An Approach to Thermocouple Temperature Measurements that Reduces Uncertainties Associated with Radiative Corrections

Obtaining accurate temperature measurements in flame environments with thermocouples is extremely challenging due to the effects of radiative heat loss. These losses are difficult to quantify and often cannot be corrected for or minimized without sacrificing spatial resolution. In this work, a new experimental methodology is presented that has shown potential to minimize the temperature correction by both increasing and controlling the effects of convection. This is accomplished through high speed rotation of the thermocouple. The rotation yields a high and known convective velocity over the thermocouple. Heat transfer can then be modeled for the thermocouple, and a functional relationship between temperature and rotational speed can be found. Experiments were conducted over a range of rotational speeds in a control flame with a known temperature to test the feasibility of the rotating thermocouple (RTC) technique for temperature measurements in high temperature gases. The experimental results are shown to closely match the theory for the experimental gas temperature, over a range of rotational speeds, yielding extremely accurate gas temperature measurements. The results also demonstrate minimal perturbation to the flow field, even at high rotational speeds. Additionally, a deconvolution technique is proposed that would significantly enhance the spatial resolution of the technique

Factors Affecting Early and 1-Year Motor Recovery Following Lumbar Microdiscectomy in Patients with Lumbar Disc Herniation: A Prospective Cohort Review

Study Design Prospective cohort study. Purpose The study was aimed at evaluating clinicoradiological factors affecting recovery of neurological deficits in cases of lumbar disc herniation (LDH) treated by lumbar microdiscectomy. Overview of Literature The majority of the available literature on neurological recovery following neurodeficit is limited to retrospective series. The literature is currently limited regarding variables that can help predict the recovery of neurodeficits following LDH. Methods A prospective analysis was performed on 70 consecutive patients who underwent lumbar microdiscectomy (L1–2 to L5–S1) owing to neurological deficits due to LDH. Patients with motor power ≤3/5 in L2–S1 myotomes were considered for analysis. Follow-up was performed at 2, 6, and 12 months to note recovery of motor deficits. Clinicoradiological parameters were compared between the recovered and nonrecovered groups. Results A total of 65 patients were available at the final follow-up: 41 (63%) had completely recovered by 2 months; four showed delayed recovery at the 6-month follow-up; and 20 (30.7%) showed no recovery at 1 year. Clinicoradiological factors, including diabetes, complete initial deficit, areflexia, multilevel disc prolapse, longer duration since initial symptoms, and ≥2 previous symptomatic episodes were associated with a significant risk of poorer recovery (p0.05 for all). Diabetes mellitus (p=0.033) and complete initial motor deficit (p=0.028) were significantly associated with delayed recovery in the multivariate analysis. Conclusions The overall neurological recovery rate in our study was 69%. Diabetes mellitus (p=0.033) and complete initial motor deficit were associated with delayed motor recovery