Abstract  A porous coordination polymer {[Mn2(DBIBA)3]NO3.3DMF.4H2O}n (1) [DBIBAH = 3,5-di(1H-benzo[d]imidazol-1-yl)benzoic acid] has been synthesized solvothermally and structurally characterized by single-crystal X-ray diffraction. The following four new coordination polymers {[Mn2(DBIBA)3].ClO4.DMF.H2O}n (2), {[Mn2(DBIBA)3].Cl.DMF.8H2O}n (3), {[Mn2(DBIBA)3].NO3.CH3OH.5H2O}n (4) and {[Mn2(DBIBA)3].NO3.3CH3COCH3.7H2O}n (5) have been synthesized from 1 via anion/solvent exchange protocols in a single-crystal to single-crystal fashion at room temperature. Gas sorption studies for desolvated compounds 1, 2, and 3 show that CO2 uptake capacity is entirely dependent upon the size of the anion present in the framework. Complex 1 also exhibits antiferromagnetic properties below 17 K, confirmed through magnetic susceptibility measurements.

Abstract  Various acidic anhydrides including cantharidin were converted into corresponding aminobenzylcantharidinimide 3a and analogous imides 3b similar to k (at the ortho, meta, and para positions) with 35 similar to 87% yields by reacting with aminobenzylamines and triethylamine. The two methyl side chains of cantharidinimides 3ao, 3am, and 3ap, and related imides had more than two chiral centers; the lone pair of electrons of nitrogen displayed a different chemical shift and coupling constant in H-NMR spectra when the amino group of benzylamine was in the ortho position. These cantharidinimides had parent aniline, pyridine, and naphthalene plane structures, and the primary amine nucleophilicity and basicity might reflect the inductive electron's negative effect on chemical shifts. We prepared cantharidinimides by heating the reactants cantharidin la, aliphatic and aromatic acid anhydrides, primary benzylic amines, and aniline derivatives to ca. 200 degrees C with 3 mL of dry toluene, and 1-2 mL of triethylamine in high-pressure sealed tubes (Buchi glasuster 0032) to produce cantharidinimides and their analogues in good yields. Thepara-aminobenzylic imides showed greater inhibition of nitric oxide (NO) synthesis by NO synthase (NOS) than did ortho-and meta-aminobenzylic imides. Compound 3fp, para-aminobenzylic norbonane-imide, had the most potent effect on inducible NOS among the tested compounds and showed 35% inhibition.

Abstract  The photocatalytic activity of TiO2 and manganese doped TiO2 nanoplates with various manganese atomic percentages, in the range of 2-7%, was studied. The undoped and doped nanoplates with exposed {001} facets were produced by a solvothermal method. The crystal structure as well as the shape of the TiO2 and Mn4+/TiO2 anatase nanoparticles was determined with X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). Both techniques revealed that the nanocrystals are in the form of plates. Moreover, the anisotropic peak broadening of the X-ray diffraction patterns was studied using the Rietveld refining method. Chemical analysis of the photocatalyst that was carried out with X-ray photoelectron spectroscopy (XPS) showed the presence of manganese ions in the.TiO2 anatase matrix. The Density Functional Theory (OFT) calculations exhibited a decrease in the energy gap and an increase in the density of the electronic stated inside the gap for the doped TiO2 These observations were in agreement with the results of the UV visible diffuse reflectance spectroscopy (DRS) that demonstrated an adsorption shift towards the visible region for the same samples.

The photocatalytic activity of the synthesized catalysts was investigated by the photocatalytic oxidation of the gaseous nitric oxide (NO) and decomposition of the gaseous acetaldehyde (CH3CHO) under visible light irradiation. The optimal concentration of dopant that improves the photocatalytic activity of the nanoplates was determined. (C) 2014 Elsevier B.V. All rights reserved.

Abstract  0.2 M CMPO in isodecanol(10%)-dodecane system was taken for evaluating the extraction behavior of actinides in different oxidation states. The order of decrease in distribution ratio at fixed acidity was found to be M4+ > MO22+ > M3+ (M = actinide ion). The metal-ligand stoichiometry was determined by slope analysis. Though, increasing isodecanol content decreases the distribution ratio, no perturbation was found on O=U=O moiety as revealed by UV-vis spectroscopy. Application of van't Hoff equation to the extraction data at different temperatures enabled the determination of thermodynamic parameters. The radiolytic stability of the solvent system was evaluated by dose dependent study (gamma exposure in the range of 0-500 kGy). Finally the solvent system was used for actinide partitioning from simulated high level waste (SHLW) of fast breeder reactor (FBR) fuel. (C) 2014 Elsevier B.V. All rights reserved.

Abstract  Currently, monomethyl hydrazine is the most widely used hypergolic rocket fuel. Due to its high toxic vapor, there is a thrust towards developing low-toxic hypergolic fuels. Ultra-low vapor pressure ionic liquids are one such potential category of fuels. However, designing ionic liquid with ignition delay comparable to monomethyl hydrazine is a challenge, because fundamental understanding of the hypergolic nature of ionic liquids is far from clear. This work used the computed energy gap values between the highest occupied molecular orbitals (HOMO) of the anions for a series of ionic liquids and the lowest occupied molecular orbital (LUMO) of HNO3, and variation in the computed relative heats of formation, H-f, of these anions to develop correlations to predict hypergol activity between an ionic liquid fuel and nitric acid as the oxidizer. The observed trends in HOMOLUMO energy gap and H-f values can be used successfully to verify not only hypergolicity of known systems but also the lack of this phenomenon in OH- and BF4- based ionic liquids. It was shown that through suitable substitution of electron withdrawing or electron donating groups in the anion, the energy gap and the H-f values could be tailored into an optimal range that would have a high probability for the new system to exhibit hypergolic reactivity. To validate our method, we suggest herein new ionic liquid structures for synthesis and experimental screening.

Abstract  Carbon nanotubes (CNT) have gained great interest for research in many applications because of their unique characteristics, such as having high porosity, high surface area and the ability to be functionalised by a wide spectrum of surface functional groups. However, owing to the hydrophobic nature, CNT could not be dispersed uniformly in the solution, thus restricting the applications of CNT in industry. In order to resolve this problem, multiwalled carbon nanotubes (MWCNT) were treated with nitric acid (HNO3), and the mixture of HNO3 and sulphuric acid (H2SO4). Different reagents for acid treatment seem to affect the bundling arrangement of nanotubes, the attachment of functional groups and the degree of functionalisation. The treated MWCNT resulted in lesser agglomeration of nanotubes, reduced the impurities, and give more attachment of functional groups. The treated MWCNT samples that have more functional groups can be considered as a potential material for applications.

Abstract  Nitric acid (HNO3) was reduced in a flow tube by volatile organic carbon compounds (VOCs) generated from engine oil vapor. The primary reaction product was believed to be HONO. The reaction was not enhanced when Teflon (R) Raschig rings were added to the flow tube to increase surface area, thereby showing the reaction to be homogeneous under the conditions studied. The HONO formation observed ranged between 0.1 and 0.6 ppb h(-1), with a mean of 0.3 +/- 0.1 ppb h(-1), for typical HNO3 concentrations of 4-5 ppb and estimated concentrations of the reactive components in the engine oil vapor between 200 and 300 ppt. The observations in this study compare well to a recently published field study conducted in Houston that observed average formation rates of 0.6 +/- 0.3 ppb h(-1). Water vapor was found to decrease the HONO formation rate by similar to 0.1 ppb h(-1) for every 1% increase in the water mixing ratio. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract  A preparatory performance and error characterization was carried out for a ground-based millimeter wave instrument designed for high Arctic atmospheric research. The instrument is a radiometer to measure rotational emission spectra of O-3, CIO, HNO3, and N2O, between 265 and 280 GHz, using a sensitive superconductor-insulator-superconductor detector. Forward and inverse modeling tests have been performed to assess the instrument/inversion system and to determine the sources of the most significant errors in the retrieval of each trace gas. The altitude ranges over which retrievals of concentrations can be made were found to be similar to 13-62 km for O-3, similar to 12.5-39 km for similar to N2O, similar to 12-36 km for HNO3, and similar to 18-46 km for CIO. For each target species the measurement and smoothing errors calculated with an optimal estimation method (OEM) were compared to the errors calculated from inversions of 500 simulated spectra. The absolute error from these inversions agreed well the OEM results, but there were systematic differences that are attributed to nonlinearities in the forward model. The results of these nonlinearities can cause biases of the order of 5-10% of the a priori profile if they are not accounted for when averaging concentration profiles or when analyzing trends in concentration. The techniques used here can be applied to any ground-based remote sounder. (C) 2014 Elsevier Ltd. All rights reserved.

Abstract  A removal of different metals using both acid reflux and the microwave assisted digestion method was investigated. As a carbon material multi-walled carbon nanotubes synthetized on iron, cobalt and iron-cobalt catalysts without support were applied. The amount of metal particles after purification was determined using a thermobalance and it was found that microwave heating improved the efficiency of purification, especially at elevated pressure. Similar removal degrees of catalyst particles were achieved using the acid reflux method for 24 h and microwave heating for 15 min at 20 at regardless of the kind of metal. Raman measurements indicate that all the obtained samples were characterized with a high ratio of peak IG/ID intensities which confirms a good quality of the materials. (C) 2014 Published by Elsevier B.V.

Abstract  Objective: To assess lymphatic flow adaptations to edema, we evaluated lymph transport function in rat mesenteric lymphatics under normal and increased fluid volume (edemagenic) conditions in situ.

Methods: Twelve rats were infused with saline (intravenous infusion, 0.2 mL/min/100 g body weight) to induce edema. We intravitally measured mesenteric lymphatic diameter and contraction frequency, as well as lymphocyte velocity and density before, during, and after infusion.

Results: A 10-fold increase in lymphocyte velocity (0.1-1 mm/s) and a sixfold increase in flow rate (0.1-0.6 mu L/min), were observed post infusion, respectively. There were also increases in contraction frequency and fractional pump flow one minute post infusion. Time-averaged wall shear stress increased 10 fold post infusion to nearly 1.5 dynes/cm(2). Similarly, maximum shear stress rose from 5 to 40 dynes/cm(2).

Conclusions: Lymphatic vessels adapted to edemagenic stress by increasing lymph transport. Specifically, the increases in lymphatic contraction frequency, lymphocyte velocity, and shear stress were significant. Lymph pumping increased post infusion, though changes in lymphatic diameter were not statistically significant. These results indicate that edemagenic conditions stimulate lymph transport via increases in lymphatic contraction frequency, lymphocyte velocity, and flow. These changes, consequently, resulted in large increases in wall shear stress, which could then activate NO pathways and modulate lymphatic transport function.

Abstract  In this study, a four stroke four cylinder direct injection CI engine was run using three different injection pressures. In all measurements, the fuel quantity per cycle, the pre injection and main injection timing, the boost pressure and the engine speed were kept constant. The motor tests were performed under 130, 140 and 150 MPa rail pressure. During the theoretical part of the study, combustion, emission, energy and exergy analysis were made using the test results. An increase in the injection pressure increases combustion efficiency. The results show that combustion efficiency is not enough by itself, because the increase in the power need of the injection pump, decreases the thermal efficiency. The increase in the combustion temperature, increases the cooling loss and decreases the exergetic efficiency. In addition, the NOx emissions increased by 12% and soot emissions decreased 44% via increasing injection pressure by 17%. The thermal and exergetic efficiencies are found inversely proportional with injection pressure. Exergy destruction is found independent of the injection pressure and its value is obtained as similar to 6%.

Abstract  We present a description of the algorithm used to retrieve peroxyacetyl nitrate (PAN) concentrations from the Aura Tropospheric Emission Spectrometer (TES). We describe the spectral microwindows, error analysis, and the utilization of a priori and initial guess information provided by the GEOS-Chem global chemical transport model. The TES PAN retrievals contain up to one degree of freedom for signal. In general, the retrievals are most sensitive to PAN in the mid-troposphere. Estimated single-measurement uncertainties are on the order of 30 to 50 %. The detection limit for a single TES measurement is dependent on the atmospheric and surface conditions as well as on the instrument noise. For observations where the cloud optical depth is less than 0.5, we find that the TES detection limit for PAN is in the region of 200 to 300 pptv. We show that PAN retrievals capture plumes associated with boreal burning. Retrievals over the Northern Hemisphere Pacific in springtime show spatial features that are qualitatively consistent with the expected distribution of PAN in outflow of Asian pollution.

Abstract  The saponification of an aromatic ester with an aqueous sodium hydroxide was studied within a heterogeneous reaction medium in order to determine the overall kinetics of the selected system. The extended thermo-kinetic model was developed compared to the previously used simple one. The reaction rate within a heterogeneous liquid-liquid system incorporates a chemical kinetics term as well as mass transfer between both phases. Chemical rate constant was obtained from experiments within a homogeneous medium, whilst the mass-transfer coefficient was determined separately. The measured thermal profiles were then the bases for determining the overall reaction-rate.

This study presents the development of an extended kinetic model for considering mass transfer regarding the saponification of ethyl benzoate with sodium hydroxide within a heterogeneous reaction medium. The time-dependences are presented for the mass transfer coefficient and the interfacial areas at different heterogeneous stages and temperatures. The results indicated an important role of reliable kinetic model, as significant difference in k(L)a product was obtained with extended and simple approach.

Abstract  Methylene blue (MB) has been used with some success as a treatment for the vasoplegia of vasopressor-refractory septic shock. The putative mechanism of action of MB is the inhibition of endothelial nitric oxide within the microvasculature and improved responsiveness to endogenous catecholamines (norepinephrine (NE)). However, to date, no study has demonstrated the microcirculatory effect of methylene blue in septic shock. The objective of this randomized, controlled, animal study was to show, in an experimentally-induced, septic shock model in rats, the effects of MB and NE on global hemodynamics and the microcirculation. Mean arterial pressure (MAP) was drastically reduced following bacterial endotoxin (lipopolysaccharide, LPS) administration in animals not receiving vasopressors. Only the combination of NE + MB restored MAP to control levels by the end of the three hour experiment. Intravital microscopy of the microcirculation was performed in the terminal ileum in order to examine functional capillary density in intestinal muscle layers and the mucosa, as well as leukocyte activation in venules (rolling, adhesion to the endothelium). Untreated LPS animals showed a significant increase in leukocyte adhesion and a decrease in capillary perfusion in the intestinal microcirculation. In groups receiving NE or NE+MB, we observed a significant decrease in leukocyte adhesion and improved functional capillary density, indicating that microvasculature function was improved. This study suggests that methylene blue may be able to improve hemodynamics while preserving microvascular function in septic shock.

Abstract  This study reports on the synthesis and fabrication of hybrid nanocomposite based on single-walled carbon nanotubes-ZnO nanorods (SWCNT-ZnONR) as resistive gas sensors for NO2 detection. The sensor was prepared using the standard simple and cost-effective hydrothermal process. The sensor was characterized by x-ray diffraction (XRD) and scanning electron microscopy. The findings revealed enhanced porous SWCNT-ZnONR nanocomposites due to the high porosity of the SWCNT. It was also found that the sensor exhibited average response and recovery times of about 70 s and 100 s, respectively. The XRD peak at 26A degrees indicated that the SWCNT pattern was not disturbed, while sensitivity increased with temperature up to 150A degrees C, at which the sensitivity was maximum. Similarly, the sensor sensitivity increased with NO2 concentration at all levels examined. Moreover, the results indicate that the sensor shows significant promise for NO2 gas sensing applications.

Abstract  The influence of long-term land application of stockpiled feedlot manure (SM) containing either wood-chip (SM-WD) or straw (SM-ST) bedding on soil properties during the barley (Hordeum vulgare L.) silage growing season is unknown. The main objective of our study was determine the effect of bedding material in stockpiled manure (i.e., SM-WD vs. SM-ST) on certain soil properties. A secondary objective was to determine if organic amendments affected certain soil properties compared with unamended soil. Stockpiled feedlot manure with SM-WD or SM-ST bedding at 77 Mg (dry wt) ha(-1) yr(-1) was annually applied for 13 to 14 yr to a clay loam soil in a replicated field experiment in southern Alberta. There was also an unamended control. Soil properties were measured every 2 wk during the 2011 and 2012 growing season. Properties included water-filled pore space (WFPS), total organic C and total N, NH4-N and NO3-N, water-soluble non-purgeable organic C (NPOC), water-soluble total N (WSTN), denitrification (acetylene inhibition method), and CO2 flux. The most consistent and significant (P <= 0.05) bedding effects on soil properties in both years occurred for total organic C, C:N ratio, and WSTN. Total organic C and C:N ratio were generally greater for SM-WD than SM-ST, and the reverse trend occurred for WSTN. Bedding effects on other soil properties (WFPS, NH4-N, NO3-N, NPOC) occurred in 2012, but not in 2011. Total N, daily denitrification, and daily CO2 flux were generally unaffected by bedding material. Mean daily denitrification fluxes ranged from 0.9 to 1078 g N2O-N ha(-1) d(-1) for SM-ST, 0.8 to 326 g N2O-N ha(-1) d(-1) for SM-WD, and 0.6 to 250 g N2O-N ha(-1) d(-1) for the CON. Mean daily CO2 fluxes ranged from 5.3 to 43.4 kg CO2-C ha(-1) d(-1) for SM-WD, 5.5 to 26.0 kg CO2-C ha(-1) d(-1) for SM-ST, and from 0.5 to 6.8 kg CO2-C ha(-1) d(-1) for the CON. The findings from our study suggest that bedding material in feedlot manure may be a possible method to manage certain soil properties.

Abstract  Structural measurements and geochemical analyses, including bulk and in situ pyrite geochemistry, sulfur isotopes, and whole-rock geochemistry, are presented for the No. 3 orebody of the Jiaojia gold deposit (JJ3), located in the Jiaodong district of northeast China. The JJ3 orebody is distinct from the main orebody of the Jiaojia deposit GM because it is characterised by steeply dipping sub-metric quartz-pyrite veins with up to 300 ppm of gold, whereas the JJ1 orebody represents an archetypal example of the disseminated and veinlet style mineralisation characteristic of regional faults in the Jiaodong district. Measurements on JJ3 veins and the host Jiaojia-Xincheng regional fault are consistent with development of mineralised, steeply dipping extension fractures during normal faulting, which produced the fault-hosted disseminated-style JJ1 orebody. Trace element geochemistry of pyrite in these veins shows that JJ3 pyrite is geochemically distinct from those of the main Jiaojia and Xincheng orebodies, being relatively enriched in Ag and Pb, as well as Ba, Bi, Te and Au, and relatively depleted in Cu and As. Enrichment in Ag and Pb is possibly related to infiltration of a saline hydrothermal fluid, as both are effectively transported as chloride complexes; however, depletion of Cu, which is also mobile as chloride complexes, requires a low temperature saline fluid where Cu is no longer soluble. The textural setting of the ore minerals suggests that these cooler fluids likely infiltrated during the waning stages of the hydrothermal system. The relative abundance of barite in the JJ3 orebody, which formed from late-stage oxidised magmatic-hydrothermal fluids, also supports the interpretation that the JJ3 orebody represents a late mineralisation event. The pervasive alteration surrounding the JJ3 orebody is K-feldspathic with a minor sericitic overprint indicating an earlier higher temperature pervasive fluid flow event that was followed by low-temperature mineralising fluids. This interpretation implies that fracture dilation post-dated the earliest alteration, and that mineralisation and pervasive alteration in the JJ3 orebody are geochemically disconnected. Thus structural analysis is expected to be the most effective targeting method in future exploration for similar ore bodies. (C) 2014 Elsevier B.V. All rights reserved.

Abstract  The aim of the paper is to describe the current status of management for the decommissioning of combustible waste in KAERI. In Korea, two decommissioning projects have been carried out due to the retiring of nuclear research facilities, i.e., the Korean research reactors (KRR-1 & KRR-2) and a uranium conversion plant (UCP). The decommissioning of KRR-2 and the uranium conversion plant (UCP) at KAERI were completely finished by 2011, whereas the decommissioning of KRR-1 is currently underway. For the purpose of a volume reduction of the combustible waste generated from the decommissioning projects, incineration technology has been selected for the treatment of combustible waste. About 16.4 tons of combustible waste has been treating using Oxygen Enriched Incineration. The temperature; pressure of the major components; stack gas concentrations, i.e., SOx, NOx, CO, CO2 and HCl and residual oxygen were measured. The major parameters measured during normal operation were sustained at a stable status within criteria of the operation condition. Oxygen enriched air, 22 vol.% (dry basis) was used for stable incineration. The volume reduction ratio achieved was about 1/65. (C) 2015 Elsevier Ltd. All rights reserved.

Abstract  A high temporal hydro-biogeochemical monitoring based on daily discharges and Total Suspended Solids concentrations and on a three-day frequency survey of nutrients (NO3-, PO42-, SiO2) and algal biomass pigments was carried out during 2012 at three strategic stations in the Loire River. In a context of a strong eutrophication history, this survey aimed at observing temporal variability and deciphering biogeochemical processes at a fine temporal scale such as nutrients uptake by different phytoplankton species, P-limitation, N losses, and the impact of hydrological events on algal biomass. (C) 2014 Published by Elsevier B.V.

Abstract  Anionic polymethine dyes were obtained from fluorene equipped with electron-withdrawing groups (SO2OCH2(CF2)(3)CHF2 in positions 2 and 7 and NO2 in positions 4 and 5). Their electronic absorption spectra in various solvents were examined and compared with the spectra of related dyes derived from tetranitrofluorene and bis(2,2,3,3,4,4,5,5-octafluoropentyl) 9H-fluorene-2,7-disulfonate. The ab initio quantum chemical calculations (DFT and TDDFT at the B3LYP/6-31G(d,p) level of theory) were used to analyze the nature of electron transitions and the orbitals involved as well as the electron density redistribution in the excited state.

Abstract  Purpose - The purpose of this article is to present a summary of recent study results on a turboelectric distributed propulsion vehicle concept named N3-X.

Design/methodology/approach - The turboelectric distributed propulsion system uses multiple electric motor-driven propulsors that are distributed on an aircraft. The power to drive these electric propulsors is generated by separately located gas turbine-driven electric generators on the airframe. To estimate the benefits associated with this new propulsion concept, a system analysis was performed on a hybrid-wing-body transport configuration to determine fuel burn (or energy usage), community noise and emissions reductions.

Findings - N3-X would be able to reduce energy consumption by 70-72 per cent compared to a reference vehicle, a Boeing 777-200LR, flying the same mission. Predictions for landing and take-off NOX are estimated to be 85 per cent less than the Tier 6-CAEP/6 standard. Two variants of the N3-X vehicle were examined for certification noise and found to have International Civil Aviation Organization Chapter 4 cumulative margins of 32EPNdB and 64EPNdB.

Practical implications - It is expected that the turboelectric distributed propulsion system may indeed provide unprecedented reductions in fuel/energy consumption, community noise and landing and take-off NOX emissions required in future transport aircraft.

Originality/value - The studied propulsion concept is a step change from the conventional propulsion system and addresses growing aviation demands and concerns on the environment and energy usage.

Abstract  Nitrogen fixation can be a dominant flux of nitrogen (N) input providing up to 97 % of new N into some terrestrial and up to 82 % into some aquatic ecosystems, yet N-2 fixation is rarely considered in the context of other N cycling fluxes. We compared N-2 fixation with dissolved inorganic N (DIN) uptake fluxes in several streams. We measured N-2 fixation in nine streams in Grand Teton National Park, Wyoming, USA and surrounding areas and we compared our estimates to the ammonium (NH4+) uptake, nitrate (NO3) uptake, and denitrification estimates from the literature for those streams. N-2 fixation was negligible or below detection in the four streams with NO3- concentrations >20 mu g NO3--N L-1 center dot N-2 fixation exceeded NO3- uptake in two of the nine streams and NH4+ uptake in one stream. To further examine the relationship between N-2 fixation and DIN uptake, we chose Ditch Creek, which is a low-N stream (<5 mu g DIN-N L-1) with high rates of N-2 fixation. We measured N-2 fixation, NH4+ uptake, and NO3+ uptake biweekly throughout one summer. In Ditch Creek, DIN uptake exceeded N-2 fixation at the beginning and end of the summer, but from July to the beginning of September N-2 fixation was up to eight times greater than DIN uptake. The epilithic biofilm in Ditch Creek accumulated 1.5 g N m(-2) throughout the summer, and N-2 fixation may have contributed up to 73 % of that accumulation. Ditch Creek N2 fixation surpassed denitrification for both Ditch Creek and many streams. N-2 fixation can be a dominant flux in low-N stream ecosystems.

Abstract  Recently, global interest in energy depletion and the issue of rapid climate change have emerged. To address these issues, research and development related to clean coal technology are currently active. In this study, a combustion experiment is performed to investigate the combustion characteristics of H-2/CO/CH4 syngas in a partially premixed model gas turbine combustor. Chemiluminescence measurements are undertaken to study the flame structure and characteristics of syngas combustion at an equivalence ratio range of 0.7-1.3. The Abel inversion method is applied to obtain 2-D chemiluminescence flame images from 3-D accumulated chemiluminescence images. EINOx is measured to investigate the relationship between the flame structure and the exhaust gas. In addition, a process using an artificial neural network (ANN) is employed to establish the EINOx prediction model. As a result, the EINOx characteristics of a partially premixed flame differ from those of a diffusion jet flame. Moreover, they are proportional to the flame temperature and correlated with the flame length at varying equivalence ratios ranging from 0.7 to 1.3 at the same heat input level. Overlapped OH*, CH*, and C-2* chemiluminescence images are more accurate for estimating EINOx for various H-2/CO/CH4 syngas compositions. This is confirmed from the ANN estimation results. The flame temperature, length, and input air flow rate are used in ANN to predict EINOx. The coefficients of correlation used for the predictions are 0.78 and 0.62 when using overlapped OH*, CH*, and C-2* chemiluminescence images and only the OH* chemiluminescence image as input parameters, respectively. The weight partition method of this ANN process also confirms that EINOx formation is affected more by the flame temperature and length than by the air mass flow rate. (C) 2015 Elsevier Ltd. All rights reserved.