Twisting Flux Tubes as a cause of Micro-Flaring Activity

High-cadence optical observations of an H-alpha blue-wing bright point near solar AR NOAA 10794 are presented. The data were obtained with the Dunn Solar Telescope at the National Solar Observatory/Sacramento Peak using a newly developed camera system, the Rapid Dual Imager. Wavelet analysis is undertaken to search for intensity-related oscillatory signatures, and periodicities ranging from 15 to 370 s are found with significance levels exceeding 95%. During two separate microflaring events, oscillation sites surrounding the bright point are observed to twist. We relate the twisting of the oscillation sites to the twisting of physical flux tubes, thus giving rise to reconnection phenomena. We derive an average twist velocity of 8.1 km/s and detect a peak in the emitted flux between twist angles of 180 and 230 degrees.Comment: 8 pages, 10 figure

Evaluation of skin dose associated with different frequencies of bolus applications in post-mastectomy three-dimensional conformal radiotherapy

<p>Abstract</p> <p>Background</p> <p>The study aimed to calculate chest-wall skin dose associated with different frequencies of bolus applications in post-mastectomy three-dimensional conformal radiotherapy (3D-CRT) and to provide detailed information in the selection of an appropriate bolus regimen in this clinical setting.</p> <p>Methods</p> <p>CT-Simulation scans of 22 post-mastectomy patients were used. Chest wall for clinical target volume (CTV) and a volume including 2-mm surface thickness of the chest wall for skin structures were delineated. Precise PLAN 2.11 treatment planning system (TPS) was used for 3D-CRT planning. 50 Gy in 25 fractions were prescribed using tangential fields and 6-MV photons. Six different frequencies of bolus applications (0, 5, 10, 15, 20, and 25) were administered. Cumulative dose-volume histograms were generated for each bolus regimen. The minimum, maximum and mean skin doses associated with the bolus regimens were compared. To test the accuracy of TPS dose calculations, experimental measurements were performed using EBT gafchromic films.</p> <p>Results</p> <p>The mean, minimum and maximum skin doses were significantly increased with increasing days of bolus applications (p < 0.001). The minimum skin doses for 0, 5, 10, 15, 20, and 25 days of bolus applications were 73.0% ± 2.0%, 78.2% ± 2.0%, 83.3% ± 1.7%, 88.3% ± 1.6%, 92.2% ± 1.7%, and 93.8% ± 1.8%, respectively. The minimum skin dose increments between 20 and 25 (1.6% ± 1.0%), and 15 and 20 (4.0% ± 1.0%) days of bolus applications were significantly lower than the dose increments between 0 and 5 (5.2% ± 0.6%), 5 and 10 (5.1% ± 0.8%), and 10 and 15 (4.9% ± 0.8%) days of bolus applications (p < 0.001). The maximum skin doses for 0, 5, 10, 15, 20, and 25 days of bolus applications were 110.1% ± 1.1%, 110.3% ± 1.1%, 110.5% ± 1.2%, 110.8% ± 1.3%, 111.2% ± 1.5%, and 112.2% ± 1.7%, respectively. The maximum skin dose increments between 20 and 25 (1.0% ± 0.6%), and 15 and 20 (0.4% ± 0.3%) days of bolus applications were significantly higher than the dose increments between 0 and 5 (0.2% ± 0.2%), 5 and 10 (0.2% ± 0.2%), and 10 and 15 (0.2% ± 0.2%) days of bolus applications (p ≤ 0.003). The TPS overestimated the near-surface dose 10.8% at 2-mm below the skin surface.</p> <p>Conclusion</p> <p>In post-mastectomy 3D-CRT, using a 1-cm thick bolus in up to 15 of the total 25 fractions increased minimum skin doses with a tolerable increase in maximum doses.</p

Britain and Revolutionary Iran 1906-1909 and 1976-1979: a comparative study

This dissertation is a comparative case study of British policy towards and perceptions of Persia/Iran during the latter's two modern revolutions, 1906-1909 (Constitutional) and 1976-1979 ('Islamic'). The study covers both official perceptions and policy, meaning that of the Foreign Office and Diplomatic Service and the perceptions of the press, civil society, Parliament and wider public opinion; thus it is not a traditional exercise in diplomatic history. It explores British views of both the Shah/government and opposition forces during these two periods in detail and presents these views in a comparative perspective. The research paints a broad social and historical picture of how changes in both British and Iranian government, society and global status affected their mutual relations. Key themes relate to how the decline of (Edwardian) Liberalism, the transformation of the Left in the twentieth century and Britain's decline as an imperial power affected its perceptions and policy-making in Iran; how civil society and public opinion exerted a disproportionately strong influence in the earlier period before Britain was even a fully democratic society; how notions of Orientalism and Aryanism shaped official and public perceptions; and how changing geopolitics impacted perceptions, particularly in the case of Tsarist Russia versus the Soviet Union. This study has revealed numerous counter-intuitive points about the foreign relations and perceptions of British government and society vis-à-vis Iran and prompts a reconsideration of the evolution of British public and official attitudes during the twentieth century as manifested in the case of Iran at two critical historical junctures. </p

A Reversal in the Global Decline of the Labor Share

This is the data set used in the paper "A Reversal in the Global Decline of the Labor Share?" by Selen Andic and Michael C. Burda (2021), forthcoming article in the Economics Letters. The data set includes 124 countries and spans the period 1980-2017. It is constructed using publicly available data from AMECO, IMF, OECD and PWT 9.1

Self-compacting lightweight aggregate concrete: design and experimental study

WOS: 000270268000004This study focuses on the production of self-compacted lightweight structural concrete. For this purpose, lightweight concrete was produced by replacing normal aggregate with pumice aggregate obtained from the Kayseri region. Three series of mixtures were prepared to obtain the proper self-compacting lightweight concrete (SCLC) mixture. The D series included normal-weight, self-compacting concrete (SCC) mixtures and the H series included SCLC mixtures having 100% lightweight coarse aggregate and different air contents. Fresh concrete test results obtained horn these mixtures were used as a basis for the T series containing different amounts of lightweight and normal-weight coarse aggregate. Some mechanical and fresh concrete properties were obtained from the T series. It was found that the loss of strength owing to lightweight aggregate addition is higher than the decrease of unit weight of the mixture. Furthermore, the decrease in flexural tensile strength owing to addition of lightweight aggregate is less than the reduction in compressive strength and splitting tensile strength. The percentage of entrained air and paste content are important factors to avoid segregation problems in lightweight SCC mixtures. There is a good relationship between 28-day compressive strength and unit weight data obtained from the H and T series.Turkish Cement Manufacturers' AssociationThe authors would like to acknowledge the Turkish Cement Manufacturers' Association for their financial and technical support, Soylu Group for supplying pumice aggregate and Konsan Bilgi ve Teknoloji A.S. for supplying Smartflow HS 100 and Softharc AL chemical admixtures

Change in serum concentrations of interleukin-2 and interferon-gamma during treatment of tuberculosis

We aimed to investigate changes in serum concentrations of the cytokines interleukin (IL)-2 and interferon (IFN)-gamma during the clinical course of active tuberculosis, to establish the presence of cellular immunity before and after treatment. Blood samples were taken from 18 patients with active tuberculosis before and 2 months after therapy; IL-2 and IFN-gamma concentrations were evaluated. The mean serum IL-2 concentration before therapy was 164.5 pg/ml (range 12 - 980 pg/ml) and the concentration 2 months after therapy was 92.11 pg/ml (range 1 - 490 pg/ml). The mean serum IFN-gamma concentrations were 10.83 pg/ml (range 1 - 22.2 pg/ml) and 4.64 pg/ml (range 1 - 28.5 pg/ml), respectively. The decrease in concentrations of both cytokines after therapy was statistically significant. Further studies investigating the benefits of adding cytokines to drug treatment for tuberculosis are needed

Natural radioactivity of barite concrete shields containing commonly used supplementary materials

WOS: 000514758800011The recycling of hazardous materials within new composites has a sustainable importance as it contributes on the reduction of high radionuclide concentrations. in this study, the effect of cementitious materials i.e. viscosity modifier, silica fume and fly ash on the Ra-226, Th-232 and K-40 activity levels of barite concrete shields was researched by using different mixing compositions in terms of binder content, w/b ratio and the amount of supplementary cementitious materials. in comparison to cement, silica fume and fly ash used in the production of concrete shields were found to have significantly higher activity levels of K-40, as well as Ra-226, Th-232 and K-40, respectively. the Ra-226, Th-232 and K-40 activity levels of concrete shields range between 2.2 and 20.7 Bq kg(-1); 2.6 and 7.0 Bq kg(-1); 51.5 and 89.3 Bq kg(-1), respectively. These activity values were found similar or less than those of building materials in the world. These satisfactory results are mostly caused by the barite source which has lower radioactivity levels. the concrete mixture details used in the study caused significant variation in the natural radioactivity of barite concrete shields. the introduction of silica fume which has high K-40 activity levels and fly ash with high Ra-226, Th-232 and K-40 activity levels compared to cement and barite aggregate, significantly increased the radiological hazard parameters, although all results were found to be below the limits recommended by international reports. in conclusion. Ra-226 activity levels of the concrete shields were significantly increased (up to 8.4 times) by the variation of mix design parameters used in comparison with concrete mixtures that have the least Ra-226 activity level. the Th-232 and K-40 activity levels were as well increased in relatively less amounts (1.7 and 0.73 times higher, respectively). (C) 2019 Elsevier Ltd. All rights reserved