni(II) by the COX considering two levels of 'upscaling': (i) from clay surfaces to rock clay fraction and (ii) from clay fraction to whole rock samples. To this end, Ni(II) adsorption was investigated by batch equilibrium, XPS, and EXAFS techniques on a representative sample extracted at the location where the storage is supposed to be built (clay content of about 50%) and on the corresponding carbonate-free <2 mu m fractions. The results showed that a simplified "bottom-up" approach based on published models available for illite and montmorillonite cannot explain Ni(II) adsorption on the <2 pm fraction when the retention is controlled only by surface complexation on the reactive clay edge sites. An operational model based on the generalized composite modeling approach was used instead. The developed model considers an interaction between two Ni(II) species with one type of clay edge sites. The model developed for the clay fraction gives a satisfactory estimation of Ni(II) adsorption data for the representative clayrock sample. Complementary experiments were performed by X-ray photoelectron (XPS) and X-ray absorption (EXAFS) spectroscopies for both clay fraction and raw COX sample at high Ni(II) loadings. Spectroscopic data were characterized by similar fitting parameters considering formation of Ni phyllosilicate. This indicates that the clay fraction governs the retention of Ni(II), as it was concluded from the batch experiments. Complementary adsorption experiments preformed with COX samples having clay contents representative of the variability occurring at the formation scale (i.e. 1.5-47% in weight) show that one cannot neglect the retention properties of the non-clay phases, mainly dominated by calcite, when the clay content becomes the minority. Retention values in the range of 60-300 L/kg can finally be given for describing adsorption properties of trace concentrations of Ni(II) for the clay contents representative of the majority of the Callovo-Oxfordian formation. (C) 2014 Elsevier B.V. All rights reserved.
Context-awareness in location-based service studies has attracted more and more attention. Awareness of a user's location and the users themselves has become the centre of these services. This paper discusses a survey conducted for developing a personalised location-based property hunting system (LBSPH), and a personalised LBSPH architecture developed from the survey results. What users wanted in the way of essential property and neighbourhood information, the best way to display the information, and the common use cases of such a location-based service (LBS) were identified from the survey. The LBSPH architecture was designed to reflect these preferences.
Chen, Z.
Diao, J.
Dharmasena, M.
Ionita, C.
Jiang, X.
Rieck, J.
Thermal inactivation of desiccation-adapted Salmonella spp. in aged chicken litter was investigated in comparison with that in a nonadapted control to examine potential cross-tolerance of desiccation-adapted cells to heat treatment. A mixture of four Salmonella serovars was inoculated into the finished compost with 20, 30, 40, and 50% moisture contents for a 24-h desiccation adaptation. Afterwards, the compost with desiccation-adapted cells was inoculated into the aged chicken litter with the same moisture content for heat treatments at 70, 75, 80, 85, and 150 degrees C. Recovery media were used to allow heat-injured cells to resuscitate. A 5-log reduction in the number of the desiccation-adapted cells in aged chicken litter with a 20% moisture content required >6, >6, similar to 4 to 5, and similar to 3 to 4 h of exposure at 70, 75, 80, and 85 degrees C, respectively. As a comparison, a 5-log reduction in the number of nonadapted control cells in the same chicken litter was achieved within similar to 1.5 to 2, similar to 1 to 1.5, similar to 0.5 to 1, and <0.5 h at 70, 75, 80, and 85 degrees C, respectively. The exposure time required to obtain a 5-log reduction in the number of desiccation-adapted cells gradually became shorter as temperature and moisture content were increased. At 150 degrees C, desiccation-adapted Salmonella cells survived for 50 min in chicken litter with a 20% moisture content, whereas control cells were detectable by enrichment for only 10 min. Our results demonstrated that the thermal resistance of Salmonella in aged chicken litter was increased significantly when the cells were adapted to desiccation. This study also validated the effectiveness of thermal processing being used for producing chicken litter free of Salmonella contamination.
Chen, Z.
Snow, M.
Lawrence, C. S.
Church, A. R.
Narum, S. R.
Devlin, R. H.
Farrell, A. P.
Rainbow trout (Oncorhynchus mykiss Walbaum) in southern Western Australia have undergone passive selection for over 19 generations to survive high water temperatures. Based on the conceptual model of 'oxygen-and capacity-limited thermal tolerance', we measured critical thermal maximum (CTmax), maximum heart rate (f(H,max)) and aerobic scope to test the hypothesis that these rainbow trout can maintain aerobic scope at high temperatures through a robust cardiac performance supporting oxygen delivery. Across five family groups CTmax averaged 29.0 +/- 0.02 degrees C. Aerobic scope was maximized at 15.8 +/- 0.3 degrees C (T-opt), while the upper pejus temperature (T-pej, set at 90% of maximum aerobic scope) was 19.9 +/- 0.3 degrees C. Although aerobic scope decreased at temperatures above T-opt, the value at 25 degrees C remained well over 40% of the maximum. Furthermore, pharmacologically stimulated f(H,max) increased with temperature, reaching a peak value between 23.5 +/- 0.4 and 24.0 +/- 0.4 degrees C(T-max) for three family groups. The Arrhenius breakpoint temperature (T-AB) for f(H,max) was 20.3 +/- 0.3 to 20.7 +/- 0.4 degrees C, while the average Q(10) breakpoint temperature (T-QB, when the incremental Q(10)<1.6) for f(H,max) was 21.6 +/- 0.2 to 22.0 +/- 0.4 degrees C. Collectively, f(H,max) progressively became less temperature dependent beyond 20 degrees C (T-AB andT(QB)), which coincides with the upper T-pej for aerobic scope. Although upper thermal performance indices for both aerobic scope and f(H,max) were compared among family groups in this population, appreciable differences were not evident. Compared with other populations of rainbow trout, the present assessment is consistent with the prediction that this strain has undergone selection and shows the ability to tolerate higher water temperatures.
CHEN, Z.
WADA, R.
BONASERA, A.
KEUTGEN, T.
HAGEL, K.
WANG, J.
HUANG, M.
QIN, L.
NATOWITZ, J.
MATERNA, T.
KOWALSKI, S.
SAHU, P. K.
NAKAGAWA, T.
The experimental results reveal the isospin dependence of the nuclear phase transition in terms of the Landau Free Energy description of critical phenomena. Near the critical point, different ratios of the neutron to proton concentrations lead to different critical points for the phase transition which is analogous to the phase transitions in He 4-He 3 liquid mixtures. The antisymmetrized molecular dynamics (AMD) and GEMINI models calculations were also performed and the results will be discussed as well.
Chen, Z.
Wang, H.H.
Vissers, D.R.
Zhang, L.
West, R.
Lyons, L.J.
Amine, K.
The solvation of lithium salts in siloxanes was investigated with the aim to understand the key barriers that limit the ionic conductivity of siloxane-based electrolytes. The conductivity and kinetic data were measured for electrolytes with different salts, different salt concentrations, and solvents. The results show that both the conductivity and the kinetics of ionic transportation were greatly impacted by the specific interactions between ions and the solvent molecules. The high content of ion pairs in the electrolytes can be one of the main reasons for the low ionic conductivity observed in the siloxane-based electrolytes.
Chen, Z.
Friedland, G. D.
Pereira, J. H.
Reveco, S. A.
Chan, R.
Park, J. I.
Thelen, M. P.
Adams, P. D.
Arkin, A. P.
Keasling, J. D.
Blanch, H. W.
Simmons, B. A.
Sale, K. L.
Chivian, D.
Chhabra, S. R.