Nondestructive evaluation of welding residual stresses in dissimilar welded pipes

This paper investigates the nondestructive capability of ultrasonic waves in residual stress evaluation of dissimilar welded pipes. Longitudinal critically refracted (L CR ) waves are employed to measure the residual stresses in a pipe-pipe joint of stainless steel 304 and carbon steel A106. Measuring the acoustoelastic constant is usually accomplished through the tensile test which needs cutting the tested material to extract tensile test specimens. However, cutting the tested pipe to complement the nondestructive ultrasonic measurement was not considered here. Instead, a dissimilar welded plate with the same welding specification, joint geometry, thickness and the same dissimilar materials is used to extract tensile test samples. The measured acoustoelastic constant of the plate along with the measured time of flight of the L CR wave on the pipe, are utilized for ultrasonic stress measurement. A finite element model of welding process validated by hole-drilling method is used to verify the ultrasonic results. The results show good agreement between finite element and ultrasonic measurements in the pipe measured without any destructive process

Using welding simulation and ultrasonic method to evaluate residual stress in stainless steel welded plates

When a material is under mechanical load, the stresses change the velocity of acoustic waves because of acoustoelastic effect. This property can be employed for stress measurement in the material itself when the stress concerns the surface of the material, or in the bulk material. This technique involves with critically refracted longitudinal waves that propagate parallel to the surface, i. e. LCR waves. This paper presents a three dimensional thermo-mechanical analysis to evaluate welding residual stresses in plate-plate joint of AISI stainless steel 304L. After finite element simulation, the residual stresses were evaluated by LCR ultrasonic waves. This paper introduces a combination of "Finite Element Welding Simulation" and "Ultrasonic Stress Measurement using the LCR Wave" which is called as "FELCR". The capabilities of FELCR in residual stress measurement are confirmed here. It has been shown that predicted residual stress from three dimensional FE analyses is in reasonable agreement with measured residual stress from LCR method

Technetium-99m methoxyisobutylisonitrile scintigraphy in the assessment of cold thyroid nodules: is it time to change the approach to the management of cold thyroid nodules?

Background Scanning with technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) is recommended for evaluating thyroid nodule metabolism. In addition, it may help differentiate between benign and malignant nodules; however, the efficacy of this technique has not been fully elucidated. Therefore, it is not currently performed for routine clinical application. This prospective study was conducted to investigate the clinical significance of 99mTc-MIBI scintigraphy in the assessment of patients with cold thyroid nodules

Evaluation of fatty acid content and nutritional properties of selected native and imported hazelnut (Corylus avellana L.) varieties grown in Iran

Hazelnut (Corylus avellana L.) is one of the most important nuts rich in valuable nutrients. In this study chemical composition of Two Iranian native varieties namely ‘Pashmineh’ and ‘Garche’ and four imported varieties, ‘Ghafghaze’, ‘Zakatala’, ‘Ronde dupimont’ and ‘Fertile decotard’ were taken under investigation. The main fatty acid in hazelnut varieties were oleic (71.02%) and linoleic acid (14.45%). The hazelnut varieties showed oil content in a range from 53.36% to 63.5%; protein, 16.03-23.26%; energy, 653.4-707.65%; ash, 2.46-3.5%; carbohydrate, 13.16-20.14%; total phenolic content, 6.4-16.42 mg GAE /g; antioxidant capacity, 57.17-72.38%; oleic acid, 64.17 - 81.34%; Linoleic acid, 10 –21.07%; Linolenic acid, 0 – 2%; myristic acid, 0 – 0.5 %; stearic acid, 0 – 7.8%; eicosenoic acid, 0 – 1.69%; palmitic acid, 0.49 – 9.61%; palmitoleic acid, 0 – 1.6 % and behenic acid, 0 – 0.25%

Comparison of Thyroid Blood Flow and Uptake Indices Using Technetium-99m Pertechnetate in Patients with Graves’ Disease and Euthyroid Subjects

Objective: The aim of the present study was to evaluate parameters of early blood flow (EBF) including duration of EBF, perfusion index (PI), uptake indexes 1 and 2 (UI1 and UI2) derived from dynamic thyroid scintigraphy in patients with Graves’ disease (GD), and euthyroid (EI). Maximum instant uptake and maximum uptake of the thyroid gland were also assessed. Methods: A total of 50 patients with GD and EI were included in this study. Each patient underwent two dynamic scans of 1-minute (20 images at 3 seconds) and 20-minute (20 images at 1 minute) with 99mTcO4. The time-activity curve of a 1-minute scan was employed to derive EBF parameters; likewise, the time-activity curve of a 20-minute scan was used to determine maximum instant uptake, and the gradient of the curve from the 10th to 20th minute was used to assess maximum uptake. Results: Values of EBF duration, PI, UI1, UI2, and maximum instant uptake were significantly lower in patients with GD than in those with EI (p<0.05). The calculated gradient of the second half of the curves for all of the patients ranged from 0 to 0.88 and was significantly higher in patients with GD than in those with EI. Conclusion: Lower values of PI, UI1, UI2 and durations of EBF, along with faster maximum instant uptake in patients with GD in comparison to EI are indicators of a heightened desire for hyper-functioning thyroid glands of patients with GD to absorb 99mTcO4. Additionally, because of the uprising gradient at the end of the 20-minute time-activity curve, a maximum thyroid uptake of 99mTcO4 was achieved at more than 20 minutes after the radiopharmaceutical injectio

A Survey of the Strengths of the Performance-Based Scheme in Selected Teaching Hospitals of Isfahan, Iran, in 2014: A Qualitative Study

Introduction: In the year 1995, the novel hospital administration plan (fee for service) was presented. Based on this plan, a percentage of specific revenues are allocated as a fee to the hospital staff. This plan was implemented in hospitals for 20 years. In early September 2104, the new guideline entitled the performance-based fee was designed with the aim of eliminating the deficiencies in the previous plan and implemented in hospitals in Isfahan, Iran. Therefore, the present study was performed with the aim of studying the strengths of the performance-based scheme in selected teaching hospitals of Isfahan in 2014. Method: This was a qualitative study. In-depth interviews were used to collect data. The study participants consisted of 11 middle managers and executive managers of university hospitals and university headquarters, faculty members, and hospital officials. The subjects were selected through purposive sampling method. All interviews were recorded and transcribed verbatim. The duration of the interviews varied between 30 to 60 minutes. Data analysis in this research was based on thematic analysis. Results: In this research, the 4 main strengths of "defining and developing appropriate guidelines, improving the monitoring system, improving the management information system, and organizing the fee payment system" were obtained. Conclusion: The results of the present study revealed the 4 main strengths of the performance-based scheme. Thus, in order for the health system to be effective, the strengths of the performance-based plan must be evaluated and used to reduce the dissatisfaction of hospital staff. Keywords: Hospital, Payment system, Executive managers, Fee for service

Economic Reform Strategies to Improve the Performance of Surveillance and Infrastructure for Implementation of New Fee for Service Guidelines, 2014: A Qualitative Study

Introduction: In year 1995, new hospital administration plan system (fee for service) was notified. Under the scheme, a dedicated percentage of specific revenues allocated as a fee for the hospital staff. In the early September 2014, new guidelines as performance-based fee for service plan with the aim to fix the deficiencies in the previous plan was reviewed and implemented in hospitals in Isfahan, Iran. This study aimed to investigate strategies for economic reforms to promote performance monitoring and improve infrastructure for implementation of the new fee for service guidelines in 2014. Method: In this qualitative study, in-depth interviews were used to collect the data. Eleven samples consisting of middle managers and senior headquarters of university hospitals, and some faculty members and hospital officials were chosen via purposive sampling method. All interviews were recorded and then written on paper. The duration of interviews varied between 30 to 60 minutes. Data analysis in this research was based on content analysis. Results: In this study, six main themes of strategies for economic reforms to promote performance monitoring and improve infrastructure for implementation of the new fee for service guidelines were obtained including payment system reform, price reform, defined package of services in public hospitals, financial and economic policies, reform and implementation of family physician referral system, and support of the insurers. Conclusion: Our results define strategies for economic reforms to promote performance monitoring and improve infrastructure for implementation of the new fee for service guidelines. The most notable findings include pay reform, price reform, and financial and economic policies. These findings can help policy makers to consider the proposed revisions with appropriate strategies to monitor and improve the implementation of new fee for service plan. Keywords: Hospitals, Fee for service, Monitorin

Technetium-99m methoxyisobutylisonitrile scintigraphy in the assessment of cold thyroid nodules: is it time to change the approach to the management of cold thyroid nodules?

methoxyisobutylisonitrile (99mTc-MIBI) is recommended for evaluating thyroid nodule metabolism. In addition, it may help differentiate between benign and malignant nodules; however, the efficacy of this technique has not been fully elucidated. Therefore, it is not currently performed for routine clinical application. This prospective study was conducted to investigate the clinical significance of 99mTc-MIBI scintigraphy in the assessment of patients with cold thyroid nodules. Patients and methods This prospective study was conducted on 104 patients with cold thyroid nodules greater than 1 cm in diameter as detected on 99mTc-pertechnetate scintigraphy. Uptake of MIBI in thyroid nodules was compared with that in the surrounding normal thyroid tissue for both early and delayed images, and a score of 0–3 was assigned to each nodule as follows: 0, cold; 1, decreased; 2, equal; 3, increased. The thyroid scan was performed 20 and 40min after intravenous injection of 555MBq of 99mTc-MIBI. The patients underwent fine-needle aspiration cytology (FNAC). Detailed statistical parameters were determined on a per-nodule basis for each qualitative and quantitative scan analysis, as defined by histology. Results A total of 104 patients (93 women and 11 men; mean age 40.76±11.40 years, range 20–73) with a total number of 167 cold nodules were included in this study. When 99mTc-MIBI uptake was regarded as the criterion of malignancy in 99mTc-MIBI scintigraphy, the accuracy was between 69.46 and 92.21% on using seven different methods. In addition, FNAC findings indicated a sensitivity of 66.66%, a specificity of 100%, a negative predictive value of 95.72%, a positive predictive value of 100%, and an accuracy of 96.06%. Six malignant cold nodules were detected on a positive 99mTc-MIBI scan, which were determined as benign nodules on FNAC examinations. Conclusion The study demonstrated that 99mTc-MIBI scanning can be complementary to other diagnostic techniques in patients with cold thyroid nodules. In addition, because of its availability, rather low cost, simple protocol, and objective semiquantitative information, 99mTc-MIBI scanning seems to hold promise in routine imaging of cold thyroid nodules. Nucl Med Commun 35:51–57 �c 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins

Comparison of 180° and 360° Arc Data Acquisition to Measure Scintigraphic Parameters from Gated Single Photon Emission Computed Tomography Myocardial Perfusion Imaging: Is There Any Difference?

Objective: The aim of the current study was to compare 180° and 360° data collection modes to measure end diastolic volume (EDV), end systolic volume (ESV) and ejection fraction (EF) values of the cardiac system by gated myocardial perfusion tomography. Methods: Thirty-three patients underwent gated myocardial perfusion tomography. Single photon emission computed tomography data of patients’ heart were acquired by 180°, 45° left posterior oblique to 45° right anterior oblique, and 360° to obtain EDV, ESV, EF and cardiac volume changes (V1, V2, V3, V4, V5, V6, V7 and V8) throughout each cardiac cycle. Results: Results of the current study indicated that there were no significant differences between 180° and 360° angular sampling in terms of measuring EDV, ESV and EF in myocardial perfusion imaging. Cardiac volume change patterns during a cardiac cycle were also similar in 360° and 180° scans. We also observed that there was no difference in EDV, ESV and EF values between the group with stress induced by exercise and the group with stress imposed by dipyridamole. Conclusion: As there is no difference between 180°and 360° cardiac scanning in terms of EDV, ESV and EF, half-orbit scan is recommended to study these cardiac system parameters because it offers more comfort to patients and a shorter scanning time. Keywords: 180° data collection, 360° data collection, ejection fraction, end diastolic volume, end systolic volume, gated myocardial perfusio