The association of head and cervical spine injury has long been recognized. Reports of the coincidence of these injuries in the literature range from 1.2 to 19%. This study was undertaken to determine the coincidence and examine the mechanisms of head and cervical spine injuries at a major trauma hospital. All cases of cervical spine injury (CSI) and head injury (HI) admitted to The Detroit Receiving Hospital during 1987 were identified using the hospital computer data bank and spine unit log book. There were 359 admissions for CSI including concussion, skull fracture, and intracranial hemorrhage. There were 92 admissions for CSI including complete or incomplete neurologic syndromes with fractures. There were 22 patients with both HI and CSI. Thus the coincidence of "primary" CSI with HI (both/CSI) is 24% while the coincidence of primary HI with CSI (both/HI) is 6%. The variety of injuries is demonstrated with appropriate imaging studies. Our study supports the view that all seriously head-injured patients should be treated as if a concomitant cervical spine injury is present until proven otherwise. It also shows that nearly one-quarter of patients with cervical spine injury have also experienced head injury. This coincidence may be an important consideration in the rehabilitation of such injured patients.

Thermoacoustic transfer functions of a full-scale gas turbine burner operating under full engine pressure have been measured. The excitation of the high-pressure test facility was done using a siren that modulated a part of the combustion airflow. Pulsation probes have been used to record the acoustic response of the system to this excitation. In addition, the flame’s luminescence response was measured by multiple photomultiplier probes and a light spectrometer. Three techniques to obtain the thermoacoustic transfer function are proposed and employed: two acoustic-optical techniques and a purely acoustic technique. The first acoustical-optical technique uses one single optical signal capturing the chemiluminescence intensity of the flame as a measure for the heat release in the flame. This technique only works if heat release fluctuations in the flame have only one generic source, e.g., equivalence ratio or mass flow fluctuations. The second acoustic-optical technique makes use of the different response of the flame’s luminescence at different optical wavelengths bands to acoustic excitation. It also works, if the heat release fluctuations have two contributions, e.g., equivalence ratio and mass flow fluctuation. For the purely acoustic technique, a new method was developed in order to obtain the flame transfer function, burner transfer function, and flame source term from only three pressure transducer signals. The purely acoustic method could be validated by the results obtained from the acoustic-optical techniques. The acoustic and acoustic-optical methods have been compared and a discussion on the benefits and limitations of each is given. The measured transfer functions have been implemented into a nonlinear, three-dimensional, time domain network model of a gas turbine with an annular combustion chamber. The predicted pulsation behavior shows a good agreement with pulsation measurements on a field gas turbine.

In this work the relationship between the ratio of the global CH* and OH* flame chemiluminescece and the global equivalence ratio of a technically premixed swirl-stabilized flame is investigated. The burner allows for a modification of the premix fuel injection pattern. The global flame chemiluminescence is monitored by a high-sensitivity light spectrometer and multiple photo-multipliers. The photo-multipliers were equipped with narrow optical band-pass filters and recorded the flame’s OH*, CH* and CO2* chemiluminescence intensity. To ensure an approximately uniform equivalence ratio distribution in the combustion zone, the spatial OH* and CH* flame chemiluminescence was recorded simultaneously with one ICCD camera using a special optical setup, which incorporated among other things one fully reflective and one semi-reflective mirror and appropriate optical filters. The flame chemiluminescence intensity was mapped for a range of equivalence ratios and air mass flows. The mapping shows that (as stated for perfectly premixed flames in the literature) the OH*, CH* and CO2* intensity of the investigated flame depends linearly on the air mass flow and exponentially on the equivalence ratio (i.e., I = km * φβ). Hence for the investigated operating conditions (i.e., quasi premix conditions) the global CH*/OH* intensity can be employed as a measure of the global equivalence ratio for the operating conditions investigated in this work. However, the contribution of broadband CO2* chemiluminescence in the wave length range of CH* chemiluminescence has to be accounted for.

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To optimise the operation of gas turbine combustors with respect to emission, cycle efficiency and components lifetime, increased attention has to be attributed to diagnostic techniques and more flexible control schemes. Chemiluminescence is an obvious choice and a relatively easy and low cost option for such a diagnostic tool. Application examples include spectral analysis and light intensity scaling, temporal analysis studying flame dynamic effects and imaging techniques resolving spatial distribution of heat release zones, as well as combinations of the methods like phase matched imaging and tracking of ignition kernels using high speed imaging. Further fundamental work should be triggered on the nature for the excited species and their formation pathways as well as their connection to heat release and the NO x formation processes.

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