DSOGI-PLL based power control method to mitigate control errors under disturbances of grid connected hybrid renewable power systems

The control of power converter devices is one of the main research lines in interfaced renewable energy sources, such as solar cells and wind turbines. Therefore, suitable control algorithms should be designed in order to regulate power or current properly and attain a good power quality for some disturbances, such as voltage sag/swell, voltage unbalances and fluctuations, long interruptions, and harmonics. Various synchronisation techniques based control strategies are implemented for the hybrid power system applications under unbalanced conditions in literature studies. In this paper, synchronisation algorithms based Proportional-Resonant (PR) power/current controller is applied to the hybrid power system (solar cell + wind turbine + grid), and Dual Second Order Generalized Integrator-Phase Locked Loop (DSOGI-PLL) based PR controller in stationary reference frame provides a solution to overcome these problems. The influence of various cases, such as unbalance, and harmonic conditions, is examined, analysed and compared to the PR controllers based on DSOGI-PLL and SRF-PLL. The results verify the effectiveness and correctness of the proposed DSOGI-PLL based power control method

Evaluation of The Factors Affecting the Choice of Profession of The Dental Students

Background: Researches on motivation of students to choose dentistry as a profession has been conducted for many years. Students may choose to become dentists for reasons such as serving, being independent, working with their hands, gaining prestige, and financial security. Purpose: The aim of this study is to evaluate the factors in the career preferences of dental students, their expectations and opinions in the education process. Methods: 1,007 participants who answered the web-based questionnaire were included in this study. Obtained data were analysed using SPSS version 23.0 (Inc., Chicago, IL, USA). The Independent t test was used for intergroup comparisons in the data were normally distributed. Variables in more than two groups were compared using the one-way ANOVA test. Statistical significance was accepted as p<0.05 in all analyses. Results: A total of 1007 dentistry students, 370 (36.7%) male and 637 (63.3%) female, with a mean age of 21.15 ± 1.96 participated in the survey study. 236 (23.4%) of the participants were in the first grade, 236 (23.4%) in the second grade, 192 (19.1%) in the third grade, 261 (25.9%) in the fourth grade, and 82 (8.1%) in the fifth grade. 44% of the participants chose the option 'they want to be medicine or dentistry, but gaining dentistry because of their score in the university entrance exam' as the reason for choosing dentistry. Conclusion: Such studies will be useful for the procedures to be followed in eliminating stress and anxiety in students and in the pre-detection of problems

Genetic relatedness among quince (<i>Cydonia oblonga</i> Miller) accessions from Turkey using amplified fragment length polymorphisms

Among fruit species cultivated in Turkey, quince shows a great deal of morphological variability and adaptability to the various environments. We attempted to study genetic relationships among 40 quince accessions using amplified fragment length polymorphisms (AFLPs) for future breeding programs. The accessions were previously characterized based on their pomological and yield characteristics and then the best ones were planted in a single collection in Ataturk Central Horticultural Research Institute, Yalova, Turkey. Six AFLP primer combinations generated a total of 746 bands, 493 of which were polymorphic (66.1%). Resolving powers of the AFLP primers ranged from 48.0 to 99.6 making a total of 421.5. Unweighted Pair Group Method with Arithmetic Average (UPGMA) clustering of the accessions showed three major clusters and ‘SapancaEsme’ and ‘Esme-3’ were the closest accessions with 95% similarity. Our study indicated that there is a high level of genetic diversity among quince accessions in Turkey and the results of this study can be used for future cultivar breeding programs in quince

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

THE EFFECTS OF THE PLANT GROWTH REGULATORS ON ANTIOXIDANT ENZYMES

This study describes in vitro the effect of three plant growth regulators (PGRs) such as mepiquat chloride, beta-naphthoxyacetic acid and gibberellic acid on the human blood antioxidant enzyme activites of glucose-6-phosphate dehydrogenase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, catalase and superoxide dismutase. Enzyme activities have determined spectrophotometrically. PGRs have different effects on antioxidant enzyme activities. I-50 values of PGRs on antioxidant enzymes were determined by means of PGR concentration-activity % graph. The activities of antioxidant enzymes were changed by different concentrations of PGRs. PGRs behaved as an inhibitor on the antioxidant enzymes. The inhibition power of PGRs was different from enzyme to enzyme. The most power inhibitor for all enzymes studied was gibberellic acid, followed by beta-naphthoxyacetic acid and mepiquat chloride. When I-50 values compared with the results of metal ions in literature, PGRs had more inhibition powder than the metal ions. PGR toxicity caused a significant decrease in the antioxidant enzyme activity

Failure pressures of composite cylinders with a plastic liner

The present experimental study deals with the temperature and the stacking sequence effects on the response of the composite cylinders under the internal pressure. GRP composite cylinders were manufactured by using E-glass fibers and epoxy resin and tested for the close-ended condition. Test specimens were manufactured of four antisymmetric layers with [theta degrees/-theta degrees/theta degrees/-theta degrees](2) orientations with five different winding angles over a plastic liner. Filament wound cylinders were subjected to internal pressure at four different temperatures such as 2 degrees C, 25 degrees C, 60 degrees C, and 80 degrees C. The aim of this study was to investigate the thermal effect on the failure pressures of filament wound cylindrical composites according to different fiber orientation angles subjected to internal pressure loading at various temperatures. The results show that the orientation angle and the temperature have significant effects on the failure pressures of the composite cylinders