116 research outputs found
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
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
The role of effective information in decision making by managers at Shahid Beheshti of teaching hospitals of Shahid Beheshti university of medical sciences
Today, one of the most fundamental factors in the field of management is providing managers with effective information in order to improve the quality of their decision-making. In this paper, we studied the role of effective information in decision making by managers and directors in 2006- 2007(From March 20, 2006 to march 19, 2007)
Designing the maternal and child health services package based on comparative study of developed countries models
Introduction: Community women�s health is more vulnerable than men due to various reasons, in addition to biological characteristics; it is influenced by cultural, social, economic and political factors. Nowadays,managing maternal health development is one of the World Health Organization priorities.This study was performed with aim to improve maternal and child health service package in Iran by providing variables derived from a comparative study conducted in selected developed countries. Methods: In thiscomparative study, the studied countries(Singapore, Australia, England and Japan) wereselectedby comparingmaternal-child healthindicators from different continentsusing cluster sampling and with studying of their maternal and child health service package through referring to valid health documents, important variablesanddimensions were identified, and based on itand designed comparative tables, the conclusion was made. Results: Free sportsandtraining classeswiththe husbands� presence, extensive maternal network emergency as specialized and boarding, varietyof vehicles fortransportto emergency centers,emotional supportpackages, home visit and delivery, newbornsfreesurgical facilitiesandcare, pregnant womenscreeningfacilitiesfor free, guideline booklet and unifiedrecording of servicesin allcountrycenters are the factorsidentified in successfulmaternal-child health servicespackage. Conclusion: The role ofsome identified factors such as home visit and deliveryis loworabsent in Iran health service package. Implementation ofthesuggested factors canplay an important rolein promotingmaternal-child healthindicators inIran. � 2016, Mashhad University of Medical Sciences. All rights reserved
Predicting Cochlear Implant Electrode Placement Using Monopolar, Three-Point and Four-Point Impedance Measurements
Objective: This study aimed to investigate the relationship between cochlear implant (CI) electrode distances to the cochleas inner wall (the modiolus) and electrical impedance measurements made at the CIs electrode contacts. We introduced a protocol for three-point impedances in which we recorded bipolar impedances in response to monopolar stimulation at a neighboring electrode. We aimed to assess the usability of three-point impedances and two existing CI impedance measurement methods (monopolar and four-point impedances) for predicting electrode positioning during CI insertion. Methods: Impedances were recorded during stepwise CI electrode array insertions in cadaveric human temporal bones. The positioning of the electrodes with respect to the modiolus was assessed at each step using cone beam computed tomography. Linear mixed regression analysis was performed to assess the relationship between the impedances and electrode-modiolar distances. The experimental results were compared to clinical impedance data and to an existing lumped-element model of an implanted CI. Results: Three-point and four-point impedances strongly correlated with electrode-modiolar distance. In contrast, monopolar impedances were only minimally affected by changes in electrode positioning with respect to the modiolus. An overall model specificity of 62% was achieved when incorporating all impedance parameters. This specificity could be increased beyond 73% when prior expectations of electrode positioning were incorporated in the model. Conclusion: Three-point and four-point impedances are promising measures to predict electrode-modiolar distance in real-time during CI insertion. Significance: This work shows how electrical impedance measurements can be used to predict the CIs electrode positioning in a biologically realistic model
A model for priority setting of health technology assessment: The experience of AHP-TOPSIS combination approach
Background: In recent times, the use of health technologies in the diagnosis and treatment of diseases experienced considerable and accelerated growth. The goal of the present study was to describe the designated pilot MCDM (Multiple Criteria Decision Making) model for priority setting of health technology assessment in Iran. Methods: Relevant articles were sought and retrieved from the most appropriate medical databases, including the Cochrane Library, PubMed and Scopus via three separate search strategies, using MESH and free text until March, 2015. Retrieved criteria were questioned from health technology assessment experts in two rounds and the relative weight for valid criteria was finally obtained from paired wise comparison method. After extraction of relative weights based on the aforementioned procedure, TOPSIS (The Technique for Order of Preference by Similarity to Ideal Solution) priority setting model was designed. The stated model was applied for assessing three technologies (adenosine, tissue plasminogen activator and mechanical thrombectomy) which were available for projects call of Iranian health technology assessment department in order to determine applicability of the model for practical purpose. Results: Nine criteria, including efficiency/effectiveness, safety, population size, vulnerable population size, availability of alternative technologies, cost effectiveness in other countries, budget impact, financial protection, quality of evidence, were extracted by the Iranian health technology assessment experts. The relative weights of these criteria were as follows 0.12, 0.2, 0.06, 0.08, 0.08, 0.13, 0.08, 0.09, and 0.15, respectively. Finally TOPSIS pilot model was designed by three health technologies and nine criteria relative weights. Results showed that, the applicability of the stated model was suitable and as the pilot testing, tissue plasminogen activator was the first priority, adenosine was second and mechanical thrombectomy was third for performing health technology assessment by the Iranian ministry of health and medical education. Conclusion: According to the results of this study, this model with nine effective criteria and their relative weights and in combination with TOPSIS approach could be used with suitable applicability by health technology assessment department in deputy of curative affairs and food and drug organization for determination of research priorities in health technology assessment. © 2016 Mobinizadeh et al
Occupational Health Services Integrated in Primary Health Care in Iran
Introduction A healthy workforce is vital for maintaining social and economic development on a global, national and local level. Around half of the world's people are economically active and spend at least one third of their time in their place of work while only 15 of workers have access to basic occupational health services. According to WHO report, since the early 1980s, health indicators in Iran have consistently improved, to the extent that it is comparable with those in developed countries. In this paper it was tried to briefly describe about Health care system and occupational Health Services as part of Primary Health care in Iran. Methods To describe the health care system in the country and the status of occupational health services to the workers and employers, its integration into Primary Health Care (PHC) and outlining the challenges in provision of occupational health services to the all working population. Findings Iran has fairly good health indicators. More than 85 percent of the population in rural and deprived regions, for instance, have access to primary healthcare services. The PHC centers provide essential healthcare and public-health services for the community. Providing, maintaining and improving of the workers' health are the main goals of occupational health services in Iran that are presented by different approaches and mostly through Workers' Houses in the PHC system. Conclusions Iran has developed an extensive network of PHC facilities with good coverage in most rural areas, but there are still few remote areas that might suffer from inadequate services. It seems that there is still no transparent policy to collaborate with the private sector, train managers or provide a sustainable mechanism for improving the quality of services. Finally, strengthening national policies for health at work, promotion of healthy work and work environment, sharing healthy work practices, developing updated training curricula to improve human resource knowledge including occupational health professionals are recommended. © 2015 The Authors
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
Immunologic status of agricultural workers in the region of Lombardy, Northern Italy
Purpose. Farming is associated with a wide variety of hazardous exposures including physical, chemicals and biological agents. Animal farmers are exposed to dust which contains microorganisms, mycotoxins, endotoxins, animal feed particles, allergens and chemical agents. Organic dust exposure is known to cause allergic and non-allergic rhinitis, and organic dust toxic syndrome. This study was undertaken to evaluate the relationship between occupational health hazards and serum pro-inflammatory cytokines among agricultural workers, in particular we investigated whether animal breeders react differently to biological agents than non breeder farmers.
Methods. One hundred subjects working in agricultural enterprises in the region of Lombardy, were enrolled into the study in 2010. Serum cytokines including interleukin (IL)-6, IL-8, IL-10, IFN\u3b3 and tumor necrosis factor-\u3b1 (TNF\u3b1) were measured. Cytokines were assessed by commercially available enzyme-linked-immunosorbent assay (ELISA).
Results of the study. Compared to control subjects, increased TNF-\u3b1, IL-8, and IL-10 levels were found in animal breeders, and a statistically significant relationship between type of job (breeder/non breeder workers) and increased serum pro-inflammatory cytokines. Results suggest that animal breeders might be at higher risk of occupational diseases and biological hazards than other farmers with less contact to animals
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