Academic literature on the topic 'Power Doppler parameters'

Objective: it is to examine the reproducibility of 3D power Doppler in the management of intrauterine growth restriction compared with the conventional 2d Doppler. Patients and Methods: This study was performed between Jan 2021 and Feb 2022 and included 100 pregnant women recruited from outpatient clinic at Elgalaa Teaching Hospital, 3D power Doppler US was done for assessment of IUGR and compare the findings with 2D Doppler. Results: it is found that 3D Power Doppler parameters were significant in prediction of poor neonatal outcome regarding development of respiratory complications, neurological complications and IUFD as complications to IUGR comparing to 2D colour Doppler parameters which were non-significant in these cases. Our results also showed that the only parameter of 2D Colour Doppler that showed significance and positive correlation to birth weight among these cases was Middle Cerebral Artery Pulpability Index. Conclusion: 2D Doppler flow-velocity waveforms are of limited value in the prediction of poor neonatal outcome in IUGR except for MCAPI. 3D power Doppler was superior in the diagnosis and prediction of neonatal outcome.

In the realm of ballistic target analysis, micro-motion attributes, such as warhead precession, nutation, and decoy oscillations, play a pivotal role. This paper addresses these critical aspects by introducing an advanced analytical model for assessing the Doppler power spectra of convex quadric revolution bodies during precession. Our model is instrumental in calculating the Doppler shifts pertinent to both precession and swing cones. Additionally, it extends to delineate the Doppler power spectra for configurations involving cones and sphere–cone combinations. A key aspect of our study is the exploration of the effects exerted by geometric parameters and observation angles on the Doppler spectra, offering a comparative perspective of various micro-motion forms. The simulations distinctly demonstrate how different micro-motion patterns of a cone influence the Doppler power spectra and underscore the significance of geometric parameters and observational angles in shaping these spectra. This research not only contributes to enhancing LIDAR target identification methodologies but also lays a groundwork for future explorations into complex micro-motions like nutation.

Abstract Stratocumulus is one of the most common cloud types globally, with a profound effect on the earth’s radiation budget, and the drizzle process is fundamental in understanding the evolution of these boundary layer clouds. In this paper a combination of 94-GHz Doppler radar and backscatter lidar is used to investigate the microphysical properties of drizzle falling below the base of stratocumulus clouds. The ratio of the radar to lidar backscatter power is proportional to the fourth power of mean size, and so potentially it can provide an accurate size estimate. Information about the shape of the drop size distribution is then inferred from the Doppler spectral width. The algorithm estimates vertical profiles of drizzle parameters such as liquid water content, liquid water flux, and vertical air velocity, assuming that the drizzle size spectrum may be represented by a gamma distribution. The depletion time scale of cloud liquid water through the drizzle process can be estimated when the liquid water path of the cloud is available from microwave radiometers, and observations suggest that this time scale varies from a few days in light drizzle to a few hours in strong drizzle events. Radar and lidar observations from Chilbolton (in southern England) and aircraft size spectra taken during the Atlantic Stratocumulus Transition Experiment have both been used to derive the following power-law relationship between liquid water flux (LWF) (g m−2 s−1) and radar reflectivity (Z) (mm6 m−3): LWF = 0.0093Z0.69. This relation is valid for frequencies up to 94 GHz and therefore would allow a forthcoming spaceborne radar to measure liquid water flux around the globe to within a factor of 2 for values of Z above −20 dBZ.

The ultrasound Doppler amplitude spectrum for a single scatterer and the power spectrum for multiple scatterers were calculated in terms of the echo signal from scatterers crossing the sample volume, defined by the transmitted pulse and the diffracted field distribution for cw. The observation time for the Doppler signal is also considered. Statistical parameters such as mean and variance of the Doppler power spectrum are studied as continuous functions of the intersection angle between the beam axis and the flow direction, the pulse length and the viewing position. The derived equations are valid whether the transit time is governed by the pulse length, or beam geometry, or both. It is shown that the Doppler power spectra calculated by the proposed model and by the Doppler signal obtained from field theory are in good agreement. It is also shown that, when the Doppler signal broadening due to the transmitted pulse and beam geometry is constant without regard to the intersection angle, the degree of spread of the velocity distribution can be estimated from the variance of the Doppler power spectrum measured by the Doppler system once the intersection angle is known.

La fécondation in vitro (FIV) est désormais largement utilisée dans le traitement de l'infertilité et son succès est la principale préoccupation des patients. Il est difficile pour les praticiens d’identifier les éléments qui pourraient conduire à une grossesse réussie par FIV en l'absence de technologies automatisées. Le développement d’une technique fiable pour estimer les chances de succès des couples reste un défi ouvert que nous allons tenter de relever en proposant notre nouvel outils SPIRL (System for Predicting the success Rate of IVF using machine Learning combining clinical and Doppler data). De nombreux facteurs contribuant à une grossesse réussie ont fait l'objet de recherches approfondies. Basées sur l’expérience du centre Al Hadi de Beyrouth, l’hypothèse de ce travail repose sur la prise en compte des paramètres écho-Doppler de l'endomètre et du myomètre. Un premier sous-objectif vise alors à explorer l'impact de ces paramètres Doppler sur le succès de la FIV. Pour ce faire, nous avons évalué les capacités prédictives de dix modèles d'apprentissage automatique différents. Ces modèles ont été entraînés à l'aide d'une combinaison de paramètres Doppler et cliniques. Parmi les techniques explorées la méthode de Bagging combinée à la sélection des caractéristiques d'importance Extra Tree a obtenu les meilleures performances (sensibilité de 100 %, spécificité de 80 % et précision de 89,4 %) pour 94 patients. Ensuite, pour 572 patients, le classifieur Bagging combiné au paramètre d’'importance de la forêt aléatoire a présenté la plus grande AUC de 78,2 %. Les résultats obtenus par l’outils SPIRL soulignent l'importance des paramètres écho-Doppler dans le taux de réussite de la FIV. D’autre part, les mesures échographiques de l’endomètres à partir de l’outils VOCAL étant très chronophage et opérateur-dépendant, le second objectif visé est la segmentation automatiquement l'endomètre. En combinant les techniques d'apprentissage automatique et de segmentation automatique et semi-automatique (techniques de Chan-Vese et de Split-Bregman) nous obtenons un indice de Jaccard supérieur ou égal à 0,5 pour plus de 60% des images traitées. Enfin, le troisième objectif était la version entièrement automatisée de SPIRL utilisant notre technique de segmentation entièrement automatisée, qui mesure la surface de l'endomètre, la moyenne de gris de l'endomètre et l'épaisseur de l'endomètre, combinée à d'autres caractéristiques cliniques. Ensuite, il classe et prédit le résultat de l'ICSI. Les résultats sont étroitement alignés avec la prédiction du résultat de l'ICSI en utilisant les mêmes caractéristiques mesurées par des cliniciens à l'aide d'échographes
In-Vitro Fertilization (IVF) and Intra-Cytoplasmic Sperm Injection (ICSI) are now widely used in the treatment of infertility. Patients' primary concern is the success of an IVF treatment, which is dependent on a variety of influencing factors. It is difficult for practitioners to detect any influencing trend of the characteristics and elements that may lead to a successful IVF pregnancy in the absence of automated technology. The goal was to develop a reliable technique for estimating the likelihood of success for couples seeking to conceive: the SPIRL tool (System for Predicting the success Rate of IVF using machine Learning combining clinical and Doppler data). Several factors that contribute to an accomplished pregnancy have been extensively researched. Based on the experience in Al Hadi Centre, the assumption of this work leads on that Power Doppler parameters related to the endometrium and myometrium play a crucial role in the treatment. The first aimed to explore the impact of Doppler parameters, specifically those related to endometrial and myometrium ultrasonography measures, on the success of IVF. The goal was to develop a reliable technique for estimating the likelihood of success for couples seeking to conceive. To achieve this, we evaluated the predictive capabilities of ten different machine learning models, including Logistic Regression, K-Nearest Neighbor, Multilayer Perceptron, Support Vector Machines, Naive Bayes, Bagging Classifier, Gradient Boosting, Extreme Gradient Boosting, AdaBoost Classifier, and Random Forest. These models were trained using a combination of Doppler and clinical parameters. Initially, among the techniques explored for predicting the outcomes of IVF using machine learning, the Bagging method combined with Extra Tree Importance Feature selection demonstrated superior performance for 94 patients. It achieved a sensitivity of 100%, specificity of 80%, and an accuracy of 89.4%. Subsequently, for 572 patients, the Bagging classifier combined with RF importance exhibited the highest AUC of 78.2%. Importantly, several variables, such as myometrium VFI, volume of the endometrium, myometrium mean grey, myometrium FI, myometrium VI, endometrium mean grey, and endometrium FI, were identified as significant factors in the prediction process. These findings underscore the importance of ultrasound measurement parameters, particularly Doppler parameters, in influencing the outcomes of IVF and ICSI. The developed technique provides valuable insights for estimating the success rates of these assisted reproduction procedures. However, these parameters of endometrium and myometrium are currently measured manually using VOCAL software, which is a time-consuming process as it requires calculations based on six slices of the endometrium. The second objective of the work aimed to automatically segment the endometrium to calculate its surface, thickness and endometrial mean grey. Then, we predict the outcome of ICSI using machine learning techniques with the new value. First, we employed automatic and semi-automatic segmentation techniques, specifically the Chan-Vese and Split-Bregman techniques. Out of the 98 ultrasound images, 60 achieved a Jaccard index greater than or equal to 0.5, indicating high-quality segmentation. This accounted for 61% of our initial database. Finally, the third goal was the fully automated version of SPIRL taking our fully automated segmentation technique, which measures the endometrium surface, endometrium mean grey, and endometrium thickness, combined with other clinical features, then classify and predict the outcome of ICSI. the results are closely aligning with the prediction of ICSI outcome using the same features measured by clinicians through ultrasound machines

In der vorliegenden Arbeit werden der Entwurf, die Technologie und die Parameteridentifikation von Silizium basierten mikroelektromechanischen Systemen (MEMS) mit piezoelektrischen Dünnschicht-Aluminiumnitrid (AlN) vorgestellt. Auf Basis des AlNs als elektromechanischer Wandler erfolgt die Fertigung eines MEMS Technologiedemonstrators für energiearme Inertialsensoren. Das AlN wird über einen reaktiven Sputterprozess auf einer Wachstumsschicht abgeschieden. Durch Parametervariation des reaktiven Sputterprozesses und der Wachstumsschicht werden die piezoelektrischen Eigenschaften des AlNs optimiert. Die Entwicklung einer Gesamttechnologie führt zu einer Integration des Dünnschicht-AlNs in Silizium-Mikromechaniken. Die Röntgenbeugung (XRD) ermöglicht die Kristallstruktur des AlNs zu qualifizieren. Darüber hinaus werden weitere Analysemethoden vorgestellt, die eine hoch genaue und reproduzierbare messtechnische Bestimmung der piezoelektrischen Koeffizienten aus mikromechanischen Messstrukturen ermöglichen. Die Determination der piezoelektrischen Koeffizienten des Dünnschicht-AlNs aus den Messstrukturen erfolgt mittels analytischen und FE Modellen sowie der Laser-Doppler-Vibrometrie (LDV). Der Fokus der Arbeit liegt hierbei auf der Identifikation der longitudinalen und transversalen piezoelektrischen Ladungskoeffizienten des AlNs. Als Technologiedemonstrator wird ein einachsiger Inertialsensor mit integriertem piezoelektrischen Dünnschicht-AlN vorgestellt. Das MEMS generiert aufgrund des piezoelektrischen Wandlers intrinsisch elektrische Ladungen bei Einwirkung einer mechanischen Energie. Dadurch ist keine elektrische Energiezufuhr für die Messung eines inertialen Ereignisses notwendig. Der vorgestellte Demonstrator wird hinsichtlich seiner Ladungs- und Spannungssensitivität optimiert. Zur theoretischen Beschreibung der Funktionsweise werden analytische, sowie FE und SPICE Modelle genutzt. Eine Charakterisierung des MEMS Bauelements erfolgt hinsichtlich der mechanischen und elektrischen Eigenschaften
The thesis includes the design, the technology and the parameter identification of silicon-based microelectromechanical systems (MEMS) with piezoelectric thin film of aluminum nitride (AlN). A low-energy inertial sensor as technology demonstrator based on AlN as an electromechanical transducer a MEMS manufacturing process is shown. The AlN is deposited via a reactive sputtering on a growth layer. By varying parameters of the reactive sputtering and the growth layer of AlN, the piezoelectric properties can be optimized. The development of an overall technology results to an integration of the thin film AlNs in silicon micromechanics. X-ray diffraction (XRD) allows to qualify the crystal structure of AlN. Further methods are developed that enable a highly accurate and repeatable metrological determination of piezoelectric coefficients measurement structures. The determination of piezoelectric coefficients of the thin film AlN from the measurement structures is resulting from analytical methods and FE models and the laser Doppler vibrometry (LDV). The identification of the longitudinal and transverse piezoelectric charge coefficient of AlN is one main focus of this work. A uniaxial inertial sensor with an integrated piezoelectric thin film of AlN is presented as technology demonstrator. The piezoelectric transducer of the MEMS is generating electric charges intrinsically as reaction of mechanical stress. Thus, no electric power supply for the measurement of an inertial event is necessary. The presented demonstrator has been optimized with respect to its charge and voltage sensitivity. For a theoretical description analytical and FE and SPICE models are used. A characterization of the MEMS device is carried out with regard to the mechanical and electrical properties

The diagnostic power of two-dimensional (2D) echocardiography resides not only in its capability of providing anatomical information and of studying myocardial contractile function, but also in the possibility of performing a non-invasive haemodynamic assessment. Such non-invasive haemodynamic assessment is the subject of this chapter.2D echocardiography, colour flow imaging, and Doppler modality make this haemodynamic assessment possible, by studying the following parameters: ◆ Blood flow velocities. ◆ Transvalvular pressure gradients. ◆ Valvular areas. ◆ Stroke volume, regurgitant volume, and regurgitant fraction. ◆ Cardiac function.The application of these concepts in clinical practice will be explained through this chapter. They can be summarized in the following points: ◆ The study of valvular insufficiencies. ◆ The study of the valvular stenosis. ◆ The study of intracardiac shunts. ◆ The study of myocardial systolic and diastolic function. ◆ The estimation of intracardiac pressures.Finally, non-invasive haemodynamic study represents an alternative to invasive procedures in some clinical circumstances and it is very important in the diagnostic and therapeutic decision making. Therefore, it is necessary for the cardiologist to understand how this echocardiographic study is performed, as well as its advantages and limitations.

Polycystic ovary syndrome (PCOS) is a common and complicated endocrine disorder, with its diagnosis based on clinical, laboratory and imaging criteria. The latter is usually assessed via two-dimensional ultrasound; however, the advent of three-dimensional ultrasound, along with three-dimensional power Doppler (3D-PD) could offer more accurate diagnoses and further our understanding of PCOS pathophysiology. Three-dimensional ultrasound (3D-US) has already been used successfully in many fields of gynecology. It offers improved image quality with stored data that can be processed either manually or automatically to assess many parameters useful in PCOS assessment, such as ovarian volume, number of follicles and vascular indices. The examination requires minimal time as data is assessed in post-processing, thus being more tolerable for the patient. 3D-US parameters are generally increased in PCOS patients when compared to controls and 2D measurements, with studies showing improved diagnostic performance, though that remains inconclusive. 3D transrectal ultrasound is more accurate in the diagnosis of virgin PCOS patients than the modalities currently available in that subgroup. Overall, though with some limitations, 3D-US is a promising diagnostic method in the assessment of PCOS which, regardless of diagnostic accuracy, can undoubtedly offer many practical advantages, more objective and reliable measurements, potentially improving PCOS diagnosis standardization.

Present work represents the second part of a two parts paper. The complex aerodynamic phenomena, which take place both inside and downstream the swirler–mixing tube assembly, have been studied with different and complementary techniques in order to have a complete characterization of the effect of the geometrical parameters variation on many aspects of the flow. The first part was focused on the aerodynamic analysis of the flow in the swirler exit plane, while this second part is focused on the experimental investigation on the flow inside and downstream the mixing tube. Measurements have been performed on three axial stations. One is placed inside the mixing tube, in order to characterize the flow arriving from the swirler. The other two are placed downstream the mixing tube discharge section in order to identify the main flow features, such as the presence of flow recirculation and consequently the radial extension of the separation bubble. A four beams two colours Laser Doppler Velocimeter (Dantec Fiber Flow), in backward scatter configuration mounted on a three-axis computer-controlled traversing mechanism, was employed for the present study. Results indicate a strong influence of the geometrical parameters on the flowfield in terms of velocity component distributions, turbulence intensity and separation bubble extension. Moreover results from the Laser Doppler Velocimeter measuring campaign allow basically to evaluate three main performance parameters which are the friction loss coefficient, the semi-theoretical swirl number evaluated from the assembly geometry and the measured swirl number, which is calculated in the mixing tube outlet section. The first one is indicative of the angular momentum dissipation, while the other two represent the main parameters which are involved in the vortex breakdown onset and evolution, that in one case is derived from measurements and in the other is partially theoretical.

Return power is perhaps the most fundamental measurement available to radar after round-trip time delay. For coherent lidars using aerosol targets that are spread in range, there are two approaches. In the more straightforward, an estimate is formed by squaring the heterodyne output of the photodetector and subtracting the mean noise level.1,2,3 This method is often analyzed in the context of heterodyne detection of static hard targets where no account need be taken of Doppler shift in the return. The alternative is, in effect, to reduce noise by filtering the return and using only data within the filter passband for power estimation. Estimation of the frequency shift is then in principle the first step, but it can be combined with estimation of return power by, e.g., forming maximum likelihood (ML) estimates of both parameters simultaneously. For Doppler radar, Zrnic4 analyzed this approach as applied to monochromatic returns and appropriately commented that the need for a filter to optimize the power estimate is 'intuitively satisfying'. The goal of this note is to compare the two approaches.

The kerosene spray generated by a pressure swirl fuel nozzle embedded in a swirling airflow in a swirl cup typical of aeroengine combustors was investigated at different levels of air pressure to assess the counter-acting effects of increasing air density and transfer of centrifugal momentum from airflow to spray. Hardware parameters investigated included air swirl angle and fuel nozzle flow number. Measurement techniques included spray visualization, Phase-Doppler Anemometry (PDA) for spray analysis and Laser-Doppler Anemometry (LDA) for investigation of the air flow field. Operating conditions for PDA measurements were 6, 12, and 18 bar at 700 K. Spray visualizations and LDA measurements were performed at scaled operating conditions. It was found that fuel placement is governed by the presence or absence of a recirculation zone inside the swirl cup and hence by the swirl angle of the airflow. Analysis of temporal aspects of the spray showed the existence of droplet clusters. Configurations characterized by strong swirl furthermore exhibited a preferred frequency of inter-particle times.

In addition to a previous isothermal study, the present work reports on reacting swirling flow fields and droplet diameter distributions. The employed combustion chamber enabled optical access from three sides allowing the application of laser based measurement techniques. It is equipped with an airblast atomizer nozzle typical for gas turbines. The parameters of the boundary conditions were varied to such an extent that laser diagnostics were feasible. The chamber pressure and the inlet temperature were 2–3 bar and 300–350°C, respectively. The analysis of the spray droplets were performed by two velocity component phase Doppler anemometry (PDA). The measurements allowed for the investigation of axial and radial droplet velocities, Sauter mean diameter (SMD) distributions and an estimation of the volume flow rates. Comparisons of the different operating conditions and the influence of the parameters are given in the discussion.

We present an experimental investigation of a spray generated by an airblast atomizer. Experiments have been performed in a pressure chamber equipped by transparent windows allowing an optical access to the spray. Several techniques of spray investigation have been applied: spray visualization using the high-speed video system, spray visualization and instantaneous velocity measurements using the PIV technique, spray velocimetry and sizing using the IPI and phase Doppler instruments. Phase Doppler instrument has been used to characterize the droplets in the spray: their diameter, two components of the velocity vector. Also the integral parameters of the spray, such as the local volume flux density, have been characterized. We conduct a parametric study of the effect of the ambient pressure, the air flow rate and the water flow rate on an atomized spray. Measurements at different radial locations in the spray and in two planes were performed. The measurements in these two planes allow one to determine the distributions of all the three components of the average drop velocity vector: axial, radial and azimuthal. PDA measurements show that atomized spray is sensitive to any change in the studied parameters. For example, increasing air flow rate from 20 SCMH to 45 SCMH and keeping same water flow rate and pressure, leads to an increase in all velocity components and also to a change in droplets diameters. On the other hand, keeping constant pressure and air flow rate and increasing water flow rate from 0.7 to 1.4 l/hr, leads to an increase in water droplets sizes and the axial velocity component, whereas the other velocity components show a non uniform change. Moreover, increasing the ambient pressure leads to the growth of the spray velocity and drops diameters.

AFGL is developing a mobile coherent, pulsed, Doppler CO2 lidar system designed to evaluate techniques for the acquisition and real-time interpretation of atmospheric wind field structure as well as aerosol attenuation and concentrations over long path lengths . The system utilizes a low chirp electron beam injection CO2 TEA laser which is mode locked by hole injection from a Littrow grating tuned low pressure flowing gas cw CO2 laser . An identical low pressure laser is used as the local oscillator . The entire optical assembly is mounted upon a 3.7m × 8.3m optical table, with the exception of the scanner which is mounted over the table on an elevator system . The scanner system is raised through a hatch in the trailer roof and is capable of full hemispherical and fixed point scanning. The return signal is detected in the usual superheterodyne technique by a Hg:Cd:Te detector. The system IF amplifier output will be split to allow simultaneous real time analog display of velocity as a function of range and digital conversion for obtaining power, velocity, and variance characteristics of the signal. A schematic of the system is shown in figure 1 and the system design parameters are given in Table 1. The entire lidar system along with field operations support equipment will be housed in a modified 12m semi trailer.

Abstract In order to more accurately simulate the strong neutronics physical and thermal-hydraulic coupling phenomenon in a typical PWR, ARMcc (a software for the physical thermal coupling calculation of PWR core) is developed. In the ARMcc, the physical calculation module is based on the fourth-order nodal expansion method (NEM) and nodal Green’s function method (NGFM), the thermal-hydraulic calculation module is based on one-dimensional single-phase single channel heat transfer model and one-dimensional cylinder heat conduction calculation model, and the finite volume method (FVM) and finite difference method (FDM) are used to solve one-dimensional cylinder heat conduction model in the program. Based on the typical PWR benchmark NEACRP-L-335, the steady-state coupling calculation ability of the program is verified. The key parameters of the core calculated by the program, such as critical boron concentration and core Doppler temperature, are in good agreement with the reference results. The deviation between the critical boron concentration and the reference results is less than 5 ‰. In addition, the influence of four calculation modes on the simulation of core physical thermal coupling process is studied, and the results of PARCS program are selected as reference. It is found that NGFM + FDM calculation mode can more accurately simulate the core fuel Doppler temperature, core outlet coolant temperature and core power distribution; NEM + FVM can more accurately simulate the core fuel maximum temperature.

Abstract Tidal power converters deployed in areas where waves and tidal currents coexist face high levels of turbulences, which can lead to unstable power generation and increase the risks of turbine blade fatigue failure. In order to improve the design and safety operation of tidal turbines in a combined wave-current environment, it is necessary to understand and characterise the turbulence parameters such as turbulence intensity (TI)/turbulent kinetic energy (TKE) etc. It is also important to characterise how waves and currents separately affect these parameters. In this study, field data collected by an Acoustic Doppler Current Profiler (ADCP) at the Pentland Firth, Orkney Islands, Scotland, are analysed to evaluate the levels of TI produced separately by waves and tidal currents. The empirical mode decomposition (EMD) method has been utilised for this analysis. At first, using the EMD, the velocity components corresponding to waves and tidal current components are separated. In order to verify the separation methodology, a two step process is adopted. In step one, wave component velocities are converted to significant wave heights using linear wave transfer function. For the second step, the significant wave heights obtained from step one are compared with the same hindcast by a coupled wave-current numerical model. A very good match between wave heights is observed with a correlation coefficient of 0.8, thus validating the methodology followed. Then, the depth-varying vertical profiles of the turbulence intensity (TI) of the decomposed wave and current components are calculated. It is found that the streamwise wave-induced TI is about 5% at the height of 15m where the turbine hub is placed, while the tidal current-induced TI is 10%–17%. The wave-current combined TI is 13%–20%. This study has demonstrated a methodology to successfully separate and quantify turbulence intensities produced individually by waves and tidal currents when they coexist at a site.

Abstract Swirling flow is widely used in gas turbine burners to promote fuel/air mixing uniformity and to stabilize lean premixed flames. In this study, numerical and experimental methods are utilized to investigate the effects of burner geometry on fuel/air mixing and combustion performance and to optimize the burner geometry. The premixed burner geometry parameters including air swirling angle and fuel injection diameter/angle are modified to achieve fuel/air mixture uniformity. Laser Doppler Velocimetry (LDV) and Particle Image Velocimetry (PIV) are adopted to examine the flow field, Planar Laser Induced Fluorescence (PLIF) for detecting OH radical distribution thus investigating the characteristics of the reaction field. Burners of different configurations are manufactured to conduct combustion experiments. The burner with the worst mixing performance can‘t ignite successfully. However, burners with better mixing performance have a homogeneous reaction field with less perturbance, and the NOX emission stays at a relatively low level around 2.5 ppm (15% O2) at the designed operating condition.