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Prussian blue (transition metal mixed valence complex) has been accomplished as an eco-friendly and efficient for the synthesis of high quality biodiesel production using Watermelon (Citrullus vulg...

The dysprosium (Dy) (1.12, 2.24, 3.33 and 4.02 at.%) modified zinc oxide (ZnO) nanoparticles were synthesized by simple chemical co-precipitation method. The prepared nanoparticles were analyzed by EDAX, TEM, FTIR, EPR, VSM and dielectric studies. The energy dispersive analysis of X-rays confirms the presence of Dy, Zn and O in the prepared samples. The transmission electron micrographs of the prepared samples show that the particles are spherical in nature with average size 22–18 nm. The shifting of Zn–O peak towards lower frequency side in the FTIR spectra of the prepared samples confirms the substitution of Dy ion in the ZnO lattice. EPR investigations exhibit paramagnetic signals at g- 1.956, 2.04 and 2.323. The magnetic properties of the synthesized Dy doped ZnO NPs reveal weak ferromagnetic behavior. The studies on electrical properties of the prepared samples provided new and interesting information on the contribution of grains, grain boundaries and interfacial polarization on dielectric parameters and electrical conductivity.

Ce-doped ZnO nanoparticles (NPs) with different Ce doping concentrations (0, 0.96, 1.96, 2.52 and 3.12 at.% of Ce) were prepared by the chemical co-precipitation method. Energy-dispersive analysis of X-rays confirms the presence of Ce in Ce-doped ZnO nanoparticles. Raman spectra revealed the hexagonal wurtzite structure of pure and Ce-doped ZnO nanoparticles and presence of various defects. The photoluminescence spectra exhibited enhanced violet and blue emission peak intensities for 0.96 at.% of Ce, while broad band green emissions decreased with Ce content. Electron paramagnetic resonance (EPR) studies revealed the presence of oxygen vacancies (V O), zinc vacancies (V Zn) and Ce3+ ions in the prepared ZnO nanoparticles. VSM studies showed room temperature ferromagnetism (RTFM) in the Ce-doped ZnO NPs. The substituted Ce3+ions found to induce RTFM along with V O, V Zn in correlation with the results obtained from the EPR, PL and Raman studies. The variation of dielectric constants (e r), dielectric loss (e″) and ac conductivity (σ ac) as a function of frequency and Ce concentration is studied using ‘Maxwell–Wagner Model.’

The reaction kinetics of Prussian blue (PB)/NaNO2 initiated for the nitration of phenols by in aqueous bisulfate and acetonitrile medium indicated first-order dependence on [phenol], [NaNO2], and [PB]. An increase in [KHSO4] accelerated the rate of nitration under otherwise similar conditions. The rate of nitration was faster in the solvent of higher dielectric constant (D). Observed results were in accordance with Amis and Kirkwood plots [log k′ vs. (1/D) and [(D − 1)/(2D + 1)]. These findings together with the linearity of plots, log k′ versus (vol% of acetonitrile (ACN)) and mole fraction of (nx) ACN, probably indicate the importance of both eloctrostatic and nonelctrostatic forces, solvent–solute interactions during nitration of phenols. Reaction rates accelerated with the introduction of electron-donating groups and retarded with electron-withdrawing groups, which are interpreted by Hammett's theory of linear free energy relationship. Hammett's reaction constant (ρ) is a fairly large negative (ρ < 0) value, indicating attack of an electrophile on the aromatic ring. Furthermore, an increase in temperature decreased the reaction constant (ρ) values. This trend was useful in obtaining isokinetic temperature (β) from Exner's plot of ρ versus 1/T. Observed β value (337.8 K) is above the experimental temperature range (303–323 K), indicating that the enthalpy factors are probably more important in controlling the reaction.

Environmental and Ecological issues call for the reduction in usage of cutting fluids in metal cutting industry. New techniques are being inquired to achieve this objective. Hard turning with minimum quantity lubrication is one such technique which can alleviate the pollution problems associated with cutting fluids. In the present work, vegetable oil based cutting fluids like castor oil, palm oil and ground nut oil is made to drop at tool-work interface using over-head system. The present paper deals with experimental investigation carried out for machinability study of AISI D3 steel in combination with CVD coated cemented carbide inserts of different styles and to obtain optimum process parameters using TOPSIS and Desirability function analysis. An orthogonal array, closeness coefficient, composite desirability and analysis of variance (ANOVA) are applied to study the performance of process parameters such as insert style, cutting fluid cutting speed, feed and depth of cut with consideration of quality characteristics i.e., Surface roughness, material removal rate and specific energy. Finally a clear comparison is presented between DFA and TOPSIS

Ultrasonic sonication and microwave irradiation exhibited pronounced effects on crystalline Mn(II) carbonate catalyzed biodiesel production using watermelon (Citrullus vulgaris) seed oil and alcohol (fibrous flesh) as exclusive green feedstock. Both ingredients, alcohol and oil, necessary for biodiesel production are extracted from watermelon fruit. Mn(II) carbonate and watermelon fruit, which are used for transesterification, are inexpensive, easily available and environmentally safe. The reactions occurred smoothly under conventional conditions and afforded good product yields. However, microwave assisted and ultrasonically assisted reactions exhibited highly significant reduction in reaction times with a trend: microwave assisted (35 min) << ultrasonically assisted (2.0 h) << conventional (8.0 h). The whole exercise is operationally simple, environmentally safe, energy saving, time saving and green, which fits well into the green chemical principles of Anastas and Warner.

In the current work, modeling and optimization of input parameters in wirecut electric discharge machine (WCEDM) of titanium [Ti-6A-4V] (Grade 5) were attempted. WCEDM working variables such as pulse-on-time (TON), pulse-off-time (TOFF), servo-voltage (SV), peak-current (IP), and wire feed were considered to study the responses of cutting speed or speed of cut (CS) and wire wear ratio (WWR). Each input parameter was set at three levels. Experiments were conducted as per central composite face (CCF)-centered design. Based upon the runs’ data, model equations for CS and WWR were developed using multiple linear regression. Optimization of practice parameters had been performed with the help of level mean analysis, response graphs, and model equations. From the analysis, it was observed that pulse-on-time was the substantial considerable input variable followed by servo-voltage, peak-current, and pulse-off-time.

Zeolite Y was found to be an efficient catalyst for a facile nitration of aromatic compounds with acetonitrile as the solvent in the presence of small amounts of HNO3 at room temperature. The reactions afforded mono-nitro derivatives of aromatic compounds in about three hours under stirred conditions with high yields and regioselectivity. The reaction times drastically reduced to about 20 min under sonication and to about 20 s under microwave irradiation. Zeolite is recovered after completion of the reaction and recycled for three to four times without any problem. The approach is particularly appropriate for the conversion of unsaturated cinnamic acids into nitrostyrenes.

Ultrasonic and microwave-assisted practical methods have been developed for the nitration of phenols using metal nitrates in aqueous polyethylene glycol (PEG) media. Solvent is recycled three times for reproducibility. It was recycled with minimum loss and decomposition. Developed protocols were cost effective, simple and efficient, which afforded nitration products in good to excellent yields. The observed hyperchromic/hypochromic shifts in the UV/VIS spectra of metal nitrates in PEG solutions could be due to the plausible in situ formation of “PEG-bound M(II) nitrate” and thereby the release of nitronium ion () during the course of reaction when metal nitrate [M(II)nitrate] is added to PEG. Nitronium thus formed most likely is captured by aromatic compound to afforded nitro aromatics.

This research work presents the synthesis, characterization, evaluation of the antibacterial and anticancer activity of ZnO nanopowders prepared by solution combustion method using the bio fuels Punica granatum L and Tamarindus indica L. The X-ray diffractograms of all the samples revealed the hexagonal Wurtzite structure with the standard JCPDS pattern of zincite [36–1451]. Surface morphology of the samples was studied by SEM. Particle shapes and sizes were determined by TEM. Qualitative phytochemical screening of the aqueous fruit extracts of Punica granatum L and T. indica L revealed the presence of many phyto-components in them. Toxicity of the nanopowders was tested on Gram-negative Escherichia coli MTCC 7410 and Pseudomonas aeruginosa MTCC 7903 by disk diffusion method. Minimum inhibitory concentration was determined by microbroth dilution technique. Anticancer activity of ZnO powders was tested against breast cancer cell line MCF-7 by MTT assay. The cytotoxicity was assessed by hemolytic activity.

Pure and erbium (1.30, 1.79, 2.83 and 3.53 at. %) doped ZnO nanoparticles are synthesized by wet chemical co - precipitation method. The synthesized s amples are characterized by powder X - ray diffraction (XRD), energy - dispersive analysis of X - rays (EDAX), transmission electron microscopy (TEM), Raman spectroscopy, UV - visible diffusion reflectance spectroscopy (DRS) and LCR Impedance spectroscopy. The XRD measurements confirmed the hexagonal wurtzite structure of all samples and size of the particle is found to be decreased with Er content. TEM images show spherical shape with more agglomeration in Er doped ZnO nanoparticles. Raman spectra confirmed the he xagonal wurtzite structure of pure and Er doped ZnO nanoparticles with E 2 (high) mode at 438 cm - 1 and presence of other possible defects. UV - visible DRS shows decrease in the band gap with increasing Er 3+ in ZnO host. Dielectric constant, dielectric loss f actor and ac conductivity properties were decreased with Er

Thiocyanation of various aromatic and heteroaromatic compounds has been studied using Zeolite H-SDUSY Powder (CBV720) as catalyst and ammonium thiocyanate (NH4SCN) as thiocyanation reagent in aceto...

Pure and Dy(1.15, 2.24, 3.33 and 4.02 at.%)-doped ZnO nanoparticles were prepared by the chemical co-precipitation method. The as prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA-DTA), Raman spectroscopy, UV–Vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) studies. XRD studies confirm both undoped and Dy-doped ZnO nanoparticles reveal wurtzite structure with average grain size in the range of 24–16 nm and are in agreement with TEM analysis. EDS confirms the presence of Dy in Dy-doped ZnO nanoparticles. Raman studies, confirm the wurtzite structure of ZnO nanoparticles besides increase in defects with doping concentration. UV–Vis DRS measurements indicated a blue shift optical band gap with Dy-doping. PL spectrum demonstrated immense enhanced green emission which attributes to the increase in defects concentration. The emissions intensity could be tuned by varying the Dy concentration and excitation wavelength as well for the application of better optoelectronic devices.

Prussian blue triggered transesterification of ethylacetoacetate with various alcohols underwent efficiently. The reaction is mild, eco-friendly, and selective with good yields. The proposed reaction pathway depicts the formation of an intermediate by the interaction of β-ketoesters with catalytic site of the Prussian blue, followed by nucleophilic attack of the alcohol at the electrophilic center followed by successive elimination of the proton to give the product. Observed longer reaction times under conventional conditions reduced amazingly under sonication and microwave irradiation followed enhanced yield of products.

Modern manufacturers, seeking to remain competitive in the market, rely on their Manufacturing engineers and production personnel to quickly and effectively set up manufacturing processes for new products. This paper presents the multi response optimization of turning parameters for Turning on AISI 4340 Alloy Steel. Experiments are designed and conducted based on Taguchi’s L27 Orthogonal array design. This paper discusses an investigation into the use of Taguchi parameter Design and Regression analysis to predict and optimize the Surface Roughness, Metal Removal Rate and Power Consumption in turning operations using CVD Cutting Tool. The Analysis of Variance (ANOVA) is employed to analyze the influence of Process Parameters during Turning. This paper also remarks the advantages of multi-objective optimization approach over the single-objective one. The useful results have been obtained by this research for other similar type of studies and can be helpful for further research works on the Tool life and Vibration of tools etc.

Cd1−xCrxTe diluted magnetic semiconductor crystals were grown by vapor phase growth technique in the composition range of 0≤x≤0.05 and the effect of Cr doping on structural, morphological, optical and magnetic properties have been explored. X-ray diffraction analysis confirmed that all the grown crystals were zinc blende in structure without having any phase transition up to a Cr doping level of x=0.05. The lattice parameter decreased with increase in Cr doping level. Optical studies indicated that the optical band gap of the crystals decreased with the increase of Cr doping level. Magnetic properties were studied using vibrating sample magnetometer at room temperature and room temperature ferromagnetism was observed in all the Cr doped CdTe crystals.

Transesterification of β-ketoesters with different alcohols has been studied under conventional and unconventional conditions using the simple desktop chemical cesium carbonate as catalyst. These methods enabled transesterification of β-ketoesters in good yields with dramatic rate acceleration and reduced reaction times. The procedures which used unconventional methods, for example sonication and microwave irradiation, are highly promising compared with conventional procedures.

Nitration of aromatic compounds and cinnamic acids with oxalylchloride/DMF afforded the corresponding nitro derivatives in the presence of KNO3 or NaNO2 under conventional and nonconventional (ultrasonic and microwave) conditions. The present methodology offers several benefits such as excellent yields, simple work-up procedure, and short reaction times. The yields obtained under present methodology are comparable with those obtained from (POCl3/DMF/KNO3 or NaNO2) and (SOCl2/DMF/KNO3 or NaNO2) systems followed by shorter reaction times. The reaction times of sonication and microwave conditions are very shorter than those of the conventional conditions.

Transesterification of β-ketoesters with various alcohols has been studied under conventional and non-conventional conditions using desktop chemicals such as Mn(II) salts as catalysts. These methods offered transesterification of β-ketoesters in good yields with dramatic rate accelerations and reduced reaction times. The developed protocols under nonconventional methods such as sonication and microwave irradiation are highly promising compared with the existing procedures.

Traditionally independent diagnostics methods were employed for health monitoring of system. These exhibited an overall satisfactory performance, but with a limited effectiveness range. A discipline that has emerged in recent years is that of an information (or data) fusion, which allows interweaving of different methods with different effectiveness ranges, to produce a wider and more reliable coverage of diagnosis. It is a multidisciplinary domain wherein, data from the various domain is blended together to arrive at a more reliable monitoring. The present paper brings out a Neural Network (NN) based approach for executing this task of combined health monitoring viz. mechanical and performance, with an example case study pertaining to a developmental power turbine. The various parameters used along with the trending methodologies both for steady state and transient operations are brought out. In addition, the influences of various parameters that can lead to deviations in the response are also discussed. The whole process of executing this task is put forward in a rather simple manner. The results accrued have been well corroborated with the findings on dismantling of the turbine.

Cd1 − xFexTe single crystals were prepared by vapour phase growth method in the composition range of 0 ≤ x ≤ 0.03. Chemical analysis, surface morphology, structural investigations and electrical properties were carried out by EDAX, SEM, XRD, TEM and transport technique, respectively. Microscopic variations between the target and actual compositions were noticed. Morphology studies revealed that dislocation aided growth is active in the present crystals. TEM and XRD studies confirmed that the samples of all compositions crystallized in zinc blende structure, and the lattice parameters varied almost linearly decreases with Fe content. At room temperature, the resistivity of the Cd1 − xFexTe crystals of all compositions (x = 0.01, 0.015, 0.02, 0.025 and 0.03) lies in the range of 3.5–6.5 M Ω, the activation energies lie in the range of 63–133 meV, and the samples were show the ‘p’ type conductivity.

The optical and electrical properties of vapour phase grown crystals of diluted magnetic semiconductor Zn 1 − x Cr x Te were investigated for 0 ≤ x ≤ 0.005. The diffuse reflectance spectra exhibited an increase in the fundamental absorption edge ( E 0 ) with composition x and were also dominated by a broad absorption band around 5200 cm − 1 arising from 5 T 2 → 5 E transition. The 5 T 2 and 5 E levels originate from the crystal field splitting of the 5 D free ion in the ground state. The electrical resistivity measurements revealed semiconducting behaviour of the samples with p-type conductivity in the temperature range of 200–450 K.

Intense photo and mechanoluminescent (ZnS) 1− x (MnTe) x powder samples with x = 0.02, 0.05, 0.10, 0.15, 0.20 and 0.25 were prepared by simple solid state reaction method. All samples were polycrystalline with wurtzite structure. Wurtzite lattice parameters increased with composition ‘ x ’ linearly obeying Vegard's law. Both in photoluminescence and in mechanoluminescence an emission band was observed in red region at 650 nm. The band gap of the samples decreased with increase of composition ‘ x ’. Metal–Semiconductor transition was observed in all (ZnS) 1− x (MnTe) x samples. The activation energies of the samples were found to be in the range 65–89 meV.

The EPR and magnetic properties were investigated on vapour phase grown Zn 1− x Cr x Te ( 0.001 ⩽ x ⩽ 0.005 ) crystal samples at room temperature. The EPR spectra were observed for samples with x = 0.001 , 0.002 only. The simulations of the spectra confirm Cr 3+ charge state of the dopant ion at tetrahedral symmetry. The magnetic behaviour of the samples with x = 0.001 and 0.002 is neither that of Brillouin paramagnets nor Van Vleck systems while the samples with compositions x = 0.003 , 0.004 and 0.005 exhibited hysteresis behaviour.

Single crystals of Zn1−xCrxTe were grown by vapour phase growth method in the composition range of 0⩽x⩽0.005. Chemical analysis, surface morphology, structural and microhardness studies were carried out by EDAX, SEM, XRD and Vicker's indentation techniques, respectively. Microscopic variations between the target and actual compositions were noticed. Morphology studies revealed that dislocation aided growth is active in the present crystals. XRD studies showed that samples of all compositions crystallized in zinc blende structure, and the lattice parameters varied linearly with x following Vegard's law. Vicker's hardness (Hv) decreased exponentially with x.

Pure and Er (2, 3 and 4 at. %) doped ZnO nanoparticles have been synthesized by chemical co-precipitation method. EDS spectrum confirmed the presence of Zn, O and Er in the synthesized samples. The XRD measurements confirmed the hexagonal wurtzite structure of ZnO for all samples. The crystallite size of the samples decreases with increase in concentration and are compatible with the results that obtained from TEM analysis.EPR spectra exhibitedferromagnetic signals the substitution Er The possible ferromagnetic zinc interstials signal is appeared for 2 at. % of Er dopant. The room temperature ferromagnetic is observed only for 2 at. % of Er while all other samples exhibiting weak ferromagnetic nature.

The paper deals with modelling and design of a friction damper. This has been done in four phases. In the first phase, modal analysis is performed to determine the modal parameters of turbine blade. In the second phase, a mathematical model for the contact region of damper and rigid surface has been developed using microslip approach. This model has the ability to account for microslip in the contact region. In the third phase, a mathematical model for the combined blade with damper is developed and in the fourth phase the damper is designed. The results of the combined blade with damper model are confirmed by experimental test.

The Aim is for HDL Design & Implementation of Multichannel frequency rate PRBS- GPS SOC Transceiver Design using VHDL & Verilog HDL. GPS SOC Transceiver contains Transmitter & Receiver and Transceiver SOC by Integration of Transmitter & Receiver. Transmitter Contains PRBS - Base Band Signal Navigation Data Generator with frequency of 50 Hz & Carrier Wave Generator with a frequency of 1.057 MHz and C(t) is Pseudo Random Code (C/A Code of Satellite is 1.023 MHz) . PRBS GPS Base Band Signal Generator & Carrier Wave Generator are XOR ed by using XOR Gate for generation of Digital Modulated Signal by Tapping Different Sequence Patterns 2e7−1,2e10−1,2e15−1,2e23−1,2e31−1 etc as per CCITT - ITU Standards (O.150,O.151,O.152) for Identification of Property of PRBS Modulated Signal codes and the same signal codes received by using PRBS GPS Receiver System and compared with the Received signal codes delayed with Transmitted one, and if the result is ‘0’, no error in the received sequence. ‘1’ means error occurred in the received sequence. Speed of Transmission & Reception rate is in terms of Gbps/Tbps/Peta/Exa/Zetta Bits Per Second. Coding done by VHDL &/ Verilog HDL. Programming & Debugging Done by Xilinx ISE 9.2i Software Design Tool and Xilinx Spartan III FPGA Development Kit.

Undoped ZnO and rare earth elements (Ce, Dy and Er with 2 at. %) doped nanoparticles were synthesized by wet chemical co-precipitation method at 90°C with Polyvinylpyrrolidone (PVP) as capping agent. The structural, morphological, compositional and photoluminescence studies were performed with X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energy dispersive spectroscopy (EDS), FTIR spectroscopy and Photoluminescence (PL) respectively. XRD results revealed hexagonal wurtzite structure with average particle size around 18 nm - 14 nm and are compatible with TEM results. EDS confirm the incorporation of Ce, Dy and Er elements into the host ZnO matrix and is validated by FTIR analysis. PL studies showed a broad intensive emission peak at 558 nm in all the samples. The intensity for Er- doped ZnO found maximum with additional Er shoulder peaks at 516nm and 538 nm. No Ce, Dy emission centers were found in spectra.

Polyvinylpyrrolidone capped ZnO and Nd (0.5 and 1 at.%) ZnO nanoparticles have been prepared by chemical co-precipitation method in aqueous media. The as-prepared nanoparticles were subjected to compositional, structural, morphological and photoluminescence studies. EDS confirmed the presence of Nd element in ZnO nanoparticles. X-ray diffraction patterns and TEM studies established that pristine and Nd doped ZnO nanoparticles exhibited wurtzite crystal structure. The average particle size obtained from the XRD and TEM were in good agreement with each other. Photoluminescence studies on Nd doping amplify the defect related emission.

Since conventional conditions require reaction times of 16-24h, the transformation of β-keto ester (I) is investigated under ultrasound or microwave conditions where the latter afford optimal results concerning the time.

The friction damping concept is widely used to reduce resonance stresses in gas turbines. A friction damper has been designed for high pressure turbine stage of a turbojet engine. The objective of this work is to find out effectiveness of the damper while minimizing resonant stresses for sixth and ninth engine order excitation of first flexure mode. This paper presents a methodology that combines three essential phases of friction damping optimization in turbo-machinery. The first phase is to develop an analytical model of blade damper system. The second phase is experimentation and model tuning necessary for response studies while the third phase is evaluating damper performance. The reduced model of blade is developed corresponding to the mode under investigation incorporating the friction damper then the simulations were carried out to arrive at an optimum design point of the damper. Bench tests were carried out in two phases. Phase-1 deals with characterization of the blade dynamically and the phase-2 deals with finding optimal normal load at which the blade resonating response is minimal for a given excitation. The test results are discussed, and are corroborated with simulated results, are in good agreement.

In this paper we present the significance of Information exchange among different departments of an E-Manufacturing system such as Head Office, Production, Multi Level Production and Sales & Service using our developed Genetic Sensor System.

Metal-mediated condensation of o-phenylenediamine with bisacetylacetone-ethylenediimine yields 14-membered tetraaza macrocyclic six-coordinate complexes of the type [M(mac)Cl2],[M(mac)SO4·H2O] (where M = FeII, CoII and CuII; mac = macrocyclic ligand formed in the template reaction). The metal ions are coordinated by four azomethine nitrogen atoms bridged by acetylacetone moieties. The electrical conductance magnetic moments, electronic and IR spectral data of all complexes are discussed.

The Ignition Over Pressure (IOP) is an unsteady pressure wave generated by the ignition of solid rocket motor during launch vehicle lift-off. This wave behaves as a blast or a shock wave followed by a low frequency excitation characterized up to 40 Hz, would cause severe damage to the launch vehicle, its structures and surroundings. However, in case of huge propulsion system, having two solid rocket motors as its boosters, due to the skew in their ignition, during lift-off, the phase difference of the wave from one side of the vehicle to the other could cause a severe moment, which is detrimental to the vehicle. The present paper deals with the occurrence of such blast waves during the testing of various scaled down solid rocket motors. Also, an attempt has been made experimentally to characterize and understand the propagation of the IOP wave causing unsteady pressure oscillations and transient pressure rise in the vicinity of a solid rocket motor. The spectral and directional characteristics of the IOP wave are also highlighted. Typical scaled-down solid rocket motors with and without nozzle shutters have been tested in horizontal firing configuration and the results are compared to study their effect. The resulting shock wave propagation has axial downstream as well as angular directivities. The pressure rise rate in the chamber is found to be directly correlated to the over pressure measured at various locations at the downstream of the nozzle.

The rate of interparticle vanadium transfer in FCC catalysts as a function of the degree of oxidation of the steaming environment has been determined. The rate of interparticle vanadium transfer is low when the atmosphere in the steamer is reducing, but increases dramatically as the mole % excess oxygen becomes greater than zero. High rate of vanadium transfer is accompanied by a greater loss of surface area and catalytic activity. XPS measurements show that the oxidation state of vanadium increases from +3 when the steamer atmosphere is reducing to +5 when the % excess oxygen is greater than zero. Surface vanadium concentration follows a similar trend. In addition, data from a commercial resid FCCU operating in a partial burn were analyzed. The results of the analyses show that defining a partial burn operation with the flue gas CO/CO 2 ratio is not adequate for characterizing the vanadium oxidation state. Carbon on regenerated catalyst is a better marker for the vanadium oxidation state in the regenerator.