Laser Doppler velocimetry for continuous flow solar-pumped iodine laser system

A laser Doppler velocimetry (LDV) system was employed to measure the flow velocity profile of iodide vapor inside laser tubes of 36 mm ID and 20 mm ID. The LDV, which was operated in the forward scatter mode used a low power (15 mW) He-Ne laser beam. Velocity ranges from 1 m/s was measured to within one percent accuracy. The flow velocity profile across the laser tube was measured and the intensity of turbulence was determined. The flow of iodide inside the laser tube demonstrated a mixture of both turbulence and laminar flow. The flowmeter used for the laser system previously was calibrated with the LDV and found to be in good agreement

Studies of new media radiation induced laser

Various lasants were investigated especially, 2-iodohepafluoropropane (i-C3F7I) for the direct solar pumped lasers. Optical pumping of iodine laser was achieved using a small flashlamp. Using i-C3F7I as a laser gain medium, threshold inversion density, small signal gain, and laser performance at the elevated temperature were measured. The experimental results and analysis are presented. The iodine laser kinetics of the C3F7I and IBr system were numerically simulated. The concept of a direct solar-pumped laser amplifier using (i-C3F7I) as the laser material was evaluated and several kinetic coefficients for i-C3F7I laser system were reexamined. The results are discussed

Application of laser Doppler velocimeter to chemical vapor laser system

A laser Doppler velocimeter (LDV) system was used to measure iodide vapor flow fields inside two different-sized tubes. Typical velocity profiles across the laser tubes were obtained with an estimated +/-1 percent bias and +/-0.3 to 0.5 percent random uncertainty in the mean values and +/-2.5 percent random uncertainty in the turbulence-intensity values. Centerline velocities and turbulence intensities for various longitudinal locations ranged from 13 to 17.5 m/sec and 6 to 20 percent, respectively. In view of these findings, the effects of turbulence should be considered for flow field modeling. The LDV system provided calibration data for pressure and mass flow systems used routinely to monitor the research laser gas flow velocity

Reduced dimer production in solar-simulator-pumped continuous wave iodine lasers based on model simulations and scaling and pumping studies

A numerical rate equation model for a continuous wave iodine laser with longitudinally flowing gaseous lasant is validated by approximating two experiments that compare the perfluoroalkyl iodine lasants n-C3F7I and t-C4F9I. The salient feature of the simulations is that the production rate of the dimer (C4F9)2 is reduced by one order of magnitude relative to the dimer (C3F7)2. The model is then used to investigate the kinetic effects of this reduced dimer production, especially how it improves output power. Related parametric and scaling studies are also presented. When dimer production is reduced, more monomer radicals (t-C4F9) are available to combine with iodine ions, thus enhancing depletion of the laser lower level and reducing buildup of the principal quencher, molecular iodine. Fewer iodine molecules result in fewer downward transitions from quenching and more transitions from stimulated emission of lasing photons. Enhanced depletion of the lower level reduces the absorption of lasing photons. The combined result is more lasing photons and proportionally increased output power

Patterns of nutrients intakes in relation to glioma: A case-control study

BACKGROUND & AIMS: Nutrient pattern analysis is an easy way to compare nutrient intakes across different nations due to the universality of nutrients nature. The current study aimed to investigate the relation between patterns of nutrients intake and glioma in a case-control study in Iranian adults. METHODS: In this hospital-based case-control study, we enrolled 128 pathologically confirmed new cases of glioma and 256 age and sex-matched controls. Dietary intakes of study participants were assessed using the validated Block-format 123-item semi-quantitative FFQ. Data on potential confounders were also collected through the use of pre-tested questionnaire. RESULTS: Four nutrient patterns were identified through the use of factor analysis. Participants were categorized based on tertiles of nutrient patterns' scores. Adherence to the first nutrient pattern was not significantly associated with the odds of glioma (0.93; 0.40-2.15). Participants with greater adherence to the second nutrient pattern were less likely to have glioma in crude model (0.48; 0.28-0.83). The inverse association remained significant after controlling for age, sex and energy intake (0.42; 0.24-0.78). Further controlling for other potential confounders, including BMI, resulted in the disappearance of the association (0.52; 0.25-1.10). Greater adherence to the third nutrient pattern was directly associated with the odds of glioma (1.92; 1.10-3.35). Even after controlling for sex, age and energy intake, the association was statistically significant (2.83; 1.28-4.21). However, when other confounders were taken into account, the association became non-significant (2.28; 0.89-5.82). The fourth nutrient pattern was not associated with the odds of glioma (0.71; 0.35-1.42). CONCLUSION: We failed to find any significant independent association between nutrient patterns and odds of glioma. Further studies needed to confirm these findings

Spaceborne Photonics Institute

This report describes in chronological detail the development of the Spaceborne Photonics Institute as a sustained research effort at Hampton University in the area of optical physics. This provided the research expertise to initiate a PhD program in Physics. Research was carried out in the areas of: (1) modelling of spaceborne solid state laser systems; (2) amplified spontaneous emission in solar pumped iodine lasers; (3) closely simulated AM0 CW solar pumped iodine laser and repeatedly short pulsed iodine laser oscillator; (4) a materials spectroscopy and growth program; and (5) laser induced fluorescence and atomic and molecular spectroscopy

Cervicofacial Actinomycosis in Man

Two cases of advanced jaw destruction du e to Act inomyces is mreported ; o ne with d iabetic d iathesis and a history o f too th ex tractio n the other had a t rauma o f the mandible wi th the fra cture; good results were obtained with penicillin thera py

Evaluation de la qualité de vie en Dialyse Péritonéale par les entretiens narratifs

It has been found that people undergoing dialysis have a lower quality of life than the rest of the population. The aim of dialysis is to improve physical health, but also well-being. We were interested in the perception of the quality of life of patients undergoing Peritoneal Dialysis. We used the narrative interview method to collect their feelings, their daily experience, and their impressions about their care. We conducted four in-depth interviews, following the principle of theoretical data saturation, with adults treated at the Hospital of Nice. These interviews indicated that Peritoneal Dialysis rapidly improves physical and emotional health. Patients are satisfied with the technique, which allows them to return to a social, familial, and professional life. However, they regret that it does not relieve them of dietary restrictions, especially on salt. Patients appreciate the temporary support of a private nurse, which is systematically offered by our center at the beginning of treatment. They wish the involvement of peers to benefit from their experience, explanations and practical demonstrations. Quality of life is important to assess when choosing a renal replacement technique. Caregivers have to understand patients’ expectations and wishes in order to guide them towards the dialysis modality that suits their lifestyle and preferences best. This will improve treatment outcomes.Il a été démontré que les personnes dialysées ont une moins bonne qualité de vie que la population générale. L’objectif de la dialyse est non seulement d’améliorer la survie des patients, mais également leur bien-être.Nous nous sommes intéressés à la perception de la qualité de vie des patients en Dialyse Péritonéale, sans comparaison avec les autres techniques de dialyse, par un recueil de leur ressenti, leur vécu au quotidien et leurs impressions concernant leur prise en charge. Nous avons pour cela utilisé la méthode de l’entretien narratif. Nous avons mené quatre entretiens approfondis, en suivant le principe de la saturation théorique des données, auprès des patients adultes pris en charge à Nice.Ces entretiens ont montré que la Dialyse Péritonéale apporte une amélioration rapide de l’état de santé, tant sur le plan physique qu’émotionnel. Les patients regrettent cependant qu’elle ne les dispense pas des restrictions alimentaires, en particulier en apport sodé. Ils apprécient un accompagnement temporaire par un infirmier libéral, proposé systématiquement par notre centre en début de traitement. L’implication, en amont de la dialyse, de patients en Dialyse Péritonéale a été suggérée tant pour leur témoignage que pour l’apport d’explications et de démonstrations pratiques.La qualité de vie est importante à évaluer lors du choix de technique de suppléance. Il est essentiel pour les soignants de comprendre les attentes et les souhaits des patients afin de les orienter vers la technique la plus adaptée à leur mode de vie et à leurs préférences. Les résultats cliniques en seront améliorés

Narrative interviews to assess quality of life in Peritoneal Dialysis

It has been found that people undergoing dialysis have a lower quality of life than the rest of the population. The aim of dialysis is to improve physical health, but also well-being.&#x0D; We were interested in the perception of the quality of life of patients undergoing Peritoneal Dialysis. We used the narrative interview method to collect their feelings, their daily experience, and their impressions about their care. We conducted four in-depth interviews, following the principle of theoretical data saturation, with adults treated at the Hospital of Nice.&#x0D; These interviews indicated that Peritoneal Dialysis rapidly improves physical and emotional health. Patients are satisfied with the technique, which allows them to return to a social, familial, and professional life. However, they regret that it does not relieve them of dietary restrictions, especially on salt. Patients appreciate the temporary support of a private nurse, which is systematically offered by our center at the beginning of treatment. They wish the involvement of peers to benefit from their experience, explanations and practical demonstrations.&#x0D; Quality of life is important to assess when choosing a renal replacement technique. Caregivers have to understand patients’ expectations and wishes in order to guide them towards the dialysis modality that suits their lifestyle and preferences best. This will improve treatment outcomes.</jats:p